By conducting organic geochemical analysis of the samples taken from the drilled wells in Baiyun Sag of Pearl River Mouth Basin,China,the development characteristics of hydrocarbon source rocks in the sag are clarifie...By conducting organic geochemical analysis of the samples taken from the drilled wells in Baiyun Sag of Pearl River Mouth Basin,China,the development characteristics of hydrocarbon source rocks in the sag are clarified.Reconstruct the current geothermal field of the sag and restore the tectonic-thermal evolution process to predict the type,scale,and distribution of resources in Baiyun Sag through thermal pressure simulation experiments and numerical simulation.The Baiyun Sag is characterized by the development of Paleogene shallow lacustrine source rocks,which are deposited in a slightly oxidizing environment.The source rocks are mainly composed of terrestrial higher plants,with algae making a certain contribution,and are oil and gas source rocks.Current geothermal field of the sag was reconstructed,in which the range of geothermal gradients is(3.5–5.2)℃/100 m,showing an overall increasing trend from northwest to southeast,with significant differences in geothermal gradients across different sub-sags.Baiyun Sag has undergone two distinct periods of extensional process,the Eocene and Miocene,since the Cenozoic era.These two periods of heating and warming events have been identified,accelerating the maturation and evolution of source rocks.The main body of ancient basal heat flow value reached its highest at 13.82 Ma.The basin modelling results show that the maturity of source rocks is significantly higher in Baiyun main sub-sag than that in other sub-sags.The Eocene Wenchang Formation is currently in the stage of high maturity to over maturity,while the Eocene Enping Formation has reached the stage of maturity to high maturity.The rock thermal simulation experiment shows that the shallow lacustrine mudstone of the Wenchang Formation has a good potential of generating gas from kerogen cracking with high gas yield and long period of gas window.Shallow lacustrine mudstone of the Enping Formation has a good ability to generate light oil,and has ability to generate kerogen cracking gas in the late stage.The gas yield of shallow lacustrine mudstone of the Enping Formation is less than that of shallow lacustrine mudstone of the Wenchang Formation and the delta coal-bearing mudstone of the Enping Formation.The numerical simulation results indicate that the source rocks of Baiyun main sub-sag generate hydrocarbons earlier and have significantly higher hydrocarbon generation intensity than other sub-sags,with an average of about 1200×10^(4)t/km^(2).Oil and gas resources were mainly distributed in Baiyun main sub-sag and the main source rocks are distributed in the 3^(rd)and 4^(th)members of Wenchang Formation.Four favorable zones are selected for the division and evaluation of migration and aggregation units:No.(1)Panyu 30 nose-shaped structural belt,No.(3)Liuhua 29 nose-shaped uplift belt and Liwan 3 nose-shaped uplift belt,No.(2)gentle slope belt of Baiyun east sag,and No.(8)Baiyun 1 low-uplift.展开更多
Shale acoustic logging response law is complex due to the multiple minerals and pores,which limits the application of acoustic logging in shale reservoir parameter evaluation,therefore clarifying the shale acoustic lo...Shale acoustic logging response law is complex due to the multiple minerals and pores,which limits the application of acoustic logging in shale reservoir parameter evaluation,therefore clarifying the shale acoustic logging response law is of great importance.Different petrophysical models are adopted for the equivalence of organic matter,clay,matrix minerals,and fractures,in Wufeng-Longmaxi shale formation in the Jiaoshiba area.Finally,the self-consistent approximation model is used to combine different components,and a shale petrophysical model with a complex pore structure is constructed.The model verification results show it has good predictability for shale.Based on the model,the effect of different mineral compositions and different types of pores are studied.The results show that:1)The effect of clay and organic matter is very complex,and the variation laws of layered clay(organic matter)and dispersed clay(organic matter)on the acoustic wave are consistent.2)Layered clay or organic matter leads to the formation anisotropy increase,which makes the acoustic time difference greater than that of containing dispersed clay(organic matter).3)The fracture is the main control factor of anisotropy,and the anisotropy of gas-bearing fracture is higher than that of water/oil fracture.展开更多
