Turbidite sandstones have become increasingly significant in hydrocarbon exploration.Carbonate cementation occur commonly in turbidite reservoirs developing within the Paleocene lacustrine basins,Northeastern China.Th...Turbidite sandstones have become increasingly significant in hydrocarbon exploration.Carbonate cementation occur commonly in turbidite reservoirs developing within the Paleocene lacustrine basins,Northeastern China.This study utilizes core data,thin section data and production data to investigate the interaction between the carbonate cementation and hydrocarbon charge within turbidite reservoirs in the Niuzhuang Sub-sag of the Dongying Sag,Bohai Bay Basin,East China.The results reveal that the carbonate cementation is mainly developed at the top and bottom of the turbidite sandbodies,and even forms carbonate cement shells.Three stages of hydrocarbon accumulation are identified based on fluid inclusion analysis:stage I(27.5–24.6 Ma),stage II(14.0–5.0 Ma),and stage III(5.0–0 Ma).The interaction between the carbonate cementation and hydrocarbon charge has significant controls on the formation of a turbidite reservoir.The temporal relations and intensity relations between the two factors should be considered significantly.Moreover,hydrocarbon charge during the early stage can inhibit the carbonate cementation,favoring the hydrocarbon accumulation in turbidite reservoirs.Many deep-lacustrine turbidite sandbodies surrounded by source rocks with abnormal high pressure,are also favorable for hydrocarbon accumulation.These results suggest that some deeply buried turbidite sandbodies with similar geological settings have high potential for hydrocarbon exploration.展开更多
Shale intercalations in salt deposits of the upper part of the third member of the Shahejie Formation （Es3） in the Liutun sag have industrial oil and gas potential. This article classifies and evaluates lithology, p...Shale intercalations in salt deposits of the upper part of the third member of the Shahejie Formation （Es3） in the Liutun sag have industrial oil and gas potential. This article classifies and evaluates lithology, pore systems, porosity, permeability and pore characteristics using core logs, XRD, SEM, lab and log porosity data of shale reservoirs in the salt formation. The lithology of these reservoirs is complex as parts of complex salt rhythms composed of clastic, carbonate and eva- poritic rocks. Their rigid minerals contents and total organic carbon are high, the organic type is good, and the maturity of organic matter ranges from medium to low. There are strong overpressures and natural hydraulic fractures. Organic matter pores and matrix-related shale pores provide an apprecia- ble part of the permeability. Different methods of measurement, sonic logging and equivalent cycle counting-point are used to evaluate the different types of porosity and permeability. A preliminary evaluation of shale permeability has been made by using fracture data from cores and image logging, and it is considered that the organic nets composed of organic matter pores generated in the maturation stage of shale have greatly increased oil permeability. On the above basis, this article proposes classifi- cation criteria for the upper Es3 inter-salt shale oil reservoirs to provide a foundation for evaluating other shale oil reservoirs in this area.展开更多
The conception of special geologic bodies has been applied in this study to define and illustrate economic oil and gas reservoirs in sandbodies, which is helpful for hydrocarbon forecast and exploration. Using the com...The conception of special geologic bodies has been applied in this study to define and illustrate economic oil and gas reservoirs in sandbodies, which is helpful for hydrocarbon forecast and exploration. Using the comprehensive analysis of drilling, logging, seismic, seismic attribute extraction, and logging constrained inversion in 3D data volume, the special geologic bodies of the Shahejie Formation（Ps^1s） in northern Qikou sag, which have good hydrocarbon potential, are identified and described under the constraint of sequence stratigraphic framework. The dimensions, geometry, and spatial distribution features of the special geologic bodies, as well as their inner architectures and sequence-structure patterns, are also ascertained. The geologic bodies evolved from relative centralization in the middle part of the lacustrine basin in the early stage of Ps1~s Formation, to several dispersive isolated parts in the later stage. This shows a small cycle interval（~2.5 Ma） at the end of the whole transgressive depositional process of Ps1（~7.5 Ma） during the expansion of the lake and relative lake level rise, with the control of sediments supply and fault-related subsidence, which effect the evolution of the sedimentary system. According to the relevance and regularity of the geologic bodies＇ development, different types of potential profitable reservoir traps, including the lithologic lenticular traps, lithologic updip pinchout traps, and structural-lithologic composite traps, can be preserved in the study area. In addition, the internal architecture models provide scientific basis for further hydrocarbon exploration in the frontier basin without enough data.展开更多
