赵建华,金振奎,耿一凯,温馨
ZHAO Jianhua,JIN Zhenkui,GENG Yikai,WEN Xin

• 1:中国石油大学地球科学学院

摘要(Abstract)：

四川盆地龙马溪组富有机质页岩是重要的烃源岩和页岩气储层。为了明确富有机质页岩形成控制因素,采用多种地球化学指标分析其沉积时的氧化还原条件、古生产力条件和陆源碎屑供给情况。结果表明:龙马溪组页岩具有高的有机碳含量,龙马溪组下部硅质页岩形成于贫氧环境,龙马溪组上部粉砂质页岩和黏土质页岩形成于氧化环境,由下至上还原环境逐渐遭受破坏;龙马溪组沉积时期古生产力为中—高等,下部硅质页岩段陆源供给较少,中部粉砂质页岩段陆源碎屑供给相对多,粗碎屑颗粒含量相对高,上部黏土质页岩以陆源黏土矿物为主;龙马溪组沉积物中埋藏有机碳含量与氧化还原环境指标、古生产力指标呈良好的相关性,与陆源碎屑供给参数相关性较差。龙马溪组富有机质页岩的形成主要受控于氧化还原条件和古生产力。
Organic matter-rich shale in Longmaxi-Formation is the important source rock and shale gas reservoir in Sichuan Basin. In order to make sure of the controlling factors of the diagenesis and formation of the shale,multiple geochemical indexes are adopted to analyze the redox and paleo-productivity conditions and terrigenous detrital supply. The achievements show that the high TOC is rich in Longmaxi shale,the lower-part siliceous shale is formed in the dysoxic/anoxic environment,while the upper silty and argillaceous shale are deposited in an oxic environment,the oxygen-free/reducing environments are gradually damaged from bottom to top; the paleo-productivity in Longmaxi-Formation sedimentary period is in the degree from medium to peak,the terrigenous supply is rather less in the lower shale,the terrigenous detrital supply is on the contrary in the middle silty shale,and moreover the content of the coarse clastic particles are pretty higher,the terrigenous clay minerals are mainly contained in the upper shale; there are much better correlations between the TOC in the sediments and redox indexes and paleo-productivity proxies,while the correlation is rather poorer with the terrigenous detrital supply. The diagenesis and formationof the organic matter-rich shale in Longmaxi-Formation is principally controlled by the redox-conditions and paleoproductivity.

关键词(KeyWords)： 四川盆地;龙马溪组;富有机质页岩;地球化学指标
Sichuan Basin;Longmaxi Formation;organic matter-rich shale;geochemical index/indicator/proxy

Abstract:

Keywords:

基金项目(Foundation): 中国石化科技攻关项目“川东地区龙马溪组页岩气富集规律与分布预测”(G5800-14-ZS-KJB158)

作者(Author): 赵建华,金振奎,耿一凯,温馨
ZHAO Jianhua,JIN Zhenkui,GENG Yikai,WEN Xin

参考文献(References)：

• [1]Demaison G J,Moore A G T.Anoxic environments and oil source bed genesis[J].AAPG Bulletin,1980,64(8):1179-1209.
• [2]Calvert S E.Oceanographic controls on the accumulation of organic matter in marine sediments[C]//Brooks J,Fleet A J.Blackwell:Marine Petroleum Source Rocks,1987:137-151.
• [3]Pedersen T F,Calvert S E.Anoxia vs.productivity:what controls the formation of organic-carbon-rich sediments and sedimentary rocks[J].AAPG Bulletin,1990,74(4):454-466.
• [4]Arthur M A,Sageman B B.Marine black shales:a review of depositional mechanisms and environments of ancient deposits[J].Annual Review of Earth and Planetary Sciences 1994,22(1):499-551.
• [5]Wignall P B..Black Shales[M].New York:Oxford University Press,1994.
• [6]Murphy A E,Sageman B B.Hollander D J,et al.Black shale deposition and faunal overturn in the Devonian Appalachian basin:clastic starvation,seasonal water-column mixing,and efficient biolimiting nutrient recycling[J].Paleoceanography,2000,15(3):280-291.
• [7]Lash G G,Blood D R.Organic matter accumulation,redox,and diagenetic history of the Marcellus Formation,southwestern Pennsylvania,Appalachian basin[J].Marine and Petroleum Geology,2014,57(2):244-263.
• [8]Caplan M L,Bustin R M.Palaeoceanographic controls on geochemical characteristics of organic-rich Exshaw mudrocks:role of enhanced primary productivity[J].Organic Geochemistry,1999,30(2-3):161-188.
• [9]Sageman B B,Murphy A E,Werne J P,et al.A tale of shales:the relative roles of production,decomposition,and dilution in the accumulation of organic-rich strata,Middle-Upper Devonian,Appalachian basin[J].Chemical Geology,2003,195(1-4),229-273.
• [10]Gallego-Torres D,Martínez-Ruiz F,Paytan A,et al.Pliocene-Holocene evolution of depositional conditions in the eastern Mediterranean:role of anoxia vs.productivity at time of sapropel deposition[J].Palaeogeography Palaeoclimatology Palaeoecology,2007,246(2-4):424-439.
• [11]Canfield D E.Factors influencing organic carbon preservation in marine sediments[J].Chemical Geology,1994,114(3-4):315-329.
• [12]Rimmer S M.Geochemical paleoredox indicators in Devonian-Mississippian black shales,central Appalachian Basin(U.S.A.)[J].Chemical Geology,2004,206(3):373-391.
• [13]张金川,金之钧,袁明生,等.页岩气成藏机理和分布[J].天然气工业,2004,24(7):15-18.
• [14]董大忠,程克明,王玉满,等.中国上扬子区下古生界页岩气形成条件及特征[J].石油与天然气地质,2010,31(3):288-301.
• [15]曾祥亮,刘树根,黄文明,等.四川盆地志留系龙马溪组页岩与美国Fort Worth盆地石炭系Barnett组页岩地质特征对比[J].地质通报,2011,30(2-3):372-384.
• [16]郭彤楼,张汉荣.四川盆地焦石坝页岩气田形成与富集高产模式[J].石油勘探与开发,2014,41(1):28-36.
• [17]汪泽成,赵文智,张林,等.四川盆地构造层序与天然气勘探[M].北京:地质出版社,2002:1-287.
• [18]翟光明.中国石油地质志:卷十:四川油气区[M].北京:石油工业出版社,1989:28-109,224-480.
• [19]牟传龙,周恳恳,梁薇,等.中上扬子地区早古生代烃源岩沉积环境与油气勘探[J].地质学报,2011,85(4):526-532.
• [20]Chen X,Rong J Y,Charles E M,et al.Late Ordovician to earliest Silurian graptolite and brachiopod biozonation from the Yangtze region,South China,with a global correlation.[J]Geol Mag,2000,137(6):623-650.
• [21]苏文博,李志明,Ettensohn F R,等.华南五峰组—龙马溪组黑色岩系时空展布的主控因素及其启示[J].地球科学,2007,32(6):819-827.
• [22]王淑芳,邹才能,董大忠,等.四川盆地富有机质页岩硅质生物成因及对页岩气开发的意义[J].北京大学学报(自然科学版),2014,50(3):476-486.
• [23]Calvert S E,Pedersen T F.Geochemistry of recent oxic and anoxic sediments:Implications for the geological record[J].Marine Geology,1993,113(1-2):67-88.
• [24]Algeo T J,Maynard J B.Trace-element behavior and redox facies in core shales of Upper Pennsylvanian Kansas-type cyclothems[J].Chemical Geology,2004,206(3-4):289-318.
• [25]Jones B,Manning D A C.Comparison of geochemical indices used for the interpretation of palaeoredox conditions in ancient mudstones[J].Chemical Geology,1994,111(1-4):111-129.
• [26]Wignall P B,Twitchett R J.Oceanic anoxia and the end Permian mass extinction[J].Science,1996,272(5265):1155-1158.
• [27]Rimmer S M.Geochemical paleoredox indicators in Devonian-Mississippian black shales,central Appalachian Basin[J].Chemical Geology,2004,206(3-4):373-391.
• [28]Meyer E E,Burgreen B N,Lackey H,et al.Evidence for basin restriction during syn-collisional basin formation in the Silurian Arisaig Group,Nova Scotia[J].Chemical Geology,2008,256(1):1-11.
• [29]Rowe H D,Loucks R G,Ruppel S C,et al.Mississippian Barnett Formation,Fort Worth Basin,Texas:Bulk geochemical inferences and Mo-TOC constraints on the severity of hydrographic restriction[J].Chemical Geology,2008,257(1-2):16-25.
• [30]Froelich P N,Klinkhammer G,Bender M L.Early oxidation of organic matter in pelagic sediments of the eastern equatorial Atlantic:Suboxic diagenesis[J].Geochimica et Cosmochimica Acta,1979,43(7):1075-1095.
• [31]Emerson S,Fischer K,Reimers C.Organic carbon dynamics and preservation in deep-sea sediments[J].Deep-Sea Research,1985,32(1):1-22.
• [32]Dymond J,Suess E,Lyle M.Barium in deep-sea sediment:a geochemical proxy for paleoproductivity[J].Paleoceanography,1992,7(2):163-181.
• [33]Francois R,Honjo S,Manganini S J,et al.Biogenic barium fluxes to the deep sea:implications for paleoproductivity reconstruction[J].Global Biogeochemical Cycles,1995,9(2):289-303.
• [34]Eagle M,Paytan A,Arrigo K R,et al.A comparison between excess barium and barite as indicators of carbon export[J].Paleoceanography,2003,18(1):2101-2113.
• [35]Averyt K B,Paytan B.A comparison of multiple proxies for export production in the equatorial Pacific[J].Paleoceanogrophy,2004,19(4):4003-4016.
• [36]Taylor S R.The abundance of chemical elements in the continental crust—a new table[J].Geochimicaet Cosmochimica Acta,1964,28(8):1273-1285.
• [37]Murray R W,Leinen M.Chemical transport to the seafloor of the equatorial Placific across a latitudinal transect at 135°w:Tracking sedimentary major,trace,and rare earth element fluxes at the equator and the itcz[J].Geochimica et Cosmochimica Acta1993,57(17):4141-4163.
• [38]Mort H,Jacquat O,Adatte T,et al.The Cenomanian/Turonian anoxic event at the Bonarelli Level in Italy and Spain:enhanced productivity and/or better preservation[J].Cretaceous Research,2007,28(4):597-612.
• [39]Tyson R V.Sedimentary organic matter:organic facies and palynofacies[M].London:Chapman and Hall,1995,321-409.