PDF Publication Title:
Text from PDF Page: 066
Chapter E, Copper River–Chugach Fossil Fuel and Geothermal Energy Sources for Local Use in Alaska rocks that are incapable of hosting exploitable accumulations of oil and gas. The Copper River basin includes Cenozoic strata less than about 65 million years old that reach thicknesses of up to approximately 1 kilometer (sheet 2; Kirschner, 1988, 1994). These younger strata overlie older Mesozoic formations of the Peninsular terrane that are closely related to Mesozoic rocks of the Alaska Peninsula and Cook Inlet. These older rocks were originally deposited in ancestral basins south of their present location, and were slowly transported long distances northward by plate tectonic processes and ultimately sutured onto the previously assembled blocks of what is now interior Alaska (Silberling and others, 1992; Plafker and others, 1994). In contrast, the Gulf of Alaska sedimentary basin (sheet 2) consists entirely of Cenozoic formations on Alaska’s present- day southern continental margin. The most prospective lands for oil and gas exploration belong to the Yakutat terrane, a crustal block composed of Cenozoic sedimentary units up to 9 kilometers thick deposited on slightly older Cenozoic and Mesozoic basement. Geologic and paleomagnetic evidence indicate that the Yakutat block originated approximately 50 million years ago near the present-day coast of British Columbia, 1,100 to 1,800 kilometers south of its current position (Risley and others, 1992). Since then, plate tectonic processes have transported the Yakutat block north along the western edge of North America, resulting in collisional deformation and mountain building in southern Alaska that continues into modern times. Source rocks. The hydrocarbon potential in the Copper River basin is likely gas. Of the 13 exploration holes drilled in the basin to date, a few of the easternmost wells have encountered mudlog shows of methane gas, but none reported significant indications of oil. Gases seeping from the Tolsona group of mud volcanoes and saline springs in the western part of the basin (fig. E2) contain methane in varying amounts ranging from <1 percent to more than 72 percent, in addition to noncombustible gases such as carbon dioxide and nitrogen (Motyka and others, 1986). Carbon isotopic signatures of nearly all the methane from these seeps suggest it is sourced from thermogenic and biogenic alteration of coal and lignite beds in late Mesozoic to early Cenozoic nonmarine units in the basin (Reitsema, 1979). The Tuxedni Formation, the Mesozoic source rock for most of the oil in Cook Inlet reservoirs, is also present in the Copper River basin, but it is sandy and apparently not as oil-prone (Magoon and Valin, 1996). Several wells have encountered overpressured Mesozoic formations at depth that contain saline formation waters charged with methane. These subsurface units are believed to be hydraulically connected with some of the mud volcanoes and saline springs at the surface (Motyka and others, 1986). The two most recent wells drilled in the basin were on private Ahtna Native Corporation lands, so complete information is not publicly available, but reports of high-pressure gas-bearing zones suggest that follow-up work may be warranted (Petroleum News, 2007). Limited thermal maturity information for the Copper River basin indicates a relatively low geothermal gradient (Motyka and others, 1986), and with the exception of the Wrangell Mountains volcanic field on the basin’s eastern edge, the petroleum generation window likely lies at depths below 8,000 feet (Magoon and Valin, 1996). Therefore, given the basin’s limited thickness, most of the basin is immature to only marginally mature for oil and gas generation (Utah International, Inc., 1987; DGSI, 1995; unknown, 1995b, 1995c). This interpretation is further evidenced by the scarcity of significant shows encountered during drilling, and it remains unclear whether the Copper River basin has generated appreciable quantities of either biogenic or thermogenic hydrocarbons. As noted above, the western segment of the Gulf of Alaska basin is the other area of oil and gas interest in the Copper River–Chugach Energy Region. The greatest petroleum potential is within the onshore portion of the Yakuta terrane; the crustal blocks of the Chugach Range and Prince William Sound to the north and west are devoid of source rocks and, for the most part, are thermally overmature. In the Katalla area, on the northwestern