Natural Gas Exploration Potential in the Alaskan Arctic

Transcription

1 Natural Gas Exploration Potential in the Alaskan Arctic Bob Swenson State Geologist Dave Houseknecht - USGS Gil Mull photo

2 Arctic Alaska - Key Geologic Features

3 Stratigraphy Known & Potential Source Rocks < Paleogene Canning < Seabee < GRZ (HRZ) < Lower Kingak < Shublik < Lisburne (Kuna) < Kekiktuk

4 Arctic Alaska Source Rock Systems

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6 Arctic Alaska - Key Geologic Features Cross Section

7 Overview of Regional Geology

8 Arctic Alaska Generalized Potential for Oil and Gas

9 Foothills Drilling and Gas Occurrences Regional Section Discovered gas accumulations in foothills Well with numerous or strong-fair gas shows Well with few or minor gas shows

10 Foothills Cross Section - Oil and Gas Shows West East Paul Decker, DOG

11 Source Rock & Hydrocarbon Characterization Synthesizing a decade of organic geochemical analyses and integrate with regional geologic data Characterization of hydrocarbon occurrences Source Rock Facies, Otuk Formation, Tiglukpuk Creek Gas sample, July 2005 Nanushuk Fm. on Colville R.

12 Reservoir Quality 1

13 Reservoir quality studies Continued sampling for porosity and permeability Correlation of reservoir quality with depositional environment, petrology, and diagenesis Fracture analysis and reservoir characteristics Skimo Anticline Overturned Forelimb n = 5 m = 9 n = 13 m = 12 n = 3 m = 1 n = 19 m = 27 n = 7 m = 8 n = 14 m = 24 n = 9 m = 12 n = 6 m = 14 n = 7 m = 4 n = 15 m = 11 n = 14 m = 20 n = 11 m = 10 n = 12 m = 9 n = 14 m = 7 Porosity (%) Porosity (%) vs. Permeability (md) North Slope Foothills Tuluvak ss Schrader Bluff Nanushuk Gilead ss Fortress Mtn Cobblestone ss Okpikruak Otuk Fm Siksikpuk Radius = 0.25 m n = 15 m = 14 Fortress Mean Density Mtn. Formation = 30.9 per m Mean Intensity = 10.9 m/m 2 Mean Length = 0.45 m Permeability (md) Lisburne Limestone P. Decker R. Reifenstuhl

14 A A

15 Regional Burial and Exhumation History of the Southern Colville Basin Building balanced structural cross sections Fission track data confirm zone of low thermal maturity Evidence for mid-cretaceous syntectonic sedimentation Constraining timing of key events affecting petroleum system A A Preliminary structural cross section, Siksikpuk River Transect R. Swenson

16 Conventional Exploration Play Types Anticline Normal Fault Reservoir Rock Gas Oil Cap Rock Reservoir Rock Source Rock Reservoir Rock Source Rock Cap Rock Oil Gas Cap Rock Reservoir Rock Source Rock Stratigraphic Thrust Fault Reservoir Rock Cap Rock Oil Source Rock Gas Cap Rock Unconformity Reservoir Rock Source Rock Oil Cap Rock Gas Gas Oil Cap Rock Reservoir Rock Source Rock Oil and Gas Trapping Mechanisms

17 Kavik River Gas Field KAVIK Modified from Grow and others, 1998 Gas Field B5 B4

18 Foothills Structural Plays Seismic Interpretation Public seismic lines EP81-27S, -27C, & -27N PLDecker, Alaska Division of Oil & Gas miles Kavik structure

19 Brooks Range Geologic Mapping Regional Geologic & Resource Analysis USGS Energy Program

20 USGS Role

21 Proved Gas Reserves

22 2006 Proved Gas Reserves: Top 15 States OCS Region Public-Domain Data *AK-DOG estimate; **difference between EIA state total and AK-DOG Cook Inlet estimate

23 Known Gas Accumulations in Arctic Alaska Burger NPRA

24 Alpine Play in NPRA More Gas than Oil??? 400 bopd +6.8 mmcfpd 60 API GOR 16, bopd mmcfpd 55 API GOR 10,200 ~500 mmbo 40 API GOR 840 No Gas Cap No Water Leg

25 Burger Prospect Nanushuk Fm. 36 ft gas pay MMS Resource Estimates (2000) (Craig & Sherwood, 2004) Kuparuk Fm. equiv. 67 ft net sandstone; Top Overpressure Ave. Por. 26.4% Ave. Perm. 312 md

26 USGS Petroleum Resource Assessments Results Methodology Geology

27 Assessment Methodology Geologic Basis

28 Undiscovered Conventional Gas Potential

29 Potential for Undiscovered Petroleum in Arctic Alaska Resource Estimates: Mean (F95 F05) Sources: OCS estimates from MMS; onshore & state waters estimates from USGS

