Jicarilla Apache Indian Reservation

Home , Cliff House Sandstone, Gallup Sandstone, Jicarilla Apache, Point Lookout Sandstone

INTRODUCTION LA PLATA SAN JUAN MTS. MTS. INDEX MAP FOUR CORNERS AREA P P K P J US 160 J TR Tv �The Jicarilla Apache Indian Reservation covers approximately A J CORTEZ J Salt Lake City Pc ARCHULETA DURANGO 35 one million acres in north-central New Mexico on the eastern edge of MONOCLINAL RIDGES SALT ANTICLINES UTE K K MTS. RIVER the San Juan Basin, comprising parts of townships 22 to 32 north and 34

BASIN EDGES UTAH 0 25 50 ANTICLINE ranges 1 east to 5 west (Figures J-1 and J-2). The San Juan Basin 34 SCALE IN MILES 1920W 18 15 14 13 PLATA 11 10 9 8 7 56 4 3 1W 1E 2 contains the second largest natural gas field in the coterminous Unit TERTIARY INTRUSIVES

SYNCLINE LA 33 ed States and has produced more oil from fractured Mancos shale RIVER 32N than any other basin in the Rocky Mountain province. The Jicarilla MONTEZUMA COUNTY LA PLATA COUNTY COLORADO ARCHULETA COUNTY U T A H River Apache Tribe is the single largest mineral owner in the basin, exclud NEW 32N MEXICO

ing the United States government. During more than 35 years of gas 31 UPLIFT RIDGE K FOUR CORNERS ANIMAS and oil activity within the Reservation, over 2,700 wells were drilled, SAN C O L O R A D O AZTEC SAN JICARILLA SHIPROCK 30 predominantly on the southern half. The 1993 production from 2,200 FARMINGTON Grand Junction PLATFORMUS 550 Green APACHE active wells was nearly 900,000 barrels of oil (BO) and 30 billion cu JUAN BLOOMFIELD J 29 T JUAN J A' bic feet of gas (BCF). SWELL K RIVER SAN RAFAEL UNCOMPAHGRE UPLIFT C INDIAN A 28 B �Two recent discoveries highlight the new potential in this mature Moab G O basin. Fruitland coal seam gas has more than doubled the basin's gas HENRY US 666 H 27 BASIN RESERVATION MOUNTAINS production. Additionally, a 1992 horizontal Mancos oil well has tap STATE 44 26 TR Tv ped an estimated 5-10 million barrel oil (MMBO) reservoir on the BASIN P CIRCLE T relatively unexplored northern half of the Reservation. 25 J SAN TR �The Jicarilla Apache Indian Tribe has successfully financed, dril PARADOX JUAN MTS. TR CLIFFS 24 T led, produced and marketed oil and gas reserves from Tribal proper River BLANDING R BASIN RIO ARRIBA COUNTY ties for more than 15 years. The Tribe plans to continue to expand its J 23 San Juan FOURPLATFORM CORNERS SANDOVAL COUNTY ARCHULETA CHUSKA MTS. P own operations and participation as a working interest owner. For en BASIN P TR UPLIFT MONUMENT Mexican UPWARP Hat 22 2 NACIMIENTO 3E tities interested in working with the Tribe, Tribal oil and gas explora 20W 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1W 1E River UPLIFT Pc P DEFIANCE 21 tion and development agreements are negotiated and structured indi UPLIFT Farmington SAN JUAN COUNTY CUBA vidually to address the needs of the outside parties and the Tribe and UPLIFT McKINLEY COUNTY Colorado K 20 the specific concerns relative to the reservoir. Agreements will follow TV SAN TR J

basic industry standards as applicable and are governed by federal JUAN 19 NACIMIENTO

laws protecting all parties. BASIN ARIZONA KAIBAB Pc �The basin contains a complete infrastructure of gas gathering and ZUNI 18

UPLIFT UPLIFT BLACK CHACO SLOPE CHACO SLOPE delivery systems, oil pipelines, and refineries to process, market and J 17 K P deliver oil and gas. Gas transportation systems such as the Williams MESA Gallup P 16 Company, El Paso Natural Gas, West Gas and The Gas Company of UPLIFT GALLUP TR Flagstaff BASIN J J New Mexico provide competitive markets in almost all directions. GALLUP Albuquerque ZUNI UPLIFT PUERCO A R I Z O N A N E W TV RESERVATION PRODUCTION OVERVIEW TR J 14 M E X I C O SAG FAULT Tv T T TR 13

�Figures J-2 and J-3 shows the outline of the Jicarilla Apache Res RIO VALENCIA COUNTY BELT Figure J-1. Regional index map of the the Four Corners area showing major uplifts and P ervation, on the eastern side of the San Juan Basin, and the general T basins with superimposed minor features (after Peterson, 1965, p. 2078). T BERNALILLO COUNTY

distribution of the primary producing fields. A stratigraphic chart of PUERCO GRANTS TR the eastern part of the San Juan Basin is shown in Figure J-4. In gen ping monocline on the east edge of the Reservation. Despite prolific production over the T Pc ALBUQUERQUE TR J J J Tv US 66 eral, the producing formations are Cretaceous-age fluvial, deltaic, and decades, more hydrocarbons are yet to be found as additional sequence stratigraphy, seis P J Q B US 66 J RIO SAN nearshore sandstones, offshore siltstones and shales and coal deposit mic interpretation, completion analysis, stimulation technology and creative geologic J Pc JOSE J 9N T TR QB J ed during numerous transgressive and regressive cycles. Typically, thinking are applied to the natural gas and oil resources of the Jicarilla Apache Reservation. TR land was to the west and southwest shedding sediment toward the SCALE IN MILES �At the present time, oil and gas production on the Reservation is from Cretaceous rocks 0 5 10 15 20 25 30 sea, and open to the east and northeast. including the Dakota, Mancos, Mesaverde (both Cliffhouse and Point Lookout) and Pic LEGEND �Most of the gas in the sandstones are stratigraphically trapped K CRETACEOUS ( WITH MINOR Qai ) INDEX MAP tured Cliffs Formations. In addition, there is coal seam gas production in the Cretaceous J JURASSIC Pc PRECAMBRIAN against shales in a structural setting of regional west dip. However, Kirtland-Fruitland interval. There is no production from the underlying Jurassic Entrada TR TRIASSIC TvQB CENOZOIC VOLCANICS TECTONIC FEATURES P PERMIAN TERTIARY localized structures may enhance trapping and productivity. Oil pro formation, but because it is possible the Entrada may yield oil or gas in the future, a discus P PENNSYLVANIAN TERT. INTRUSIVES ducing sandstones such as the Dakota may require more structural sion of the interval is included in the play information in a later section of this atlas. Figure J-2. Index map of the San Juan Basin with major tectonic features. Position of cross section A-A' (see Figure 5) is closure. The Mancos Shale occurs in fractures along the steeply dip shown (after Peterson, 1965, p. 2079).

JICARILLA APACHE INDIAN RESERVATION Reservation Overview - Production Overview 1 NEW MEXICO REGIONAL GEOLOGY COLORADO NEW MEXICO Dakota Formation �The Dakota Sandstone is a transgressive marine unit formed as the Late Creta ceous sea moved from east to west across the land. It contains coastal barrier ma ERA SYSTEM SERIES LITHOLOGIC UNIT THICKNESS (ft) rine sandstones and continental fluvial sandstone units. It is a dominantly strati Recent & Pleistocene Alluvium in valleys 0 -100' + graphic gas play in the basin and a structural and stratigraphic oil and gas play Quaternary Pleistocene Terrace gravel & gravelly stream channel 0- 100' +/- along the basin's flanks. The rocks represent a wide variety of depositional envi alluvium in the upper parts of some valleys ronments, ranging from braided and meandering stream complexes to nearshore Quaternary or Tertiary Pleistocene or Plicoene Gravel capping high terraces 0- 100' +/- PRIMARY IGNACIO BLANCO/ MESA VERDE GAS FIELD JICARILLA deposits. Lithologies vary considerably, as do reservoir quality and trapping mech Miocene (?) Lamprophyre dikes BLANCO EAST anisms. Eocene San Jose Formation 200' +/- 1800' CENOZOIC Tertiary APACHE �The first Dakota discoveries were made in the early 1920's on the northwestern Nacimiento Formation < 537' - 1,750' Paleocene INDIAN flank of the basin and a central basin discovery well was drilled in 1947 south of Ojo Alamo Sandstone 70' - 200' Bloomfield, New Mexico in the Angel Peak area. A few additional discoveries Kirtland Shale and Kirtland Form. Undivided 100' +/- 450' * Pictured Cliffs Sandstone 0 - 235' RESERVATION were made in the 1950's. In 1961 several fields were combined to form the Basin * Upper Lewis Shale 500' - 1,900' Dakota field, which by the end of 1976 contained 2,400 producing wells that had La Ventana Tongue of 37' - 1,250' Total produced over 2.7 trillion cubic feet (TCF) of gas with an estimated total produc Cretaceous Cliff House Sandstone 560' - * Cretaceous Menefee Formation 345' - 375' 1,825'

Group * tion of over 5 TCF. The field produces from a combination of hydrodynamic and Point Lookout Sandstone 110' - 200' +/- +/- Mesaverde * BOULDER stratigraphic traps. Dakota fields range in size from 40 to 10,000 acres with most PRIMARY FRUITLAND Mancos Shale 2,300' - 2,500' * COAL TREND production from fields of 100 to 2,000 acres (Huffman, 1987). Production of oil ranges from field totals of 1-7 MMBO. Over 14 BCF of associated gas has been Upper & Lower Dakota Sandstone 150' - 200' Cretaceous * produced. RIO ARRIBA COUNTY �Potential still exists for future discoveries in the Dakota interval and the limits Upper Morrison Formation 350' - 600'

SANDOVAL COUNTY of the Basin Dakota field have not yet been defined. Exploration in the Dakota is MESOZOIC BEAR Jurassic BLANCO CANYON challenging and demands an understanding of basin structure and complex Dakota Tocito Formation 60' -125' SOUTH TAPACITO SLEEPER PUERTO depositional patterns. New production techniques for tight gas sandstones and new Jurassic interpretive tools such as 3-D seismic and the application of sequence stratigraphy Entrada Sandstone < 227' CHIQUITO * will be critical in the development of future Dakota reserves. Triassic Upper Triassic Chinle Formation 1,050' +/- Mancos Formation OTERO �The monoclinal flexure surrounding the east, north and west flank of the San Permian Cutler Formation 500' - 950' LINDRITH Juan Basin concentrates most of the Mancos oil production in fractured dolomitic WEST DEVIL'S siltstones sandwiched by marine shale. The Jicarilla Apache Indian Reservation FORK Madera Limestone 0 - 800' +/- LINDRITH lies along the east rim of the basin and the southeastern part of the central basin. Upper & Middle SOUTH Pennsylvanian Pennsylvanian Sandia Formation (upper clastic member 0 - 200' of Sandia Formation

PALEOZOIC PALEOZOIC Lower Pennsylvanian of Wood & Northrop, 1946) Magdalena Group OTERO Carboniferous Upper Arroyo Penasco Formation FIVE LAKES Mississippian 0 -158' Mississippian (lower limestone member of Sandia VENADO PARLAY Formation of Wood & Northrop, 1946)

oil PRECAMBRIAN Granitic and Metamorphic Rocks STATE 44 gas Figure J-3. Outline of the Jicarilla Apache Indian oil & gas Reservation on the east side of Figure J-4. Stratigraphic chart of the eastern part of the San Juan Basin. Symbols indicate formations RIO PUERCO the San Juan Basin showing the that produce oil or gas in the region (after Baltz, 1967). outline of major producing oil and gas fields.

