From the outcrops in the Yaomoshan and Hongyanchi sections, oil shales, deep dark mudstones or black mudstones with better organic richness were found. Through the analysis of the samples in the organic petrology meth...From the outcrops in the Yaomoshan and Hongyanchi sections, oil shales, deep dark mudstones or black mudstones with better organic richness were found. Through the analysis of the samples in the organic petrology method, the microscope features of the sedimentary organic matter were studied. The results indicate that three types of kerogens present in the measured samples. Kerogen type I consists of the laminate algainite, abundant sporinite and only little content of cutinite, which can mainly generate oil. The generation hydrocarbon components of the type II kerogen are dominated by the sporinite, cutinite and little the exinite debris. The type III kerogen is comprised of the sporinite and debris of the exinite with some components of gas generation. Through the analysis of the experiments, the organic kerogen of the Lucaogou formation is mostly comprised of the type I, partially type II, and particularly type III. In Hongyanchi formation, the organic type is mixed by the types II and III. The plot of the （$1＋$2） or TOC value and the content of exinite show two trends. From the evolution of burial and the Permian source rocks in Changji Depression, the Permian formation source rock has ended the generation of hydrocarbon. A significant difference in constituents of the organic macerals among three kerogens in these samples leads to the distinction of the potential hydrocarbon generation. The Lucaogou formation for kerogen type I has better potential hydrocarbon generation. It can reach the oil peak with Ro ratio Of 0.9%. For the kerogen II, the oil peak of the source rocks comes late with the Ro ratio of 1.0% with less quantity of the generation hydrocarbon than the kerogen I. For type III, it can mainly generate gas and reach the gas peak with the Ro ratio of 1.3%. In a word, the Lucaogou formation and Hongyanchi formation source rocks with high organic richness in Permian source rocks have well exploration prospects.展开更多
The Chihsia Formation is one of the four sets of regional marine hydrocarbon source rocks from South China.In the past two decades,detailed geochemical and sedimentological studies have been carried out to investigate...The Chihsia Formation is one of the four sets of regional marine hydrocarbon source rocks from South China.In the past two decades,detailed geochemical and sedimentological studies have been carried out to investigate its origination,which have demonstrated that the high primary productivity plays a primary role in the deposition of sediments enriched in the organic matter.However,the mechanism of this high productivity and the path of the deposition and burial of the organic matter have always been a mystery.Based on the previous studies on the Shangsi Section in Guangyuan City,Sichuan Province,we proposed that the development of the equatorial upwelling due to the sea level rise is responsible for the relatively high productivity in the Chihsia Formation.The sea waters with high nutrient were transported by the sub-surface currents along the equator.High organic carbon flux was deposited on the deeper shelf,and then decomposed by bacteria,leading to the occurrence of anaerobic respiration.The metabolism of the microorganisms consumed the dissolved oxygen in waters,which was in favor of the preservation of the organic matter.This suggested geobiological model integrating with paleoclimatology,paleoceanography and geomicrobiology will help us to understand the causes of this particular sedimentary sequence.展开更多
Gypsum-salt rocks and coccolith calcareous shale are widely deposited in the lower part of the Paleogene Shahejie Formation in the Dongying Sag, Sbandong Province. The gypsum-salt rock is believed to be formed during ...Gypsum-salt rocks and coccolith calcareous shale are widely deposited in the lower part of the Paleogene Shahejie Formation in the Dongying Sag, Sbandong Province. The gypsum-salt rock is believed to be formed during the earlier deposition in salt lake, while the overlying coccolith shale in saline lake with relatively low salinity. By comparing the lake environment and la- custrine microbial communities between ancient and recent lakes, cyanobacteria are regarded as the main representative of productivity during the formation of gypsum-salt strata series, with the annual productivity of 1500-2000 gC m-2 yr1. Based on the research of ultramicrofossils in the calcareous shale, coccolith is considered as the main contributor to the productivity during the formation of calcareous shale. On the basis of statistic data of sedimentary rates, shale laminations, and coccolith fossils in each lamination, the quantitative value of productivity is calculated, with the annual productivity of 2250 3810 gC m 2 yr-1 （averagely 3120 gC m-2 yr-1）. Statistic data of large amount of pyrite framboids indicate that the lower water col- umn was persistently in sulfidic or anoxic conditions during the deposition of gypsum-salt strata series, but it changed to be dysoxic when the coccolith calcareous shale was deposited. Both of these water conditions are favorable for the preservation of organic matter. It is estimated that the organic carbon burial efficiency of the Lower Paleogene salt lakes and saline lakes of Dongying Depression is about 10%-15%, which is calculated and analyzed using the multi-parameter geobiological model.展开更多
