Addendum to November 2009 Vantage EA

Transcription

1 Addendum to November 2009 Vantage EA Introduction This document includes additional information, supplemental to that already provided within the Vantage Energy Uintah LLC Ashley National Forest Oil and Gas Exploration Project Environmental Assessment (2009 Vantage EA), published in November This additional information is being provided to respond to information requests via public comments on the published Vantage EA, as well as to address changed information or conditions since that time. Minerals and Geology Additional information on minerals and energy resources within the project area is being provided below, as requested, and to address the potential for conflict or limitation of future options for minerals extraction. Oil and Gas Resources As indicated in Section of the 2009 Vantage EA, virtually all of the current and past oil and gas production in the vicinity of the Project Area is oil from the Green River Formation. Gas production has been obtained from the Wasatch and Mesaverde formations from nearly 200 wells at several fields 6 to 20 miles southeast of the Project Area. The Wasatch Formation is productive of oil elsewhere in the Uinta Basin, such as at the large Altamont-Bluebell Field, located eight miles north of the Project Area. The Wasatch and Mesaverde formations are productive of gas elsewhere in the Uinta Basin, such as at the large Greater Natural Buttes complex, about 25 miles east-northeast of the Project Area (Chidsey et al 2004, UDOGM 2010). As indicated in Section 2.3 of the EA, oil or gas production from the Mesaverde Formation is a principal objective of the Proposed Action. A map illustrating active oil and gas fields within the vicinity of the Project Area is indicated in the attached addendum map. Lands in the vicinity of the Project Area are heavily leased for oil and gas development (BLM 2010). The U.S. Geological Survey (USGS) has estimated the potential for undiscovered oil and gas resources within the greater Uinta-Piceance Basin based on systems of closely related source rocks and reservoirs (USGS 2003). Within the portion of the greater Uinta-Piceance Basin containing the Project Area, the USGS identified the following petroleum systems: Green River System - comprising uppermost Cretaceous and Tertiary rock units, including the gas and oil productive Green River and upper Wasatch formations; Mesaverde System - comprising mainly uper Cretaceous rock units, including the principally gas productive Mesaverde, Price River, Castlegate, and Blackhawk formations;

2 Mancos/Mowry System - comprising mainly gas productive Cretaceous and upper Jurassic rock units, including Manco and Mowry formations, Dakota Sandstone, and Morrison Formation; and Phosphoria System - comprising mainly oil productive Permian and Pennsylvanian rock units, including the Park City, Phosphoria, and Weber formations. Oils from this system have also been identified in younger formations of Mesozoic age. To date, area production has been limited to reservoirs from the Green River and Mesaverde petroleum systems. Depths to the Mancos/Mowry and Phosphoria petroleum systems would be greater than 14,000 feet over the Project Area, based on Mesaverde depths at Vantage s existing Ashley Federal #2 well. Oil Shale The term "oil shale" refers to rock bearing the organic material kerogen, which may be processed to yield liquid hydrocarbons. The world's greatest known deposits of oil shale are located in the upper portion of the Green River Formation, a principally marlstone unit formed in several large Eocene lakes in Utah, Colorado, and Wyoming, including the Uinta Basin. Oil shale has been defined to include kerogen-bearing rocks which are capable of yielding 15 gallons or more of oil per ton of rock. The Mahogany Zone, in the uppermost part of the Green River Formation, is the most kerogen-rich portion of the unit. The Project Area does not overlap any identified Known Oil Shale Leasing Area (KOSLA), although small KOSLAs are situated immediately southwest of the Project Area in Argyle Canyon and about 15 miles to the east (BLM 2002). The upper Green River Formation crops out in portions of Sowers Canyon and in the Bad Land Cliffs south of the Project Area. Over the Project Area, the Mahogany Zone is located between approximately 1,000 and 2,500 feet below the surface. Over most of the Project Area, a continuous interval of oil shale with an estimated yield exceeding 35 gallons/ton is present at thicknesses of feet. Approximately 1/4 of the Project Area is underlain by 5-10 feet of oil shale with an estimated yield of 50 gallons/ton. Because there is currently no commercial technology available for extracting liquid hydrocarbons from oil shale, attempts to estimate the potential economic value of oil shale are necessarily hypothetical. Assuming that ultimately commercial deposits would be at least five feet thick, with a minimum yield of at least 35 gallons/ton, and an overburden of less than 3,000 feet (per Vanden Berg 2008), the total in-place oil shale resource in the Uinta Basin has been estimated at approximately 77 billion barrels of oil (Vanden Berg 2008). The oil shale deposits within the Project Area would be included as part of this potential resource. Tar Sands Tar sands are deposits of degraded oil or liquid hydrocarbons which have lost the original volatiles components. The degraded oil (bitumen) is typically found in Tertiary sand units of the Green River, Uinta, and Duchesne River formations and can be liberated by heat or certain other chemical processes. In the Uinta Basin, the USGS has designated seven areas of particularly rich deposits as Special Tar Sand Areas (STSAs). In addition, there are a number of minor deposits. Tar sands are not currently commercially competitive with conventional reservoirs as a source of oil.