JICARILLA APACHE INDIAN RESERVATION Production Overview 2 NEW MEXICO West COLO.N. Mex East SW EXPLOR. SW EXPLOR. UTE MTN. CONTINENTAL DERBY PENN. NO-1 MESAVERDE NATL. SO DULCE NO-1 22-28N - 2E MARTINEZ NO-4 APACHE NO-1 14-28N - 3E BLANCO GAS FIELD 6-28N - 2W 33-28N - 1W RIO ARRIBA CO. PARK RIO ARRIBA CO. RIO ARRIBA CO. BARKER CR. EL PASO RIO ARRIBA CO. FOREST OIL PAN.AM. SAN JUAN 29-5-50 7-29N - 5W UTE NO 31-1 EL PASO UTE D-1 RIO ARRIBA CO. N.M. 31-21N - 19W UTE NO-6 10-31N - 14W INTERNATIONAL SAN JUAN CO. 17-323N - 14W SAN JUAN CO. HUMBLE FOGELSON 1-25 SAN JUAN CO. N. KIRTLAND SUNRAY KD 11-30N - 14W FED N-1 25-30N - 11W xx KP SAN JUAN CO. 17-30N - 12W SAN JUAN CO. xx xx x x

SAN JUAN CO. x 1000 x KD 1000 x 1000 x JM 1000 xx JE x x xx x x x x

KMV x x x x 2000 PC x x

x JE x 1000 KOA xx

1000 x x

KOA x xxx x

2000 2000 x KD x 1000 x T.D.1902 x x x 1000 x x x

1000 x KOA T.D.2460 1000 x TERTIARY x

? x 1000 x x xx x x 2000 2000 x x

x JE x ? 3000 x 3000 x x 2000 xx x x 2000 x KPC x x

GREENHORN LS. x x x 2000 2000 KOA x x x x x xx xxxx xx NACIMIENTO

2000 x x x x

x PC 3000 x 3000 KPC

KPC x

4000 4000 x 3000 UPLIFT xxx KD 3000 x KPC

x x xx 3000 3000

xx x 3000 x 4000x x x x x x

x 4000 x xx 5000 4000 KMV x 5000 PH x x x x 4000 x x x JE x xxx x x 4000 4000 x x

x LEGEND

x 4000 x

JE x x 5000 x x KMV CRETACEOUS 5000 xx x x

INTRUSIVE INTRUSIVE KMV TERTIARY TERTIARY

xx 6000 x x x

5000 x x T.D.5987 x x

5000 xx KMV x 5000 5000 SANDSTONE, ARKOSE

xx x x x xx 5000 xx

6000 xxxx 6000 PDC AND CONGLOMERATE 6000 7000 x x 6000 xx

6000 xx x 6000 SEA LEVEL SEA LEVEL 6000 x

x SHALE & SILTSTONE 7000 x 7000

xx KD 8000 x

7000 x x x x x GREENHORN LS.

7000 x x x x x x 7000 7000 x KD LIMESTONE, DOLOMITE x KD x x x T.D.6671

PH x x x T.D.7080 KD 8000 8000 AND ANHYDRITE

xx 9000 8000 x JE x 8000 x x x JE x x x 8000 JURASSIC x x

xx COAL x x x 9000 x 9000 JE xx x xx x x 10000 PARADOX 9000 9000

x PC x SALT 9000 x TRIASSIC

PDC x x x

10000 x ML 10000

PC x 11000 POROSITY T.D.10010 T.D.9804 PC x x x 10000 x x PERMIAN KOA - OJO ALAMO CGL. KPC - PICTURED CLIFFS S.S.

xx 11000 FACIES KMV - MESAVERDE FM. KD - DAKOTA S.S. FOUR CORNERS x ARKOSIC 12000 PH JE - ENTRADA S.S. PDC - DE CHELLY S.S. PH PC - CUTLER FM. PH - HERMOSA FM. PLATFORM 11000 x ML - LEADVILLE LS. 12000 13000 2000'

x PH 12000 T.D.13250 x

xxx PENNSYLVANIAN 13000 1000' x x 13000 x ML LOWER T.D.13016 PALEOZOIC 14000 0 20 MI. 10 MI. PRECAMBRIAN T.D.14423

Tectonic activity associated with the Laramide Orogeny in late Cre �Mancos oil production in the San Juan Basin is nearly 30 duction. Hence the potential is quite high for additional Mancos dis Figure J-5. East-west cross section through the San Juan taceous to early Tertiary time resulted in the subsidence of the cen MMBO. Seventy five per cent of the total or 23.3 MMBO comes coveries in the area. Basin (see Figure J-2 for line of section) showing lithologies tral basin, uplifts of the surrounding rim and associated fracturing of from the four Mancos fields that lie within and just outside the Reser and structure. The Jicarilla Apache Indian Reservation is located on the steeply dipping eastern flank, west of the brittle beds (Fassett, 1985 and 1991; Baltz, 1967). Figure J-5 is an vation boundary. Mancos oil production on the Reservation has been Nacimiento uplift (after Peterson, 1965, p. 2088). east-west section through the San Juan Basin showing the central ba 5.1 MMBO. The unexplored northern part of the Reservation lies on sin and marginal steeply dipping strata. the same geologic and structural trend of this prolific Mancos pro

JICARILLA APACHE INDIAN RESERVATION Production Overview 3 NEW MEXICO �The three primary oil bearing reservoirs of the Mancos occur in R 3 W R 2 W R 1 W Upper Cliff House Sandstone, the middle within the central part of the Jicarilla Apache Reservation. As of fractured dolomitic siltstone beds (London, 1972) within a 300 foot shales, coals, sandstones and siltstones of the December 1992, approximately 300 Mesaverde wells were producing

24 19 24 21

interval of the Niobrara called the "A", "B" and "C" zones. The + 150 19 Menefee Formation and the lower Point on the Reservation. These wells have produced over 216 BCF of gas + 100 100 + + 250 more brittle rocks, such as the calcareous siltstones of the Niobrara + 200 Lookout Sandstone. The Group produces pre cumulative and over 1.1 million barrels of associated oil. Oil is also pro

A, B and C zones, fractured more easily when bent or folded than + 300 T dominantly gas with some related oil. Gas duced from scattered small fields in the basin. Three of these, Parlay, 26 25 2 5 30 28 the more plastic encasing shales. The zones are 20-60 feet thick with 30 26 bearing sandstones in all three members of Venado and Otero, lie within Reservation boundaries to the south of the individual siltstone beds within the zones 5-20 feet thick. The A and + 350 N the Mesaverde Group have been selectively main gas producing fairway of the Blanco Mesaverde trend.

B zones are the main productive intervals near the study area, as 35 31 36 32 36 33 perforated and produced. Volumetrically �Several key factors control the occurrence and quality of gas found in East Puerto Chiquito field and the northern part of West + 400 most gas comes from the Point Lookout. production and provide the framework for successful completions in Puerto Chiquito field. The C zone produces the most oil in the Geologically it is a regressive coastal-barrier this reservoir: 2 1 6 southern part of West Puerto Chiquito field. Increased resistivity in + 450 1 6 4 beach deposit, developed as the Cretaceous 1.�Developme nt of cleaner, relatively well sorted, thicker sandstones the Niobrara zones may be due to the tightly cemented dolomitic sea moved eastward away from the land. The that were deposited in elongate benches or lenses. siltstone and/or oil in the fractures. Menefee consists of rocks laid down on the 2.�Structural elements which have created fracturing in these 11 �The abrupt bending of the rocks along the monoclinal rim 12 7 + 500 9 continent under swampy, nearshore condi sandstones and which greatly enhance reservoir quality. Average resulted in many north-south trending faults and fractures. Emmen tions. The uppermost unit, the Cliff House porosities are approximately nine percent and permeabilities average from five tenths to two millidarcies. With these low permeabilities dorfer (1989) showed a prevailing north to south fracture orientation 14 13 18 Sandstone, records a time when once more 16 and porosities, fracturing is thought to be a critical factor in in the greater Puerto Chiquito/Gavilan area based on wireline dip T the sea inundated the land and sandstones + 550 productivity. meter fracture logs (Figure J-6). This trend extends into the Jicarilla 25 formed in primarily barrier island beach front 3.�Stratigraphic and possible hydrodynamic elements which have 23 24 N Apache Reservation. Remote sensing data such as satellite, radar 19 24 21 environments. 19 created permeability barriers and serve as trapping mechanisms. and photo images and surface mapping also show similar lineament �The Mesaverde Group is the largest pro 4.�Black organic-rich shales which lie below and intertongue laterally and fracture orientations in the eastern San Juan Basin. The larger ducer of natural gas (excluding coalbed gas) with the Mesaverde sandstones, providing the source of 26 30 features appear to be reactivated basement fault zones that control 25 of all geologic units in the San Juan Basin, hydrocarbons. subsidence, uplift, fracturing and folding throughout geologic time followed by the Dakota Sandstone and the �Research supports a model in which gas is trapped in stratigraphic (Dart, 1992). Pictured Cliffs Sandstone. The Mesaverde 35 36 31 36 31 traps developed by localized changes in the sandstone reservoir rocks �Five structural settings of fracture intensity and associated oil has furnished energy to Native Americans in and by the existence of permeability barriers. One can correlate the production have been recognized in the central Jicarilla Apache In the region for several hundred years, begin Point Lookout and the Cliff House over long distances, but on a local dian Reservation area. These include: monoclinal flexure, basal 6 1 6 4 ning with oil and gas seeps. Oil production scale the sandstones are quite variable. The coarser, cleaner sandstones monoclinal flexure, anticlinal nose, synclinal trough and central ba was established from these rocks in 1911 on readily thin laterally or pinchout into siltstones and shales. Although in sin structures. The central basin structures contain low relief anti + 550 T the Chaco Slope, on the southwestern side of the past these gas producing sandstone bodies were considered to be clines and synclines but are west of the monocline. The common 7 12 7 24 the San Juan Basin, in a well drilled for wa sheet-like layers with interconnected permeability basinwide, subse N structural traits of these five settings are maximum curvature of the ter. This well stimulated interest in the possi quent studies have shown that each of them consists of a complex of in brittle beds and a sudden change in the rate of dip. + 600 ble existence of oil and gas reservoirs deeper 18 13 18 16 dividual sandstone beds separated by impervious mudstone layers (Fas �The four Mancos fields in the area (23.3 MMBO) are Boulder, + 650 in the basin. Success was finally achieved in sett, 1991). East Puerto Chiquito, West Puerto Chiquito and Gavilan (see Figure 1927 with the completion of the Huntington �In general the cleaner, coarser sandstone bodies trend northwest 3). The structural settings of these fields have been classified in the 1mi 1/2mi 0 2640' 5280' Park Oil Company No. 1 Goede in Section southeast, thinning to the northeast. The thicker sandstones correspond following manner: Boulder Field, monoclinal flexure; East Puerto GAVILAN MANCOS OIL POOL 29, T30N-R9W near Blanco, New Mexico. to the areas of best production. In detail, however, the productive sand Chiquito Field, anticlinal nose and synclinal trough; West Puerto RIO ARRIBA COUNTY, NEW MEXICO The well was a dual Pictured Cliffs-Cliff bodies consist of several different sandstone lenses, each with a unique STRUCTURE MAP: TOP OF NIOBRARA "A" ZONE Chiquito Field, basal monoclinal flexure; Gavilan Field, central ba C. I. = 50' House completion. The Point Lookout was geometry. Individual sandstones are developed within genetic shoreline sin structures of low relief anticlines and synclines. Figure J-6. Dipmeter derived fracture orientation plots on a structure map of Gavilan Mancos never reached because of lost tools in the facies and pinch out or grade into less permeable siltstones or shales �The American Hunter Exploration, Jicarilla 3-F well discovered Oil Pool. The field is located in and around T25N, R2W in Rio Arriba County, New Mexico hole. For many years the well furnished gas (Wright, 1986). The character of the sandstones appears to be the pri a new Mancos field in 1992. This horizontal well flowed at rates up (after Emmendorfer, 1989, p. 66). to the town of Aztec, New Mexico, produc mary control on productivity of a particular area. Differences in produc to 600 BOPD and has produced over 150 MBO. The Jicarilla 3-F reservoir beds. ing from the Pictured Cliffs in the summer and from the more prolif tivity may also be related to fracturing of the sandstones (Pritchard, well lies in the basal monoclinal flexure along structural strike with 3. �Black organic rich shales within the lower Mancos which provid ic Cliff House during the winter. No additional Mesaverde wells 1973 and Fassett, 1991). ed a local source of hydrocarbons (see Gries, et. al., 1997, p. West Puerto Chiquito field, hence this new field discovery has the were drilled until the 1950's when the great population growth in �Large relatively unexplored areas exist on the Reservation which 1133, for an excellent discussion of the source rock characteris potential to produce over 5 MMBO. The 3- F well also sets up fur tics of the Mancos in the adjacent San Juan Sag). California created demand and a pipeline was built. This caused ex are underlain by rocks of the Mesaverde Formation. Stratigraphic ther exploration to the north along undrilled segments of the mono 4.�Structural features such as anticlines, synclines, monoclines and tensive activity and almost all of the commercial locations on the changes can occur over very short distances and remarkably good wells clinal flexure. faults which have enhanced both the fracturing of the rock and original 320 acre drilling blocks were drilled within the next decade can lie close to marginal producers or dry holes. Most of the exploration �Five key factors control the occurrence and quality of Mancos the migration and trapping of oil. (Pritchard, 1973). In 1975 new rules were approved to allow two in the Mesaverde reservoirs occurred in the 1950's and again in the oil production in these fields and provide the framework for success 5.�Gravity drainage drive mechanism which maximizes oil recovery wells per 320 acres and a wave of infill drilling followed. 1970's. Several detailed studies by recent workers illustrate the strati ful exploration and development:. compared to solution gas drive. �The Mesaverde has produced close to 7.5 trillion cubic feet graphic complexity of the Mesaverde rocks when interpreted in light of 1.�Reservoir rock consisting of a primary open fracture set and sec Mesaverde Group (TCF) of gas from 13 fields, the largest of which is the Blanco Mesa sequence stratigraphy. The potential for additional Mesaverde produc ondary conjugate fracture set in brittle dolomitic siltstones of the verde Field. The Blanco Mesaverde trends northwest-southeast tion on the Jicarilla Apache Reservation needs to be thoughtfully ana Niobrara Member of the Mancos Formation. �The Late Cretaceous Mesaverde Group lies stratigraphically across the basin (Figure J-3). The southeastern part of the field lies 2.�Topseal of impermeable shale which traps the oil in the fractured above the Mancos Formation. It consists of three basic units -- The lyzed in light of new ideas and application of seismic data and interpre tation.