基金supported by the Open Fund(Grant No.PLC20190101)of State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation,Chengdu University of Technologythe National Natural Science Foundation of China(Grant No.41703060)+2 种基金the Fundamental Research Funds for the Central Universities(Grant No.20CX02118A)the Opening Fund of Key Laboratory of Deep Oil&Gas,the Major Scientific and Technological Innovation Project of Shandong Province(Grant Nos.2017CXGC1602,2017CXGC1608)the Innovation Project of Postgraduate in Shandong University of Science and Technology(Grant No.SDKDYC190211)。
文摘Turbidite sandstones have become increasingly significant in hydrocarbon exploration.Carbonate cementation occur commonly in turbidite reservoirs developing within the Paleocene lacustrine basins,Northeastern China.This study utilizes core data,thin section data and production data to investigate the interaction between the carbonate cementation and hydrocarbon charge within turbidite reservoirs in the Niuzhuang Sub-sag of the Dongying Sag,Bohai Bay Basin,East China.The results reveal that the carbonate cementation is mainly developed at the top and bottom of the turbidite sandbodies,and even forms carbonate cement shells.Three stages of hydrocarbon accumulation are identified based on fluid inclusion analysis:stage I(27.5–24.6 Ma),stage II(14.0–5.0 Ma),and stage III(5.0–0 Ma).The interaction between the carbonate cementation and hydrocarbon charge has significant controls on the formation of a turbidite reservoir.The temporal relations and intensity relations between the two factors should be considered significantly.Moreover,hydrocarbon charge during the early stage can inhibit the carbonate cementation,favoring the hydrocarbon accumulation in turbidite reservoirs.Many deep-lacustrine turbidite sandbodies surrounded by source rocks with abnormal high pressure,are also favorable for hydrocarbon accumulation.These results suggest that some deeply buried turbidite sandbodies with similar geological settings have high potential for hydrocarbon exploration.
基金supported by the National Science and Tech-nology Major Project(No.2011ZX05006-004)Open Foundation of the Key Laboratory of Tectonics and Petroleum Resource of Ministry of Education(No.TPR-2013-21)Fundamental Research Funds for the Central Universities,China University of Geosciences(Wuhan)(No.CUGL140808)
文摘Shale intercalations in salt deposits of the upper part of the third member of the Shahejie Formation （Es3） in the Liutun sag have industrial oil and gas potential. This article classifies and evaluates lithology, pore systems, porosity, permeability and pore characteristics using core logs, XRD, SEM, lab and log porosity data of shale reservoirs in the salt formation. The lithology of these reservoirs is complex as parts of complex salt rhythms composed of clastic, carbonate and eva- poritic rocks. Their rigid minerals contents and total organic carbon are high, the organic type is good, and the maturity of organic matter ranges from medium to low. There are strong overpressures and natural hydraulic fractures. Organic matter pores and matrix-related shale pores provide an apprecia- ble part of the permeability. Different methods of measurement, sonic logging and equivalent cycle counting-point are used to evaluate the different types of porosity and permeability. A preliminary evaluation of shale permeability has been made by using fracture data from cores and image logging, and it is considered that the organic nets composed of organic matter pores generated in the maturation stage of shale have greatly increased oil permeability. On the above basis, this article proposes classifi- cation criteria for the upper Es3 inter-salt shale oil reservoirs to provide a foundation for evaluating other shale oil reservoirs in this area.
基金provided by colleagues of Petro China Dagang Oilfield Companythe National Key Projects of China (Nos. 2011ZX05009-002, 2016ZX05006006-002) for financial support
文摘The conception of special geologic bodies has been applied in this study to define and illustrate economic oil and gas reservoirs in sandbodies, which is helpful for hydrocarbon forecast and exploration. Using the comprehensive analysis of drilling, logging, seismic, seismic attribute extraction, and logging constrained inversion in 3D data volume, the special geologic bodies of the Shahejie Formation（Ps^1s） in northern Qikou sag, which have good hydrocarbon potential, are identified and described under the constraint of sequence stratigraphic framework. The dimensions, geometry, and spatial distribution features of the special geologic bodies, as well as their inner architectures and sequence-structure patterns, are also ascertained. The geologic bodies evolved from relative centralization in the middle part of the lacustrine basin in the early stage of Ps1~s Formation, to several dispersive isolated parts in the later stage. This shows a small cycle interval（~2.5 Ma） at the end of the whole transgressive depositional process of Ps1（~7.5 Ma） during the expansion of the lake and relative lake level rise, with the control of sediments supply and fault-related subsidence, which effect the evolution of the sedimentary system. According to the relevance and regularity of the geologic bodies＇ development, different types of potential profitable reservoir traps, including the lithologic lenticular traps, lithologic updip pinchout traps, and structural-lithologic composite traps, can be preserved in the study area. In addition, the internal architecture models provide scientific basis for further hydrocarbon exploration in the frontier basin without enough data.
