Favorable Geology, Advanced Technology May Unlock Labrador's

E XPLORATION & DEVELOPMENT

Several large gas discoveries were ies, the Hopedale basin has considerable made along the Canadian Labrador shelf potential for natural gas development during an early exploration cycle that and presents a wide variety of large, extended through the 1970s into the undrilled structural and stratigraphic early 1980s. With the focus at the time features. However, oil shows in two of being strictly on oil exploration, no de- the Labrador wells, as well as on the HOPEDALE BASIN—1 velopment and no further drilling have conjugate margin off west Greenland, occurred in the area since 1983. also indicate that there is a good pos- That early drilling, which included sibility of oil fi nds. only 27 wells (21 located in the Hope- The increasing demand for clean dale basin) proved the presence of 4.2 tcf of recoverable natural gas in the fi ve discoveries made and Favorable geology, advanced technology demonstrated the presence of a rich petroleum system may unlock Labrador’s substantial resource over a vast area. With recent trends in commodity prices and the need for energy in the Eastern US and Canada is new supply regions it is understand- being supplemented by the emergence able that industry is now revisiting this of new cold-ocean production and Michael Enachescu highly prospective frontier located on transportation technologies (CNG, LNG, Memorial University the northeast corner of North America. GTL tankers, for example) and is setting St. John’s, Newf. To date this renewed activity has been the stage for a new cycle of exploration in the form of modern 2D seismic data drilling and monetizing the stranded across the shelf and into the unexplored gas resources off Labrador. slope and deepwater area. Although there are two major basins HOPEDALE, OTHER EAST CANADA BASINS Fig. 1 in the Labrador Sea, the focus in the Labrador SeaSea new exploration cycle is the Hopedale Anticosti basin basin which contains the signifi cant Paleozoic basins are labeled in blue text discoveries from the earlier cycle. The Saglek Sable basin basinBasin Mesozoic basins are labeled in purple text Hopedale basin is a large Mesozoic Hopedale rifted area that covers 175,000 sq km Basinbasin and extends from the modern day shelf OrphanOrphan F llemishe to the lower slope (200 to 3,000 m of basinBasin PaPass mishB s s B water). JeanneJea n ne d Based on the characteristics of the Bbasin a d’Arc s ’ in A prerift basement and of the sedimen- rc tary infi ll, the Hopedale basin can be Area shown Anticosti subdivided into a series of subbasins Basinbasin Port au Port #1 S. Whale and ridges probably offset on strike Sidney basinBasin LaurentianLaurentian Basinbasin by transfer faults. Several larger dep- basinBasin MaritimeMaritime ocenters are recognized on the shelf Basinbasin and slope that contain thick Mesozoic Sable sequences including mature Cretaceous Basinbasin source rocks and possibly Late Jurassic alt basinAtlantic Ocean aged sediments at deeper locations. tian S

The improved resolution of seismic Georges Bank ScotianSco Salt BasinAtlantic Ocean basinBasin data shows a number of large, previous- 0 249 ly unknown structural and stratigraphic Miles Sources: Bathymetry of Canadian margin after Km leads on the distal continental shelf and NRCan; North America map reproduced from 0 400 on the slope. www.randonneetours.com As attested by the existing discover-

ATLANTIC CANADA BASINS AND NL LAND TENURE MID-2006 Fig. 2

3,000 m

Landsale parcels Saglek basin Labrador Mesozoic basin Sea Carboniferous basin Okak arch Early Paleozoic basin Labrador Exploration license shelf Hopedale basin

2,000 m

m 200 Hawke basin right w Labrador rt h Ca arc

Quebec St. Anthony basin

m 2,000 m 0 Parcel 5 0 m 00 m 20 2, 200 Orphan Parcel 4 Gulf of Knoll St. Lawrence Parcel 3 200 m East Orphan basin Parcel 2 Anticostibasin Quebec 200 m Deer Lake m n Bay St. George basin 00 i ,0 s basin 2 a 200 Newfoundland 0 m b Atlantic 20 m Parcel 1 Bonav s s Flemish Cap ista platfor a P len basin Ocean St.St. John’sJohn’s h s Magda m i Parcel 1 J m New Parcel 2 Jeanne d’Arc 200 m m e 0 l 0 2,0 Brunswick basin F PE Sydney Parcel 3 I basin Hibernia Laurentian Terra Nova White Rose 0 m basin 3,00 Whale US Orpheus graben basin n itio n Canso ridge n Nova Scotia o ve m ar Newfoundland Seamounts ha tfor basin in La la Sal p Carson/B bas 200 m Sable project South Whale basin Scotian shelf asin 20 b 0 m Deep Panuke 2, 000 m m 0124Miles 200 Scotian m 2,000 m Annapolis discovery 0200Km 200 Provincial Jurisdiction Boundary