3 The Project Area does not overlap any STSA or identified minor deposit. The Sunnyside and Argyle Canyon-Willow Creek STSAs are located immediately southwest of the Project Area and the Pariette STSA is located about 10 miles to the northeast. The bitumen in these three STSAs occurs in the Wasatch, Green River, and Uinta formations, respectively. Estimated in place reserves for the three STSAs are billion barrels, million barrels, and million barrels, respectively (BLM 2002). Gilsonite Gilsonite is the American Gilsonite Company's trademarked name for the mineral uintaite or uintahite. Gilsonite is a black hydrocarbon resin similar to coal or asphalt in appearance and is not known to occur in commercial quantities outside the Uinta Basin. The mineral's chemical properties make it useful in the production of dark-colored printing inks and paints, oil well drilling muds and cements, asphalt modifiers, and various chemical products (BLM 2002). Gilsonite occurs in generally northwest-southeast trending veins from a few inches up to 30 feet wide. The origin of the gilsonite is believed to be the oil shale-rich portions of the Green River Formation. During times of maximum burial, hydrocarbon generation and fluid expulsion in the oil shales is believed to have led to forceful emplacement of bitumen into the vein fractures (Monson and Parnell 1992). The nearest known gilsonite-bearing vein is located approximately 15 miles northeast of the Project Area and the bulk of the veins are located more than 20 miles to the northeast (AGRC 2009, BLM 2002). Other Mineral Resources There are no other solid minerals leases, wind energy rights-of-way, or active mining claims located within the Project Area (BLM 2010). Environmental Consequences Direct impacts to energy and mineral resources can result from conflict between oil and gas development, and attempts to develop other mineral or energy resources when such resources cooccur. The only likely candidate for such a potential conflict, within the project area, appears to be oil shale development. However there are no active oil shale leases in or near the Project Area and the Project Area does not overlap an oil shale KOSLA. Further, since no currently commercial extraction techniques exist, it is uncertain how oil shale development would conflict with oil and gas development. The potential for conflict between extractions of these two resources appears to be minimal at this time. Wildlife Additional information regarding wildlife is being provided below, to address several decisions released by the U.S. Fish and Wildlife Service (USFWS) since the EA was released. The greater sage grouse was designated by the USFWS as a candidate species for listing on March 5, 2010, the mountain plover was designated as proposed for listing as threatened on June 28, 2010, and the wolverine was designated as a candidate for listing on December 14, 2010 (USFWS 2010a,