Evaluating the pre-Jurassic marine source rocks in China has been difficult because these rocks are generally too highor over-maturated for most traditional methods to work.As to the remaining parameter TOC (%),its lo...Evaluating the pre-Jurassic marine source rocks in China has been difficult because these rocks are generally too highor over-maturated for most traditional methods to work.As to the remaining parameter TOC (%),its lower limit for recognizing the carbonate source rocks in China has been in dispute.Nineteen Phanerozoic sections in the Middle-Upper Yangtze Platform and the Guizhou-Hunan-Guangxi Basin have been studied in search for a different approach to complementing the traditional evaluation method for these source rocks.We have applied a geobiological approach to tracing the organic carbon (OC) output and accumulation from the living stage (primary productivity) to the post-mortem deposited remains,and finally to the preserved burial organics.Four biological and geological parameters are employed to represent the OC of the three stages.A series of proxies of these parameters are discussed and integrated to establish a geobiological evaluation system independent of TOC and other traditional methods.Here we use the Guangyuan section in Sichuan as an example for the geobiological evaluation.Our results indicate that in the argillaceous rocks,the geobiological parameters show the qualified source rocks in accordance with high TOC values;but in the carbonates,the good source rocks delineated by the geobiological parameters have a wide range of TOC,from 0.03% to 1.59%,mostly<0.3%.We suggest that it is still premature to set TOC=0.3% or 0.5% as the lower limit for the pre-Jurassic carbonate source rocks in South China.展开更多
To determine geochemical indicators for depositional environment favored by terrestrial petroleum source rocks, we selected 40 source rock samples from the Late Cretaceous Qingshankou Formation （Kzqn） and the first ...To determine geochemical indicators for depositional environment favored by terrestrial petroleum source rocks, we selected 40 source rock samples from the Late Cretaceous Qingshankou Formation （Kzqn） and the first member of Nenjiang Formation （K2n1） in the Songliao Basin to qualify saturate fraction and aromatic fraction using GC-HRT （gas chromatography high resolution time-of-flight mass spectrometry） and quantify important biomarkers using GC-MS. The results reveal that source rocks from the 1st member of Qingshankou Formation （K2qn1） are characterized by not only high contents of terpanes, regular steranes and 4-methylsteranes but also high contents of dinosteranes, C31 steranes and aryl isoprenoids. Presence of specific biomarkers like elementary sulfur and lanostanes indicates a depositional environment of lagoon characterized by water stratification and high salinity. In the 2nd-3rd members of Qingshankou Formation （K2qn2＋3）, source rocks contain lower contents of biomarkers, indicating a depositional environment of shallow fresh-water lake delta. Source rocks in the K2n1 contain high contents of terpanes, regular steranes and 4-methylsteranes but lower contents of dinosteranes, C31 steranes and aryl isoprenoids, indicating a depositional environment of fresh-brackish open lake characterized by low salinity and poor water stratification, where organic matter is seriously altered by bacteria. Overall analysis shows that primary geochemical indicators for terrestrial petroleum source rocks are as follows： 1） C30 hopanes 〉 1500 ppm; 2） gammacerane 〉190 ppm; 3） C27 steranes 〉200 ppm; 4） 4-methylsteranes 〉 100 ppm; 5） aryl isoprenoids 〉 3 ppm; 6） dehydroxyl-vitamin E 〉 10 ppm.展开更多
基金Project(2011ZX05002-006)supported by the National Science and Technology Project,China
文摘From the outcrops in the Yaomoshan and Hongyanchi sections, oil shales, deep dark mudstones or black mudstones with better organic richness were found. Through the analysis of the samples in the organic petrology method, the microscope features of the sedimentary organic matter were studied. The results indicate that three types of kerogens present in the measured samples. Kerogen type I consists of the laminate algainite, abundant sporinite and only little content of cutinite, which can mainly generate oil. The generation hydrocarbon components of the type II kerogen are dominated by the sporinite, cutinite and little the exinite debris. The type III kerogen is comprised of the sporinite and debris of the exinite with some components of gas generation. Through the analysis of the experiments, the organic kerogen of the Lucaogou formation is mostly comprised of the type I, partially type II, and particularly type III. In Hongyanchi formation, the organic type is mixed by the types II and III. The plot of the （$1＋$2） or TOC value and the content of exinite show two trends. From the evolution of burial and the Permian source rocks in Changji Depression, the Permian formation source rock has ended the generation of hydrocarbon. A significant difference in constituents of the organic macerals among three kerogens in these samples leads to the distinction of the potential hydrocarbon generation. The Lucaogou formation for kerogen type I has better potential hydrocarbon generation. It can reach the oil peak with Ro ratio Of 0.9%. For the kerogen II, the oil peak of the source rocks comes late with the Ro ratio of 1.0% with less quantity of the generation hydrocarbon than the kerogen I. For type III, it can mainly generate gas and reach the gas peak with the Ro ratio of 1.3%. In a word, the Lucaogou formation and Hongyanchi formation source rocks with high organic richness in Permian source rocks have well exploration prospects.
基金supported by National Basic Research Program of China (Grant No. 2011CB808800)National Natural Science Foundation of China (Grant No. 41072078)
文摘The Chihsia Formation is one of the four sets of regional marine hydrocarbon source rocks from South China.In the past two decades,detailed geochemical and sedimentological studies have been carried out to investigate its origination,which have demonstrated that the high primary productivity plays a primary role in the deposition of sediments enriched in the organic matter.However,the mechanism of this high productivity and the path of the deposition and burial of the organic matter have always been a mystery.Based on the previous studies on the Shangsi Section in Guangyuan City,Sichuan Province,we proposed that the development of the equatorial upwelling due to the sea level rise is responsible for the relatively high productivity in the Chihsia Formation.The sea waters with high nutrient were transported by the sub-surface currents along the equator.High organic carbon flux was deposited on the deeper shelf,and then decomposed by bacteria,leading to the occurrence of anaerobic respiration.The metabolism of the microorganisms consumed the dissolved oxygen in waters,which was in favor of the preservation of the organic matter.This suggested geobiological model integrating with paleoclimatology,paleoceanography and geomicrobiology will help us to understand the causes of this particular sedimentary sequence.
基金supported by National Science and Technology Major Project (Grant No. 2009ZX05009)National Basic Research Program of China (Grant No. 2011CB808800)+1 种基金National Natural Science Foundation of China (Grant Nos. 41172036, 40730209)the "111" Project (Grant No. B08030)
文摘Gypsum-salt rocks and coccolith calcareous shale are widely deposited in the lower part of the Paleogene Shahejie Formation in the Dongying Sag, Sbandong Province. The gypsum-salt rock is believed to be formed during the earlier deposition in salt lake, while the overlying coccolith shale in saline lake with relatively low salinity. By comparing the lake environment and la- custrine microbial communities between ancient and recent lakes, cyanobacteria are regarded as the main representative of productivity during the formation of gypsum-salt strata series, with the annual productivity of 1500-2000 gC m-2 yr1. Based on the research of ultramicrofossils in the calcareous shale, coccolith is considered as the main contributor to the productivity during the formation of calcareous shale. On the basis of statistic data of sedimentary rates, shale laminations, and coccolith fossils in each lamination, the quantitative value of productivity is calculated, with the annual productivity of 2250 3810 gC m 2 yr-1 （averagely 3120 gC m-2 yr-1）. Statistic data of large amount of pyrite framboids indicate that the lower water col- umn was persistently in sulfidic or anoxic conditions during the deposition of gypsum-salt strata series, but it changed to be dysoxic when the coccolith calcareous shale was deposited. Both of these water conditions are favorable for the preservation of organic matter. It is estimated that the organic carbon burial efficiency of the Lower Paleogene salt lakes and saline lakes of Dongying Depression is about 10%-15%, which is calculated and analyzed using the multi-parameter geobiological model.
基金supported by National Basic Research Program of China(Grant No.2011CB808800)Key Project of China Petroleum&Chemical Corporation(Grant No.G0800-06-2S-319)+1 种基金NSFC Program for Innovative Research Team(Grant No.40621002)the"111"Project(Grant No.B08030)
文摘Evaluating the pre-Jurassic marine source rocks in China has been difficult because these rocks are generally too highor over-maturated for most traditional methods to work.As to the remaining parameter TOC (%),its lower limit for recognizing the carbonate source rocks in China has been in dispute.Nineteen Phanerozoic sections in the Middle-Upper Yangtze Platform and the Guizhou-Hunan-Guangxi Basin have been studied in search for a different approach to complementing the traditional evaluation method for these source rocks.We have applied a geobiological approach to tracing the organic carbon (OC) output and accumulation from the living stage (primary productivity) to the post-mortem deposited remains,and finally to the preserved burial organics.Four biological and geological parameters are employed to represent the OC of the three stages.A series of proxies of these parameters are discussed and integrated to establish a geobiological evaluation system independent of TOC and other traditional methods.Here we use the Guangyuan section in Sichuan as an example for the geobiological evaluation.Our results indicate that in the argillaceous rocks,the geobiological parameters show the qualified source rocks in accordance with high TOC values;but in the carbonates,the good source rocks delineated by the geobiological parameters have a wide range of TOC,from 0.03% to 1.59%,mostly<0.3%.We suggest that it is still premature to set TOC=0.3% or 0.5% as the lower limit for the pre-Jurassic carbonate source rocks in South China.
基金supported by Major State Basic Research Development Program of China (Grant No. 2009CB219308) and Petro China Daqing Oilfield Company Ltd.
文摘To determine geochemical indicators for depositional environment favored by terrestrial petroleum source rocks, we selected 40 source rock samples from the Late Cretaceous Qingshankou Formation （Kzqn） and the first member of Nenjiang Formation （K2n1） in the Songliao Basin to qualify saturate fraction and aromatic fraction using GC-HRT （gas chromatography high resolution time-of-flight mass spectrometry） and quantify important biomarkers using GC-MS. The results reveal that source rocks from the 1st member of Qingshankou Formation （K2qn1） are characterized by not only high contents of terpanes, regular steranes and 4-methylsteranes but also high contents of dinosteranes, C31 steranes and aryl isoprenoids. Presence of specific biomarkers like elementary sulfur and lanostanes indicates a depositional environment of lagoon characterized by water stratification and high salinity. In the 2nd-3rd members of Qingshankou Formation （K2qn2＋3）, source rocks contain lower contents of biomarkers, indicating a depositional environment of shallow fresh-water lake delta. Source rocks in the K2n1 contain high contents of terpanes, regular steranes and 4-methylsteranes but lower contents of dinosteranes, C31 steranes and aryl isoprenoids, indicating a depositional environment of fresh-brackish open lake characterized by low salinity and poor water stratification, where organic matter is seriously altered by bacteria. Overall analysis shows that primary geochemical indicators for terrestrial petroleum source rocks are as follows： 1） C30 hopanes 〉 1500 ppm; 2） gammacerane 〉190 ppm; 3） C27 steranes 〉200 ppm; 4） 4-methylsteranes 〉 100 ppm; 5） aryl isoprenoids 〉 3 ppm; 6） dehydroxyl-vitamin E 〉 10 ppm.