JICARILLA APACHE INDIAN RESERVATION Regional Geology Overview 4 NEW MEXICO Pictured Cliffs o o o (Rascoe and Baars, 1972, p. 146) that lie conformably on Pennsylva 109 Cortez 108 107

� Hydrocarbon production in the Pictured Cliffs has been primari GEOLOGIC HISTORY CO nian sediments (Peterson, 1965, p. 2094). By this time, the Zuni-De Pagosa Springs ly gas trapped in sandstone beds which are enclosed in shales or �The Jicarilla Apache Reservation is located on the east Durango fiance Uplift was of minor importance and a majority of the sedi coals at the top of the unit. The Pictured Cliffs Sandstone is similar side of the San Juan Basin in northwest New Mexico (Fig PLATA ments came from the north and northeast off the Uncompahgre Up

River LA CO A CO T to the Cliff House Sandstone in that it is a regressive marine sand ure J-1), comprising parts of Townships 22 to 32 N and UTAH lift, Archuleta Uplift and Nacimiento Uplift. The influx of clastics ARCHULETA ARCHULETA stone and contains steps or benches which record stillstands or build Ranges 1 E to 5 W (Fig. J-2). The outcrop of the Cretaceous Kkf from the Nacimiento Uplift to the east caused almost total regression o COLORADO MONTEZUMALA PLA CO ups of the sandstone bodies. Stillstands in the regression of the sea Fruitland formation is generally accepted as the outer limit 37 of marine depositional systems (Peterson, 1965, p. 2092). On the

NEW MEXICO La Plata produced thicker shoreline sandstones and the best reservoirs. of the geologic San Juan Basin and the outcrop trends gen Dulce northeast, Cutler arkoses are the predominant lithology and these are River River Thickness of the formation ranges from 0 to 400 feet and it is con erally north to south along the east side of the Reservation San Juan JICARILLA overlain southwestward by the Coconino and De Chelly Sandstones. Aztec San Juan Shiprock formable with both the underlying marine Lewis Shale and the over (Figure J-7). The east edge of the basin marks the approxi Animas APACHE There is an erosional hiatus at the top of the Permian section (Childs, River lying non-marine Fruitland Formation. mate eastern edge of the Colorado Plateau physiographic Bloomfield INDIAN et. al., 1988).

ARIZONA ARIZONA Farmington �Gas was first discovered in the Pictured Cliffs in 1927 at the province. RESERVATION Triassic� Blanco and Fulcher Kutz fields of northwest New Mexico. Most of �Formations present in the eastern part of the San Juan �During the Lower Triassic, parts of the future San Juan Basin the Pictured Cliffs fields were discovered early, with only a few hav Basin and under the Reservation range in age from Kkf became elevated as seen in thinning of the section from about 1,500 ing been discovered in recent years. Discoveries since the mid- Mississippian to recent as shown in Figure J-4. feet on the southwest to less than 750 feet on the northeast (Peterson, 1950's have averaged 3,000 acres in size and 11 BCF estimated ulti Llaves 1965, p. 2099). In Middle Triassic the Basin was high and became a mate recovery. In the central basin and on the Jicarilla Reservation Sedimentary History source area, experiencing active erosion. By the Late Triassic time, Pictured Cliffs production, while perhaps not outstanding on its �The eastern part of the San Juan Basin was an area of Newcomb RIO ARRIBA CO

JUAN JUAN the area was low and was accumulating shales and sandy shales we own, is commingled with the Mesaverde (or other horizons) and can erosion or non-deposition until Mississippian time. Even SANDOVAL CO now call the Chinle and Dolores Formations. There appear to be SAN CO be a critical factor in the economics of the well. Much of the re then, sediments deposited during the Mississippian and about 1,500 to 2,000 feet of Triassic rocks in the present San Juan source potential of the Pictured Cliffs depends on new technology in Pennsylvanian range from 0 to a few hundred feet thick un Cuba o SAN JUAN CO Basin (MacLachlan, 1972, p. 169), thickening to the southwest. 36 recovering gas from tight sandstones. der the Jicarilla Apache Indian Reservation. The first forma McKINLEY CO �A proto San Juan Basin south of the Central Colorado Uplift was �Stratigraphic traps which result from the landward pinchout of tion that appears to be present under all parts of the Reser 0 10 20 30 MILES open to the northwest into the Utah-Idaho trough and was the site of nearshore and foreshore sandstones into siltstones, shales or coals of vation is the Permian Cutler. From Cutler level upward deposition of about 1,250 feet of Jurassic sediments (Peterson, 1972, Figure J-7. Outline of the San Juan Basin as defined by the outcrop of the the Fruitland produce most of the hydrocarbons, especially in areas there can be units that reach zero thickness, such as the Cre p. 180) thinning to about 1,000 to the north and south (Peterson, of stratigraphic rises. These rises are concentrated along a north taceous Pictured Cliffs sandstone, but it is more likely that Cretaceous Fruitland formation. Position of the Jicarilla Apache Indian Reservation is shown (after Fassett, 1988, p. 24). 1965, p. 2108). From the base of the Jurassic section upward, these west- southeast trending fairway in the central part of the basin, gen the pinchouts represent true depositional edges rather than erally coinciding with similar trends in the Gallup and Mesaverde erosional truncation. Basin and in the far southeast part where they are are the Entrada Sandstone, To sections (Huffman, 1987.) The most important factor in reservoir �Thickness variations and pinch-outs in the pre-Pennsylvanian known as the Arroyo Penasco Formation. Thick dilto Formation and Morrison Formation. The Entrada is a pe quality is the abundance of authigenic clay in the sandstones, limit section seem to be a result of the San Juan Basin depositional area ness of the section is less than 200 feet (Craig, GREENLAND ing the porosity and permeability. Average porosity is about 15 per being on the northwest flank of the early Paleozoic Transcontinental 1972, p. 103). Mississippian rocks overlie an ero ALASKA troleum reservoir in parts of the cent and permeability averages 5.5 millidarcies, although many Arch (Peterson, 1965, p. 2087). sional surface developed on Devonian, Cambrian Basin where it is overlain by the fields are less than 1 millidarcy. Thickness of pay ranges from 5 to and Precambrian rocks. All of the present day San evaporites of the Todilto. Cambrian and older SEA EPEIRIC CRETACEOUS 150 feet and is often less than 40 feet. �A very thin section of Ignacio Quartzite is present in the north Juan Basin was emergent at the end of Mississip Cretaceous west part of the San Juan Basin. It rests nonconformably on Precam pian time (Peterson, 1965, p. 2097). �The present San Juan Basin Fruitland Formation Coal Seam Gas brian rocks equivalent in age to the Belt Supergroup and is overlain Pennsylvanian was on the west edge of the �Currently the Fruitland Formation coals produce more than half disconformably by Devonian rocks (Lochman-Balk, 1972, p. 64). �Uplift of the Ancestral Rockies led to deposi Western Interior Cretaceous Sea of the daily gas volume from the San Juan Basin and are currently C A N A way (Figure J-8) and received a Devonian tion of thick arkose and sandstone sequences adja D A the best gas resource in the San Juan Basin. The most prolific gas thick section of sedimentary �Up to 300 feet of lower Devonian Elbert Formation carbonates cent to local structures. During this time, the in wells in both Colorado and New Mexico are Fruitland coal gas rocks related to transgression are present in the Four Corners area and these thin eastward into the cipient San Juan Basin was bounded on the north wells. At depths of less than 4,000 feet, this unconventional gas re east by the Uncompahgre Uplift and on the south and final regression of the west San Juan Basin where they disconformably overlie both the Cam U N source has been the primary objective of the San Juan Basin in the I T ern shoreline. Most of the sec brian Ignacio Quartzite and Precambrian rocks. According to Baars west by the Zuni-Defiance Uplift and formed a E D last five years. The expired "Section 29" tax credit provided an eco S T A T E S tion is Upper Cretaceous in age, (1972, p. 96) the overlying McCracken sandstone is areally restricted shallow seaway that accumulated mostly limey SAN JUAN nomic incentive to develop this giant resource. However with im BASIN but up to 200 feet of Lower Cre to the Four Corners Platform although one field in the San Juan Ba shale and shaley carbonates. From the base of the proved technology and good geology, commercial wells will contin taceous Burro Canyon Forma sin produced oil from possible McCracken sandstone for a short time section upward, the three main Pennsylvanian ue to be discovered. units in the Basin are the Molas Shale, Hermosa tion were deposited within and �The coals of the Fruitland Formation were deposited landward (Dawson, 1983, p. 918). The upper Devonian Ouray limestone con M E aligned approximately with the formably overlies both the Elbert and McCracken Formations and is Formation and Rico Formation. Pennsylvanian and stratigraphically above the Pictured Cliffs Sandstone. Region X older Jurassic depositional trend rocks lie disconformably on the Mississippian sec I restricted to approximately the same area within the northwest San C ally, Fruitland coals thin to the east and southeast in the basin, pro O (McGookey, 1972, p. 197). Juan Basin. The Devonian section thins southward, reaching zero tion (Childs, et. al., 1988). The section in the San viding limited gas potential on the Jicarilla Apache Reservation These were separated from the feet across the north-central part of the basin (Peterson, 1965, p. Juan Basin reaches about 2,500 feet in thickness However, conventional traps and localized thickening are likely to Jurassic section by an erosional 2081). in the far northwest (Mallory, 1972, p. 115). 0 500 1000 Miles occur behind the regressing Pictured Cliffs marine sands, creating hiatus (Childs, et. al., 1988). potential drilling targets. The Fruitland is the shallowest of the San Mississippian Permian Figure J-8. Probable configuration of the North American Epeiric Seaway at the time the Upper Cretaceous rocks of Juan Basin reservoirs. Therefore, recompleting wells in the coals can �Mississippian carbonates equivalent to the Redwall (Madison, �There are over 2,000 feet of Permian-age rocks in the deepest part of the San Juan Basin the San Juan Basin accumulated (after Fassett, 1988, p. add reserves at minimal cost. Leadville) limestone are present in the northwest part of the San Juan 26).

