USGS: 2.4 tcf of gas beneath eastern >Oregon, Washington

Nov. 17, 2008
An estimated 2.4 tcf of natural gas and 9.8 million bbl of natural gas liquids lie beneath eastern Oregon and Washington, the US Geological Survey reported.

An estimated 2.4 tcf of natural gas and 9.8 million bbl of natural gas liquids lie beneath eastern Oregon and Washington, the US Geological Survey reported.

The figures are mean estimates of undiscovered gas resources beneath 60,000 sq miles of the two Pacific Northwest states. A USGS team conducted a geology-based assessment using the total petroleum system approach, the US Department of the Interior agency said. The work was done in 2006, but specific figures were not released until recently, a spokeswoman said.

The report said the Columbia River Basalt Group, 4,000-18,000 ft in thickness, overlies the Cretaceous Tertiary total petroleum system in the area east of the Cascade Mountains. Volcanic rock units from the Miocene epoch through the Quaternary period overlying the province’s most southern part had previously limited knowledge of that area’s stratigraphy and structural geology, USGS said.

In the hypothetical Columbia basin assessment unit (AU), which covers more than 4 million acres, the assessment team estimated that 2.1 tcf of gas and 9.2 million bbl of NGL are in Tertiary rocks beneath the Columbia River basalt, according to the report. The largest undiscovered gas field in the AU holds a mean estimate of 362.9 bcf, it added.

In a second area, the hypothetical Eastern Oregon and Washington conventional gas AU covering more than 22.2 million acres, the report listed a mean estimate of 300 bcf of conventional gas and 610,000 bbl of NGL. It said the estimated mean size of the AU’s largest undiscovered gas field is 78.3 bcf (OGJ, Jan. 14, 2008, p. 35).

The report said that the assessment team identified a third area, the Republican Graben Gas AU, but did not quantitatively assess it.

Known to be present beneath the basalt of north-central Oregon and central Washington are some 5,000-10,000 ft of arkosic sandstone, mudstone, lacustrine shale, and coal, which include potential source and reservoir rocks. The province’s only discovered commercial gas accumulation is the abandoned Rattlesnake Hills field, in Benton County, Wash., which produced about 1.3 bcf of gas.

Numerous other gas shows are known in the province, but as of 2006 no new commercial accumulations have been found, the report said.

Israel

Zion Oil & Gas Inc., Dallas, plans to spud the Ma’anit-Rehoboth-2 well in Israel in early 2009.

Aladdin Middle East Ltd. has refurbished a 2,000-hp rig to directionally drill the well deeper than 18,000 ft. Pending the receipt of permits from Israel, the rig is to be shipped from Turkey in January 2009.

Zion’s overall work plan, depending on funds raised, is to drill a second well on the Joseph license to the Triassic at 15,400 ft and-or Permian at 18,040 ft, drill a well on the Asher-Menashe license to the Triassic and, if appropriate, the Permian, and prepare to drill a further well on either license (see map, OGJ, July 5, 2004, p. 42).

Kazakhstan

Tethys Petroleum Ltd., Toronto, gauged gas at the rate of more than 10.2 MMcfd at the AKK-16 well in Kazakhstan’s North Ustyurt basin and named the discovery Southeast Akkulka.

The discovery well is northwest of the Aral Sea and 22.5 miles southeast of Kyzyloi gas field. The gas flow came from a 26-ft sand on a 1.4-in. choke with 183.5 psig flowing tubinghead pressure. The company said 73-mm tubing appears to have restricted the flow rate.

Seismic and geological analysis indicates that the Paleogene basin in which these sands were deposited deepens to the south and east and the reservoir in the AKK-6 well, which initial data indicate to have high porosity and permeability, may represent a more distal equivalent of the Paleogene sand sequence productive in Kyzyloi field, the company said.

Gulf of Mexico

A group led by Noble Energy Inc., Houston, plans to start gas production by the end of 2008 from the deepwater Raton discovery in Mississippi Canyon Block 248 in the Gulf of Mexico, said 33% interest owner Energy Partners Ltd., New Orleans.

Noble Energy has 68% working interest in Raton and the nearby Redrock discovery in Mississippi Canyon Block 204. The finds are in 3,300-3,400 ft of water.

Alaska

GeoPetro Resources Co., San Francisco, plans to spud an exploratory well in Alaska’s Cook Inlet basin in May 2009.

The planned 8,000-ft Frontier Spirit-1 well is to evaluate a 100% owned, 11,500-acre prospect identified on 50 miles of reprocessed 2D seismic acquired from Amoco Production Co. Primary objective is conventional gas in Middle and Lower Tyonek. Secondary target is the Hemlock formation. All are of Tertiary age.

The prospect is 6 miles north of Anchorage and less than 2 miles from the Enstar 20-in. gas pipeline.

Montana

Continental Resources Inc., Enid, Okla., and several other companies have formed the Montana Bakken EOR Consortium to conduct a carbon dioxide pilot project in Richland County, Mont.

The other parties in the consortium asked that their names not be revealed as yet, Continental Resources said.

The group plans to begin gas injection by the end of 2008, inject for one month, and then shut in the well for one month. They will then produce the well and analyze data to determine EOR potential.

Pennsylvania

Atlas Energy Resources LLC, Pittsburgh, said it has 90 wells, some of which have been on line for 2 years, producing a combined 25 MMcfd of gas into a pipeline from Devonian Marcellus shale in Pennsylvania.

Cumulative production exceeds 4 bcf, making Atlas Energy the largest Marcellus producer (OGJ Online, Oct. 8, 2008).

The last 13 vertical Marcellus completions have averaged an initial 1.3 MMcfd, and one vertical well in Fayette County came on at 3.6 MMcfd and has produced 132 MMcf in 60 days.

The company plans to drill 32 vertical wells between next week and Mar. 31, 2009, and 75 more vertical wells the rest of 2009. It is also drilling 12 horizontal wells by next Mar. 31 as operator with 50% working interest and 12 more horizontals with 100% by the end of 2009.