0 m 3,00 Source: Modiﬁed after the GSC, C,-NLOPB and Enachescu, 2005

Introduction A new exploration program off 338,000 b/d, representing around 10 Although almost 10 tcf of recover- Labrador may bring the large future gas million bbl/month, the province of able natural gas has been discovered discoveries that provide the critical mass Newfoundland and Labrador is produc- offshore Newfoundland and Labrador, and will launch offshore Newfoundland ing at the level of a world class produc- (4.2 tcf offshore Labrador and 5.99 tcf and Labrador as a new gas supply area er from one giant, Hibernia, and two on the Grand Banks), commercial pro- for North America. Alternatively it may large fi elds, Terra Nova and White Rose. duction of gas has yet to proceed.1-4 bring new oil discoveries to a province This production represents about 40% The solution gas being produced that it will soon produce 400,000 b/d of Canada’s light oil output and it is with the oil on the Grand Banks is of oil.5 equivalent to about 40% of the present presently being re-injected to main- The passive continental margin of deepwater Gulf of Mexico production. tain reservoir pressure and for eventual Atlantic Canada stretches on for more White Rose fi eld began production commercialization. Work is under way than 3,000 km from Georges Bank, at in late 2005 and is expected to ramp in government agencies, at Memorial the Canada-US border to the northern up this summer to about 100,000 b/d, University, and among the industry tip of Labrador (Figs. 1 and 2) and off while the other two fi elds have reached players on the best means to bring this Baffi n Island.1 2 6-8 their production peaks. These fi elds are gas to market. With production of more than in the increasingly productive Jeanne d’Arc basin, which is only one of the HOPEDALE BASIN STRUCTURAL SUBDIVISIONS, DISCOVERIES, SEISMIC DATA Fig. 3 many Mesozoic basins located in Atlan- tic Canada. Saglek basin Continent-Ocean Boundary Labrador 2004 - approx. 8.971 km Based on latest geologic, petrophysi- Labrador 2003 - approx 1.148 km cal, and reservoir simulation studies Pre 1990 data - approx. 31,240 km Reprocessed data - approx. 19,800 km and drilling results, the C-NLOPB has Limit Mesozoic basin revised upward its estimates of recover- Hawke Channel includes 10 km buffer able reserves-resources. It put Hibernia fi eld oil reserves at 1.244 billion bbl, 0 Miles 62 Okak arch an increase of 379 million bbl, and the 0Km 100 Hebron complex at 731 million bbl of Nain Igneous e proven and probable oil resources, an subbasin xtru J-90 si increase of 317 million bbl. ve prov Labrador H ince These amounts bring the total of oil Sea reserves-resources in the Newfoundland o and Labrador offshore area to 2.75 bil- p lion bbl, an increase of 696 million bbl e Harrison Continent-Oce d subbasin from previous estimates. This combined a reserve boost generously counterbal- l ances the already produced oil from E-33 e F-06 an Boundary Hibernia and Terra Nova fi elds. H-81 Hamilton Newfoundland and Labrador’s area Ter subbasin tiary gravity of petroleum potential extends far b

H-55 fol beyond the boundaries of the produc- a ds prov 6-8 Tertiar ing Jeanne d’Arc basin. Mesozoic s I-05 ince y l i istri sedimentary basins are found from prov c f n ince aul the Laurentian basin, across the Grand t Banks basins, through the deeper waters Hawke of the Flemish Pass basin, and into the CTFZ basin arch Orphan basin, where activity is now ht focused, and continuing northward into Cartwrig several basins along the Labrador shelf Labrador and slope (Figs. 1 and 2).7 9-11 Hawke Channel Also present are Paleozoic basins that occupy several large areas on land and the entire Gulf of St. Lawrence, off Newfoundland’s west coast.12 Recent petroleum land sales including the pres- tion and harsh environment character- compared to the Scotian shelf or South- ent 2006 Call for Bids (closing Novem- ize the Labrador Sea. ern Grand Banks margins. ber 2006) have targeted both Mesozoic The Hopedale basin is the southern- The Labrador Sea is an Atlantic-type and Paleozoic basins, with major ex- most rift basin within the Labrador Sea extensional margin, initially part of ploration programs ongoing in the East and is positioned just north of the Or- the intracontinental network of basins Orphan and Laurentian basins.6 7 phan basin, which is an area of current formed during the Mesozoic between The Labrador Mesozoic area (Fig. exploration drilling by Chevron, Exxon- North America and North Africa and 2) is the most northerly of the Atlantic Mobil, Imperial Oil, and Shell (Figs. 1 Europe.2 7 13-19 Canada basins, and it appears that the and 2). The basin has an elongated area The region was subjected to rift- large 2D programs in the area are part of 175,000 sq km situated between 55° ing, continental mantle exhumation, of a reconnaissance phase that is likely and 59° N. Lat. (same latitude as North drifting, seafl oor spreading between to lead to a licensing round in the near Sea) and in 100 to 3,000 m of water. Labrador and Greenland, oceanic rift future. The shelf part of the basin has water cessation, ridge abandonment, and sig- as deep as 400 m, was recently glaciat- nifi cant thermal subsidence.2 5 17 20-24 Regional geology ed, and contains several banks, plateaus, The prerift basement consists of Pre- Favorable geology with proven large and troughs. The slope is relatively cambrian metamorphic and magmatic gas discovery but relatively remote loca- gentle and less sculptured by canyons as rocks and Paleozoic clastics and carbon- E XPLORATION & DEVELOPMENT

ates.12 25-28 The Mesozoic sedimentary ing 21 industry wells within the basin present study extends the Hopedale fi ll contains faulted and slightly folded were drilled.7 14 29-32 Several wells did basin description into the deeper parts mostly Early Cretaceous synrift sedi- not reach their petroleum targets and of the basin and to the outer shelf and mentary rocks, all covered by a thick only 16 wells provide signifi cant data in slope area (up to 3,000 m of water) wedge of Tertiary and recent glacial terms of basin analysis. and helps evaluate its further petroleum deposits. This earlier seismic and drilling potential Geologically, the Hopedale rift basin information helped to identify the main All fi ve Labrador shelf gas discoveries is bounded: stratigraphic units and structurally map have come from shallow targets in the • To the west by the onlap of Meso- the shelfal Late Mesozoic-Cenozoic Hopedale basin (Figs. 1 through 4). The zoic beds into a prerift basement hinge basinal area that contains proven reser- fi rst discovery, Bjarni H-81 in 1973, zone or in places by a down-to-the-sea voirs and source rocks.29 30 33 was followed by Gudrid H-55 (1974), basin-bounding fault; The Geological Survey of Canada Snorri J-90 (1975), Hopedale E-33 • To the south by the Cartwright (GSC) provided a thorough portrayal (1978), and North Bjarni F-06 (1980) Transfer Fault Zone (CTFZ) that sepa- of Labrador Sea basins based on in- (Figs. 3 and 4).2 4 13 29 30 32 These wells rates it from the Cartwright arch and terpretation of earlier seismic data in tested between 8 and 20 MMcfd. Hawke basin; its monumental Labrador Atlas.14 The The computed recoverable resources • To the east by the linea- (P50) are for North Bjarni ment marking the Continent- 2.2 tcf, Bjarni 0.9 tcf, Hoped- OPEDALE BASIN GAS DISCOVERIES* Fig. 4 Ocean Boundary (COB) that H ale 0.1 tcf, Gudrid (0.9 tcf), is placed beyond the end of and Snorri 0.1 tcf.3 7 31 34 No the seismic survey; and drilling has occurred in the • To the north by Okak basin since 1983. arch and an implied transfer Snorri The excellent quality zone separating it from the reservoirs encountered at Saglek basin (Fig. 3). Hopedale depths of 2 km to 3.5 km are Recent seismic explora- North Bjarni Late Cretaceous sandstones Bjarni tion in the basin began in of the synrift sequence and Gudrid 2002 and includes more Paleozoic prerift limestone than 30,000 line km of and dolomites.5 14 29 33 The speculative 2D seismic, LABRADOR discoveries have estimated predominantly acquired by 0Miles 124 total reserves of 4.2 tcf of gas Km Geophysical Services Inc. 0 200 and 123 million bbl of NGL

