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
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.