One of the most important tasks of evaluating natural resources of petroliferous basins is to determine the organic matter abundance of source rocks in the basin.The usual method for assessing the organic carbon conte...One of the most important tasks of evaluating natural resources of petroliferous basins is to determine the organic matter abundance of source rocks in the basin.The usual method for assessing the organic carbon content of source rocks is based on laboratory analyses.There is a deviation in calculating organic carbon content due to the heterogeneous distribution of organic matter and the artificial factors when sampling.According to the continuous characteristics of information logging,the conventional logging curves(mainly acoustics and resistivity,etc.) were calibrated with the organic carbon experimental data of cores,cuttings or sidewall cores.The organic carbon content of source rocks of the 4 th(Es 4) and 3 rd(Es 3) members of the Shahejie Formation in western sag in the Liaohe depression was estimated directly by a great amount of continuous data including resistivity and acoustic logging,etc.Comparison between the results from computer processing and lab analysis of logging data shows that the organic carbon contents derived from the computer processing of logging data have the same reliability and accuracy as the lab analysis results.The present data show that this method is suitable to evaluate the source rocks of western sag in the Liaohe depression and has great potential in evaluating natural resources of sedimentary basins in the future.On the basis of logging data of source rocks,experimental data and existing geochemical analyses of the Liaohe Oilfield,the corresponding total organic carbon(TOC) isograms of source rocks were plotted.The source rocks of Es 4 and Es 3 of the Shahejie Formation are thought to be beneficial to hydrocarbon accumulation due to the high TOC.展开更多
The unconformity surface at the bottom of the Paleogene, located in the Sikeshu Sag of the Junggar Basin, Northwest China, is one of the most important hydrocarbon migration pathways and characterized by 3 layers of u...The unconformity surface at the bottom of the Paleogene, located in the Sikeshu Sag of the Junggar Basin, Northwest China, is one of the most important hydrocarbon migration pathways and characterized by 3 layers of upper coarse clastic rock, lower weathering crust and leached zone. The upper coarse clastic rock displays features of higher density, lower SDT and gamma-ray logging while the weathering crust in the lower part displays opposite features. The formation water is of NaHCO 3 type but at lower mineralization degree. The QGF indices are generally between 2.19 and 3.77 and the GOI parameters vary from 1% to 5%. From the southeast to the northwest of the sag, the content of saturated hydrocarbon increases from 30.81% to 53.74% while that of non-hydrocarbon and asphaltene decreases. The Pr/nC 17 decreases from 0.65 to 0.47 while the Ph/nC 18 decreases from 0.66 to 0.27, and the content of benzo[c] carbazole declines while the benzo[a] carbazole amount and (alkyl carbazole)/(alkyl+benzo carbazole) ratio both increase. These revealed that the hydrocarbons migrated from the sag to the ramp region along the unconformity surface.展开更多
Gas expansion caused by significant exhumation in the Sulige gas field in the Ordos Basin since Late Cretaceous and its effects on hydrocarbon accumulation have been investigated systematically based on comprehensive ...Gas expansion caused by significant exhumation in the Sulige gas field in the Ordos Basin since Late Cretaceous and its effects on hydrocarbon accumulation have been investigated systematically based on comprehensive analysis of geochemical,fluid inclusion and production data.The results indicate that gas volume expansion since the Late Cretaceous was the driving force for adjustment and secondary charging of tight sandstone gas reservoirs in the Sulige gas field of the Ordos Basin.The gas retained in the source rocks expanded in volume,resulting in gas re-expulsion,migration and secondary charging into reservoirs,while the gas volume expansion in the tight reservoirs caused the increase of gas saturation,gas-bearing area and gas column height,which worked together to increase the gas content of the reservoir and bring about large-scale gas accumulation events.The Sulige gas field had experienced a two-stage accumulation process,burial before the end of Early Cretaceous and uplifting since the Late Cretaceous.In the burial stage,natural gas was driven by hydrocarbon generation overpressure to migrate and accumulate,while in the uplifting stage,the gas volume expansion drove internal adjustment inside gas reservoirs and secondary charging to form new reservoirs.On the whole,the gas reservoir adjustment and secondary charging during uplifting stage is more significant in the eastern gas field than that in the west,which is favorable for forming gas-rich area.展开更多