edge of the Yakutat block, natural oil and gas seeps and historic oil production from a shallow, fractured shale reservoir point to a petroleum system with moderate potential. Source rocks for onshore oil and gas seeps in the northern Gulf of Alaska region include shales of the Poul Creek Formation and coals of the Kulthieth Formation (Risley and others, 1992; Magoon 1994; Larson and Martin, 1998; Van Kooten and others, 2002). In the Katalla area, these source rocks range from early mature to overmature for hydrocarbon generation (Mull and Nelson, 1986). Reservoir rocks. There is relatively little data available from the Copper River basin to estimate the subsurface extent of formations with sufficient porosity and permeability to serve as conventional oil or gas reservoirs. Published resource assessments invoke upper Mesozoic to lower Cenozoic sandstones as the most likely reservoirs (Magoon and Valin, 1996). These formations are near the top of the basin’s stratigraphic succession, where it is thought they may have retained more porosity and permeability than older units buried to greater depths. The slightly older and overpressured Nelchina Formation has been targeted as a gas reservoir by recent drilling (Petroleum News, 2007), and further drill stem tests and other reservoir evaluation techniques will be required to determine whether this unit will be capable of sustained hydrocarbon production. In the Gulf of Alaska basin, potential conventional reservoir rocks are restricted to the Yakutat block; other terranes are made up of highly altered formations with insufficient porosity and permeability. Reservoir candidates in the Yakutat terrane include wave-reworked sandstones of Copper River–Chugach Page 46PDF Image | FOSSIL FUEL AND GEOTHERMAL ENERGY SOURCES FOR LOCAL USE
PDF Search Title:
FOSSIL FUEL AND GEOTHERMAL ENERGY SOURCES FOR LOCAL USEOriginal File Name Searched:
sr066.pdfDIY PDF Search: Google It | Yahoo | Bing
NFT (Non Fungible Token): Buy our tech, design, development or system NFT and become part of our tech NFT network... More Info
IT XR Project Redstone NFT Available for Sale: NFT for high tech turbine design with one part 3D printed counter-rotating energy turbine. Be part of the future with this NFT. Can be bought and sold but only one design NFT exists. Royalties go to the developer (Infinity) to keep enhancing design and applications... More Info
Infinity Turbine IT XR Project Redstone Design: NFT for sale... NFT for high tech turbine design with one part 3D printed counter-rotating energy turbine. Includes all rights to this turbine design, including license for Fluid Handling Block I and II for the turbine assembly and housing. The NFT includes the blueprints (cad/cam), revenue streams, and all future development of the IT XR Project Redstone... More Info
Infinity Turbine ROT Radial Outflow Turbine 24 Design and Worldwide Rights: NFT for sale... NFT for the ROT 24 energy turbine. Be part of the future with this NFT. This design can be bought and sold but only one design NFT exists. You may manufacture the unit, or get the revenues from its sale from Infinity Turbine. Royalties go to the developer (Infinity) to keep enhancing design and applications... More Info
Infinity Supercritical CO2 10 Liter Extractor Design and Worldwide Rights: The Infinity Supercritical 10L CO2 extractor is for botanical oil extraction, which is rich in terpenes and can produce shelf ready full spectrum oil. With over 5 years of development, this industry leader mature extractor machine has been sold since 2015 and is part of many profitable businesses. The process can also be used for electrowinning, e-waste recycling, and lithium battery recycling, gold mining electronic wastes, precious metals. CO2 can also be used in a reverse fuel cell with nafion to make a gas-to-liquids fuel, such as methanol, ethanol and butanol or ethylene. Supercritical CO2 has also been used for treating nafion to make it more effective catalyst. This NFT is for the purchase of worldwide rights which includes the design. More Info
NFT (Non Fungible Token): Buy our tech, design, development or system NFT and become part of our tech NFT network... More Info
Infinity Turbine Products: Special for this month, any plans are $10,000 for complete Cad/Cam blueprints. License is for one build. Try before you buy a production license. May pay by Bitcoin or other Crypto. Products Page... More Info
CONTACT TEL: 608-238-6001 Email: greg@infinityturbine.com (Standard Web Page)