JICARILLA APACHE INDIAN RESERVATION Geology Overview 5 NEW MEXICO �Upper Cretaceous rocks are more than 6,000 feet thick and Tertiary and Younger cene time, peaking during the Oligocene and tapering off in the 10). Figure J-11 is an east-west cross section through the Basin show comprise all the rocks shown in Figure J-9. The vast majority of �The Paleocene saw deposition of the continental San Jose and Miocene. Surficial deposits derived from this activity are present in ing the shape of units above the Huerfanito Bentonite. Major structural petroleum in the San Juan Basin is from rocks of upper Cretaceous Nacimiento formations and these are the surface formations much of the basin. features of the basin are shown in Figures J-1, J-2 and J-12. age. The present San Juan Basin did not form until the Laramide throughout most of the San Juan Basin today. There is as much as �Until Pennsylvanian time, the San Juan Basin depositional area orogency. However, a pre-Laramide low aligned approximately 2,300 feet of San Jose Formation present in the northern parts of Structural Geology was located on the northwest flank of the soutwestward trending Trans north-south allowed accumulation and preservation of the Creta the basin (Peterson, 1972, p. 249). There was much volcanic activ �Structurally, the Jicarilla Apache Reservation extends over and continental Arch. The entire area was emergent in late Mississippian ceous sediments (McGookey, 1972, p. 207). ity north and northwest of the San Juan Basin starting in late Eo east of the deepest part of the asymmetric San Juan basin and up time (Peterson, 1965, p. 2087). For most of the period between the end onto the westward dipping eastern flank as defined by structure of the Mississippian and beginning of the Tertiary, the area was a low SSW 146 Miles ( 235 Kilometers ) NNE NEW MEXICO COLORADO contours on the Huerfanito Bentonite of the Lewis Shale (Figure J- adjacent to a series of uplifts to the north, northwest, southwest and ZUNI UPLIFT SAN JUAN BASIN east and received most of its fill during this time. SAN JUAN MTNS Durango SAN JUAN BASIN GAS FIELD Pagosa 108 107 COLO Springs ? TERT. R16W 15 14 13 12 11 10 9 8 7 6 5 4 3 2 R 1 W R 1 E N. MEX ? Tertiary Ojo Alamo Sandstone L A P L A T A C O U N T Y Farmington and younger rocks T 36 N ARIZ UTAH SAN JUAN BASIN Durango 4400 M O N T E Z U M A A R C H U L E T A C O U N T Y 35 Cuba Maastricht. 4000 AREA Kirtland shale 3600 Gallup ZUNI ? ? UPLIFT 3200 34

Grants 2800 Albuquerque GENERAL Fruitland Formation 0 25 Miles Pictured Cliffs Sandstone 33 ZUNI IN BASIN 0 25 Km COLORADO 2400 32 INDEX MAP 37 NEW MEXICO 13 12 11 10 9 78 6 5 4 3 METERS FEET Huerfanito Bentonite Bed R 1 W R 1 E SURFACE ? Outcrop of Fruitland Dulce 600 2,000 Kcht Cliff House Sandstone Formation and 2000 VERT. EXAG. = 84 Lewis Shale Kirtland Shale 4800 31 500 La Ventana

Cliff House Campanian 1,500 R 16 W 5200 Sandstone 400 Tongue 30 EROSION Menefee Formation 300 1,000 Farmington Y 2400 29 200 Mesaverde Group

500 Allison Member UPPER CRETACEOUS 100 RIO ARRIBA COUNTY 28 PRESENT - DA Point lookout Sandstone Cleary Coal Member ? 0 0 2800 27 Kph Satan Tongue Mancos Shale 26 Gibson Coal Kcda 3200 Crevasse Canyon S A N J U A N Formation Member

Tocito Sandstone Lentil San. 25 Kcbp Mulatto Tongue 3600

Dilco Member ? ? Con. 24 Gallup Sandstone 4000 mber of Dakota Ss Graneros Member Juana Lopez Me Turon. ? ? Mancos Bridge Creek Limestone Member Paguate Tongue

Cen. 23 Twowells Tongue of Dakota Ss Shale Clay Mesa Tongue of Mancos Shale 4400 4800 Dakota Sandstone 22 Whitewater Tongue of Mancos Shale S A N D O V A L COUNTY

5200 EXPLANATION Cuba 21 36 Non-marine rocks Kph Hosta Tongue of Point Lookout Ss 5600 6000 COLO 20 Marine and coastal sandstone Kcda Dalton Ss Mbr of Crevasse Canyon Fm Area M c K I N L E Y of this Marine shale, siltstone, and minor Report N MEX Kcpb Borrego Pass Sandstone Lentil of 19 amounts of sandstone and limestone � � � ��Crevasse Canyon Formation Kcht Sandstone exposed at Tsaya Canyon - - - - Time marker bed, e.g., bentonite or � �calcareous z one 0 5 10 15 20 MILES Figure J-9. Stratigraphic cross section showing upper Cretaceous rocks across the San Juan Basin, New Mexico and Colorado (after Nummedal and Molenaar, 1995, p. 279). Figure J-10. Structure contour map on the Huerfanito Bentonite in the San Juan Basin. Contour intervals are in feet (after

JICARILLA APACHE INDIAN RESERVATION Geology Overview 6 NEW MEXICO o o o NORTH 109 108 107 Figure J-12. Major structural elements in the San Juan Basin SOUTH (after Rice, et. al., San Juan uplift topography 1988, p. 52). Pictured Cliffs Paradox Sandstone Present Basin

Ojo Ute Mtn Animasyounger Formation rocks and Alamo Durango 5000 ft above sea level Sandstone

Lewis and UTAH younger beds o FEET Shale COLORADO Fruitland Formation and 37 2000 Carrizo Chama embayment Brazos uplift Huerfanito Bentonite Bed Mts 1500 Kirtland Shale Hogback monocline Farmington 1000 Shiprock Four - Corners platform 500

5 10 15 MILES monocline monocline 0 Hogback VERTICAL EXAGGERATION ABOUT X 34 CENTRAL BASIN A

Jemez Mts Nacimiento uplift caldera EAST 36 o uplift uplift monocline

Mesa

Gallup Present topography

WEST Defiance CHACO SLOPE Defiance Black Gallup 5000 ft above sea level

basin Pictured Fruitland Formation and Kirtland ShaleOjo Zuni uplift Cliffs Alamo FEET Sandstone Sandstone Grants 2000 and younger Lewis beds 1500 Shale ault belt Zuni Puerco platform monocline Albuquerque o embayment 1000 35 Huerfanito Bentonite Bed 500 Ignacio 5 10 15 MILES Acoma 0 embayment B Rio Grande f VERTICAL EXAGGERATION ABOUT X 34 ARIZONA

Figure J-11. North (A) and east (B) trending structural cross sections across the San Juan Basin showing the present structure (after NEW MEXICO Lucerouplift Fassett, 1988, p. 37). � The San Juan Basin as we know it today is a Laramide age fea San Juan Basin. Erslev (1997, p. 2) suggests that later activity along San Juan Basin and according to Woodward and Callender (1977, p. na-Archuleta Arch is at least 13,000 feet. ture that resulted as the North American plate drifted westward and the Sevier thrust belt imposed a northwest-southeast compression on 210): � Verbeek and Grout (1997, p. 7) indicate that post-Laramide uplift impinged on an eastward dipping subduction zone (Woodward and the basin. Evidence for this is found on the north side of the basin The eastern boundary of the San Juan Basin is marked by a monocline and regional extension associated with basin and range faulting have Callender, 1977, p. 209). Because of the bend in the Cordilleran fold near Durango where northwest-southeast dike swarms show exten along the west side of the Gallina-Archuleta Arch and by range-margin created a significant joint network that is locally more important than belt in southern California, the predominant stress direction was to sion, not compression. Condon (1997, p.85) thinks that clockwise ro al upthrust and reverse faults on the west side of the Nacimiento Uplift. those resulting from Laramide movements. Significance of these most the northeast, creating the dominant northwest trending folds and tation during the main Laramide event may have been responsible for A sharp synclinal bend that is locally overturned occurs west of the up ly northwest-southeast trending extensional fractures to subsurface flu thrust and reverse faults. There is at least 10,000 feet of structural relief northeast trending normal faults we see today. Several northwest- the observed extension. id migration is not known, although they may have an influence on between the highest part of the Nacimiento Uplift and the adjacent part plunging, en echelon, open folds and northeast-trending, high-angle coal cleat orientation and subsequent effect on coal bed methane recov � The Jicarilla Apache Indian Reservation is on the east side of the of the San Juan Basin. Structural relief between the Basin and the Galli faults of small displacement occur along the eastern margin of the ery.

JICARILLA APACHE INDIAN RESERVATION Geology Overview 7 NEW MEXICO Summary of Play Types JICARILLA APACHE INDIAN RESERVATION, NEW MEXICO Total Production Reservation: Jicarilla Apache San Juan Basin Cumulative Totals Undiscovered resources and numbers of fields are Geologic Province: San Juan Basin (022) �Oil: >240,000,000 BO for Province-wide plays. No attempt has been made Province Area: Approximately 8,000 sq miles (basin only) �Gas: >18,000,000,000 CFG to estimate number of undiscovered fields within the Reservation Area: Approximately 1,000,000 acres �NGL: Included Jicarilla Apache Indian Basin (figures from NMOGA, 1997 & FCGS, 1983) USGS Play Type Description of Play Oil or Gas Known Accumulations Undiscovered Resource (MMBOE) Play Probability Drilling depths Favorable factors Unfavorable factors Designation Field Size (> 1 MMBOE) min, median, mean (chance of success)

1) produces south of reservation 1) no Entrada production on 2204 Associated with relict dune Oil 4,360 MBO (1995) 1.0 5,000-6,000 ft. 1 21.3 MMBO (mean) 2) excellent porosity and permeablility reservation at present topography, sealed by anhydrite 3) trend in southeast part of the basin 2) sand rapidly looses perm in overlying Todilto limestone untreated eablity below 9,000 feet Entrada Sandstone 4) reservation location favorable 3) requires favorable paleo structurally topographic relief 4) must lie within depositional area of overlying Todilto

2206 Marine transgressive sand and non Both 22.9 MMBO 30.5 MMBO 1.0 1,000-3,000 ft. 1) multiple plays 1) stratigraphic traps 2 marine channel sand structural and 62.1 BCFG 91.6 BCFG associated 2) natural fractures enhance low 2) low matrix permeability Basin Margin stratigraphic play, becoming more 29.6 BCFG non-associated (mean) permeability 3) need fracture enhancement marine to the southeast. 3) relatively shallow drilling to basin 4) comingled production Dakota Oil margin oil play 4) close market

2207 Oil and associated gas play in Both 170 MMBO 31.4 MMBO 1.0 1,100-6,800 ft. 1) possible multiple plays 1) stratigraphic traps 3 lenticular sandstone bodies of the 200 BCFG 62.9 BCFG associated 2) high gas BTUs (1275) 2) low volume recoveries Tocito Gallup Upper Cretaceous Gallup sandstone 93.1 BCFG non-associated (mean) 3) relativly shallow on east 3) confusion in use of "Gallop" and Tocito sandstone lentil associated 4) broad sand/reservoir distribution 4) little to no secondary recovery Sandstone Oil with Mancos Shale source rocks lying immediately above an unconformity.

2210 Confirmed stratigraphic oil play Oil Unknown 7.8 MMBO 0.80 1,000-3,000 ft. 1) possible multiple plays 1) future discoveries likely to be 4 around margins of San Juan Basin. 7.8 BCFG associated (mean) 2) high oil gravities small Can be structurally enhanced. Point 3) thick pay sections 2) stratigraphic/hydrodynamic Basin Margin Lookout sand intertounges with and 4) ready market traps sources from Mancos shale. 3) low oil recoveries Mesaverde Oil 4) drilled with natural gas

2212 The play covers the central part of the Gas 1.5 TCFG 261.1 TCFG 1.0 1,500-2,700 ft. 1) wide sand distribution in San 1) largest fields are already found 5 basin and is characterized by gas prod Juan Basin 2) produces very little condensate duction from stratigraphic traps in lenti 2) considered tight gas sands 3) low permeability Fruitland-Kirkland cular fluvial sandstone bodies enclosed 3) high porosity 4) produces from discontinous, in shale source rocks and (or) coal. The 4) produces coal-bed methane lenticular channel sands Fluvial Sandstone upper Cretaceous Fruitland formation and from lower Fruitland Kirkland shale are continental deposits Gas and have a maximum combined thickness of more than 2,000 feet.

Conventional play type

Unconventional/Hypothetical play type

Table 1. Play summary chart.

JICARILLA APACHE INDIAN RESERVATION Summary of Play Types 8 NEW MEXICO Summary of Play Types JICARILLA APACHE INDIAN RESERVATION, NEW MEXICO

Total Production Reservation: Jicarilla Apache San Juan Basin Cumulative Totals Undiscovered resources and numbers of fields are Geologic Province: San Juan Basin (022) �Oil: >240,000,000 BO for Province-wide plays. No attempt has been made Province Area: Approximately 8,000 sq miles (basin only) �Gas: >18,000,000,000 CFG to estimate number of undiscovered fields within the Reservation Area: Approximately 1,000,000 acres �NGL: Included Jicarilla Apache Indian Basin (figures from NMOGA, 1997 & FCGS, 1983) USGS Play Type Description of Play Oil or Gas Known Accumulations Undiscovered Resource (MMBOE) Play Probability Drilling depths Favorable factors Unfavorable factors Designation Field Size (> 1 MMBOE) min, median, mean (chance of success)

6 2205 Stratigraphic traps with coastal Gas Unknown 8.2 TCFG (mean) 1.0 6,500-7,500 ft. 1) multiple plays 1) strati graphic traps marine barrier bars and non-marine 2) natural fractures enhance low 2) low matrix permeability Dakota Central fluvial sands. permeability 3) need fracture enhancement Basin Gas 4) source rock quality variable

2208 Structural, monoclinical flexure, Oil 30 MMBO total for basin 188.9 MMBO 1.0 1,400-7,500 ft. 1) shallow drilling depths 1) new reserves will require 7 anticlinal nose, fractured shale play 23.3 MMBO on reservation 94.4 BCFG (mean) 2) fracture enhanced permeability directional drilling on San Juan margin. 3) nearby market 2) requires pressure main Mancos Fractured 4) gravity drainage tenance 3) small volume of gas produced Shale is reinjected 4) must locate suitable fracture system

2209 Comprises the Point Lookout and Gas 9.6 TCFG (mean) 1.0 4,000-5,300 ft. 1) possible multiple plays 1) future discoveries likely to be 8 Cliffhouse members of the Mesaverde 2) high oil gravities small formation in sandstone buildups assoc 3) ready market 2) commonly drilled with natural iated with strati graphic "benches." The 4) thick pay sections gas Central Basin thickness of this interval may be control 3) strati graphic/hydrodynamic led to some extent by underlying structures traps Mesaverde Gas oriented in a northwest direction. The 4) low oil recoveries Upper Mancos Shale intertongues with the basal Point Lookout Sandstone and has been positively correlated with oil prod- used from this interval (Ross 1980).

