The source of marine crude oils from Tarim Basin is still disputed.However,research on the reservoir bitumens may provide a piece of new evidence to elucidate oil source.Geochemical characteristics of reservoir bitume...The source of marine crude oils from Tarim Basin is still disputed.However,research on the reservoir bitumens may provide a piece of new evidence to elucidate oil source.Geochemical characteristics of reservoir bitumens from different strata from Well Zhong 1 in the Katake Uplift were discussed here in detail.Pr/Ph ratios of reservoir bitumen from Well Zhong 1 range from 1.14 to 1.39,CPI ratios from 1.01 to 1.08,which indicates no odd-even predominance of normal alkanes,with OEP ratios ranging from 0.98 to 1.05.The contents of gammacerane and C28 sterane of reservoir bitumen from Well Zhong 1 are low,while dibenzothiophene series are abundant.Ster-ane isomerization maturity parameter and Ts/(Ts+Tm) ratio indicate that the reservoir bitumen from Well Zhong1 is mature to highly mature.Based on the differences in biomarker distribution,it is concluded that reservoir bitumen from Well Zhong 1,of which molecular parameters are contrary to those in Cambrian oil from Well Tadong 2,origi-nated from the Upper Ordovician source rocks.展开更多
Abundant organic inclusions are present in the Qinglong antimony deposit. However, the source rocks of these organic matters have not been reliably identified. Recently, a paleo--oil reservoir was found in the Qinglon...Abundant organic inclusions are present in the Qinglong antimony deposit. However, the source rocks of these organic matters have not been reliably identified. Recently, a paleo--oil reservoir was found in the Qinglong antimony deposit. In view of similar components of gaseous hydrocarbon, we propose that the organic matters observed in inclusions in Qinglong antimony deposit would come from this paleo-oil reservoir. We used the Re-Os dating method to determine the age of the bitumen from this paleo-oil reservoir, and obtained an isochron age of 254.3~2.8 Ma. The age indicates that the oil- generation from source rock occurred in the early Late Permian, earlier than the Sb mineralization age （-148~8.5 Ma） in the Qinglong antimony deposit area. After oil generation from Devonian source rock, first and secondary migration, the crude oil have probably entered into the fractures and pores of volcanic rocks and limestone and formed a paleo-oil reservoir in the western wing of Dachang anticline. As burial process deepened, the crude oil has turned into natural gas, migrates into the core of Dachang anticline and formed a paleo-gas reservoir. The hydrocarbons （including CH4） in the reservoirs can serve as reducing agent to provide the sulfur required for Sb mineralization through thermal chemical reduction of sulfates. Therefore, the formation of oil-gas in the area is a prerequisite for the Sb mineralization in the Qinglong antimony deposit.展开更多
Natural bitumen is the evolutionary residue of hydrocarbon of sedimentary organic matter. Several kinds of bitumen with different occurrences, including bitumen in source rock, migration bitumen filled in fault, oil-b...Natural bitumen is the evolutionary residue of hydrocarbon of sedimentary organic matter. Several kinds of bitumen with different occurrences, including bitumen in source rock, migration bitumen filled in fault, oil-bed bitumen and paleo-reservoir bitumen, are distributed widely in the Dabashan foreland. These kinds of bitumen represent the process of oil/gas formation, migration and accumulation in the region. Bitumen in source rock fiUed in fractures and stylolite and experienced deformation simultaneously together with source rock themselves. It indicated that oil/gas generation and expelling from source rock occurred under normal buried thermal conditions during prototype basin evolution stages prior to orogeny. Occurrences of bitumen in source rock indicated that paleo- reservoir formation conditions existed in the Dabashan foreland. Migration bitumen being widespread in the fault revealed that the fault was the main channel for oil/gas migration, which occurred synchronously with Jurassic foreland deformation. Oil-bed bitumen was the kind of pyrolysis bitumen that distributed in solution pores of reservoir rock in the Dabashan foreland depression, the northeastern Sichuan Basin. Geochemistry of oil-bed bitumen indicated that natural gas that accumulated in the Dabashan foreland depression formed from liquid hydrocarbon by pyrolysis process. However, paleo-reservior bitumen in the Dabashan forleland was the kind of degradation bitumen that formed from liquid hydrocarbon within the paleo-reservior by oxidation, alteration and other secondary changes due to paleo-reservior damage during tectonics in the Dabashan foreland. In combination with the tectonic evolution of the Dabashan foreland, it is proposed that the oil/gas generated, migrated and accumulated to form the paleo-reservoir during the Triassic Indosinian tectonic movement. Jurassic collision orogeny, the Yanshan tectonic movement, led to intracontinental orogeny of the Dabashan area accompanied by geofluid expelling and paleo-reservoir damage in the Dabashan foreland. The present work proposed that there is liquid hydrocarbon exploration potential in the Dabashan foreland, while there are prospects for the existence of natural gas in the Dabashan foreland depression.展开更多
Fifteen oil seepage and solid bitumen samples in the Southern Guizhou Depression were analyzed with GC–MS. Characteristics of molecular markers and carbon isotopes are discussed systemically. The results showed that ...Fifteen oil seepage and solid bitumen samples in the Southern Guizhou Depression were analyzed with GC–MS. Characteristics of molecular markers and carbon isotopes are discussed systemically. The results showed that the oil seepage and solid bitumen samples in the Southern Guizhou Depression could be divided into two families: Ordovician and Siluric samples, and Permian samples. The two families are different in alkanes distribution, biomarkers, aromatic hydrocarbon composition,and stable carbon isotopes; differences mainly caused by source rock variation.展开更多
基金funded by the National Natural Science Foundation of China(Grant No.40773039)the Open Fund(Grant No.DMSM 200806) of Key Laboratory of Depositional Mineralization & Sedimentary Mineral(Shandong University of Science and Technology)+2 种基金Shandong Province,and Natural Science Foundation of Hubei Province of China(Grant No.2010CDB04306)CNPC Innovation Foundation the Open Fund(Grant No.2010D-5006-0105)also funded by the open fund(Grant No.2009005) of the State Key Laboratory of Petroleum Resource and Prospecting
文摘The source of marine crude oils from Tarim Basin is still disputed.However,research on the reservoir bitumens may provide a piece of new evidence to elucidate oil source.Geochemical characteristics of reservoir bitumens from different strata from Well Zhong 1 in the Katake Uplift were discussed here in detail.Pr/Ph ratios of reservoir bitumen from Well Zhong 1 range from 1.14 to 1.39,CPI ratios from 1.01 to 1.08,which indicates no odd-even predominance of normal alkanes,with OEP ratios ranging from 0.98 to 1.05.The contents of gammacerane and C28 sterane of reservoir bitumen from Well Zhong 1 are low,while dibenzothiophene series are abundant.Ster-ane isomerization maturity parameter and Ts/(Ts+Tm) ratio indicate that the reservoir bitumen from Well Zhong1 is mature to highly mature.Based on the differences in biomarker distribution,it is concluded that reservoir bitumen from Well Zhong 1,of which molecular parameters are contrary to those in Cambrian oil from Well Tadong 2,origi-nated from the Upper Ordovician source rocks.
基金financially supported by Natural Science Foundation of China (No.41362007)The Research of Scientific Base of Typical Metal Mineral from the Ministry of Land and Resources (No.20091107)the Research Project on the Metallogenic Regularity of the Typical Strata Controlled Deposits of National Crisis Mines in Southwest China (No.20089943)
文摘Abundant organic inclusions are present in the Qinglong antimony deposit. However, the source rocks of these organic matters have not been reliably identified. Recently, a paleo--oil reservoir was found in the Qinglong antimony deposit. In view of similar components of gaseous hydrocarbon, we propose that the organic matters observed in inclusions in Qinglong antimony deposit would come from this paleo-oil reservoir. We used the Re-Os dating method to determine the age of the bitumen from this paleo-oil reservoir, and obtained an isochron age of 254.3~2.8 Ma. The age indicates that the oil- generation from source rock occurred in the early Late Permian, earlier than the Sb mineralization age （-148~8.5 Ma） in the Qinglong antimony deposit area. After oil generation from Devonian source rock, first and secondary migration, the crude oil have probably entered into the fractures and pores of volcanic rocks and limestone and formed a paleo-oil reservoir in the western wing of Dachang anticline. As burial process deepened, the crude oil has turned into natural gas, migrates into the core of Dachang anticline and formed a paleo-gas reservoir. The hydrocarbons （including CH4） in the reservoirs can serve as reducing agent to provide the sulfur required for Sb mineralization through thermal chemical reduction of sulfates. Therefore, the formation of oil-gas in the area is a prerequisite for the Sb mineralization in the Qinglong antimony deposit.
基金funded by CNSF (No.41173055)and marine department,Sinopec
文摘Natural bitumen is the evolutionary residue of hydrocarbon of sedimentary organic matter. Several kinds of bitumen with different occurrences, including bitumen in source rock, migration bitumen filled in fault, oil-bed bitumen and paleo-reservoir bitumen, are distributed widely in the Dabashan foreland. These kinds of bitumen represent the process of oil/gas formation, migration and accumulation in the region. Bitumen in source rock fiUed in fractures and stylolite and experienced deformation simultaneously together with source rock themselves. It indicated that oil/gas generation and expelling from source rock occurred under normal buried thermal conditions during prototype basin evolution stages prior to orogeny. Occurrences of bitumen in source rock indicated that paleo- reservoir formation conditions existed in the Dabashan foreland. Migration bitumen being widespread in the fault revealed that the fault was the main channel for oil/gas migration, which occurred synchronously with Jurassic foreland deformation. Oil-bed bitumen was the kind of pyrolysis bitumen that distributed in solution pores of reservoir rock in the Dabashan foreland depression, the northeastern Sichuan Basin. Geochemistry of oil-bed bitumen indicated that natural gas that accumulated in the Dabashan foreland depression formed from liquid hydrocarbon by pyrolysis process. However, paleo-reservior bitumen in the Dabashan forleland was the kind of degradation bitumen that formed from liquid hydrocarbon within the paleo-reservior by oxidation, alteration and other secondary changes due to paleo-reservior damage during tectonics in the Dabashan foreland. In combination with the tectonic evolution of the Dabashan foreland, it is proposed that the oil/gas generated, migrated and accumulated to form the paleo-reservoir during the Triassic Indosinian tectonic movement. Jurassic collision orogeny, the Yanshan tectonic movement, led to intracontinental orogeny of the Dabashan area accompanied by geofluid expelling and paleo-reservoir damage in the Dabashan foreland. The present work proposed that there is liquid hydrocarbon exploration potential in the Dabashan foreland, while there are prospects for the existence of natural gas in the Dabashan foreland depression.
基金funded by the State Key Project of Petroleum (2008ZX05005-001009HZ)the National Natural Science Foundation of China (41172126)+1 种基金the State Key Laboratory of Petroleum Resources and Prospecting (PRP2010-01)the Science Foundation of China University of Petroleum (LLYJ-2011-05 and KYJJ-2012-01-01)
文摘Fifteen oil seepage and solid bitumen samples in the Southern Guizhou Depression were analyzed with GC–MS. Characteristics of molecular markers and carbon isotopes are discussed systemically. The results showed that the oil seepage and solid bitumen samples in the Southern Guizhou Depression could be divided into two families: Ordovician and Siluric samples, and Permian samples. The two families are different in alkanes distribution, biomarkers, aromatic hydrocarbon composition,and stable carbon isotopes; differences mainly caused by source rock variation.
