1

Petroleum Systems and Geologic Assessment of Oil and Gas in the San Joaquin Basin Province, California

Chapter 13 Miocene Total Petroleum System—Southeast Stable Shelf Assessment Unit of the San Joaquin Basin Province

By Donald L. Gautier and Allegra Hosford Scheirer

to present from Monterey Forma- Contents tion. Summary------1 Existing Fields Ant Hill, Dyer Creek, Edison, Description------1 Edison Northeast, Fruitvale, Kern Source Rocks------2 Bluff, Kern Front, Kern River, Maturation------2 Mount Poso, Mountain View, Poso Migration------2 Creek, Rosedale Ranch, Round Reservoir Rocks------2 Traps and Seals------3 Mountain, Union Avenue. Exploration Status and Resource Potential------3 Exploration Status Heavily explored (2.3 wells per References Cited------4 square mile and 67 percent of all Figures------8 sections have at least one explor- Table------19 atory well). Appendixes (.pdf files) Resource Potential Mainly growth of reserves in exist- ing fields. Summary Description Boundaries Neogene-age shelf-slope break of the San Joaquin Basin on the west; The confirmed stratigraphic and structural-stratigraphic onlap of Neogene rocks on Sier- Southeast Stable Shelf Assessment Unit (AU) of the Miocene ran basement to the east; petroleum Total Petroleum System (San Joaquin Basin Province) com- system limit on the north; White prises all hydrocarbon accumulations within the geographic Wolf Fault on the south; topographic limits of the AU. Traps typically display low dip angles, gentle surface to crystalline basement. folds, and normal faults. Reservoirs, which range in age from Source Rocks Miocene Monterey Formation; pos- fractured Mesozoic basement rocks to Holocene nonmarine sibly minor other sources. rocks, are mainly Oligocene to Miocene sandstones from the Reservoir Rocks Mainly Oligocene to Pleistocene uppermost slope and adjacent shelf of the San Joaquin Basin, and even Holocene sandstones; shallow marine shelf sandstones mainly of Miocene age, and minor older sandstones and crystal- nonmarine sandstones and conglomerates mostly of Pliocene- line basement rocks. Pleistocene age. Faults have relatively small vertical displace- Traps Pinchouts, truncations, tar seals, ments. extensional faults. Map boundaries of the assessment unit are shown in fig- Migration Eastward and up-dip through sand- ures 13.1 and 13.2; this assessment unit replaces the Southeast stones, fractures, and faults. Stable Shelf play 1002 considered by the U.S. Geological Timing Oil generation from mid-Pliocene Survey (USGS) in its 1995 National Assessment (Beyer, 1996). 2 Petroleum Systems and Geologic Assessment of Oil and Gas in the San Joaquin Basin Province, California

Stratigraphically, the AU extends from the uppermost crystal- 1988), but burial depths of 3 to 4 kilometers are generally line basement to the topographic surface (fig. 13.3). The AU is thought necessary for significant oil generation in strata of the bounded on the west by the approximate location of the shelf- Monterey Formation (Graham and Williams, 1985; Kruge, slope break of the San Joaquin Basin in late Miocene time, thus 1985). Geochemical analyses and petroleum systems model- excluding reservoirs in the deep-water Stevens sand of Eckis ing conducted for the San Joaquin Basin Province assess- (1940). The eastern boundary of the AU is the edge of onlap of ment confirm thisinterpretation and constrain burial depths Neogene sedimentary sequences on crystalline basement rocks of Monterey Formation source rocks to 4 to 4.6 kilometers of the Sierra Nevada. The northern AU boundary is placed at (Peters, Magoon, Lampe, and others, this volume, chapter the approximate northern extent of oils in shelf-facies reservoirs 12). known to be sourced by the Miocene Total Petroleum System. Shales of the Monterey Formation, which are interpreted This northern boundary explicitly excludes the Deer Creek and to be the likely source for all known oil in this AU, prob- Jasmin fields, which were included in the corresponding earlier ably achieved maturation sufficient for initial oil generation (1995) USGS play (Beyer, 1996), but which are now known by early Pliocene time (4.6 Ma); generation continues to the to contain oil generated from Eocene source rocks. The White present (Peters, Magoon, Lampe, and others, this volume, Wolf Fault bounds the AU on the south. chapter 12). Since initial maturation of the Monterey source rock, well in excess of four billion barrels of oil and unknown quantities of associated gas have migrated into and through Source Rocks reservoirs of this AU.