30 Estimates of Gas Accumulation Sizes

31 Economic Analysis Simulates Exploration and Development

32 Central North Slope Assessment Area Economic Analysis based on Three Sub-Areas

33 Costs Included in Economic Analysis Exploration Geology & Geophysics Exploration Drilling (including all preparation & mobilization) Development Construction of production pads Development wells Construction of processing facilities Production All operational costs Abandonment costs Transportation New pipelines from fields to gas-processing plant near PB Pipeline tariff to market in lower-48 Taxes All applicable Federal and State Return on Investment 12% rate of return Analysis conducted in 2005 using 2003 dollars & costs

34 Central North Slope Economically Recoverable Gas Undiscovered, Non-Associated Natural Gas Resources

35 Conventional and Unconventional Accumulations Prudhoe Bay Gubik NPRA

36 Undiscovered, Total Gas Resources of the U.S. Wyoming Arctic Alaska total = 227 TCF

37 Wyoming Gas Reserves & Production History

38 Arctic Alaska Exploration Maturity Prospective area onshore & offshore shelves ~ 150,000 mi 2 (~400,000 km 2) Fewer than 500 exploration wells (red dots) Arctic Alaska Exploration Well Density ~3 wells/1,000 mi 2 Prudhoe Bay Burger Wyoming Exploration Well Density ~250 wells/1,000 mi 2 Entire state of Wyoming ~100,000 mi 2 (~250,000 km 2 ) Petroleum-prospective area ~75,000 mi 2 (~250,000 km 2 ) ~19,371 exploration wells Wyoming natural gas (EIA data): Cumulative Production 21 TCF ( ) Proved Reserves ~24 TCF (2006)

39 Wyoming Ten Largest Gas Fields

40 Unconventional Gas Resources (continuous resources) Coalbed Gas Overpressured, Basin-centered Gas Roberts USGS Gas Hydrates Houseknecht USGS Collett USGS

41 Overpressured Natural Gas in the Colville Basin Brookian strata (Torok & Fortress Mountain Formations) Potential reservoirs mostly low-permeability sandstone Shale reservoirs possible Is this a low-permeability basin-centered gas accumulation?

42 Overpressured Natural Gas in the Colville Basin Beaufortian Strata (Kingak Shale) Potential reservoirs mostly shale Low-perm sandstone reservoirs possible Is this a low-permeability basin-centered gas accumulation?

43 Overpressured Natural Gas in the Colville Basin

44 Gas Hydrate Stability

45 North Slope, AK BP Exploration Alaska Arctic Slope Regional Corporation Ryder Scott Company RPS - APA Energy Interpretation Services, Inc. Doyon Drilling, Inc. ReedHycalog (Corion) Drill Cool Systems, Inc. Omni Laboratories Schlumberger MI Swaco Mallik 98/02/07/08 99/00 MITI 05 Toai-oki Kumano-nada ODP 204 IODP 311 ODP 164 UBGH X01 Gulf of Mexico JIP Georgia Tech Rice Univ Scripps Inst. Ocean Woods Hole Oc Inst International Gas Hydrate Research India Binghamton University Colorado School of Mines Fugro-McClelland, Inc. GAIL Ltd Geological Survey of Canada Geotek Ltd Idaho National Laboratory Integrated Ocean Drilling Program JOI, Inc. Lamont-Doherty Earth Obs Ministry of Petrol and Natural Gas McGill University DOE-NETL Natl Inst of Oceanography Natl Inst of Ocean Tech Ocean Drilling Limited Oregon State University OIL India Ltd Pacific Northwest Natl Lab Reliance Industries Limited Schlumberger Technical University of Berlin Texas A&M University University of California, SD University of Cardiff University of New Hampshire Universität Bremen University of Rhode Island U.S. Department of Energy U.S. Geological Survey U.S. NSF Woods Hole Ocean Inst GMGS X01

46 GH-Saturated conglomerate NW Canada (Mallik) Gas Hydrate sample 2002 Mallik Gas Hydrate Production Test A Mallik GH-saturated turbidite Nankai trough B GH-saturated fractured clays Bay of Bengal The Gas Hydrate Resource Pyramid A B C D C Massive GH seafloor mound Gulf of Mexico D increasing in-place decreasing reservoir quality decreasing confidence in resource estimates increasing technical challenges and likely decreasing % recoverable

47 Gas Hydrates Northern Alaska Zone of Potential Hydrate Stability Information from Tim Collett (USGS)

48 Known Gas Hydrate Accumulations Tarn trend: 60 tcf hydrate gas Eileen trend: 44 tcf hydrate and associated free gas Known gas hydrate accumulations (blue) and hydrate-associated free gas accumulations (orange) in the vicinity of the major North Slope oil fields (green). The USGS estimates up to 100 tcf in place of hydrate in the Eileen and Tarn trends combined. From T.S. Collett, 10/01 and Hunter and Collett, (2004). Modified from T.S. Collett, USGS Open File Report

49 BP DOE Mt Elbert-01 MDT C FBHP Hydrate Stability FBHT 35.0 FBHP, psi 1000 Hydrate Stability FBHT-3 F FBHT 34.0 FBHT, F Test Time, hours 49

50 Wyoming Gas Reserves & Production History

51 Thank you for your attention!