9 2211 Gas production is from strati graphic Gas 9 fields average 11 BCFG 3.3 TCFG (mean) 1.0 1,000-3,000 ft. 1) good porosities and permeabilities 1) smectite/illite pore fill in deeper traps in sandstone reservoirs enclosed 2) ready market areas in shale or coal at the top of the Upper 3) high flow rates 2) strati graphic traps Cretaceous Pictured Cliffs sandstone 4) higher than average BTU content 3) non associated gas contains Pictured Cliffs Gas and is confirmed to the central part of (1175) little condensate the basin. Thicker shoreline sandstones 4) highly variable thickness up to produced by still sands, or brief reversals 400 feet in the regression of the Cretaceous sea to the northeast have been most productive.

Table 2. Play summary chart (continued). Conventional play type

Unconventional/Hypothetical play type

JICARILLA APACHE INDIAN RESERVATION Summary of Play Types (continued) 9 NEW MEXICO SUMMARY OF PLAY TYPES Timing and migration: Maximum depth of burial throughout most A' A'' PETRO LEWIS CORP. - 7-22 MILLER FEDERAL �The United States Geological Survey identifies several petrole of the San Juan Basin occurred at this time. In the eastern part of the Section 22, T19N, R3W (1335' fnl 1980' fel) N W S E SANDOVAL Co., NEW MEXICO um plays in the San Juan Basin Province and classifies them as Con 5 basin the Todilto entered the oil generation window during the Oli 5-22 7-22 w TD - 5466' KB - 6865' COMPLETION 4 - 12 - 76 ventional and Unconventional. The discussions that follow are limit gocene. Migration into Entrada reservoirs either locally or updip to +1700 ed to those with direct significance for future petroleum development the south probably occurred almost immediately; however, in some TODILTO LIMESTONE in the Jicarilla Apache Indian Reservation. Much of the following is fields, remigration of the original accumulations has occurred subse MORRISON SHALE 5205' extracted from USGS CD-ROM DDS-30, Release 2 (Gautier, et. quent to original emplacement. al.,1995). Table 1 is a summary of USGS plays in the San Juan Ba Traps: All traps so far discovered in the Entrada Sandstone are sin. stratigraphic and are sealed by the Todilto limestone and anhydrite. DEFINITION OF A CONVENTIONAL PLAY Local faulting and drape over deep-seated faults has enhanced, TODILTO LIMESTONE & GYPSUM Discrete deposits, usually bounded by a downdip water contact, from modified, or destroyed the potential closures of the Entrada +1600 which oil, gas, or NGL can be extracted using traditional develop sandstone ridges. Hydrodynamic tilting of oil-water contacts and for ment practices, including production at the surface from a well as a "base of movable oil'' interfaces has had a destructive influence on ENTRADA SANDSTONE consequence of natural pressure within the subsurface reservoir, arti the oil accumulations because the direction of tilt typically has an 5291' ENTRADA SANDSTONE ficial lifting of oil from the reservoir to the surface where applicable, updip component. All fields developed to date have been at depths OIL - WATER CONTACT + 1540' and the maintenance of reservoir pressure by means of water or gas of 5,000 - 6,000 ft. Because of increase in cementation with depth, injection. the maximum depth at which suitable reservoir quality can be found is approximately 9,000 ft. +1500 ENTRADA PLAY Exploration status and resource potential: The initial Entrada 0 500' 1000' + DATUM TOP OF THE ENTRADA SS USGS 2204 discovery, the Media field (Figs. J-13, -14, -15), was made in 1953. Figure J-13. Southwest Media Entrada Field Development was inhibited by problems of high water cut and high section along A-A' - see Figure J-14 (after �The Entrada sandstone produces south and west of the Jicarilla pour point of the oil, problems common to all subsequent Entrada Reese, 1978). Figure J-15. Southwest Media Apache Indian Reservation. This discussion is included here because field development. Between 1972 and 1977, seven fields similar to Entrada Field example electric log of the possibility that Entrada production may develop on the Reser Media were discovered, primarily using seismic techniques. Areal (from Reese, 1978). GAMMA RAY RESISTIVITY vation in the future. sizes of fields range from 100 to 400 acres, and total estimated pro �The Entrada play is associated with relict dune topography on duction of each varies from 150,000 BO to 2 MMBO. A number of PETRO LEWIS CORP. top of the eolian Middle Jurassic Entrada Sandstone in the areas of anomalously thick Entrada in the southeastern part of the R 3 W southeastern part of the San Juan Basin and is based on the presence Figure J-14. Southwest San Juan Basin have yet to be tested, and there is a good probability Media Entrada Field. A' of organic-rich limestone source rocks and anhydrite in the overlying +1550' that at least a few of these areas have adequate trapping conditions Structure contours on top of Todilto Limestone Member of the Wanakah Formation. North of the for undiscovered oil accumulations, but with similar development Entrada Sandstone. Figure J- present producing area, in the deeper, northeastern part of the San 13 is section along A-A' (from +1560' +1570' problems as the present fields. Limiting factors to the moderate fu +1570' Juan Basin, porosity in the Entrada decreases rapidly (Vincelette and ture oil potential of the play include the presence of sufficient paleo Reese, 1978). 7-22 Chittum. 1981). Compaction and silica cement make the Entrada very +1574' +1560' topographic relief on top of the Entrada, local structural conditions, TD-5466' A'' tight below a depth of 9,000 ft. No eolian sandstone buildups have hydrodynamics, source-rock and oil migration history, and local po +1550' been found south and west of the producing area. rosity and permeability variations. +1540' Reservoirs: Some of the relict dunes are as thick as 100 ft but have flanks that dip only 2 degrees. Dune reservoirs are composed of fine- Analog Field T grained, well-sorted sandstone, massive or horizontally bedded in the SOUTHWEST MEDIA ENTRADA 22 19 upper part and thinly laminated, with steeply dipping crossbedding in Figures J-13, J-14 and J-15 N the lower part. Porosity (23 percent average) and permeability (370 millidarcies average) are very good throughout. Average net pay in Location: � � � �T19N, R3W, south of Reservation N developed fields is 23 ft. Formation:� � � �Entrada +1550' +1550' Source rocks: Limestone in the Todilto Limestone Member has been Lithology: � � � �Sandstone identified as the source of Entrada oil (Ross, 1980). There is a Average Depth: � � � �5,360 ft +1560' reported correlation between the presence of organic material in the Porosity: � � � �23.8% Todilto Limestone and the presence of the overlying Todilto Permeability: � � � �361 md anhydrite (Vincelette and Chittum, 1981). This association limits the Oil/Gas Column: � � � �30 feet source rock potential of the Todilto to the deeper parts of the Average Net Pay Thickness: � �30 feet depositional basin in the eastern San Juan Basin. Elsewhere in the Estimated Ultimate Recovery: � �1,800,000 BO basin, the limestone was oxygenated during deposition and much of Other Information: � � �Oil gravity 33.5 degrees API, asphaltic base with high pour 0 1,000' 2,000' DATUM TOP OF ENTRADA SANDSTONE the organic material destroyed. � � � � �poi nt. Reservoir is in structurally enhanced stratigraphic trap. feet

JICARILLA APACHE INDIAN RESERVATION CONVENTIONAL PLAY TYPE: Entrada Sandstone 10 NEW MEXICO Basin Margin Dakota Oil Play USGS 2206 SOUTH LINDRITH TYPE LOG CHACE GALLUP - DAKOTA FIELD JIC. No. 361 - 1 � The Basin Margin Dakota Oil Play is both a structural and strati Timing and oil migration: Depending on location, the Dakota Sand 4 - T23N - R4W RIO ARRIBA CO., NEW MEXICO graphic play on the northern, southern, and western sides of the cen stone and lower Mancos Shale entered the oil window during the Oli KB. 7141' TD. 7442' tral San Juan Basin. Because of the variability of depositional envi gocene to Miocene. In the southern part of the area, migration was ronments in the transgressive Dakota Sandstone, it is difficult to still taking place in the late Miocene or even more recently. characterize a typical reservoir geology. Most production has been 6100 PAY from the upper marine part of the interval. but significant amounts of Traps: Fields range in size from 40 to 10,000 acres and most produc 19 20 21 22 T both oil and gas have also been produced from the nonmarine sec tion is from fields of 100 - 2,000 acres. Stratigraphic traps are typical - 150 tion. ly formed by updip pinchouts of porous sandstone into shale or coal. 24 A' 6200 Structural traps on faulted anticlines sealed by shale form some of the N GALLUP Reservoirs: The Late Cretaceous Dakota Sandstone varies from pre larger fields in the play. Oil production ranges in depth from 1,000 to 6 dominantly nonmarine channel deposits and interbedded coal and 3,000 ft. 6300 - 50 - 100 conglomerate in the northwest to predominantly shallow marine, 30 29 28 commonly burrowed deposits in the southeast. Net pay thicknesses Exploration status and resource potential: The first discoveries in 5 range from 10 to 100 ft; porosities are as high as 20 percent and per the Dakota play were made in the early 1920's on small anticlinal 6400 0 meabilities as high as 400 millidarcies. structures on the Four Corners platform. Approximately 30 percent of N the oil fields have an estimated total production exceeding 1 MMBO, 4

Source rocks: Along the southern margin of the play, the Creta and the largest field (Price Gramps) has production of 7 MMBO. 6500 + 50 ceous marine Mancos Shale was the source of the Dakota oil. API Future Dakota oil discoveries are likely as basin structure and Dakota 31 32 33 3 gravities range from 44 degrees to 59 degrees. On the Four Corners depositional patterns are more fully understood. platform to the west, nonmarine source rocks of the Menefee Forma 6600 A TYPE LOG tion were identified as the source (Ross, 1980). The stratigraphically Chase higher Menefee is brought into close proximity with the Dakota 361-1 M A N C O S S H . across the Hogback Monocline. 1 2 6700

6 4 + 100 6800 Analog Field + 150 LINDRITH GALLUP-DAKOTA SOUTH + 100 Figures J-16 and J-17 T 6900 + 200 23 7 8 9 10 DATUM Location: � � � �T23-24N, R4W, on Reservation N

Formation: � � � �Dakota 7000 GREENHORN LS. MBR. Lithology: � � � �Sandstone 0 1 MI. GRANEROS SH. MBR. Average � � � �Depth: 7200 feet R 4 W Porosity: � � � �12% Permeability: � � �0.1 to 0.5 md, fracture enhanced STRUCTURE MAP Oil/Gas Column: � � �200 feet DATUM: BASE GREENHORN LS. Average Net Pay Thickness: � �40 feet C I = 25 Other Information: � � �Estimated ultimate recovery 80,000 BO per well, DAKOTA PAY

� � � � �comingled. Oil averages 43 degrees API and is a LEGEND 7300 7200 7100

� � � � �sweet crude. DAKOTA SS. OIL & GAS WELL

DISCOVERY WELL PERFS:� 5831' - 6268' & 7054' - 7283' �(GR OSS) SD WTR. FRAC. Figure J-16. South Lindrith Gallup-Dakota Field, DRY HOLE IPF: �105 BOD , 60 MCFGD, 40 BWD. structure map and example log (from Matheny, �COMPLETED 9 - 24 - 82 1978, p. 982).