4 b, and c). Consultation with USFWS is not required for no effect determinations and is not needed for candidate species. Wolverine Wolverine are also a Forest Service sensitive species for Region 4, and potential impacts to wolverine from the project were considered in the Biological Evaluation prepared for this project. The five wells and well pads considered under the current decision do not occur within wolverine habitat and there would be no effect to the wolverine or its habitat from approval of operations for these five wells (USFWS 2010c). Mountain Plover Although there have been mountain plovers documented in recent years, to the northeast of the Forest, no habitat for the mountain plover has been identified on the Forest, nor have there been any mountain plovers documented on the Forest. The five wells and well pads considered under the current decision occur in Wyoming big sagebrush and pinon/juniper communities, with the sagebrush having high percent canopy cover and few openings, which is not typical habitat for the mountain plover (USFWS 2010b). Additionally, there are no prairie dog towns, which are often associated with mountain plover habitat (USFWS 2010b), on the Forest or near the five wells and well pads being approved. Therefore, it is determined that there would be no effect to the mountain plover from approval of operations for these five wells. Sage Grouse Sage grouse are also a Forest Service sensitive species for Region 4, and potential impacts to sage grouse from the project were analyzed in the Biological Evaluation prepared for this project. The five wells and well pads considered under the current decision occur within pinon/juniper and sagebrush, but do not occur within occupied sage grouse habitat. The nearest well location is approximately 3½ miles to the southwest of the nearest occupied sage grouse habitat, 6½ miles to the southwest of the nearest lek, and located in the bottom of a canyon (Christensen 2006, Christensen 2007, USFS 2010). Additionally, these five wells maintain the one well pad per square mile requirement that has been suggested in recent literature for oil and gas development in sage grouse habitat (Holloran 2005, USFWS 2010a). The Anthro sage grouse population has been intensely studied since 2002, and it has been found that the sage grouse use the sage brush ridge tops and do not use the canyon bottoms, and no sage grouse have been located near any of these five well pads (Christensen 2006, Christensen 2007, USFS 2010). Therefore, it has been determined that the approval of operations for these five wells may impact individual sage grouse, but would not cause a trend toward their federal listing or cause a loss of viability to the population of this species. Migratory Birds An additional mitigation has been included into the decision, to help protect migratory birds. This mitigation will require netting to be placed over reserve pits to prevent migratory birds and other wildlife from coming in contact with reserve pit fluids.

5 Alternative 3 - Buried Pipelines During preparation of the Vantage EA, the required seeding and stabilization of disturbed areas associated with burial of production pipelines was inadvertently omitted from the alternative description. Seeding and soil stabilization will be required, for all areas disturbed by activities related to burial of production pipelines. References Cited Chidsey, Thomas, Sharon Wakefield, Bradley Hill, and Michael Hebertson Oil and Gas Fields Map of Utah, Map 203 DM, Utah Geological Survey, Salt Lake City, Utah. Christensen B Anthro Mountain sage grouse study Power point presentation Christensen B Anthro mountain sage grouse project report. March Holloran M. J Greater sage grouse population response to natural gas field development in western Wyoming. Monson B. and J. Parnell The Origin of Gilsonite Vein Deposits in the Uinta Basin, Utah, Contract Report 92-4, Utah Geological Survey. Salt Lake City, Utah. U.S. Bureau of Land Management (BLM) Final Mineral Potential Report for the Vernal Planning Area, U.S. Bureau of Land Management, Vernal Field Office, Vernal, Utah. U.S. Bureau of Land Management (BLM) GeoCommunicator, National Integrated Lands System, online data retrieved from USFS Anthro sage grouse habitat mapping. Map based on sage grouse telemetry locations from and available habitat. USFWS. 2010a. 12 month finding on a petition to list the Greater sage grouse as endangered or threatened. March 5 th, USFWS. 2010b. 12 month finding on a petition to list the Mountain plover as endangered or threatened. June 28 th, USFWS. 2010c. 12 month finding on a petition to list the Greater sage grouse as endangered or threatened. March 5 th, U.S. Geological Survey (USGS) Assessment of Undiscovered Oil and Gas Resources of the Uinta-Piceance Province of Colorado and Utah, U.S. Geological Survey, Denver, Colorado.

6 Utah Automated Geographic Reference Center (AGRC) GIS Data for the State of Utah, Utah Automated Geographic Reference Center, Salt Lake City, Utah. Online data retrievable from Utah Division of Oil, Gas, and Mining (UDOGM) Online Database of Oil and Gas Data and GIS Information, Utah Division of Oil, Gas, and Mining, Salt Lake City, Utah. Online data retrieved from May 6, Vanden Berg, Michael Basin-wide Evaluation of the Uppermost Green River Formation's Oil-shale Resource, Uinta Basin, Utah and Colorado, Special Study 128, Utah Geological Survey, Salt Lake City, Utah. ( end of document )