基金supported jointly by the Science and Technology Project of Oil and Gas Exploration of the China National Petroleum Corporation (CNPC)(07-01c-01-04)the State Key Laboratory of Petroleum Resource and Prospecting of China University of Petroleum (pro 2009-02)
文摘One of the most important tasks of evaluating natural resources of petroliferous basins is to determine the organic matter abundance of source rocks in the basin.The usual method for assessing the organic carbon content of source rocks is based on laboratory analyses.There is a deviation in calculating organic carbon content due to the heterogeneous distribution of organic matter and the artificial factors when sampling.According to the continuous characteristics of information logging,the conventional logging curves(mainly acoustics and resistivity,etc.) were calibrated with the organic carbon experimental data of cores,cuttings or sidewall cores.The organic carbon content of source rocks of the 4 th(Es 4) and 3 rd(Es 3) members of the Shahejie Formation in western sag in the Liaohe depression was estimated directly by a great amount of continuous data including resistivity and acoustic logging,etc.Comparison between the results from computer processing and lab analysis of logging data shows that the organic carbon contents derived from the computer processing of logging data have the same reliability and accuracy as the lab analysis results.The present data show that this method is suitable to evaluate the source rocks of western sag in the Liaohe depression and has great potential in evaluating natural resources of sedimentary basins in the future.On the basis of logging data of source rocks,experimental data and existing geochemical analyses of the Liaohe Oilfield,the corresponding total organic carbon(TOC) isograms of source rocks were plotted.The source rocks of Es 4 and Es 3 of the Shahejie Formation are thought to be beneficial to hydrocarbon accumulation due to the high TOC.
基金financially supported jointly by the National Key Project of Science and Technology for Development of Large-size Oil & gas Fields and Coal-bed Gas (Grant No. 2008ZX05003-002)the State Key Laboratory of Petroleum Resources and Prospecting (No. prp2009-02)
文摘The unconformity surface at the bottom of the Paleogene, located in the Sikeshu Sag of the Junggar Basin, Northwest China, is one of the most important hydrocarbon migration pathways and characterized by 3 layers of upper coarse clastic rock, lower weathering crust and leached zone. The upper coarse clastic rock displays features of higher density, lower SDT and gamma-ray logging while the weathering crust in the lower part displays opposite features. The formation water is of NaHCO 3 type but at lower mineralization degree. The QGF indices are generally between 2.19 and 3.77 and the GOI parameters vary from 1% to 5%. From the southeast to the northwest of the sag, the content of saturated hydrocarbon increases from 30.81% to 53.74% while that of non-hydrocarbon and asphaltene decreases. The Pr/nC 17 decreases from 0.65 to 0.47 while the Ph/nC 18 decreases from 0.66 to 0.27, and the content of benzo[c] carbazole declines while the benzo[a] carbazole amount and (alkyl carbazole)/(alkyl+benzo carbazole) ratio both increase. These revealed that the hydrocarbons migrated from the sag to the ramp region along the unconformity surface.
基金Supported by the National Natural Science Foundation of China(41502132)China National Demonstration Project(2016ZX05050).
文摘Gas expansion caused by significant exhumation in the Sulige gas field in the Ordos Basin since Late Cretaceous and its effects on hydrocarbon accumulation have been investigated systematically based on comprehensive analysis of geochemical,fluid inclusion and production data.The results indicate that gas volume expansion since the Late Cretaceous was the driving force for adjustment and secondary charging of tight sandstone gas reservoirs in the Sulige gas field of the Ordos Basin.The gas retained in the source rocks expanded in volume,resulting in gas re-expulsion,migration and secondary charging into reservoirs,while the gas volume expansion in the tight reservoirs caused the increase of gas saturation,gas-bearing area and gas column height,which worked together to increase the gas content of the reservoir and bring about large-scale gas accumulation events.The Sulige gas field had experienced a two-stage accumulation process,burial before the end of Early Cretaceous and uplifting since the Late Cretaceous.In the burial stage,natural gas was driven by hydrocarbon generation overpressure to migrate and accumulate,while in the uplifting stage,the gas volume expansion drove internal adjustment inside gas reservoirs and secondary charging to form new reservoirs.On the whole,the gas reservoir adjustment and secondary charging during uplifting stage is more significant in the eastern gas field than that in the west,which is favorable for forming gas-rich area.
