INDICATIONS FOR EFFECTIVE PETROLEUM SYSTEMS IN BOWSER BASIN: IMPLICATIONS FOR PETROLEUM EXPLORATION AND RESOURCE ASSESSMENTS

K.G. Osadetz, C. A. Evenchick, F. Ferri, L. D. Stasiuk and N. S. F. Wilson Geological Survey of Canada and B.C.E.M. New Ventures Branch N C R e C s

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Presentation Outline

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Review the Revised Thermal Maturity model for Bowser Basin.

Indicate the relative location of Shows, Stains and Seeps.

Discuss the Composition and Sources of Stains.

Deep Gas Province Characteristics.

Indicate Exploration Implications of the new data and interpretations.

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Complicated Patterns of thermal maturation and maximum temperatures indicate that large areas of the Bowser Basin are in the oil and gas windows.

K BP JK B T JK B E JK B T JK B MC

GOOD

JK B S Q JK B T JK B E JK B T JK B S JK B T JK B GG K TC Q JK B T JK B S JK B RA JK B JC K TC K TC JK B T

H IG

JK B MC BP

H

JK B E

ES

JK B E K TC

T

K BP JK B T JK B S JK B RA JK B RA JK B GG Q

GOOD

JK B MC JK B RA

UNCERTAIN

Q JK B MC JK B RA Q JK B GG JK B MC Q JK B S JK B MC

LOW

JK B T Q JK B MC JK B JC JK B MC Q K TC K TC K BP K BP

Revised Thermal Maturity Model

K K

CRETACEOUS Sustut Group

Brothers Peak Formation Tango Creek Formation

MIDDLE JURASSIC TO MID-CRET.

Bowser Lake Group

K B Devils Claw Formation JK B Jenkins Creek assemblage (nonmarine) JK B Groundhog-Gunanoot assemblage (deltaic) JK B S Skelhorne assemblage (deltaic) JK B E Eaglenest assemblage (deltaic) JK B Muskaboo Creek assemblage (shallow marine) JK B T Todagin assemblage (slope) JK B Ritchie-Alger assemblage (submarine fan)

EARLY MIDDLE JURASSIC AND OLDER

upper Hazelton Group clastic rocks Hazelton Group volcanic rocks undivided Hazelton Group and lower

PALEOZOIC

Permian carbonate Devonian

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Shows, Stains

0 kilometres

and Seeps

K BP K TC JK B E JK B T •

Shows, stains and possible seeps occur within a region of over 10,000 km2.

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The are many other petrographic indications for bitumen.

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There is an unexplored region the size of a European country in our backyard.

JK B RA JK B RA JK B E JK B T JK B MC

GOOD

JK B S Q JK B T JK B T Q JK B S JK B T JK B GG JK B GG

GOOD

JK B MC JK B RA Q JK B RA JK B S JK B T Q JK B GG JK B MC Q JK B JC K TC JK B RA K TC JK B MC JK B MC JK B T

H IG

JK B MC BP

H

JK B E

ES

JK B E K TC

T

K BP JK B S

LOW UNCERTAIN

Q Q JK B T JK B S JK B MC JK B JC JK B MC JK B T Q K TC

Relative to

K TC K BP K BP

Thermal Maturity

K K

CRETACEOUS Sustut Group

Brothers Peak Formation Tango Creek Formation

MIDDLE JURASSIC TO MID-CRET.

Bowser Lake Group

K B Devils Claw Formation JK B Jenkins Creek assemblage (nonmarine) JK B Groundhog-Gunanoot assemblage (deltaic) JK B S Skelhorne assemblage (deltaic) JK B E Eaglenest assemblage (deltaic) JK B Muskaboo Creek assemblage (shallow marine) JK B T Todagin assemblage (slope) JK B Ritchie-Alger assemblage (submarine fan)

EARLY MIDDLE JURASSIC AND OLDER

upper Hazelton Group clastic rocks Hazelton Group volcanic rocks undivided Hazelton Group and lower

PALEOZOIC

Permian carbonate Devonian

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Locations of Shows, Stains and Seeps

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Oweegee Dome, the site of the two Ritchie wells, one with by-passed pay.

Tatogga Lake, the site of a locally reported, but unconfirmed gas seep.

Tsatia Mountain, A breeched oil field in Bowser Lake Group sourced from Stikinia.

Confluence of Buckinghorse Creek and Spatsizi River, An oil stain in Eaglenest assemblage (deltaic) BLG in the footwall of the Crescent Fault.

Triangle Zone, An oil stain in Tango Creek Formation Sandstones in the roof of the Triangle Zone north of Cold Fish Lake.

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Oweegee Dome and Ritchie Wells:

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Two Ritchie wells down-plunge on the SE of the culmination,

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By-passed gas pay, Favourable cuttings gas log, Live Oil Stains, Fetid, bituminous bioclastic rudstone

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Conglomeratic potential reservoirs.

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Probable By passed gas pay, untested

Oweegee Dome: Amoco Ritchie a-3-J/104-A-6: By-passed Gas Pay?

Gamma Ray – Neutron SP – Resistivity 2700 feet

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Dry and wet gas in cuttings <2600’,

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Gas Detector >40 units, compared to background (10 20 units).