Oil correlation analyses conducted for the San Joaquin Basin Province assessment (Lillis and Magoon, this volume, Migration chapter 9) confirm earlier studies (Peters and others, 1994), which indicate that all known oil and gas accumulations Source rocks within the Monterey Formation, from which in this AU are derived from source rocks of middle and the oil in this AU was generated, were deposited in funda- late Miocene age. The principal source for oil in this AU mentally different settings than were the reservoir rocks of is the fine-grained, biosiliceous, organic-rich facies of the this AU. Although the eastern boundary of the pod of active Monterey Formation located on the basin’s southwest margin source rock lies adjacent to the AU (fig. 13.5), the bulk of (figs. 13.4 and 13.5). However, in considering the resource thermally mature source rock in the Tejon depocenter lies ~20 potential of this assessment unit, it is important to empha- miles west-southwest of the center of the assessment unit. size that the richest (most oil prone) facies of the Monterey Therefore, relatively long and somewhat complex migra- Formation were deposited on slopes and in bathyal settings tion pathways are necessary to transport oil from bathyal and to the west and outside of this AU. Though less likely, slope-deposited source rocks into the upper slope, shelf, and pre-Monterey Formation organic-carbon-rich shales, such nonmarine sandstone reservoirs of the assessment unit (fig. as those of the Tumey formation of Atwill (1935) and Krey- 13.6). Complex submarine canyon, channel, and fan depos- enhagen Formation, could also have served as hydrocarbon its that intersect the western margins of the shallow shelf are source rocks. However, oils analyzed to date are derived postulated as the conduits for hydrocarbon fluids (Lamb and exclusively from Miocene-aged source rocks (Lillis and others, 2003). Up-dip migration pathways are believed to Magoon, this volume, chapter 9). have included faults and fractures, as well as porous and per- Thus, for the purposes of assessment, the Southeast Stable meable sandstones. Shelf Assessment Unit is assigned to the Miocene Total Petro- leum System, which consists of two pods of active source rock in the Buttonwillow and Tejon depocenters (fig. 13.5; Magoon and others, this volume, chapter 8; Peters, Magoon, Lampe, Reservoir Rocks and others, this volume, chapter 12). On the basis of spatial Oil accumulations have been found in sandstones of and geochemical considerations, the most likely provenance nearly all Oligocene- through Pleistocene-age formations for the hydrocarbons found in the assessment unit is the Tejon that were deposited on the stable southeastern shelf of the depocenter, although hydrocarbons generated farther to the San Joaquin Basin (fig 13.4). In addition, oil has been found northwest in the Buttonwillow depocenter may also have in older sandstones of the nonmarine Walker Formation of charged reservoirs in the AU (fig. 13.5). Eocene age in Edison field and in fractured crystalline base- ment rocks in parts of the Edison (White, 1955) and Mountain View fields (Park, 1966). The most prolific hydrocarbon pro- Maturation ducing reservoirs in this assessment unit are upper slope, shel- fal, and nonmarine sandstones of the Kern River and Chanac The Monterey Formation may have generated sulfur- Formations, Santa Margarita Sandstone, Jewett Sand, Freeman rich liquids early in its burial history (Fischer and others, Silt, and Vedder Sand. Generally, reservoirs tend to pinch Miocene Total Petroleum System—Southeast Stable Shelf Assessment Unit of the San Joaquin Basin Province 3 out to the east and to pass into deep-water facies to the west Exploration Status and Resource (MacPherson, 1978). Reservoirs typically exhibit high poros- ity and permeability, but diagenesis adversely affects reservoir Potential quality in the deeper parts of the AU. Figure 13.7 illustrates the paleogeography of the San The AU has been intensively drilled along the up-dip Joaquin Basin in the Pliocene between 4 and 3 Ma. At this basin margin to the east and southeast of the Bakersfield time, the southeast stable shelf occupied an entirely nonma- Arch (fig. 13.2). Other areas of the AU have also been rine depositional environment following a marine regression extensively explored, and little space remains for undiscov- that began during the middle to late Miocene (Bartow, 1991). ered resources other than small, subtle, and difficult-to-find The nonmarine Chanac Formation, which is the principal traps. Known accumulations are found at depths between oil reservoir at Rosedale Ranch and Fruitvale fields, was ~8,000 feet and the surface, if oil seeps on the east side of deposited on the basin’s southeast margin during the marine the assessment unit are considered. No new accumulation regression. has been found in this assessment unit in the last several The major reservoir in this assessment unit, the Kern decades in spite of more than 250 exploratory wells drilled River Formation, was deposited between 8 Ma and 0.7 Ma since 1960 (fig. 13.10). (Graham and others, 1988), although recent evidence suggests The largest discoveries within the Southeast Stable the upper age of the formation may be as old as 6 Ma (Miller, Shelf Assessment Unit, in order of decreasing recoverable 1999; Golob and others, 2005). The Kern River Formation oil volume, are shown in table 13.1. Two-thirds of the ~3.7 consists mainly of a series of coarse-grained, braided stream billion barrels of recoverable oil in this assessment unit are deposits that emanated from the adjacent Sierra Nevada to in the Kern River field. Mount Poso and Kern Front fields the east and were delivered to the basin by the ancestral Kern account for ~9 percent and ~6 percent of the known oil, River (Graham and others, 1988). In the subsurface, the respectively. lower Kern River Formation grades basinward into marine Undiscovered accumulations are expected to be small Etchegoin Formation, while the upper Kern River Formation and located primarily in the deeper areas near the western grades laterally into the San Joaquin and Tulare Formations margin of the AU. Down-dip sandstone objectives at depth (Bartow and McDougall, 1984). in the northern part of the AU have not been as extensively Initial reservoir pressures in existing fields of the assess- drilled as other areas within the AU. Additionally, sandstones ment unit range from 100 to 3,200 pounds per square inch, at in the Vedder Sand-Jewett Sand stratigraphic interval have reservoir depths of 400 to 7,300 feet, respectively (CDOGGR, not been exhaustively explored, and a high probability exists 1998). The mean reported reservoir depth of ~3,600 feet for the discovery in these sandstones of small (less than 10 indicates that typical exploration depths are moderate. Within million barrels of oil) accumulations in subtle stratigraphic the AU, reservoir depths generally decrease from west to east traps. approaching the basin margin. Oil gravity ranges from about The estimates of undiscovered petroleum resources in 10 degrees API in the Kern River Field to 45 degrees API in this AU reflect the judgment of the USGS that all but the the deepest reservoirs of the Mountain View field. Average smallest, most subtle traps have already been tested during reservoir porosity varies from 15 to 45 percent, with a median more than 100 years of nearly unrestricted exploration. porosity of 30 percent (CDOGGR, 1998). Because the discovery history reveals no accumulations of less than one million barrels, we are convinced that at least one, and probably several, small fields remain to be Traps