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The Monterey Formation is an extensive Miocene oil-rich geological sedimentary formation in California, with outcrops of the formation in parts of the California Coast Ranges, Peninsular Ranges, and on some of California's off-shore islands. The formation is the major source-rock for 37 to 38 billion barrels of oil in conventional traps such as sandstones.〔(Monterey Shale Gets New Look ), AAPG Explorer, Nov 2010. Accessed 03/21/2014〕 This is most of California's known oil resources.〔(The Monterey Formation of California: New Research Directions ) by Richard J. Behl, California State University, Long Beach, 2012〕 The Monterey has been extensively investigated and mapped for petroleum potential, and is of major importance for understanding the complex geological history of California. Its rocks are mostly highly siliceous strata that vary greatly in composition, stratigraphy, and tectono-stratigraphic history. The US Energy Information Administration (EIA) estimated in 2014 that the 1,750 square mile Monterey Formation could yield about 600 million barrels of oil, from tight oil contained in the formation, down sharply from their 2011 estimate of a potential 15.4 billion barrels.〔Sahagun, Louis (May 21, 2014) ("U.S. officials cut estimate of recoverable Monterey Shale oil by 96%" ) ''Los Angeles Times''〕〔(Drilling California: A Reality Check on the Monterey Shale ) J. David Hughes, Post Carbon Institute, 2013.〕 An independent review by the California Council on Science and Technology found both of these estimates to be "highly uncertain." 〔(CCST Releases Report on Well Stimulation Technologies ), August 28, 2014. "The 2011 EIA report suggested 15-billion barrels of recoverable oil in these source rocks but a subsequent 2014 correction by EIA reduced the estimate to 0.6 billion barrels. Recovering these resources would certainly require well stimulation. However, Berkeley Lab investigators found no reports of successful production from these deep source rocks and had questions about the EIA estimation methodology. The study's review of the two resource projections from deep source rocks in the Monterey Formation developed by EIA concluded that both these estimates are highly uncertain."〕 Despite intense industry efforts, there has been little success to date (2013) in producing Monterey-hosted tight oil/shale oil, except in places where it is already naturally fractured, and it may be many years, if ever, before the Monterey becomes a significant producer of shale oil.〔(So Much Shale Oil—but So Hard to Get ), Wall Street Journal, Updated Sept. 23, 2013〕 The Monterey Formation strata vary. Its lower Miocene members show indications of weak coastal upwelling, with fossil assemblages and calcareous-siliceous rocks formed from diatoms and coccolithophorids. Its middle and upper Miocene upwelling-rich assemblages, and its unique highly siliceous rocks from diatom-rich plankton, became diatomites, porcelainites, and banded cherts. ==Shale oil resources and exploitation== The Monterey formation has long been recognized as the primary source of the oil produced from other formations in Southern California; the Monterey itself has been very productive where it is naturally fractured. Since 2011, the possibility that hydraulic fracturing might make the Monterey Shale productive over large areas has gained widespread public attention.〔Josie Garthwaite, (Monterey Shale shakes up California energy future ), National Geographic, 27 May 2013.〕 According to the US Energy Information Administration (EIA) in 2011, the 1,750 square mile Monterey Shale Formation contained more than half of the United States’s total estimated technically recoverable shale oil (tight oil contained in shale, as distinct from oil shale) resource, about 15.4 billion barrels.〔US Energy Information administration, (Review of emerging resources US shale gas and shale oil plays ), July 2011.〕 In 2012, the EIA revised its recoverable volume downward, to 13.7 billion barrels.〔US Energy Information Administration, (Geology and technology drive estimates of technically recoverable resources ), 20 July 2012.〕 As of 2013 advances in hydraulic fracturing commonly called "fracking," and the high price of oil resulted in spirited bidding by oil companies for leases. Occidental Petroleum and Venoco were reported to have been major players. The deposit lies 6,000 and 15,000 feet below the surface. A widely cited March 2013 study released by the University of Southern California (USC) estimated that if extensive resource-play development of the Monterey through hydraulic fracturing were successful, it could generate as many as 2.8 million jobs and as much as $24.6 billion in state and local taxes.〔(The Monterey Shale and California’s Economic Future ) University of Southern California, USC Price School of Public Policy, (March 2013.〕 However, observers have pointed out that as of 2012, however large its theoretical potential, no one as yet has succeeded in making the Monterey Shale widely economic through hydraulic fracturing; to date it has been economic only in those limited locations already naturally fractured.〔David Brown, (The Monterey Shale, big deal, or big bust? ), AAPG Explorer, Nov, 2012.〕 Richard Behl, a geology professor who heads the "Monterey And Related Sediments" (MARS) consortium at California State University Long Beach, said that "The () numbers probably were overblown, but it was a simple method and had an essence of truth.” Compared to other shale oil plays, the Monterey formation is much thicker and more areally extensive, but also much more geologically complex and deformed. See the linked photos from a field trip to Monterey outcrops at Vandenberg Air Force Base. "To say California geology is complex is an understatement. ... The Monterey play is no slam-dunk."〔 In 2013, Bakken shale-oil pioneer Harold Hamm said the Monterey "might have a lot of potential, but there are reasons why it’s not being produced.” 〔(Monterey/Santos: Operators struggle with cracking code ), World Oil, Nov. 2013 (Google title to bypass paywall)〕 J. David Hughes, a Canadian geoscientist and Fellow of Post Carbon Institute, published a report〔 in December 2013 analyzing the assumptions behind the EIA's forecast of Monterey tight oil production and the USC's forecast of resulting job and tax revenue growth. He found the EIA report's assumptions on prospective well productivity to be "extremely optimistic," and the total estimate of 15.4 billion barrels of recoverable oil "highly overstated." He also found the USC study's assumption that development of the Monterey shale could increase California oil production as much as seven-fold to be "unfounded," and the economic projections regarding jobs and tax revenue to be "extremely suspect."〔Purd'homme, Alex (December 29, 2013) ("'Fracking' the Monterey Shale -- boon or boondoggle?" ) ''Los Angeles Times''〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Monterey Formation」の詳細全文を読む スポンサード リンク
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