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Conglomeratic Member

Oweegee Dome: Conglomeratic Members of the Hazelton Group

Highway Thick (~200 metres), rudaceous and arenaceous potential reservoirs lacking volcanic clasts.

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Tatogga Lake Resort: Possible Seep

(NAD 27, UTM Zone V, E440380 N6396997 ~+825m elev.) crashed aircraft

• • •

Persistent: Althaus’s had been aware of the seepage in the same location for about ten years; Of noticeable volume: They had observed anomalous freezing and melting behaviour in the lake over the possible seepage identical to petroleum gas seepages elsewhere, and; Flammable. Mr. Althaus recounted how he had once ignited gas from the seepage N C R e C s

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Tsatia Mountain: Residual Oil Stain in Muskaboo Creek Assemblage

02-OE-36 (NAD 27, UTM Zone V E442468 N6380068) A complicated residual stain, ~35 – 45 API, in shoreface sandstones within a breeched field that pre-dates the pore-filling silica cement.

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Tsatia Mountain: Residual Oil Stain in Muskaboo Creek Assemblage

C34 hopane prominence indicates a probable carbonate source rock deposited in a mesohaline to hypersaline depositional environment.

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Tsatia Mountain: Residual Oil Stain in Muskaboo Creek Assemblage

C 28 << C 29 Steranes The composition of this oil suggests that it was derived from an Upper Paleozoic to Early Mesozoic marine, carbonate source rock deposited in a hypersaline to mesohaline depositional environment, probably lying within the Stikine Assemblage.

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Todogin Assemblage Slope and Basin Floor Turbidite Channel Complexes: A Possible Stratigraphic Play, Visible From Tsatia Mountain N C R e C s

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Triangle Zone: Tango Creek Fm. Stain

104H10 E511100 N6396070 N C R e C s

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Traces of blue fluorescing, high maturity petroleum inclusions,~ >>45 API, in fractured quartz,

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Possibly biodegraded blue and yellow oil globules, and

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Degraded bitumen within pores in calcite and as minor inclusions within calcite Occurs within the roof of the Triangle Zone in Tango Creek Fm.

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Triangle Zone: Tango Creek Fm. Stain

C 28 :C 29 < 1 104H10 E511100 N6396070

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Probably derived from a Jurassic Lower Cretaceous, euxinic marine clastic source rock, possibly the “Pajama Beds”.

Pr/Ph =0.69

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Confluence of Buckinghorse Creek and Spatsizi River: Eaglenest Assemblage (Deltaic) 104H10 E525670 N6366320

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A visible bitumen stain that could be extracted and characterized,

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Occurs in Deltaic BLG strata in the Footwall of the Crescent Fault (major thrust) on the southeast side of the Griffith Creek Fault (oblique), and

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Lies west of the Triangle zone.

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Confluence of Buckinghorse Creek and Spatsizi River: Eaglenest Assemblage (Deltaic) Probably derived from a Jurassic-Lower Cretaceous, euxinic marine clastic source rock, possibly the “Pajama Beds”.

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DEEP GAS: DEFINITIONS

• From geologic perspective deep resources occur below 15,000 ft.

• Operationally, deep is “relative” based on geologic and technologic knowledge.

• Deep Anadarko vs deep San Juan.

• Ultra-deep resources generally defined as those resources below 25,000 ft.

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HISTORICAL PERSPECTIVE

(Data from IHS Energy Corp, Jan 1999)

• 20,715 wells drilled >15,000 ft in U.S. but <1% of total wells drilled.

• 11,522 producing wells.

• 5,119/11,522 producing from FMTD.

• First deep discovery in 1956 Carter-Knox field Anadarko basin.

• Record-breaking deep drilling in Anadarko basin in 1970s-80s.

• Lone Star Bertha Rogers (TD 31,236) • Lone Star Earnest Baden (TD 30,050)

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DEEP WELL STATISTICS

• In 15-16 ft K interval, gas wells 68% to more than 90% in 22-23,000 ft interval – overall 76% gas • Rocky Mt region has highest % of deep oil wells (197/298 > 15,000 ft) • 52 ultra-deep wells in U.S mostly in Anadarko (19) and Permian (21) basins • Ellenberger tops with 15 penetrations

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DEEP GAS PRODUCTION: U.S.A

• According to GTI production data (Hill, 2001) Lower 48 U.S. deep production was 1.5 Tcf in 1999 • Regional shifts: from Permian to Gulf Coast

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Summary

Effective Sources and Changing Concepts; Structural and Stratigraphic Traps; Favourable Timing and History; Shows, Stains and Seeps; = OPPORTUNITY N C R e C s

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Recommendations

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Both Oil and Gas prospects exist, even below BLG.

At least two effective petroleum systems are operating in the basin.

One petroleum system has sources in the Stikine Assemblage that underlies the Hazelton Group.

The other petroleum system has sources probably in the Hazelton Group, but Bowser Lake and Sustut Group sources may also exist, particularly in lower BLG.

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Recommendations

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There is petroleum in this basin, the only question is in what size are the accumulations.

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Some stains might indicate prospects directly (Tsatia Mtn.).

“Deep Gas” plays may exist in those regions now considered least prospective.

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Much more work is required.

There is an opportunity for Industry to become involved with much lower risks than previous analysis suggested, especially compared to other Intermontane or Frontier Basins.

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