(GSI), Calgary. The original *North Bjarni-Bjarni complex (3 tcf) is the largest Canadian Atlantic gas ﬁeld of 50-60º API. The undis- programs were more of a Source: After Geological Society of Canada covered gas potential in the regional grid to defi ne the Labrador shelf is estimated at major structural and stratigraphic elements of the basin, but each year GSI has returned to acquire NORTH BJARNI GAS FIELD, FLAT SPOT, AND COMPLEX BASEMENT ARCH Fig. 5 SW NE denser coverage that is more suitable for 10400 10800 11200 11600 12000 12400 12800 13200 13600 14000 14400 identifi ed leads and prospects. GSI has North Bjarni F-06 donated the data to Memorial Univer- sity for regional geology studies and 1,000 made the data available for illustrations in this article. 1,500

Exploration history 2,000 Over 40 years of petroleum explora- G/W tion has unlocked the regional geology 2,500 and unveiled some of the petroleum wealth of the sedimentary basins. 3,000 0 1.24 Miles The shelf of the Hopedale basin was Km 02 intensively explored in the 1970s-early 3,500 1980s when over 120,000 km of 2D Source: Seismic line courtesy of GSI. seismic data was collected and all exist- 22 tcf.34 LABRADOR SHELF LITHOSTRATIGRAPHY AND TECTONIC STAGES Fig. 6 One complex Age Formation Tectonic stage Legend formed by adja- WE Pleistocene UNNAMEDUnnamed glacialGLACIAL beds BEDS cent Bjarni and Pliocene SAGLEKSaglek North Bjarni fi elds contains more gas Miocene 4. Postdrift than the currently Mokami Sandstone producing Sable Oligocene Conglomerate, coal Project (Sable is Bafﬁn Bay unc ? ? LEIFLeif MBRmbr Argillaceous ss composed of fi ve KENAMUKenamu Eocene 3.2. Syndrift medium size fi elds UPPERUpper Gudrid GUDRID mbr MBR Oceanic crust creation Shale off Nova Scotia) or Gudrid CARTWRIGHTCartwright Paleocene Baylot unc Metasediments Lower Gudrid mbr the large (2.7 tcf) Maastrichtian Dolomite White Rose gas Campanian Freydis Markland mbr cap in the Jeanne Santonian Limestone 3. Postrift d’Arc basin (Figs. Coniacian 3.1. Mantle exhumation Arkosic 3 to 5). Turonian Volcanics Cenomanian Umpleby de- Avalon unc fi ned the strati- Albian Source rock Aptian Bjarni graphic nomen- Gas reservoir Barremian clature of the 2. Synrift Hauterivian Alexis Gas/oil reservoir Labrador shelf se- Valanginian quence.33 McWhae Berriasian Labrador unc et al.29 redefi ned Paleozoic the basin stratigra- PC 1. Prerift phy using sev- Source: Modiﬁed after Umpleby, 1979; McWhea et al., 1980; GSC, 1987; and Enachescu et al., 2006. eral new seismic stratigraphic units; GSC adapted his published chart, which economic, environmental and well data rial University for regional structural was largely accepted by the exploration has accumulated in the Labrador Sea studies and investigation of its petro- community. and are available for consultation from leum systems (Fig. 3). This data set was A lithostratigraphic chart modi- the GSC, C-NLOPB, Government of used in this study. The GSI dip lines fi ed from these authors and including Newfoundland and Labrador, Memorial cover the entire continental margin tectonic evolution, source, and reser- University, and other sources. extending into the deep and ultradeep voir intervals and main unconformities Only the geoscience database is water. marked by regional seismic markers discussed here, and the reader can fi nd A dozen basin-crossing strike lines is presented in Fig. 6. During the early more detailed information in the at- were collected to tie most of the sig- exploration cycle, drilling targeted base- tached references. nifi cant exploration wells and correlate ment highs, drape anticlines, sand pin- Seismic data. The early seismic data regional markers. Evidently, this data chouts, and several listric fault blocks. base is extensive, comprising well over grid contains better quality imaging One well, North Leif I-05, has recov- 100,000 km of data spanning over than data collected 30-35 years ago, ered small quantities of 33° API waxy 15 years of seismic exploration and and it extends from the near shore to oil from the Bjarni sandstone (Fig. 3). research in the Labrador Sea area. Most the lower slope of the basin, which is It is worth mentioning that gas of the older data were collected only on a very important factor in allowing the discoveries were recorded accidentally the continental shelf and upper slope deciphering of the basins evolution, during the search for oil reservoirs. No and are not migrated. and in the identifi cation of new play systematic gas drilling, using DHI or Several multichannel deep seismic concepts. AVO analysis of the seismic data, was lines were also acquired by research in- Additionally, 20,000 km of older GSI ever performed in this area. stitutes in Canada and abroad.18 19 24 GSI lines have been reprocessed and added and TGS recently recorded high quality to the current grid. Geoscience data base long lines and made them available to Seismic data parameters. The 2003-04 GSI A large variety of industry and the industry. 2D seismic grid contains 10,121 line research refl ection, refraction, gravity, The GSI 2003-2004 Hopedale basin km. Acquisition was done with 6 to 8 magnetic, bathymetric, engineering, 2D seismic grid was donated to Memo- km long streamers and recorded to a E XPLORATION & DEVELOPMENT