基金Supported by the National Oil and Gas Resource Evaluation Project for the 14th Five Year Plan of the Ministry of Natural Resources(QGYQZYPJ2022-3)China National Offshore Oil Corporation"14th Five Year Plan"Major Science and Technology Project(KJGG2022-0103-03)。
文摘By conducting organic geochemical analysis of the samples taken from the drilled wells in Baiyun Sag of Pearl River Mouth Basin,China,the development characteristics of hydrocarbon source rocks in the sag are clarified.Reconstruct the current geothermal field of the sag and restore the tectonic-thermal evolution process to predict the type,scale,and distribution of resources in Baiyun Sag through thermal pressure simulation experiments and numerical simulation.The Baiyun Sag is characterized by the development of Paleogene shallow lacustrine source rocks,which are deposited in a slightly oxidizing environment.The source rocks are mainly composed of terrestrial higher plants,with algae making a certain contribution,and are oil and gas source rocks.Current geothermal field of the sag was reconstructed,in which the range of geothermal gradients is(3.5–5.2)℃/100 m,showing an overall increasing trend from northwest to southeast,with significant differences in geothermal gradients across different sub-sags.Baiyun Sag has undergone two distinct periods of extensional process,the Eocene and Miocene,since the Cenozoic era.These two periods of heating and warming events have been identified,accelerating the maturation and evolution of source rocks.The main body of ancient basal heat flow value reached its highest at 13.82 Ma.The basin modelling results show that the maturity of source rocks is significantly higher in Baiyun main sub-sag than that in other sub-sags.The Eocene Wenchang Formation is currently in the stage of high maturity to over maturity,while the Eocene Enping Formation has reached the stage of maturity to high maturity.The rock thermal simulation experiment shows that the shallow lacustrine mudstone of the Wenchang Formation has a good potential of generating gas from kerogen cracking with high gas yield and long period of gas window.Shallow lacustrine mudstone of the Enping Formation has a good ability to generate light oil,and has ability to generate kerogen cracking gas in the late stage.The gas yield of shallow lacustrine mudstone of the Enping Formation is less than that of shallow lacustrine mudstone of the Wenchang Formation and the delta coal-bearing mudstone of the Enping Formation.The numerical simulation results indicate that the source rocks of Baiyun main sub-sag generate hydrocarbons earlier and have significantly higher hydrocarbon generation intensity than other sub-sags,with an average of about 1200×10^(4)t/km^(2).Oil and gas resources were mainly distributed in Baiyun main sub-sag and the main source rocks are distributed in the 3^(rd)and 4^(th)members of Wenchang Formation.Four favorable zones are selected for the division and evaluation of migration and aggregation units:No.(1)Panyu 30 nose-shaped structural belt,No.(3)Liuhua 29 nose-shaped uplift belt and Liwan 3 nose-shaped uplift belt,No.(2)gentle slope belt of Baiyun east sag,and No.(8)Baiyun 1 low-uplift.
基金financially supported by the National Natural Science Foundation of China(NSFC)Basic Research Program on Deep Petroleum Resource Accumulation and Key Engineering Technologies(Grant No.U19B6003-04-03-03)The Key Project of Sinopec Ministry of Science and Technology(Grant No.PE19012-1)the National Research Council of Science and Technology Major Project(Grant No.2016ZX05060-001-012)。
文摘Shale acoustic logging response law is complex due to the multiple minerals and pores,which limits the application of acoustic logging in shale reservoir parameter evaluation,therefore clarifying the shale acoustic logging response law is of great importance.Different petrophysical models are adopted for the equivalence of organic matter,clay,matrix minerals,and fractures,in Wufeng-Longmaxi shale formation in the Jiaoshiba area.Finally,the self-consistent approximation model is used to combine different components,and a shale petrophysical model with a complex pore structure is constructed.The model verification results show it has good predictability for shale.Based on the model,the effect of different mineral compositions and different types of pores are studied.The results show that:1)The effect of clay and organic matter is very complex,and the variation laws of layered clay(organic matter)and dispersed clay(organic matter)on the acoustic wave are consistent.2)Layered clay or organic matter leads to the formation anisotropy increase,which makes the acoustic time difference greater than that of containing dispersed clay(organic matter).3)The fracture is the main control factor of anisotropy,and the anisotropy of gas-bearing fracture is higher than that of water/oil fracture.