JICARILLA APACHE INDIAN RESERVATION CONVENTIONAL PLAY TYPE: Basin Margin Dakota Oil Play 11 NEW MEXICO Analog Field * Well numbers correspond to Fig. J-16. #1* BLANCO TOCITO SOUTH #2 * #3* #4 #5* #6* Figures J-18 and J-19 6600

7100 Location: � � �T26N, R5-6W, on Reservation 7000 7100 7000 GREENHORN LS. MBR. DATUM Formation: � � �Tocito Sandstone Lentil of Mancos Shale

6700 GRANEROS SH. MBR. Lithology: � � �Sandstone 7100 7200

7100 Average Depth: � � �6,625 feet 7200 7100 Porosity: � � �15.1%

6800 Permeability: � � �138 mD 7200 7300

7200 Oil/Gas Column: � � �30 feet oil, 50 feet gas 7300 7200 DST Average Net Pay Thickness: �16 feet DAKOTA PAY PAY DAKOTA 6900 Other Information: � �Oil is 43 degree API, paraffin based. Gas contains 7300 7400 7300 � � � �1,233 Btu/CF with 0.0002% H 2S. Field primary recovery 7400 � � � �is 12% OIP or 1,680,000 BPO increased by secondary DST SS. DAKOTA 7000 � � � �recovery to 40% OIP or 5,600,000 BO. 7400 STRATIGRAPHIC CROSS SECTION A - A' (Fig. J-16) RIO ARRIBA CO., NEW MEXICO TYPICAL ELECTRIC LOG Figure J-17. South Lindrith Gallup-Dakota Field, cross section along A-A' (figure J-16) (from Matheny, 1978, p. 983). CAULKINS OIL CO. NO. 140 Breech D T NE NE SEC. 11, T26N, R6W 27 ELEVATION: 6600 feet (K.B.) 36 31 32 33 34 35 36 31 TOCITO-GALLUP SANDSTONE OIL PLAY Timing and migration: The upper Mancos Shale of the central part of N USGS 2207 the San Juan Basin entered the thermal zone of oil generation in the 6200 -160 late Eocene and gas generation in the Oligocene. Migration updip to -120 UPPER UNIT 20 � The Tocito-Gallup Sandstone Oil Play is an oil and associated reservoirs in the Tocito Sandstone Lentil and regressive Gallup fol -140 1 2 1 6 A 11 -180 6300 gas play in lenticular sandstone bodies of the Upper Cretaceous Gal lowed pathways similar to those determined by present structure be 102 -100 -200 lup Sandstone and Tocito Sandstone Lentil associated with Mancos cause basin configuration has changed little since that time. 132 140 A' T Shale source rocks lying immediately above an unconformity. The Traps: Almost all Gallup production is from stratigraphic traps at 6400 -200 -280 26 -260 -300 play covers almost the entire area of the province. Most of the pro depths between 1,500 and 5,500 ft. Hospah and Hospah South, the 12 -240 N -180 S.I. -220 M ducing fields involve stratigraphic traps along a northwest-trending largest fields in the regressive Gallup Sandstone, are combination -160 EL VADO 6500 A belt near the southern margin of the central part of the San Juan Ba stratigraphic and structural traps. The Tocito sandstone stratigraphic -120 -140 sin. Almost all production has been from the Tocito Sandstone Lentil -100 SANDSTONE N traps are sealed by, encased in, and intertongue with the marine Man MEMBER 13 18 17 13 18 C of the Mancos Shale and the Torrivio Member of the Gallup Sand cos Shale. Similarly, the fluvial channel Torrivio Member of the Gal 6600 stone. lup is encased in and intertongues with finer grained, organic-rich O Reservoirs: The Tocito Sandstone Lentil of the Mancos Shale is the coastal-plain shales. R 7 W 0 1/2Mi. 1 Mi. R 6 W R 5 W S STRUCTURE MAP 6700 TOP OF TOCITO SANDSTONE LENTIL major oil producing reservoir in the San Juan Basin. The name is ap Exploration status and resource potential: Initial Gallup field dis Producing interval OF THE MANCOS SHALE 6817' to 6828' S plied to a number of lenticular sandstone bodies, commonly less than coveries were made in the mid 1920's; however, the major discoveries CONTOUR INTERVAL: 20 FEET 50 ft thick, that lie on or just above an unconformity and are of unde A A' 6800 H were not made until the late 1950's and early 1960's. These were in ( TO BASE OF MESA VERDE TOCITO SS LENTIL termined origin. Reservoir porosities in producing fields range from 4 11 102 132 140 GROUP ) A the deeper Tocito fields, the largest of which, Bisti, covers 37,500 MIDDLE UNIT

to 20 percent and average about 15 percent. Permeabilities range acres and has estimated total ultimate recovery of 51 MMBO. Gallup 6900 L E L V A D O S A N D S T O N E M E M B E R 400' from 0.5 to 150 mD and are typically 5 - 100 mD. The only signifi producing fields are typically 1,000 to 10,000 acres in area and have JUANA LOPEZ E cant production from the regressive Gallup Sandstone is from the TOCITO SANDSTONE MEMBER 15 to 30 ft of pay. About one-third of these fields have an estimated M I D D L E U N I T LENTIL (Pay Sandstone) 300' 7000 Torrivio Member, a lenticular fluvial channel sandstone lying above cumulative production exceeding 1 MMBO and 1 BCF of associated "GALLUP * J U A N A L O P E Z M E M B E R PRODUCING and in some places scouring into the top of the main marine Gallup gas. All of the larger fields produce from the Tocito Sandstone Lentil 200' INTERVAL" Sandstone. of the Mancos Shale and are stratigraphically controlled. South of the LOWER UNIT 7100 zone of sandstone buildups of the Tocito, the regressive Gallup Sand L O W E R U N I T 100'

Source rocks: Source beds for Gallup oil are the marine Upper Cre M A N C O S S H A L E taceous Mancos Shale. The Mancos contains 1-3 weight percent or stone produces primarily from the fluvial channel sandstone of the DATUM : TOP OF GREENHORN LIMESTONE MEMBER 7200 Torrivio Member. The only large fields producing from the Torrivio 0 GREENHORN LS ganic carbon and produces a sweet, low-sulfur, paraffin-base oil that 1.0 MI. 1.5 MI. 2.0 MI. 1.3 MI. MEMBER ranges from 38 degrees to 43 degrees API gravity in the Tocito fields are the Hospah and Hospah South fields, which have combination * A s d e f i n e d b y N e w M e x i c o O i l C o n s e r v a t i o n C o m m i s s i o n STRATIGRAPHIC CROSS SECTION VERTICAL EXAGGERATION = X 17 and from 24 degrees to 32 degrees API gravity farther to the south in traps. Similar, undiscovered traps of small size may be present 0 1/2 MI. 1 MI. Figure J-19. Bianco Tocito South the Hospah and Hospah South fields. in the southern half of the basin. The future potential for oil and Field example electric log (from gas is low to moderate. Figure J-18. Blanco Tocito South Field structure map and cross section (from Fassett and Jentgen, Fassett and Jentgen, 1978, p. 234). 1978, p. 233).

JICARILLA APACHE INDIAN RESERVATION CONVENTIONAL PLAY: Tocito-Gallup Sandstone Plays 12 NEW MEXICO �BASIN MARGIN MESAVERDE OIL POSSIBLE USGS 2210 PRODUCTIVE AMERADA PET. CORP. LIMITS N RIO ARRIBA CO. JICARILLA APACHE A # 5 R 3 W �The Basin Margin Mesaverde Oil Play is a con 990' SL 990' EL 25 - T25N -R5W. TESORO PETROLEUM CORP. firmed oil play around the margins of the central San T RIO ARRIBA CO., NEW MEXICO TESORO PET. CORP. 1-A +2842 Juan Basin. Except for the Red Mesa field on the Four 2 5 GALLUP 6470' N Corners platform, field sizes are very small. The play 4

6500 + 2800 + 2775 2 N 22 T

depends on intertonguing of porous marine sandstone + 600 + 2825 + 2850 31 30 31 + 2843 at the base of the Upper Cretaceous Point Lookout 36 + 2750 PERFS: + 2837 28 Sandstone with the organic-rich Upper Mancos Shale. 6550'- 30 29 3 + 700 6560' Reservoirs: Porous and permeable marine sandstone 1 6 1 6 6600 beds of the basal Point Lookout Sandstone provide the + 800 + 2825 principal reservoirs. The thickness of this interval and + 2875 + 2850 2-A of the beds themselves may be controlled to some ex + 900 + 2900 + 2875 tent by underlying structures oriented in a northwest Parlay Parlay TESORO PET. CORP. TESORO PETROLEUM CORP. erly direction. 6700 + 1000 Source rocks: The upper Mancos Shale intertongues + 2925 SAN EI SHALE LEWIS

with the basal Point Lookout Sandstone and has been T 3500 JUAN GROUP positively correlated with oil produced from this inter 2 4 N

val (Ross, 1980). API gravity of Mesaverde oil ranges 3600 6800 31 32 from 37 degrees to 50 degrees. R 6 W R 5 W 3700 Timing: Around the margin of the San Juan Basin the CLIFF HOUSE ss. upper Mancos Shale entered the thermal zone of oil

generation during the Oligocene. 3800 OTERO GALLUP FIELD 6900 Traps: Structural or combination traps account for CONTOURED ON TOP OF GALLUP Parlay Parlay

most of the oil production from the Mesaverde. Seals CI = 100 ft 3900 SANOSTEE 6949' ss.9 are typically provided by marine shale, but paludal GROUP MESAVERDE EXPANDED DETAIL, 4250 MENEFEE sediments or even coal of the Menefee Formation may MENEFEE ss. No. 4. ss.8 4000 DUAL INDUCTION LOG, also act as the seal. LOGARITHMIC SCALE. DISCOVERY WELL ss.7

Exploration status and resource potential: The first 4100

Figure J-20. Otero Gallup Field structure map and example electric log (from Brown, 1978, p. 444). FORMATION ss.6 oil-producing area in the State of New Mexico, the

Seven Lakes Field was discovered by accident in 1911 4200 PARLAY MESAVERDE FIELD ss.5 when a well being drilled for water. It produced oil SANDOVAL COUNTY, N.M. from the Menefee Formation at a depth of approxi ss.4 4300 mately 350 ft. The only significant Mesaverde oil Analog Field: PARLAY MESAVERDE STRUCTURE MAP ss.3 POINT LOOKOUTss. field, Red Mesa, was discovered in 1924. Future dis Figure J-21 TOP MENEFEE SANDSTONE (ss.4) C. I.25 FT. 4400 coveries are likely to be small. Location: � � �T22N, R3W, on Reservation 0 1 2 3 4 5

Analog Field: OTERO GALLUP 4500 Formation: � � �Mesaverde, Point Lookout member SCALE IN 1000 FEET S.P. Figure J-20 Lithology: � � �Sandstone Average Depth: � � �4,250 feet Figure J-21. Parlay Mesaverde Field, structure map and example electric log (after Gray, 1978, p. 453). Location: � � �T24-25N, R4-6W, on Reservation Porosity: � � �19% Formation: � � �Gallup Permeability: � � �6.45 mD Lithology: � � �Sandstone Oil/Gas Column: � � �30 feet Average Depth: � � �6500 feet Average Net Pay Thickness: �15 feet Porosity: � � �6%, fracture enhanced Permeability: � � �Unknown Other Information: � �Oil gravity is 44.2 degrees API, high paraffin. Oil/Gas Column:� � �10 feet per bench � � � �Estimated ultimate recovery is 18% of OOIP or Average Net Pay Thickness: �8 feet one bench, 14 feet two benches � � � �121,200 BO for the field. Associated gas yields Other Information: � �Oil is 40.7 degrees API. Reservoir has gas drive. � � � �1,279 Btu with no sulfur.

JICARILLA APACHE INDIAN RESERVATION CONVENTIONAL PLAY: Basin Margin Mesaverde Oil Play 13 NEW MEXICO �FRUITLAND-KIRTLAND FLUVIAL tional Fruitland gas accumulations on the far west side of the Reser ies. ANALOG FIELD: Los Pinos Fruitland, South SANDSTONE GAS PLAY Figure J-22 vation. Please see the discussion on Pictured Cliffs coal gas, USGS Timing and migration: In the northern part USGS 2212 Play 2211, in the Unconventional Play section that follows. of the basin, the Fruitland Formation and Location: � � �T31N, R7W, west of Reservation �The Fruitland-Kirtland Fluvial Sandstone Gas Play covers the Kirtland Shale entered the thermal zone of �On the Jicarilla Apache Indian Reservation, the uppermost Cre central part of the basin and is characterized by gas production from Formation: � � �Fruitland oil generation during the latest Eocene and Lithology: � � �Sandstone taceous Fruitland Formation produces coal gas methane. West of the stratigraphic traps in lenticular fluvial sandstone bodies enclosed in the zone of wet gas generation probably Average Depth: � �3,000 feet Reservation, the gas source is the associated Kirtland shale. This dis shale source rocks and (or) coal. Production of coalbed methane during the Oligocene. Migration of hydro Porosity: � � �11.9% cussion is included here because of the possibility of finding conven from the lower part of the Fruitland has been known since the 1950's. carbons updip through fluvial channel Permeability:� �0.96 md The Upper Cretaceous Fruitland Formation and Kirtland Shale are sandstone is suggested by gas production Oil/Gas Column: � �200 feet continental deposits and have a from immature reservoirs and by the areal Average Net Pay Thickness: �41 feet POSSIBLE maximum combined thickness of Other Information: � �Gas yields 980 Btu per CF and contains about 4% carbon PRODUCTIVE distribution of production from the Fruit LIMITS N more than 2,000 ft. The Fruitland is land. � � � �dioxide and nitrogen. Estimated ultimate recovery is composed of interbedded sandstone, � � � �2.5 BCFG per well. R 3 W Traps: The discontinuous lenticular TESORO PETROLEUM CORP. siltstone, shale, carbonaceous shale, TESORO PET. CORP. 1-A channel sandstone bodies that form the and coal. Sandstone is primarily in TYPE LOGS +2842 reservoirs in both the Fruitland Formation northerly trending channel deposits NORTH LOS PINOS FRUITLAND NORTH LOS PINOS 4 and Kirtland Shale intertongue with AND 2600

+ 2800 in the lower part of the unit. The + 2775 2 N 22 T overbank mudstone and shale and paludal SOUTH LOS PINOS FRUITLAND + 2825 + 2850 lower part of the overlying Kirtland + 2843 coals and carbonaceous shale in the lower COLORADO NORTH LOS PINOS + 2750 T/Kf + 2837 Shale is dominantly siltstone and 28 part of the Fruitland. Although some 12 7 30 29 3 shale, and differs from the upper NEW MEXICO 10 producing fields are on structures, the 2766 Fruitland mainly in its lack of carbo PRODUCING actual traps are predominantly stratigraphic 2800 INTERVAL naceous shale and coal. The upper T + 2825 3590 2806 + 2875 and are at updip pinchouts of sandstone 32 + 2850 two-thirds or more of the Farming 2-A into the fine-grained sediments that form N + 2900 ton Sandstone Member of the Kirt + 2875 the seals. Most production is from depths Parlay Parlay land Shale is composed of interbed TESORO PET. CORP. TESORO PETROLEUM CORP. of 1,500-2,700 ft. Production from the 3000 ded sandstone lenses and shale. Farmington Sandstone Member is from 3590 T/Kpc Sands + 2925 SAN Reservoirs: Reservoirs are predom 36 31 34

EI SHALE LEWIS depths of 1,100-2,300 ft.

3500 Correlative

JUAN GROUP inantly lenticular fluvial channel 3570 Prod. Interval Exploration status and resource 6 sandstone bodies, most of which are 1 3 Wilner Cyn #1 potential: The first commercially produced 3200 31 32 3600 considered tight gas sandstones. gas in New Mexico was discovered in 1921 3550 They are commonly cemented with SOUTH Phillips Petroleum in the Farmington Sandstone Member at a LOS PINOS

3700 calcite and have an average porosity Mesa Unit 32-7 #3-18 CLIFF HOUSE ss. depth of 900 ft in what later became part of T of 10 -18 percent and low permea NE/4 Sec.18 T32N R7W the Aztec field. Areal field sizes range 31 San Juan Co., New Mexico

3800 bility (0.1 - 1.0 millidarcy). Pay from 160 to 32,000 acres, and almost 50 19 N thickness ranges from 15 to 50 ft. 24 22 SOUTH LOS PINOS Parlay Parlay percent of the fields are 1,000-3,000 acres The Farmington Sandstone Member R 8 W R 7 W 3900 ss.9 in size. The almost linear northeasterly

is typically fine grained and has po 3000 EAED GROUP MESAVERDE alignment of fields along the western side Structure map with Pool Outlines T/Kf Datum Top of Fruitland Kf EXPANDED DETAIL, 4250 rosity of from 3 to 20 percent and Correlative MENEFEE MENEFEE ss. No. 4. ss.8 4000 of the basin suggests a paleofluvial channel 10 foot contours DUAL INDUCTION LOG, permeability of from 0.6 to 9 milli Production Interval LOGARITHMIC SCALE. system of northeasterly flowing streams. San Juan County, New Mexico on Producing Well ss.7 darcies. Pay thicknesses are general SJU32 - 7 #6-17

4100 Similar channel systems may be present in

FORMATION ss.6 ly 10 to 20 ft. Wells & Pool outlines posted to 3-15-78

other parts of the basin and are likely to 3200 Source rocks: The Fruitland-Kirt contain similar amounts of hydrocarbons. Kf PARLAY MESAVERDE FIELD ss.5 4200 land interval produces non-associat Kpc Future potential for gas is good, and Kmv SANDOVAL COUNTY, N.M. ed gas and very little condensate. Its ss.4 undiscovered fields will probably be in the Kd 4300 chemical composition (C1/C1-5) T/Kpc Sands STRUCTURE MAP ss.3 25 sq mi size range at depths between Kmv-Kd Compl. POINT LOOKOUTss. ranges from 0.99 to 0.87 and its iso Pool Discovery Well 3400 TOP MENEFEE SANDSTONE (ss.4) 1,000 and 3,000 ft. Because most of the C. I.25 FT. 4400 topic (d13C1) compositions range large structures have probably been tested, Phillips Petroleum SJU 32-7 5-8 0 1 2 3 4 5 from -43.5 to -38.5 per mil (Rice. future gas resources probably will be found NE/4 Sec. 8 T31N R7W

4500 1983). Source rocks are thought to SCALE IN 1000 FEET S.P. in updip stratigraphic pinchout traps of San Juan Co., New Mexico be primarily organic-rich non-ma channel sandstone into coal or shale in Figure J-22. Los Pinos Fruitland South Field, structure map and example electric logs (from rine shales encasing sandstone bod Figure J-21. Parlay Mesaverde Field, structure map and example electric log (after Gray, 1978, p. 453). traps of moderate size. Bowman, 1978, p. 393).

JICARILLA APACHE INDIAN RESERVATION CONVENTIONAL PLAY: Fruitland-Kirtland Fluvial Sandstone Gas Play 14 NEW MEXICO Unconventional Plays -- Definition BASIN DAKOTA (GAS) A broad class of hydrocarbon deposits of a type (such as gas SOUTHLAND ROYALTY COMPANY UTAH COLORADO in "tight" sandstones, gas shales, and coal-bed gas) that 17 16 15 14 13 ARIZONA NEW MEXICO 12 11 10 9 8 7 6 5 4 3 2 1 historically has not been produced using traditional # 12-D CAIN 20' 20' 20' 32 development practices. Such accumulations include most NE 16-T 28N - R10W 40' 31 I. P. = 7.8 MMCFGD 40' 31 continuous-type deposits. 20' 40' 20' 30 40' 40' MANCOS 40' 30 �DAKOTA CENTRAL BASIN GAS PLAY 40' 6300 USGS 2205 FARMINGTON 29 20' 20' 29 GREENHORN �The Jicarilla Apache Indian Reservation is on the east flank of 28 40'

the San Juan Basin but extends sufficiently westward that there is a 6350 28 possibility of finding unconventional Dakota formation gas reser 27 20' 40' 40' 40' voirs. The preceding discussion on the conventional Basin Margin 27 FOUR CORNERS PLATFORM 40' Dakota Play, USGS Play 2206, characterizes existing Reservation 40' 6400 26 20' 26 Dakota production on the Reservation. GRANEROS 20'

40' �The Dakota Central Basin unconventional continuous-type play 40' 25 20' 20' 25 is contained in coastal marine barrier-bar sandstone and continental 40' fluvial sandstone units, primarily within the transgressive Dakota 6450 PICTURED CLIFFS 20' 20' 40' 24 Sandstone. 24 OUTCROP Reservoirs: Reservoir quality is highly variable. Most of the marine RIO ARRIBA CO. 40' 23 23 6500 SANDOVAL CO. sandstone reservoirs within the Basin field are considered tight, in DAKOTA

that porosities range from 5 to 15 percent and permeabilities from L

22 22 P

0.1 to 0.25 millidarcies. Fracturing, both natural and induced, is U

essential for effective field development. 6550

21 CUBA 21 O O Source rocks: Quality of source beds for oil and gas is also SAN JUAN CO. T N

McKINLEY CO. E variable. Non-associated gas in the Dakota pool of the Basin field I 20 20

M I

was generated during late mature and postmature stages and 6650 6600 CHACO SLOPE C

A probably had a marine Mancos Shale source (Rice, 1983). 19 19 N 1W 1E Timing and migration: In the northern part of the central San Juan 20 4 3 2 Basin, the Dakota Sandstone and Mancos Shale entered the oil gen eration window in the Eocene and were elevated to temperatures ap BASIN DAKOTA (Gas) propriate for the generation of dry gas by the late Oligocene. Along Completed: 6-29-61 the southern margin of the central basin, the Dakota and lower Man 3668 MMCF = Cumulative Prod. (1-1-77) MARINE SANDSTONE ISOPACH cos entered the thermal zone of oil generation during the late Mio 450 MCFD 28,156 BO = Cumulative Prod. (1-1-77) RESISTIVITY > 25 OHMS C.I. = 20' cene (Huffman, 1987). It is not known at what point hydrodynamic 2.6 BOPD forces reached sufficient strength to act as a trapping mechanism, but Figure J-24. Basin Dakota Field, area and marine sandstone isopach map (from Hoppe, 1978, p. 204). early Miocene time is likely for the establishment of the present-day Figure J-23. Basin Dakota Field, example uplift and erosion pattern throughout most of the basin. Migration of electric log (after Hoppe, 1978, p. 205). ANALOG FIELD: BASIN DAKOTA oil in the Dakota was still taking place in the late Miocene, or even Figures J-23 and J-24 more recently, in the southern part of the San Juan Basin. Exploration status and resource potential: The Dakota discovery Location: � � � �T23-32N, R3-14W, partly on Reservation Traps: The Dakota gas accumulation in the Basin field is on the well in the central basin was drilled in 1947 southeast of Farming Formation: � � � �Dakota flanks and bottom of a large depression and is not localized by struc ton, New Mexico, and the Basin field, containing the Dakota gas Lithology: � � � �Sandstone tural trapping. The fluid transmissibility characteristics of Dakota pool, was formed February 1, 1961 by combining several existing Average Depth: � � �6,500 feet sandstones are generally consistent from the central basin to the out fields. By the end of 1993 it had produced over 4.0 TCFG and 38 Porosity:� � � �5 to 15% crop. Hydrodynamic forces, acting in a basinward direction, have MMB condensate. Almost all of the Dakota interval in the central Permeability: � � �0.1 to 0.25 md, fracture enhanced been suggested as the trapping mechanism, but these forces are still part of the basin is saturated with gas, and additional future gas dis Oil/Gas Column: � � �250 feet poorly understood. The seal is commonly provided by either marine coveries within the Basin field and around its margins are probable. Average Net Pay Thickness: � �50 to 70 feet shale or paludal carbonaceous shale and coal. Production is primarily Other Information: � � � Gas yields 1,100 Btu per CF and contains 3 to 5% � � at depths ranging from 6,500 to 7,500 ft. � � � � �carbon dioxide. Estimated ultimate recovery for � � � � �the Basin Dakota Gas Field is 5 TCFG.

JICARILLA APACHE INDIAN RESERVATION UNCONVENTIONAL PLAY: Dakota Central Basin Gas Play 15 NEW MEXICO R 1 E �MANCOS FRACTURED SHALE PLAY Figure J-25. Puerto Chiquito Mancos Common Boundary R 1 W Between East & West + 5000 USGS 2208 East and West Fields with structure + 3000 + 4000 Puerto Chiquito Pools 12 7 8 map and example electric log. T East Puerto Chiquito Pool Boundary � The Mancos Fractured Shale Play Play is a confirmed, unconven Contoured on top of "A" zone (from 27 Greer, 1978, p. 468). N tional, continuous-type play. It is dependent on extensive fracturing in 13 18 17 the organic-rich marine Mancos Shale. Most developed fields in the + 2000

play are associated with anticlinal and monoclinal structures around the + 1000 eastern, northern, and western margins of the San Juan Basin. 24 19 2 0 21 CANADA OJITOS UNIT #B-18 nw ne 18-25N-1E Reservoirs: Reservoirs are comprised of fractured shale and interbed 2 9 2 8 2 7 2 6 25 30 28 ded coarser clastic intervals at approximately the Tocito Lentil level. TOP ZONE "A"

Source rocks: The Mancos Shale contains 1-3 weight percent organic 4 3 2 1 6 5 4 carbon and produces a sweet, low-sulfur, paraffin-base oil that ranges from 33 degrees to 43 degrees API gravity. 7 Timing: The upper Mancos Shale of the central part of the San Juan 5300 Basin entered the thermal zone of oil generation in the late Eocene, and of gas generation in the Oligocene. 16 1 3 1 8 T TOP ZONE "B" Traps: Combination traps predominate; Traps formed by fracturing of 26 shale and by interbedded coarser clastics on structures are common. N 2 4 1 9 Exploration status and resource potential: Most of the larger discov eries such as Verde and Puerto Chiquito were made prior to 1970, but directional drilling along the flanks of some of the poorly explored 2 5 3 0 structures could result in renewed interest in this play.