minimum of 12 sec. Processing to 10 While several wells have encountered Several authors20 21 23 37 discussed the sec includes modern multiple elimina- gas in Cretaceous and Tertiary reservoir magnetic data when trying to establish tion routines and Kirchoff prestack time sandstones as well as in Paleozoic car- the seaward extension of continental migration resulting in ninety-sixfold bonates, no Kimmeridgian source rock and transitional crust and discuss the data with excellent to fair quality data (the prolifi c source of Grand Banks) geodynamic evolution of the Labrador (depending on geological complexity). was penetrated, but source rocks with Sea. Data quality suffers on the shelf high TOC were drilled in Cretaceous Based on analysis of the potential break and upper slope whenever a and Lower Tertiary formations. Excel- fi eld data integrated with refl ection rough and-or hard water bottom is lent cores through reservoir and source lines we can extend the area viable for present. The regional dip grid is gener- rock intervals are available from the oil and gas exploration farther into the ally 30 km spaced and in places it gets C-NLOPB Core Repository. deep water where we can interpret a denser to 20 and 10 km spacing. Dip Well history reports and various thick, mainly Tertiary, sedimentary cover lines are tied by very long strike lines information (logs, check-shot surveys, over large swaths of transitional crust, that are denser on the shelf and 80 km tops, drillstem tests, etc.) are publicly containing peridotite ridges disposed apart on the slope. available from Canada-Newfoundland parallel to the Labrador coast.5 22 23 A denser grid was recorded over Labrador Offshore Petroleum Board Next: A look at the Hopedale basin’s structural North Bjarni and several other dis- (C-NLOPB) and from the Geological and tectonic evolution, petroleum system, and coveries. During 2005, GSI more than Survey of Canada (GSC) Basin web site exploration potential. ✦ doubled its Labrador Sea coverage and (www.gsca.nrcan.gc.ca/BASIN) extended the work north into the Saglek Potential fi eld data. A compilation of basin using the same acquisition pa- marine magnetic and gravity data is rameters and data processing sequence. available from GSC in both map and The author 35 Michael E. Enachescu The company plans more data acquisi- digital form. This dataset was used ([email protected]) is Husky tion (15,000 km) in the 2006 season. to correlate the tectonic and structural Energy Senior Fellow in Explo- Well data. A total of 21 wells were elements observed on the refl ection ration Geophysics at Memorial drilled in the Hopedale basin during data and estimate sediment thickness on University of Newfoundland, the late 1970s-early 1980s; only 19 are the margin.24 25 36 Satellite gravity is also St. John’s, and an advisor to Palo Alto Investors of Cali- classifi ed as exploration and two are available in the public domain. fornia. He has been involved delineation wells (Bjarni O-82 and Her- Potential fi eld data provided by the with major exploration drilling jolf M-92). Only 16 exploration wells GSC help to better estimate the com- programs in the Grand Banks, Scotian shelf and reached the planned exploration target. position of the numerous large rotated slope, Labrador Sea, Arctic, and Beaufort Sea. He Good electric and radioactive logs exist fault blocks and ridges that form the was a member of the regional mapping, discovery, and delineation teams and a contributor to the for most wells as well as good velocity prerift basement and are covered by Development Plan Applications for Terra Nova and information for seismic data correlation Early Cretaceous clastics and volcanics White Rose fi elds. He has worked in various basins and depth conversion. and draped by later sediments.5 in more than 20 countries. E XPLORATION & DEVELOPMENT

This is the second of two parts places highly interpretive refl ector due on the geology and potential of the to faulting; and c) Base Tertiary (Baylot Hopedale basin off Labrador, site of unconformity)—most continuous and several gas-condensate discoveries in correlatable horizon. A few intra-Ter- HOPEDALE BASIN—2 the 1970s-80s on the shelf. tiary markers are well expressed and in places show signifi cant amplitude Seismic data interpretation anomalies (Fig. 6). Interpretation of GSI seismic data Based on the interpretation of the in conjunction with marine potential prerift, synrift, and syndrift seismic fi eld data provided by GSC and infor- sequences, the area covered by the new mation from the 19 industry wells has seismic survey allowed the identifi cation of a number can be subdivid- of subsurface structural-physiographic ed from south to subdivisions including several deeper north into several Atlantic off Labrador poised sedimentary areas that contain attractive physiographic exploration targets (Figs. 3 and 5-10). and structural for modern exploration round Tertiary beds onlap the prerift base- sectors (Fig. 3): ment at a structural lineament (orange 1. Hawke basin. interrupted line on Fig. 3) situated This is a deepwater Mesozoic rift basin between 40 and 75 km from the shore- located east of the Cartwright arch and line, while the Mesozoic sediments in communication with deepwater Michael Enachescu onlap against a hinge zone or are fault Hopedale basin. The Cartwright Transfer Memorial University bounded 80-100 km away from the Fault Zone (CTFZ) that separates the St. John’s, Newf. shoreline. More than 10 km of Meso- two basins is evident in the potential zoic and Tertiary sediments are present fi eld data but is more elusive on the in the deeper parts of the basins, with seismic lines crossing this tectonic zone. the entire Mesozoic basinal area located An abrupt change in the direction of within C-NLOPB jurisdiction. main structural lineaments (ridges, Most of the wells have been drilled elongated fault blocks, and half gra- in a narrow strip of about 50 km, with bens) marks this transfer zone. locations selected on the shallower 2. Cartwright arch. This is a prerift emerging basement ridges with Creta- basement high area that is comprised ceous cover (Fig. 3). of a) a shelfal sector with thin Tertiary Basinwide seismic interpretation can sequences overlying strongly refl ective be done using the following markers: a) top prerift basement and b) an upper prerift basement (Labrador unconfor- slope sector marked by a down-to- mity)—excellent on the shelf and poor sea bounding fault, where numerous under deeper half-grabens and on the rotated basement blocks containing a slope; b) Mid-Cretaceous (Avalon un- stratifi ed Paleozoic section can be inter- conformity)—fair to excellent, and in preted. Another down-to-sea fault zone