and Seals found. The volume of total undiscovered oil is estimated to be small, however, ranging from nearly nothing to 70 mil- Traps are commonly controlled by high-angle extensional lion barrels of oil (MMBO), with a mean of 24 MMBO (fig. faults (down-to-the-east) that place west-dipping sandstone 13.11). However, we think that this AU has considerable reservoirs against low-permeability mudstones (fig. 13.8). potential for significant additions to reserves in the form of Stratigraphic traps are present at the lateral limits of sandstone reserve growth within the large, existing fields as a result of reservoirs, where highly permeable sandstones and conglom- technological developments, extensions, and higher average erates are adjacent to lower permeability mudstones. Sand- oil prices in the future (see Tennyson, this volume, chapter stone pinchouts and truncations are common along the eastern 23, for a discussion of reserve growth in Kern River, Fruit- margin of the AU. Unusual trapping mechanisms exist in the vale, Edison, Kern Front, Mount Poso, and Round Mountain dominant field of the assessment unit, the Kern River field, fields). within which tar seals and hydrodynamic trapping near the All assessment results and supporting documentation eastern onlap of Neogene sediments on Sierran basement are for the Southeast Stable Shelf Assessment Unit of the San responsible for the largest accumulations in the AU (fig. 13.9; Joaquin Basin Province are available in filesc100401.pdf table 13.1). Gentle structures, including anticlines and faulted (data form for conventional assessment unit), d100401.pdf anticlines, form traps as well. Diagenetic traps remain a pos- (summary of discovery history), em100401.pdf (probabi- sibility, especially at depth in the AU. listic estimates), g100401.pdf (graphs of exploration and 4 Petroleum Systems and Geologic Assessment of Oil and Gas in the San Joaquin Basin Province, California discovery data for grown volumes), and k100401.pdf (graphs economic development of the oil and gas fields of California: of exploration and discovery data for known volumes). Klett San Francisco, State of California, Department of Natural and Le (this volume, chapter 28) summarize the contents of Resources, Division of Mines Bulletin No. 118, p. 571-574. these files. Fischer, K.J., Heasler, H.P., and Surdam, R.C., 1988, Hydrocarbon maturation modeling of the southern San Joaquin Basin, California, in Graham, S.A., and Olson, H.C., eds., Studies of the geology of the San Joaquin Basin: References Cited Los Angeles, Pacific Section, Society of Economic Paleontologists and Mineralogists, book 60, p. 53-64. Adkison, W.L., 1973, Lithologic characteristics of upper Golob, E.M., Baron, D., Negrini, R., and Sarna-Wojcicki, A., Oligocene and Miocene rocks drilled at Elk Hills, Kern 2005, Trace-element analysis of four Neogene volcanic County, California: U.S. Geological Survey Bulletin 1375, ashes—Implications for the stratigraphy of petroleum- 113 p. bearing formations in the San Joaquin Valley, CA [abs.]: Atwill, E.R., 1935, Oligocene Tumey Formation of California: Geological Society of America Abstracts with Programs, v. Bulletin of the American Association of Petroleum 37, no. 7, p. 181. Geologists, v. 19, no. 8, p. 1192-1204. Graham, S.A., Carroll, A.R., and Miller, G.E., 1988, Kern Bartow, J.A., 1991, The Cenozoic evolution of the San River Formation as a recorder of uplift and glaciation of the Joaquin Valley, California: U.S. Geological Survey southern Sierra Nevada, in Graham, S.A., and Olson, H.C., Professional Paper 1501, 40 p. eds., Studies of the geology of the San Joaquin Basin: Los Bartow, J.A., and McDougall, K., 1984, Tertiary stratigraphy Angeles, Pacific Section, Society of Economic of the southeastern San Joaquin Valley, California: U.S. Paleontologists and Mineralogists, book 60, p. 319-331. Geological Survey Bulletin 1529-J, 41 p. Graham, S.A., and Williams, L.A., 1985, Tectonic, Bawden, G.W., 2001, Source parameters for the 1952 Kern depositional, and diagenetic history of Monterey Formation County earthquake, California—A joint inversion of (Miocene), central San Joaquin Basin, California: American leveling and triangulation observations: Journal of Association of Petroleum Geologists Bulletin, v. 69, no. 3, Geophysical Research, v. 106, no. 1, p. 771-785. p. 385-411. Bent, J.V., 1985, Provenance of upper Oligocene-middle Hoots, H.W., Bear, T.L., and Kleinpell, W.D., 1954, Miocene sandstones of the San Joaquin Basin, California, in Geological summary of the San Joaquin Valley, California, Graham, S.A., ed., Geology of the Temblor Formation, in Jahns, R.H., ed., Geology of southern California: San western San Joaquin Basin, California: Los Angeles, Pacific Francisco, State of California, Department of Natural Section, Society of Economic Paleontologists and Resources, Division of Mines Bulletin No. 170, p. 113-129. Mineralogists, v. 44, p. 97-120. Kasline, F.E., 1942, Edison oil field,in Summary of Beyer, L.A., 1996, San Joaquin Basin Province, in Gautier, operations, California oil fields: San Francisco, Annual D.L., Dolton, G.L., Takahashi, K.I., and Varnes, K.L., eds., Report of the State Oil and Gas Supervisor, v. 26, p. 12-18 1995 National assessment of United States oil and gas [also available in California Division of Oil and Gas, resources—Results, methodology, and supporting data, U.S. Summary of Operations, 1915-1999: California Division of Geological Survey Digital Data Series DDS-30, release 2. Conservation, Division of Oil, Gas, and Geothermal Callaway, D.C., 1962, Distribution of upper Miocene sands Resources, Publication No. CD-3, and at ftp://ftp.consrv. and their relation to production in the North Midway area, ca.gov/pub/oil/Summary_of_Operations/1940/]. Midway Sunset field, California: Selected Papers Presented Kodl, E.J., Eacmen, J.C., and Coburn, M.G., 1990, A geologic to San Joaquin Geological Society, v. 1, p. 47-55. update of the emplacement mechanism within the Kern CDOGGR, 1998, California oil and gas fields: Sacramento, River Formation at the Kern River field,in Kuespert, J.G., Calif., California Department of Conservation, Division of and Reid, S.A., eds., Structure, stratigraphy, and Oil, Gas, and Geothermal Resources, Publication No. CD-1, hydrocarbon occurrences of the San Joaquin Basin, 1472 p. California: Bakersfield, Calif., Pacific Sections, Society of CDOGGR, 2003, 2002 Annual Report of the State Oil and Gas Economic Paleontologists and Mineralogists and American Supervisor: Sacramento, Calif., California Department of Association of Petroleum Geologists, v. 64, p. 59-71. Conservation, Division of Oil, Gas, and Geothermal Kruge, M.A., 1985, Organic geochemistry and comparative Resources, Publication No. PR06, 263 p. [also available at diagenesis—Monterey Formation, Lost Hills oil field and ftp://ftp.consrv.ca.gov/pub/oil/annual_reports/2002/]. vicinity, west San Joaquin Basin, California: Berkeley, Eckis, R., 1940, The Stevens sand, southern San Joaquin University of California, Ph. D. thesis, 266 p. Valley, California [abs.]: Bulletin of the American Lamb, M.A., Anderson, K.S., and Graham, S.A., 2003, Association of Petroleum Geologists, v. 24, no. 12, p. 2195- Stratigraphic architecture of a sand-rich, deep-sea 2196. depositional system—The Stevens sandstone, San Joaquin Edwards, E.C., 1943, Kern Front area of the Kern River oil Basin, California: Bakersfield, Calif., Pacific Section, field, in Jenkins, O.P., ed., Geologic formations and American Association of Petroleum Geologists Publication Miocene Total Petroleum System—Southeast Stable Shelf Assessment Unit of the San Joaquin Basin Province 5