3 3 3 6 3 1 CANADA OJITOS UNIT 5400

4 1 6

12 7 TOP ZONE "C" OUTCROP Analog Field B-18 PUERTO CHIQUITO MANCOS, WEST T (Figure J-25) 25 N 2 4 1 9 5500 Location:� � � �T25-27N, R1E and R1W, partly on Reservation +600

Formation: � � � �Mancos, Niobrara equivalent section + 1400 2 8 +800 2 5 3 0 28 + 1200 + 1600 Lithology: � � � �Shale + 1000 + 1800 Average Depth: � � �5,400 feet East & West Porosity: � � � �Indefinite, fracture porosity 3 3 3 6 3 1 Permeability: � � �Unknown, transmissibility up to 6 darcy-feet Puerto Chiquito Oil/Gas Column:� � �250 feet 4 1 6 Mancos Fields Average Net Pay Thickness: � �Unknown, less than 50 feet Rio Arriba County, New Mexico Other Information: � � �The Canada Ojitos Units lies totally within the Puerto

� � � � �Chiquito West Field. Originally a gravity drainage field, 9 1 2 7

+ 3000 + + 6000 6000 +

+ 5000 + + 4000 + STRUCTURE CONTOUR MAP � � � � �final stages of development will include expansion gas T � � � � �drive and reinjection of produced gas. Oil gravity is 39 to 24 CONTOURED ON TOP OF ZONE "A" � � � � �40 degrees API. N 1 5 1 3 1 8 Benson - Montin - Greer Drilling Corp.

+ 2000 December ,1977 Well Converted To Gas Injection North , West , and South Pool Boundaries For W P C M Approx. 2 Miles Beyond Mapped Area

JICARILLA APACHE INDIAN RESERVATION UNCONVENTIONAL PLAY: Mancos Fractured Shale Play 16 NEW MEXICO �CENTRAL BASIN MESAVERDE GAS PLAY A' USGS 2209 La Plata Co., Colorado San Juan Co., New Mexico Rio Arriba Co. T �The unconventional continuous-type Central Basin Mesa marine sediments account for almost all of the stratigraphic traps with 32 verde Gas Play is in sandstone buildups associated with stratigraphic a shale or coal seal. N rises in the Upper Cretaceous Point Lookout and Cliff House Sand stones. The major gas-producing interval in the San Juan Basin, the Exploration status and resource potential: The Blanco Mesaverde 31 +1400' Upper Cretaceous Mesaverde Group, is comprised of the regressive field discovery well was completed in 1927, and the Ignacio Blanco marine Point Lookout Sandstone, the nonmarine Menefee Forma Mesaverde field discovery well was completed in 1952. Areally, +1500' tion, and the transgressive marine Cliff House Sandstone. Total these two closely adjacent fields cover more than 1,000,000 acres, 30 thickness of the interval ranges from about 500 to 2,500 ft, of which encompass much of the central part of the San Juan Basin, and have +1600' 20 - 50 percent is sandstone. The Mesaverde interval is enclosed by produced almost 7,000 BCFG and more than 30 MMB of condensate, +1700' marine shale: the Mancos Shale is beneath the interval and the approximately half of their estimated total recovery. Most of the re +1800' 29 Lewis Shale above. cent gas discoveries range in areal size from 2,000 to 10,000 acres +1900' and have estimated total recoveries of 10 to 35 BCFG. +2100' Reservoirs: Principal gas reservoirs productive in the Mesaverde +2300' 28 interval are the Point Lookout and Cliff House marine sandstones. +2500' Smaller amounts of dry, nonassociated gas are produced from thin, +2700' lenticular channel sandstone reservoirs and thin coal beds of the A 27 Menefee. Much of this play is designated as tight, and reservoir quality depends mostly on the degree of fracturing. Together, the R-12-W 11 10 9 R-8-W ANALOG FIELD Blanco Mesaverde and Ignacio Blanco fields account for almost half 26 Blanco Mesaverde of the total nonassociated gas and condensate production from the Figure J-26 BLANCO MESAVERDE FIELD San Juan Basin. Within these two fields porosity averages about 10 T percent and permeability less than 2 mD; total pay thickness is 20 (GAS) 25 Location: � � �T25-32N, R2-13W, on N 200 ft. Smaller Mesaverde fields have porosities ranging from 14 to � � � �Reservation 28 percent and permeabilities from 2 to 400 Md, with 6 - 25 ft of Formation: � � �Mesaverde, Cliff House and R-7-W 6 5 4 3 R-2-W pay thickness. � � � �Point Lookout members STRUCTURE CONTOUR ON GREEN MARKER HORIZON Lithology: � � �Sandstone Source rocks: The carbon composition (Cl/Cl-5) of 0.99-0.79 and Average Depth: �� 4,500 feet isotopic carbon (dl3Cl) range of -33.4 to -46.7 per mil of the nonas Porosity: � � �10 to 16% sociated gas suggest a mixture of source rocks including coal and Permeability: � � �Cliff House 0.5 md, A carbonaceous shale in the Menefee Formation (Rice, 1983). A' � � � �Point Lookout 2.0 md Oil/Gas Column: � �400 feet Timing and migration: In the central part of the basin, the Mancos Average Net Pay Thickness: �80 to 200 feet Shale entered the thermal zone of oil generation in the Eocene and of gas generation in the Oligocene. The Menefee Formation also en Other Information: � �Gas carries 1,194 Btu per CF, � � � �about 1% inert (carbon dioxide GREEN MARKER HORIZON tered the gas generation zone in the Oligocene. Because basin con � � � �and nitrogen). Associated oil figuration was similar to that of today, updip migration would have � � � �ranges between 33 and 60 CLIFF HOUSE FM. LEWIS FORMATION been toward the south. Migration was impeded by hydrodynamic � � � �degrees API. Estimated field pressures directed toward the central basin, as well as by the deposi � � � �ultimate recovery 12 TCFG. In tion of authigenic swelling clays due to dewatering of Menefee � � � �1975 field spacing was � � � �changed to 1 well per 320 acre MENEFEE coals. FORMATION � � � �spacing unit.

Traps: Trapping mechanisms for the largest fields in the central part LOOKOUT FM. of the San Juan Basin are not well understood. In both the Blanco GROUP MESAVERDE MANCOS FORMATION Mesaverde and Ignacio Blanco fields, hydrodynamic forces are be lieved to contain gas in structurally lower parts of the basin, but oth er factors such as cementation and swelling clays may also play a role. Production depths are most commonly from 4,000 to 5,300 ft. CROSS SECTION A-A' OF THE MAJOR MESAVERDE BENCHES Updip pinchouts of marine sandstone into finer grained paludal or Figure J-26. Blanco Mesaverde Field structure map and cross section showing Point Lookout and Cliff House sandstones (from Pritchard, 1978, p. 222).

JICARILLA APACHE INDIAN RESERVATION UNCONVENTIONAL PLAY: Central Basin Mesaverde Gas Play 17 NEW MEXICO PICTURED CLIFFS GAS PLAY - USGS 2211 excellent source rocks are present in the deeper parts of the basin, but Analog Field: Blanco Pictured Cliffs, South low permeabilities due to authigenic illite-smectite clay have thus far Figures 27, 28 and 29 �The Pictured Cliffs unconventional continuous-type play is de limited production. fined primarily by gas production from stratigraphic traps in sand Location: � � �T23-28N, R1-9W, partly on Reservation Formation: � � �Pictured Cliffs stone reservoirs enclosed in shale or coal at the top of the Upper Cre R9W R8W R7W R6W R5W R4W R3W R2W R1W Lithology: � � �Sandstone taceous Pictured Cliffs Sandstone and is confined to the central part 50' Average Depth: � � �3,000 feet of the basin. Thicker shoreline sandstones produced by stillstands, or T Porosity: � � �15% brief reversals in the regression of the Cretaceous sea to the northeast 28 A N Permeability: � � �0 to 5.5 mD have been the most productive. The Pictured Cliffs is the uppermost 30' Oil/Gas Column: �� less than 100 feet

regressive marine sandstone in the San Juan Basin. It ranges in thick 50' T Average Net Pay Thickness: �30 feet 27 ness from 0 to 400 ft and is conformable with both the underlying N Other Information:� �Gas yields 1,177 BTU per CF. Estimated ultimate marine Lewis Shale and the overlying nonmarine Fruitland Forma 50' � � � �recovery for the field is 1.4 TCFG. Wells are on 160 acre tion. 30' 30' T � � � �spacing. 26 N Reservoirs: Reservoir quality is determined to a large extent by the 50' abundance of authigenic clay. Cementing material averages 60 per Environment of Fruitland Formation Coal Beds 30' 30' cent calcite, 30 percent clay, and 10 percent silica. Average porosity 30' 50' T 25 SPONTANEOUS CONDUCTIVITY 30' is about 15 percent and permeability averages 5.5 millidarcies, al N POTENTIAL (Millimhos/m) Blanco Pictured Cliffs 30' (Millivolts) though many field reservoirs have permeabilities of less than 1 mD. 10 400 200 0 - + 600 400 South Field 30' 0 50 100 Pay thicknesses range from 5 to 150 ft but typically are less than 40 T 0 500 1000 24 RESISTIVITY OJO ALAMO ft. Reservoir quality improves south of the deepest parts of the basin N (Ohms m2/m) SANDSTONE SAN JUAN CO. SAN JUAN due to secondary diagenetic effects. RIO ARRIBA CO. A' 30' Source rocks: The source of gas was probably marine shale of the T BLANCO PICTURED CLIFFS SOUTH (GAS) RIO ARRIBA CO. 23 1400 underlying Lewis Shale and nonmarine shale of the Fruitland Forma SANDOVAL CO. RIO ARRIBA, SANDOVAL & SAN JUAN CO. N.M. N EXPLANATION tion. The gas is non-associated and contains very little condensate FARMINGTON SANDSTONE ISOPACH OF NET PAY MEMBER (0.006 gal/MCFG). It has a carbon composition (C1/C1-5) of 0.85- AND Figure J-27. Blanco Pictured Cliffs Field map with isopach of net pay (from Brown, 1978, p. 230). 0.95 and an isotopic carbon (dl3C1) range of -43.5 to -38.5 per mil UPPER SHALE MEMBER Sandstone OF (Rice, 1983). 1600 KIRTLAND SHALE Timing and migration: Gas generation was probably at a maximum during the late Oligocene and the Miocene. Updip gas migration was BLANCO PICTURED CLIFFS SOUTH (GAS) Shale predominantly toward the southwest because the basin configuration LOWER SHALE MEMBER OF KIRTLAND SHALE was similar to that of today. EPNG CO. EPNG CO. EPNG CO. EPGN CO. 1800 Traps: Stratigraphic traps resulting from landward pinchout of near No. 7 Filan No. 16 Klein No. 3C Jicarilla No. 59 Lindrith Unit SE 5 - 27N - 8W SW 33 - 26N - 6W SE 21 - 25N - 4W NW 32 - 24N - 2W Coal shore and foreshore marine sandstone bodies into finer grained silty, 3200 shaly, and coaly facies of the Fruitland Formation (especially in the

3000 FRUITLAND areas of stratigraphic rises) contain most of the hydrocarbons. Seals DEPTH, IN FEET FORMATION 2000 are formed by finer grained back-beach and paludal sediments into 2800 FRUITLAND Siltstone, sandy shale

which marine sandstone intertongues throughout most of the central 2200 part of the basin. The Pictured Cliffs Sandstone is sealed off from any

connection with other underlying Upper Cretaceous reservoirs by the PICTURED CLIFFS 3300 Lewis Shale. The Pictured Cliffs crops out around the perimeter of T/PC Figure J-29. Electric log SANDSTONE A A' 2200 Sandy limestone

the central part of the San Juan Basin and is present at depths of as 3100 and lithologic section much as 4,300 ft. Most production has been from depths of 1,000- PICTURED showing relationship of 2900 CLIFFS Pictured Cliffs sandstone

3,000 ft. 2300 to other upper Creta LEWIS Exploration status and resource potential: Gas was discovered in ceous sandstones. Note SHALE 2400 the Huerfano Bentonite the play in 1927 at the Blanco and Fulcher fields of northwest New LEWIS Mexico. Most Pictured Cliffs fields were discovered before 1954, and 3400 bed - see Figures J-10 and J-11 (from Fassett, only nine relatively small fields have come into production since I.P. 2806 MCF CHACRA I.P. 3401 MCF I.P. 7488 MCF 1988, p.27). then. Discoveries since 1954 average about 11 BCFG estimated ulti HUERFANITO BENTONITE BED mate recovery. A large quantity of gas is held in tight sandstone res 2600 LEWIS Figure J-28. Blanco pictured Cliffs Field cross section (from Brown, 1978, p. 230). ervoirs north of the currently producing areas. Stratigraphic traps and SHALE

JICARILLA APACHE INDIAN RESERVATION Unconventional Plays 18 NEW MEXICO