HOPEDALE BASIN SEISMIC STRATIGRAPHIC SEQUENCES AND STRUCTURAL ELEMENTS Fig. 7 SW NE 9,000 10,000 11,000 12,000 13,000 14,000 15,000 16,000 17,000 18,000 19,000 20,000 21,000 22,000 23,000 24,000 25,000 26,000 27,000 28,000 29,000 30,000 30,000 30,000 30,000 30,000 30,000 30,000 30,000

1,000 05 Postrift Miles Km 2,000 Postrift basalt ﬂoods 08 3,000 Serpentinized peridotite ridges 4,000 Synrift 5,000 Prerift bsm 6,000

7,000

8,000 Synrift

9,000 Source: GSI E XPLORATION & DEVELOPMENT

marks the contact between Cart- HOPEDALE BASIN DEPOCENTERS AND FAULTED BASEMENT RIDGES Fig. 8 SW NE wright arch and 0 Hawke basin. 3. Hopedale basin 1,000 Postdrift 05Miles shelfal sector. This Km includes three 08 in-communication 2,000 Syndrift depocenters named Hinge here: a) Hamilton 3,000 Synrift subbasin, b) Har- Prerift rison subbasin, and 4,000 Complex bsm c) Nain subbasin. Rotated block They contain several almost parallel 5,000 lineaments of ridges, elongated Source: GSI fault blocks, and half grabens sepa- rated on strike by transfer faults and ac- ism may also play a role in the forma- Labrador included a Lower Paleozoic commodation zones. The offset on these tion of these large folds. period of basin formation and lime- transfer zones is 10-15 km. Only about a 7. Igneous extrusive province. The east- stone platform deposition, followed by dozen of the identifi ed highs have been ernmost part of the Nain and Harrison a long period of peneplanization.12 25 27 drilled; just a few of them are situated subbasins is occupied by an igneous Several episodes of Precambrian shield/ on the most prospective side of the shelf province formed by lava fl ows cover- Paleozoic platform crustal stretching where deeper source rock depocenters ing thinned continental crust. The fl ows took place fi rst as part a Mesozoic intra- are located. have been faulted and intruded by igne- continental network of basins and then 4. Hopedale outer shelf sector. The base- ous bodies. The succession is probably during slow emplacement of transi- ment plunges deep under the shelf; a of Late Cretaceous age and contains tional and oceanic crust in the southern large basinal trend exists followed by interbedded sedimentary successions. Labrador Sea. several high trending ridges. In certain Flows and emerging mantle derived It is possible that during the North parts of the basin a large anticlinal lin- serpentinite ridges are overlain by par- Atlantic rifting stage (Late Jurassic- eament is placed before the shelf break. allel layers of Tertiary sediments (Fig. 5). Early Cretaceous), when basins in the The shelf break is generally marked by No salt was observed on the seismic south underwent extension and when down-to-sea large faults affecting the data from the Canadian Labrador Sea. excellent source and reservoir rocks basement and its sedimentary cover. Amplitude anomalies and other vari- were deposited, parts of the Labrador/ 5. Hopedale upper slope. The upper slope ous direct hydrocarbon indicators are Greenland area had already started to of the Hamilton subbasin dips gentler observed throughout the Cretaceous- be subjected to sag or intracontinental and is occupied by a large Mesozoic Tertiary sequence.5 7 rifting with alluvial and lacustrine stage depocenter. Specifi c for this area is a de- deposition and even sea incursions tached Tertiary sedimentary cover form- Structural-tectonic evolution from the south. ing numerous fault-bounded rotated New regional seismic grids are es- Several arguments for the existence blocks and named here the Tertiary sential for geological description and of an incipient Jurassic marine seaway listric fault sector. investigation of petroleum potential of in the area have been presented by 6. Hopedale lower slope. The lower slope such a large offshore area. Danish geoscientists for the Greenland of this subbasin is occupied by a large The Labrador Sea is an Atlantic-type side;38 however no Jurassic rocks have Mesozoic depocenter that contains rifted margin and consists of Precam- been recovered up to now from the numerous structural features. In places, brian metamorphic basement, Paleo- Labrador Sea wells. The older synrift age due to reduced resolution these features zoic platform deposits, and faulted and identifi ed in the Hopedale basin Herjolf are hard to correlate. Structurally in- slightly folded mostly Early Cretaceous M-92 well is Berriassian.14 29 triguing is a cluster of Tertiary gravity synrift sedimentary rocks, all covered Signifi cant faulting and tectonic detachment folds that exists between by Late Cretaceous and Tertiary postrift subsidence took place during most of the Hamilton and Harrison subbasins in and recent glacial deposits (Fig. 5). the Cretaceous and lasted in some areas, this region. Transtension or shale diapir- The geologic evolution of southern up to Paleocene time, interrupted by and Leif sandstones HOPEDALE BASIN STRUCTURAL HIGHS WITH BJARNI AND YOUNGER SANDSTONES RESERVOIR POTENTIAL Fig. 9 (Figs. 5 and 7-10) SW NE 2,000 that have increas- 0Miles 6.2 ingly better reser- 010Km voir properties (up to 25% porosity). It is accepted that 3,000 the Hopedale basin had a high thermal gradient (2.7° C.) and that source 4,000 rocks started expel- ling wet gas after reaching depths of approximately 5,000 2,500 m probably Source: GSI in Late Oligocene- Early Miocene time.14 31 Accord- several episodes of thermal subsidence. III terrestrial organic content.39 The source ing to Fowler et al.,39 the oil window is The initial Early Cretaceous rifts formed interval is quite thick—more than 500 m deeper at 3,000-3,500 m. in several parallel strips, now located at the Herjolf well with TOC of 5%—and Numerous horst and fault blocks are close to the basin western margin, thickens in the numerous half grabens. seen on the seismic data, some forming on the middle of the shelf and in the After the Labrador/Greenland impressive exploration leads. Paleozoic downthrown side of a major fault that break-up, basin subsidence followed limestones and dolomites found on approximately marks the shelf break. with deposition of a thick, fi ne-grained the tops or sides of higher basement The amplitude of tectonic subsidence Markland formation that according blocks often have reservoir proper- varies across the basin, with the deepest to several authors includes high TOC ties. Drape over these high blocks and troughs existing east of the earlier well shales. The thick Markland shale also lateral pinchouts of Bjarni and younger locations. Some fault activity continues forms an excellent regional seal. Other sandstones are other possible hydrocar- during the continent break-up, mantle regional seals are in Eocene (Kenamu bon plays. On the outer shelf and slope, exhumation, and drifting. shales) and Oligocene (Mokami shales). listric faults and their associated rollover The Labrador rift system spreads are exploration targets (Fig. 10). Petroleum system from northern Orphan basin to the A proven petroleum system exists in Baffi n Island area. Continuous exten- Exploration potential the Hopedale basin, and expectations sion and minor transtension during the With a long intracontinental rift evo- are high for further gas discoveries. North Atlantic and Labrador rift phases lution, terrestrial and probably marine During the initial intracontinental resulted in a landscape of alternating interludes of source rock deposition extension, elongated rift valleys and the ridges and deep half grabens, mostly and numerous synrift and postrift struc- intervening ridges have received a ma- oriented NW-SE. Fault activity may have tural and stratigraphic trapping possibil- jor pulse of coarse clastics that formed lasted up to Early Tertiary in some areas. ities, the Hopedale basin has signifi cant the Bjarni formation. The most wide- To give an indication of the scale of undrilled petroleum potential. spread reservoir, Bjarni sandstone (12% these structural elements, the ridges and Only 16 wells have reached planned porosity and 100 md permeability) is troughs have lengths of more than 100 targets at signifi cant depths resulting thick in the grabens and thins on the km while individual subbasins extend in fi ve gas discoveries, with one, North ridges, showing syntectonic deposition. for more than 400 km (Figs. 3 and 4). Bjarni F-06 (Fig. 5), proving a giant Until recently, Cenomanian to Maas- There are several structural and gas discovery. An excellent success ratio trichtian Markland shales were considered stratigraphic trapping mechanisms for for a frontier basin of over 30% was the main source rock.3 6 14 31 32 Recent the Bjarni sandstone, which was de- recorded. Rock-Eval analysis of cuttings, geochemi- rived from both rift shoulders and from Improved seismic imaging and cal analysis of organic-rich interval, and intrabasinal ridges (Figs. 5 and 7-10). recording of data into deepwater areas organic petrology show that the best Three coarse clastic pulsations originat- is key to understanding the tectonic source rocks occur in the Early Cretaceous ing mostly from the western rift shoulder evolution and the exploration poten- Bjarni formation and contain mostly type formed the younger Freydis, Cartwright, tial of the Labrador basins. As proven E XPLORATION & DEVELOPMENT