MP-47, 64 p. Petroleum Geologists, v. 24, no. 7, p. 1330-1333. MacPherson, B.A., 1978, Sedimentation and trapping Park, W.H., 1966, Main area of Mountain View oil field, in mechanism in upper Miocene Stevens and older turbidite Summary of operations, California oil fields: Sacramento, fans of southeastern San Joaquin Valley, California: Calif., Annual Report of the State Oil and Gas Supervisor, v. American Association of Petroleum Geologists Bulletin, v. 52, no. 1, p. 37-45 [also available in California Division of 62, p. 2243-2274. Oil and Gas, Summary of Operations, 1915-1999: McMasters, J.H., 1948, Oceanic sand [abs.]: Bulletin of the California Division of Conservation, Division of Oil, Gas, American Association of Petroleum Geologists, v. 32, no. and Geothermal Resources, Publication No. CD-3, and at 12, p. 2320. ftp://ftp.consrv.ca.gov/pub/oil/Summary_of_ Miller, D.D., 1999, Sequence stratigraphy and controls on Operations/1966/]. deposition of the upper Cenozoic Tulare Formation, San Peters, K.E., Pytte, M.H., Elam, T.D., and Sundararaman, P., Joaquin Valley, California: Stanford, Calif., Stanford 1994, Identification of petroleum systems adjacent to the University, Ph.D. dissertation, 179 p. San Andreas Fault, California, USA, in Magoon, L.B., and Miller, R.H., and Bloom, C.V., 1939, Mountain View oil field, Dow, W.G., eds., The petroleum system—From source to in Summary of operations, California oil fields: San trap: Tulsa, Okla., American Association of Petroleum Francisco, Annual Report of the State Oil and Gas Geologists Memoir 60, p. 423-436. Supervisor, v. 22, no. 4, p. 5-36 [also available in California White, J.L., 1955, Edison oil Field, in Summary of operations, Division of Oil and Gas, Summary of Operations, 1915- California oil fields: San Francisco, Annual Report of the 1999: California Division of Conservation, Division of Oil, State Oil and Gas Supervisor, v. 41, no. 2, p. 5-23 [also Gas, and Geothermal Resources, Publication No. CD-3, and available in California Division of Oil and Gas, Summary at ftp://ftp.consrv.ca.gov/pub/oil/Summary_of_ of Operations, 1915-1999: California Division of Operations/1937/]. Conservation, Division of Oil, Gas, and Geothermal Noble, E.B., 1940, Rio Bravo oil field, Kern County, Resources, Publication No. CD-3, and at ftp://ftp.consrv. California: Bulletin of the American Association of ca.gov/pub/oil/Summary_of_Operations/1955/]. 6 Miocene Total Petroleum System—Southeast Stable Shelf Assessment Unit of the San Joaquin Basin Province

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Figures 8 Petroleum Systems and Geologic Assessment of Oil and Gas in the San Joaquin Basin Province, California Miocene Total Petroleum System—Southeast Stable Shelf Assessment Unit of the San Joaquin Basin Province

38˚N 38˚N miles

0 25 2003 Assessment Unit 1995 Play Boundary

37˚N 37˚N

36˚N 36˚N

Pacific Ocean 35˚N 35˚N

121˚W 120˚W 119˚W

Figure 13.1. Map of the San Joaquin Basin, illustrating San Joaquin Basin Province boundary (bold line), county boundaries (thin gray line), Southeast Stable Shelf Assessment Unit boundary (blue line), play boundary from previous USGS assessment (purple line), and oil (green) and gas (red) fields in the province. Gray shading shows the locationFigure of 13.1 the Bakersfield Arch, which is mapped on the basement surface in a three-dimensional geologic model of the basin (Hosford Scheirer, this volume, chapter 7). In figures 13.1 and 13.2, dashed line indicates surface and subsurface traces of the White Wolf Fault, as modeled by Bawden (2001). Miocene Total Petroleum System—Southeast Stable Shelf Assessment Unit of the San Joaquin Basin Province 9

miles

25S/28E DC 0 10 MP

PC RM ° ° 35 30'N KF 35 30'N RR KB AH 29S/25E B Ed EdNE F KR UA

MV

32S/27E

35°00'N 35°00'N 119°00'W 118°30'W

Figure 13.2. Detailed map of Southeast Stable Shelf Assessment Unit (AU). The blue line indicates the geographic limit of the AU. Oil fields in the AU are colored green. Fields outside the AU are outlined in black. Filled circles represent 1705 exploratory wells drilled for petroleum within the AU between 1901 and 1995. Well locations are from the California Department of Conservation, Division of Oil, Gas, and Geother- mal Resources, and are available in databases at ftp://ftp.conservation.ca.gov/pub/oil/maps/dist4. Township and range grid is indicated for scale and location; scattered labels are relative to the Mount Diablo baseline and meridian. Gray shading shows the location of the Bakersfield Arch. City of Bakersfield (B) denoted with filled square. Oil field labels are: AH=Ant Hill, DC=Dyer Creek, Ed=Edison, EdNE=Edison North- east, F=Fruitvale, KB=Kern Bluff, KF=Kern Front, KR=Kern River, MP=Mount Poso, MV=Mountain View, PC=Poso Creek, RR=Rosedale Ranch, RM=Round Mountain, and UA=Union Avenue.

Figure 13.2 10 Petroleum Systems and Geologic Assessment of Oil and Gas in the San Joaquin Basin Province, California

Stockton

Modesto

N Merced

Fresno

Parkfield

Bakersfield

~230 miles

Ma alluvium/ nonmarine 5 Etchegoin Fm Fruitvale shale of ~10 miles 10 Miller and Bloom (1939), Round 15 Mountain Silt ~100 miles

20 Olcese Sand, Jewett Sand, 25 Vedder Sand, Walker Fm, 30 upper Famoso sand of Edwards 35 (1943) 40 lower Famoso sand of Edwards 45 (1943) 50 unnamed (Domengine Fm equivalent) 120 ~ ? Basement rocks

Figure 13.3. Three-dimensional stratigraphy model of the SoutheastFigure Stable Shelf 13.3 AU extracted from the EarthVision® model of the basin by Hosford Scheirer (this volume, chapter 7). The bounding polygonal block illustrates the model space within which the EarthVision® model is constructed. The major stratigraphic units within the AU are listed; see figure 13.4 for stratigraphic relationships between the units. Forma- tion names in italics are informal. Note that Eocene-aged rocks rest directly on basement, indicating the absence of Cretaceous rocks on and south-southeast of the Bakersfield Arch. Pliocene-aged San Joaquin Formation is absent in this AU. Oil fields (green) are draped on the topo- graphic surface. The San Joaquin Basin Province boundary (bold line), AU boundary (dashed line), and city names and locations float above the surface of the model. View is from due south at a 30° inclination angle. Vertical exaggeration is 4. EarthVision is a registered trademark (Marca Registrada) of Dynamic Graphics, Inc., Alameda, Calif. Fm, Formation. Miocene Total Petroleum System—Southeast Stable Shelf Assessment Unit of the San Joaquin Basin Province 11

SYSTEM Mega- SOUTH SERIES sequences West East Ma (2nd order) STAGE basin axis Alluvium 0 PLEIS. Tulare Fm PLIO. San Joaquin Fm 5 Etchegoin Fm unnamed Trans- Reef Ridge Sh Mbr pression Chanac

DEL. Antelope sh KR Fm Stevens sd Santa Margarita 10 Monterey Fm Fruitvale shale Ss McDonald Sh Mbr MOHNIAN

NEOGENE Devilwater Sh Round Mtn Silt LUI.

Mbr/Gould Sh unnamed 15 Mbr, undiff

migration Nozu sd MIOCENE B REL. Triple junction Triple Media Sh Mbr Olcese Sand Carneros Ss Mbr 20 Temblor Fm Santos Jewett Figure 13.4. Generalized stratigraphic column for

SAUCESIAN Freeman Sand Silt the southern San Joaquin Basin, showing hydro-

Agua SsMbr Sh PH 25 Bed carbon reservoir rocks and potential hydrocarbon Rio Bravo sd source rocks. See Hosford Scheirer and Magoon (this volume, chapter 5) for complete explanation

30 Walker Fm of the figure. Formation names in italics are infor- Subduction and magmatism Wygal Ss Mbr Vedder Sand mal and are defined as follows: Antelope shale ZEMORRIAN OLIGOCENE Cymric Shale of Graham and Williams (1985), Stevens sand of Mbr REF. Eckis (1940), Fruitvale shale of Miller and Bloom 35 Tumey formation Oceanic sand (1939), Nozu sand of Kasline (1942), Rio Bravo sand of Noble (1940), Oceanic sand of McMas- ters (1948), Tumey formation of Atwill (1935), and 40 Famoso sand of Edwards (1943). Point Kreyenhagen Formation of Rocks Ss unnamed Mbr sand Famoso EOCENE 45

subsidence Canoas Slts Mbr Diablo Range Diablo unnamed

uplift and basin basin and uplift B=Buttonbed Ss Mbr PH=Pyramid Hill Sd Mbr KR=Kern River Fm 50

PALEOGENE Oil reservoir rock Gas reservoir rock

PENUTIAN ULATSIAN NARIZIAN Potential marine Potential nonmarine reservoir rock 55 reservoir rock Nonmarine Marine coarse coarse grained TIAN BULI- grained rock rock orogeny Clay/shale/ ~ ~ Coast Range mudstone/ ~ ~ ophiolite/ Granitic basement and Laramide biosiliceous ZIAN YNE- 60 Oil-prone source Hiatus or loss by rock/ erosion Gas-prone source rock Flat slab subduction PALEOCENE undifferentiated Cretaceous 65 CHENEYIAN 121˚W 120˚W 119˚W 38˚N miles Stockton Arch basin axis San Joaquin0 Basin 25Province

70 MAASTRICH. COAST RANGES North SIERRA NEVADA 75 37˚N

80 LATE CAMPANIAN SAN ANDREAS FAULT Central 85 SANT. DCN CON. 36˚N DR DC T 90 PH South TUR. DD J Bakers eld Arch

95 CRETACEOUS Pacific Ocean WWF CENO. 100 35˚N SAN EMIGDIO,TECHAPI MOUNTAINS Sierran magmatism Sierran 160 Ma 120 Ma

105 and margin Convergent EARLY

ALBIAN Basement rocks 110

Figure 13.4 12 Petroleum Systems and Geologic Assessment of Oil and Gas in the San Joaquin Basin Province, California

38°N 38°N miles

0 25

37°N 37°N

36°N Buttonwillow 36°N

Oil from Monterey Formation

Oil suspected from Monterey Formation

Pod of active Tejon 35°N source rock 35°N

121°W 120°W 119°W

Figure 13.5. Location of Southeast Stable Shelf AU (blue line) with respect to the pods of active source rock of the Miocene Total Petroleum System as mapped by Peters, Magoon, Lampe, and others (this volume, chapter 12). The bold line is the San Joaquin Basin Province bound- ary, and thin gray lines are county boundaries. Gray shading shows the location of the Bakersfield Arch. See Magoon and others (this volume, chapter 8) for details of oil field assignment to petroleum systems based on geochemical analyses.

Figure 13.5 Miocene Total Petroleum System—Southeast Stable Shelf Assessment Unit of the San Joaquin Basin Province 13

Southeast Stable Shelf AU A Asphalto field Elk Hills field Canal field Strand field McClung field Bellevue field Fruitvale field Kern River field Round Muuntain field Pleistocene North Coles field Tulare Fm

Alluvium (Holocene) OlceseSd San Joaquin Formation Graham and Williams (1985) Pliocene Kern River Formation Antelope shale of Pleistocene-Pliocene, undifferentiated Olcese Sand

Olig sd-Potter sd Kern River Fault

Etchegoin Formation Chanac Fm WalkerFm

3 Santa Margarita Ss

Pyramid Hill Sd Miocene RoundFreeman Mountain Silt-Silt Reef Ridge Shale Jewett Sand Stevens sd Etchegoin Fm 1 1 Vedder Sand Carneros Ss Mbr Stevens sand Ss Macoma shale2 Santa Margarita Miocene 1 Santos Sh Mbr Stevens sand Oligocene CymricWygal Sh Mbr Ss Mbr Tumey fm of Atwill (1935)

McDonald Shale Fruitvale sh Devilwater Sh Mbr- WalkerFm Gould Sh Mbr Media Sh Mbr Eocene Temblor Fm Monterey Fm Fruitvale shale of Miller and Bloom (1939) Oligocene Basement rocks Mbr Rio Bravo sd (Jurassic (?) granitics and

pre-Cretaceous meta-sediments) Round Mountain Silt Freeman Silt- Jewett Sand Walker Fm

1Stevens sand of Eckis (1940) Vedder Sand 2 Macoma shale of Hoots and others Rio Bravo sd Tumey fm (1954) of Noble (1940) of Atwill (1935) 3Olig sand of Adkison (1973), Oligocene Potter sand of Callaway (1962) Kreyenhagen Fm

Eocene

B

6 miles 6 miles

Figure 13.6. A, Generalized geologic cross section of the southern San Joaquin Basin. Orange fill denotes approxi- mate location of oil-generative shales of the Monterey Formation. Formations in italics denote informal geologic names. Informal units not previously defined include the Macoma shale of Hoots and others (1954), the Olig sand of Adkison (1973), and the Potter sand of Callaway (1962). B, Map view illustrating cross-section location, as well as the AU boundary and the pods of active source rock asFigure mapped 13.6 by Peters, Magoon, Lampe, and others (this volume, chapter 12). Figure modified from CDOGGR (1998). Fm, Formation; fm, formation; Mbr, Member; Sd, Sand; sd, sand; Ss, Sandstone; Sh, Shale; sh, shale. 14 Petroleum Systems and Geologic Assessment of Oil and Gas in the San Joaquin Basin Province, California

San Francisco Mount Diablo

? HAYWARD-CALAVERAS FAULT

Stockton TESLA ? FAULT

?

SAN

ORTIGALITA FAULT

ANDREAS

SAN GREGORIO FAULT

Santa Cruz

Monterey Fresno

FAULT

Coalinga FAULT

SUR

Paso Robles N Bakersfield

FAULT

30 WHITE WOLF FAULT 0 10 20 40 50 KILOMETERS

HOSGRI GARLOCK FAULT

Marine deposits—Solid line indicates inferred shoreline; hachures indicate inferred shelf edge; queried where uncertain

Nonmarine deposition—Dotted line indicates inferred extent

Emergent area

Faults—Arrows indicate direction of relative movement

Probably active

Possibly active

Figure 13.7. Paleogeography of the San Joaquin Basin (red outline) during the early Pliocene (4 to 3 Ma). The Southeast Stable Shelf AU (blue line) and known oil fields (green) are superimposed for reference. Deposition of the major reservoir rock in the AU, the Kern River Formation, began in the late Miocene. Figure modified from Bartow (1991). Miocene Total Petroleum System—Southeast Stable Shelf Assessment Unit of the San Joaquin Basin Province 15

EDISON OIL FIELD Jeppi Area

1 mile FORMATION COMPOSITE

AND ELECTRIC -5100

-5200 8 _ SERIES MEMBER LOG + + -5300

-5000

-5400 -4900

_ -4800 -5500 + B

7 -5600 -5000 PLIOCENE + -5200 _ Kern River - -5700

-5300 -5200

Chanac 2800 -5800 _

+

-5400 _ Formations + -5300 + (undifferentiated) -5300 _ -5500 -5400

-5600

+ _ -5400

_ -5400 +

_ -5500 3000 -5900 + -5600 -5800 -5700 -5400 -6000 -5500

-5600 -5500

_

_

+

+

Santa Margarita _

-5700 + -5500 3800 Sandstone -5800 -5600 -5900 -5600 -6200 -6000 -5700 -6300 -6100 -5800 -6400 A -5900 -6500 -6000 -6100 1 mile 4000 -6600 -6200 -6700 -6800 17 18

MIOCENE Fruitvale T 30 S R 29 E 4200 shale + _ of Miller and

Bloom sand Wicker (1939) of Kasline (1942) Contours on top of Pyramid Hill Sand Member of Jewett Sand 4400

Round Mountain (1942) of Kasline

Silt sand Nozu 4800

A B Kern River-Chanac Freeman Silt- Formations Jewett Sand (undifferentiated) 30003000 3000

5800 Santa Margarita Sandstone

Pyramid Hill Sand Member of Jewett Sand 4000 4000 4000

Vedder Sand 6000 Wicker sand of Kasline (1942) OLIG- OCENE

SEPTEMBER 1992 Fruitvale shale(*Nozu sand**) Round Mountain Silt 5000 50005000

Freeman Silt contoured horizon Jewett Jewett Sand Sand Vedder Sand Jewett Sand 6000 Pyramid Hill Sand Pyramid Hill Sand Vedder Sand Vedder Sand Pyramid Hill Sand *Fruitvale shale of Miller and Bloom (1939) **Nozu sand of Kasline (1942)

Figure 13.8. Figure of the Jeppi area of Edison oil field, illustratingFigure typical 13.8 trapping mechanism in the assessment unit in which down- to-the-east normal faults place sandstone reservoirs against mudstones. Green shading (underlying township-range grid) denotes reported 1998 limits of productive sand units within the field. All depths are in feet. Formations in italics denote informal geologic names. Township-range grid in figures 13.8 and 13.9 is relative to the Mount Diablo baseline and meridian; one mile by one mile sections within the township-range grid are numbered in italics. See figure 13.2 for location of field. Figure modified from CDOGGR (1998). 16 Petroleum Systems and Geologic Assessment of Oil and Gas in the San Joaquin Basin Province, California

KERN RIVER OIL FIELD

COMPOSITE ELECTRIC LOG SERIES FORMATION 1 mile

13 18 17 16 15 T 28 S R 27 E T 28 S R 28 E

_ + B 1 mile 24 19 20 21 22 Kern Formation RIver China Grade “sand” PLIOCENE-PLEISTOCENE of Kodl and others (1990) 25 30 29 28 27

Fm +400 +200 Chanac

36 Santa Margarita 31 32 0 33 34 Sandstone -200 A Fruitvale shale of Miller -400 and Bloom (1939) -600

-800 6 5 4 3 2

Silt China Grade + Mc Van sand** Fault _ 8 9 -200 10

Round Mountain 7 _ +

-1000 -800 -600 T 29 S R 28 E MIOCENE

Olcese SandOlcese Contours on top of R series sand of Kodl and others (1990)

B

A Freeman Silt-Jewett Sand Silt-Jewett Freeman

contoured horizon

C series sand* *

Vedder Sand Vedder G series sd OLIGOCENE K series sand* Kern River Formation

Famoso sand of R series Edwards (1943)

Walker Walker sand* EOCENE Formation

Basement rocks UPPER JURASSIC (?) ** McVan sand of Bent (1985) * C series, G series, K series, and R series sands of Kodl and others (1990)

Figure 13.9. Figure of Kern River oil field, illustrating the absence of typical trap types such as those created by faults. Green shading (under- lying township-range grid) denotes reported 1998 limits of productive sand units within the field. All depths are in feet. Formations in italics denote informal geologic names. See figure 13.2 for location of field. Figure redrafted from CDOGGR (1998). Fm, Formation; sd, sand.

Figure 13.9 Miocene Total Petroleum System—Southeast Stable Shelf Assessment Unit of the San Joaquin Basin Province 17

Southeast Stable Shelf, Assessment Unit 50100401 A 1,800

1,600

1,400

1,200

1,000

800

600

400

200

0 CUMULATIVE NEW-FIELD CUMULATIVE WILDCAT WELLS (number) 1880 1900 1920 1940 1960 1980 2000 DRILLING-COMPLETION YEAR

B 10,000

1,000

100

10

1 KNOWN OIL-ACCUMULATION SIZE (MMBO) SIZE OIL-ACCUMULATION KNOWN

0 1880 1900 1920 1940 1960 1980 2000 ACCUMULATION-DISCOVERY YEAR

Figure 13.10. A, Cumulative number of new-field wildcat wells versus drilling completion year in the Southeast Stable Shelf AU. B, Oil accumulation size versus year of accumulation discovery in the Southeast Stable Shelf AU. Both graphs are excerpted from data file k100401.pdf (see Klett and Le, this volume, chapter 28, for explanationFigure 13.10 of data file). 18 Petroleum Systems and Geologic Assessment of Oil and Gas in the San Joaquin Basin Province, California

50100401 Southeast Stable Shelf Monte Carlo Results

Forecast: Oil in Oil Fields

Summary: Display range is from 0.00 to 70.00 MMBO Entire range is from 0.52 to 92.66 MMBO After 50,000 trials, the standard error of the mean is 0.06

Statistics: Value Trials 50000 Mean 23.78 Median 21.39 Mode --- Standard Deviation 14.04 Variance 196.99 Skewness 0.73 Kurtosis 3.12 Coefficient of Variability 0.59 Range Minimum 0.52 Range Maximum 92.66 Range Width 92.13 Mean Standard Error 0.06

Forecast: Oil in Oil Fields 50,000 Trials Frequency Chart 49,877 Displayed .022 1100

.017 825 Frequency

.011 550

Probability .006 275

.000 0 0.00 17.50 35.00 52.50 70.00 MMBO

Figure 13.11. Probabilistic estimate of total oil volume in undiscovered oil fields in the Southeast Stable Shelf AU. Figure is excerpted from data file em100401.pdf (see Charpentier and Klett, this volume, chapter 26, for details of the calculation and Klett and Le, this volume, chapter 28, for expla- nation of data file).

Figure 13.11 Miocene Total Petroleum System—Southeast Stable Shelf Assessment Unit of the San Joaquin Basin Province 19

Table 13.1. Production statistics for primary fields in the Southeast Stable Shelf Assessment Unit

[Recoverable oil is the sum of cumulative production and estimated proved reserves. Data source is CDOGGR (2003). MMB, millions of barrels. Primary fields are defined as those with recoverable oil equal to or greater than 0.5 MMB]

Recoverable Oil Number of Field through 2002 Percent of Total Producing Wells (MMB) in 2002 Kern River 2451.3 67.0 8600 Mount Poso 313.8 8.6 548 Kern Front 216.9 5.9 688 Round Mountain 180.7 4.9 207 Edison 153.1 4.2 812 Fruitvale 125.8 3.4 233 Mountain View 91.0 2.5 157 Poso Creek 86.5 2.4 333 Rosedale Ranch 16.9 0.5 35 Kern Bluff 12.2 0.3 35 Ant Hill 8.6 0.2 17 Union Avenue 1.9 0.1 4 Total 3658.7 100 11669