by this study the continental crust HOPEDALE BASIN LARGE ROLLOVER ANTICLINES TRIGGERED BY LISTRIC FAULTS Fig. 10 SW NE extends more than 0

300 km from the 0Miles 3.1

Mesozoic onlap 1,000 05Km on basement and

this entire area 2,000 is prospective

for hydrocarbon 3,000 exploration (Figs.

5 and 7). 4,000 The most im-

portant reservoir 5,000 in the basin is the

Bjarni sandstone, 6,000 and this has been the most success- Source: GSI ful play in the basin. The un- biodegraded oil encountered at North trial dominated source rock with some It is encouraging that gas prospects Leif I-05 shows immaturity,39 but more marine infl uence. are now in the drilling inventory of mature source rock and reservoired oil Several large anticlinal features are some of the operators, and research may exist in deeper parts of the basin. located under the shelf break area. These into ways to monetize the stranded The Top Bjarni formation (Avalon can be hydrocarbon sourced from both gas resource of the Jeanne d’Arc and unconformity) is a good quality marker the western and eastern depocenters. Hopedale basins is ongoing. Advance- that can be mapped now with relative Whether oil prone Jurassic source ments in seismic acquisition and tech- confi dence east of the Bjarni fi eld and rocks exist in these deeper undrilled niques coupled with regional geological North Leif lineament into deep water. depocenters remains to be proven. studies are key to successful drilling of Younger sandstone with reservoir prop- Increased exploration activity has taken high-risk, high-reward frontier areas erties has been deposited in the basin place across the sea on Greenland’s such as the Hopedale basin. during the Neogene uplift of the basin continental margin where indications of Important improvements in the fl ank (Labrador Peninsula), and prob- older sequences, including Late Juras- offshore regulation regime of the ably turbidites have been accumulated sic source rocks, have been observed in Newfoundland and Labrador E&P on the slope and in deepwater, a play outcrop and on seismic data. were recently taken by the federal and that is yet undrilled in the Hopedale While exploration for offshore oil in provincial governments. One excellent basin or anywhere on the Grand Banks Newfoundland and Labrador has been initiative that will considerably reduce and Labrador slope. ongoing for over 40 years, no system- the overall cost of drilling is to intro- The Paleozoic “basement” sediments atic effort has yet been undertaken to duce discretionary requirements related cannot be written off as exploration fi nd natural gas. As it stands the almost to fl ow testing of the fi rst well drilled targets, as two large gas discoveries 10 tcf of recoverable gas that has been on a new hydrocarbon prospect.40 have been made in the carbonates. The discovered is a byproduct of oil explo- The earlier Hopedale basin gas fi nds Gudrid discovery (924 bcf recoverable) ration. and eventual new large discoveries may tested 20 MMcfd, and the Hopedale dis- With the recent increases in North be utilized in the future for: covery (105 bcf recoverable) tested 20 American natural gas prices and the ob- • Smelting and providing electricity MMcfd from a Paleozoic dolomite. This vious need to develop new supply areas, to Labrador’s emerging nickel industry. play should be particularly found in the serious discussions have begun on ways • Supplementing Labrador hydro- southern part of the basin. and means to bring the Newfoundland electricity exported to North America. The Bjarni and Markland shales deep and Labrador natural gas to market. • Supplying gas to the Canadian hydrocarbon kitchen existing on the Possible modes of transportation under Atlantic provinces and US using any of outer shelf seems to be the source of consideration include pipeline, com- the CNG, GTL, or LNG technology. the gas fi lling the fi ve discovered accu- pressed natural gas, LNG, and gas to In spite of harsh environment the mulations. Another, probably Markland liquid tankers. Oil is currently being Labrador fi elds are signifi cantly closer to shale fi lled depocenter, exists in front of transported from the Grand Banks fi elds the East US or central Canadian markets the slope. The Markland is also a terres- by shuttle tankers. than many of the alternatives. Opera- tions on the Grand Banks have shown made it less attractive when cheap gas 2006, available at http://www.cnopb. that iceberg management using towing was widely available elsewhere. Higher nfnet.com/publicat/other/sch_well/ by standby vessels is effective and eco- prices, new technologies, and political longind.htm nomic, particularly as such vessels must considerations of the alternatives (LNG 5. Enachescu, M., Hogg, J., and Ke- be onsite in support of drilling opera- for example) are changing the equation. arsey, S., “The Hopedale Basin, Offshore tions in any case. And it can be also said The area’s proven resource is substantial Labrador, Canada: Stranded Gas and that much greater transport distances and the potential resource is enormous. Remaining Petroleum Potential,” AAPG (such as Siberia to Western Europe) and No doubt challenges to explora- Convention, Houston, 2006. comparable logistical challenges are be- tion and production of the hydrocar- 6. Enachescu, M., and Fagan, ing met in other areas of the world. bons from Labrador Sea remain great P.,“Newfoundland’s Grand Banks pres- and many, but the demand for cleaner ents untested oil and gas potential in The big picture energy, increased commodity prices, eastern North America,” OGJ, Feb. 14, The Hopedale basin had a complex improved government regulations, 2005a. geological evolution, starting with in- large size of the prize, technological 7. Enachescu, M., and Fagan, P., tracontinental rifting in the Early Creta- advancements, and relative proximity “Newfoundland and Labrador Call ceous (possible Jurassic?) and followed to the largest world markets will place for Bids NF05-01, Parcels 1, 2 and 3, by signifi cant subsidence and accumula- the Hopedale basin and the rest of the Regional setting and petroleum geology tion of passive margin sediments. Labrador shelf clearly on the industry evaluation,” Government of New- Large gas discoveries were made radar screen in the coming years. foundland and Labrador, Department during the 1970s exploration cycle in of Natural Resources, 2005b, 35 p., 27 the shallow Labrador Sea, proving the Acknowledgments fi gs.; also available at http://www.gov. presence of a rich petroleum system. Davey and Paul Einarsson at GSI for nl.ca/mines&en/oil/call_for_bids_ No follow-up drilling has taken place, seismic data donation to Memorial nf04_01.stm and only during the past few years has University and permission to show 8. Enachescu, M.E., and Hogg, J.R., exploration returned with the acqui- the Hopedale basin lines. John Hogg “Exploring for Atlantic Canada’s next sition of modern, high quality 2D at ConocoPhillips, Phonse Fagan at A.J. giant petroleum discovery,” CSEG Re- seismic data. Fagan Consulting/MUN; Sam Nader, corder, Vol. 30, No. 5, 2005, pp. 19-30. While numerous drillable structures consultant, and Steve Kearsey at MUN/ 9. Enachescu, M.E., “Doing business have been identifi ed in the past, all located Husky Energy for collaboration on in the Atlantic offshore: Essential infor- in the inner shelf area, new seismic data the Labrador Sea project. J. Wright, H. mation every explorer needs to know,” allow the extension of the geophysical Miller, I. Atkinson, M. Martin, V. Hardy, Atlantic Business Magazine, Vol. 15, No. study into outer-shelf and deepwater, and S. Schwartz, and A. Dearin at Memorial 4, 2004, pp.12-22. show several previously unknown large University; D. Hawkins, T. Bennett at 10. Enachescu, M., Fagan, P., and depocenters and anticlinal features, some C-NLOPB; M. Fowler, S. Dehler at GSC Smee, G., “Exploration opportunities of which are accompanied by amplitude Atlantic; W. Foote, L. Hicks, and L. Stead abound in Orphan basin off Newfound- anomalies. at the Government of Newfoundland, land,” OGJ, Aug. 5, 2005. The Bjarni sandstone is recognized and D. Chafe at ABM. ✦ 11. Enachescu, M., Fagan, P., and as the main reservoir target, but quality Smee, G., “Orphan basin set for multi- reservoirs have been encountered in References year exploration program,” OGJ, Aug. prerift, synrift, and syndrift sequences. 1. Enachescu, M.E., “Offshore New- 12, 2005b. The Bjarni formation also contains in- foundland and Labrador: An Emerging 12. Fagan, P., and Hicks, L., “Call for terbedded shales with terrestrial organic Energy Powerhouse,” Offshore Technol- Bids NL05-01, Parcels four to seven,” content that constitute an excellent type ogy Conference Paper #17570, Hous- Government of Newfoundland and Lab- III source rock. Source rocks are also ton, 2005a, pp. 1-8. rador, Department of Natural Resources, present in Late Cretaceous and Early 2. Enachescu, M., “Energy In-Wait- 2005, 15 p., 12 fi g.; also available at Tertiary, while the occurrence of a Late ing: Discovered Reserves and Explora- www.gov.nl.ca/mines&en/oil/ Jurassic marine source is still unproven tion Potential for Gas in Newfoundland 13. Balkwill, H.R., “Labrador Basin: on the Canadian side of the rift but has & Labrador,” NOIA Fall Seminar, St. structural and stratigraphic style,” in been documented on the conjugate John’s, Oct. 26, 2005. Beaumont, C., and Tankard, A.J., eds., margin off west Greenland. 3. Klassen, H.J., “Labrador Shelf “Sedimentary basins and basin-forming The discovered gas has remained Petroleum System: A Review, Offshore mechanisms,” CSPG Memoir 12, 1987, stranded due to its more remote loca- Newfoundland and Labrador, Canada,” pp. 17-43. tion and some logistical challenges AAPG Convention, Calgary, 2005. 14. Geological Survey of Canada, (such as iceberg management) that 4. C-NLOPB, “Schedule of Wells,” “East Coast Basin Atlas Series, Labrador E XPLORATION & DEVELOPMENT

Sea,” (compiled by S. Bell), 1989. tectonic history,” PhD thesis, Ohio State Exploration History—Gas Potential,” 15. Balkwill, H.R., McMillan, N. J., University, 1999. NOIA Seminar, 2003. MacLean, B., Williams, G.L., and S.P. 23. Chalmers, J.A., and Pulvertaft, 32. Meneley, R.A., “Exploration His- Srivastava, “Geology of the Labrador T.C.R., “Development of the continental tory of Frontier Basins in Canada—Ig- Shelf, Baffi n Bay and Davis Strait,” in margins of the Labrador Sea—a review,” nore It At Your Peril,” abs. and presenta- Keen, M.J., and Williams, G.L., eds., in Wilson, R.C.L., Whitmarsh, R.B., Tay- tion, CSPG/CSEG Convention, 2003. “Geology of the continental margins of lor, B., and Froitzheim, N., eds., “Non- 33. Umpleby, D.C., “Geology of the eastern Canada,” Geology of Canada, Volcanic Rifting of Continental Margins: Labrador Shelf,” Geological Survey of Vol. 2, 1990, pp. 293-348. A comparison of Evidence from Land Canada, Paper 79-13, 1979. 16. Grant, A.C., and McAlpine, K.D., and Sea,” Geological Society, London, 34. Drummond, K.J., “East coast “The continental margin around New- Special Pub. 187, 2001, pp. 77-105. gas—the big picture,” CERI Eastern Ca- foundland,” in Keen, M.J., and Williams, 24. Louden, K., “Tectonic evolu- nadian Natural Gas Conference, Halifax, G.L., eds., “Geology of the Continental tion of the east coast of Canada,” CSEG NS., 1998. Margin of Eastern Canada,” Geological Recorder, 2002, pp. 37-48. 35. Oakey, G.N., and Dehler, S.A., Survey of Canada, Geology of Canada 25. Williams, H., Dehler, S.A., Grant, “Atlantic Canada Magnetic Map Series: Vol. 2, 1990, pp. 239-292. A.C., and Oakey, G.N., “Tectonics of At- Grand Banks and surrounds,” Geologi- 17. Dehler, S.A., and Keen, C.E., lantic Canada,” Geoscience Canada, Vol. cal Survey of Canada, Open File 1816, “Effects of rifting and subsidence on 26, No. 2, 1999, pp. 51-70. 2004, 1:1 500 000. thermal evolution of sediments in 26. Cooper, M., Weissenberger, J., 36. Oakey, G.N., and Stark, A., “A Canada’s east coast basins,” Canadian Knight, I., Hostad, D., Gillespie, D., Wil- digital Compilation of Depth to Base- Journal of Earth Science, Vol. 30, 1993, liams, H., Burden, E., Porter-Chaudhry, ment and Sediment Thickness for the pp. 1,782-98. J., Rae, D., and Clark, E., “Basin Evolu- North Atlantic coastal Land Areas,” 18. Keen, C.E., Potter, P., and Sriv- tion in Western Newfoundland: New Geological Survey of Canada Open File astava, S.P., “Deep seismic refl ection Insights From Hydrocarbon Explora- report No. 3039, 1995. data across the conjugate margins of tion,” AAPG Bull., Vol. 85, No. 3, 2001, 37. Chalmers, J.A., and Laursen, the Labrador Sea,” Canadian Journal of pp. 393-418. K.H., “Labrador Sea: the extent of con- Earth Sciences, Vol. 31, 1994, pp. 192- 27. Atkinson, I., and Fagan, P., tinental crust and the timing of the start 205. “Sedimentary basins and hydrocarbon of sea-fl oor spreading,” Marine and 19. Chian, D., Keen, C., Reid, R., and potential of Newfoundland and Lab- Petroleum Geology, Vol. 12, 1995, pp. Louden, K.E., “Evolution of nonvolca- rador,” Government of Newfoundland 205-217. nic rifted margins: New results from and Labrador Report 2000-01, 2000, 38. Bojesen-Koefoed, J.A., Nytoft, the conjugate margins of the Labrador also available at http://www.gov.nl.ca/ H.P., and Christiansen, F.G., “Age of oils Sea,” Geology, Vol. 23, No. 7, 1995, pp. mines&en/oil in West Greenland: Was there a Mesozoic 589-592. 28. Hall, J., Louden, K.E., Funck, T., seaway between Greenland and Cana- 20. Srivastava, S.P., and Verhoef, J., and Deemer, S., “Geophysical character- da?,” Geological Survey of Denmark and “Evolution of Mesozoic sedimentary istics of the continental crust along the Greenland Bull. 4, 2004, pp. 49-52. basins around the North Central Atlan- Lithoprobe Ecsoot transect: a review,” 39. Fowler, M.G., Stasiuk, L.D., and tic: a preliminary plate kinematic solu- Canadian Journal of Earth Sciences, Vol. Avery, M., “Potential Petroleum Systems tion,” in Parnell, J., ed., Basins of the 31, 2002, pp. 569-587. in the Labrador and Baffi n Shelf Areas, Atlantic Seaboard,” Petroleum Geology, 29. McWhae, J.R.H., Elie, R., Laugh- Offshore Eastern Canada,” abs. GAC/ Sedimentology and Basin Evolution, ton, K.C., and Gunther, P.R., “Stratig- MAC/CSPG/CSSS Conference Halifax Geological Society Special Publication raphy and Petroleum Prospects of the 2005, NS and https://www.gac.ca/ No. 62, 1992, pp. 397-420. Labrador Shelf,” Bull. of Canadian Petro- ANNMEET/2005Abstracts.html. 21. Srivastava, S.P., and Roest, W.R., leum Geology, Vol. 28, No. 4, 1980, pp. 40. Government of Canada, “Regu- “Extent of oceanic crust in the Labrador 460-488. lations Amending the Newfoundland Sea,” Marine and Petroleum Geology, 30. McMillan, N.J., “Canada’s east Offshore Petroleum Drilling Regula- Vol. 16, 1999, pp. 65-84. coast: the new super petroleum prov- tions,” Canada Gazette, Vol. 140, No. 15, 22. Roman, D.R., “An integrated ince,” Technology, 1982, pp. 95-109. 2006. geophysical investigation of Greedland’s 31. De Silva, N., “Offshore Labrador: