The rich coal-bed methane resources in the Turpan-Hami Basin are mainly located in the Shisanjianfang,Hami,Shanshan,Sha'erhu,Kekeya,Kerjian,Aidinghu inclines and the Dananhu coal-bed methane reservoirs. The big-ge...The rich coal-bed methane resources in the Turpan-Hami Basin are mainly located in the Shisanjianfang,Hami,Shanshan,Sha'erhu,Kekeya,Kerjian,Aidinghu inclines and the Dananhu coal-bed methane reservoirs. The big-ger coal-bed reservoirs are sitting at a depth of less than 1500 m. The coalbed methane generation,storage and confin-ing conditions of the Turpan-Hami basin can be indicated by eight key parameters. They are coal-bed thickness,coal rank,missing period,permeability,Langmuir volume,rock covering ability,structural confinement and hydrodynamic sealing environment. These parameters constitute a comprehensive appraisal index system of the coal-bed methane res-ervoir characteristics of the Turpan-Hami basin. In these parameters,the missing period of coal-bed methane is indi-cated by a stratum missing intensity factor. It reflects the relative exposure period of coal series. The results of a fuzzy comprehensive judgment showed that the Shisanjianfang coal-bed methane reservoir has the best prospects for exploita-tion and the Sha'erhu,Shanshan,Hami coal-bed methane reservoirs are next in line.展开更多
Achieving a thorough understanding of how primary sedimentary granularity drives considerable heterogeneity in internal reservoir attributes of terrigenous fine-grained deposits is of great significance.We investigate...Achieving a thorough understanding of how primary sedimentary granularity drives considerable heterogeneity in internal reservoir attributes of terrigenous fine-grained deposits is of great significance.We investigated the quantitative differentiation and its corresponding driving forces of physical reservoir properties and pore-structure characteristics of silty-mud sediments in the Upper Triassic Xujiahe Formation(SW China)using a multi-method approach.The results show that the micro-mesopore volume and surface area of mudstones/shales are apparently higher than those of silty mudstones and a remarkable threefold rise in average permeability also presents.Extensively distributed bitumen pores occurring mostly along brittle mineral grains or forming clay-organic complexes make considerable contributions to shrinking microcracks.Furthermore,an evidently higher concentration of clay minerals in mudstone/shale reservoirs is primarily responsible for development of the two types of clay intercrystalline pores distributed along grain aggregates and between well-oriented platelets.These two major causes facilitate the formation of micro-bedding fractures/non-bedding micro fractures and connected fracture and pore-fracture networks,and also high-quality argillaceous reservoirs by strongly enhancing storage spaces and seepage capacities.Finally,a conceptual model is established for interpreting a differential reservoir-forming mechanism and corresponding two-sided effects on petrophysical and reservoir quality properties for continental silty-mud sediments.展开更多
Based on core observation, thin section examination, fluid inclusions analysis, carbon and oxygen isotopic composition analysis, and other approaches, the structural and burial evolution histories were investigated, a...Based on core observation, thin section examination, fluid inclusions analysis, carbon and oxygen isotopic composition analysis, and other approaches, the structural and burial evolution histories were investigated, and the diagenetic evolution process and genetic/development models were systematically discussed of the Upper Paleozoic Permian clastic rock reservoirs in the Bohai Bay Basin, East China. The Bohai Bay Basin underwent three stages of burial and two stages of uplifting in the Upper Paleozoic. Consequently, three stages of acid dissolution generated by the thermal evolution of kerogen, and two stages of meteoric freshwater leaching occurred. Dissolution in deeply buried, nearly closed diagenetic system was associated with the precipitation of authigenic clay and quartz, leading to a limited increase in storage space. Different structural uplifting–subsidence processes of tectonic zones resulted in varying diagenetic–reservoir-forming processes of the Permian clastic reservoirs. Three genetic models of reservoirs are recognized. The Model I reservoirs with pores formed in shallow strata and buried in shallow to medium strata underwent two stages of exposure to long-term open environment and two stages of meteoric freshwater leaching to enhance pores near the surface, and were shallowly buried in the late stage, exhibiting the dominance of secondary pores and the best physical properties. The Model Ⅱ reservoirs with pores formed in shallow strata and preserved due to modification after deep burial experienced an early exposure-open to late burial-closed environment, where pore types were modified due to dissolution, exhibiting the dominance of numerous secondary solution pores in feldspar and the physical properties inferior to Model I. The Model Ⅲ reservoirs with pores formed after being regulated after multiple periods of burial and dissolution experienced a dissolution of acidic fluids of organic origin under a near-closed to closed environment, exhibiting the dominance of intercrystalline micropores in kaolinite and the poorest physical properties. The target reservoirs lied in the waterflood area in the geological period of meteoric freshwater leaching, and are now the Model Ⅱ deep reservoirs in the slope zone–depression zone. They are determined as favorable options for subsequent exploration.展开更多
The Upper Paleozoic in the north part of Tianhuan depression in the Ordos Basin,NW China has lower hydrocarbon generation intensity and complex gas-water relationship,the main factors controlling the formation of tigh...The Upper Paleozoic in the north part of Tianhuan depression in the Ordos Basin,NW China has lower hydrocarbon generation intensity and complex gas-water relationship,the main factors controlling the formation of tight sandstone gas and the distribution of tight sandstone gas in the low hydrocarbon generation intensity area are studied.Through two-dimensional physical simulation experiment of hydrocarbon accumulation,analysis of reservoir micro-pore-throat hydrocarbon system and dissection of typical gas reservoirs,the evaluation models of gas injection pressure,reservoir physical property,and gas generation threshold were established to determine the features of tight gas reservoirs in low hydrocarbon intensity area:(1)at the burial depth of less than 3 000 m,the hydrocarbon generation intensity ofis high enough to maintain effective charging;(2)tight sandstone in large scale occurrence is conducive to accumulation of tight gas;(3)differences in reservoir physical property control the distribution of gas pool,for the channel sandstone reservoirs,ones with better physical properties generally concentrate in the middle of sandstone zone and local structural highs;ones with poor physical properties have low gas content generally.Based on the dissection of the gas reservoir in the north Tianhuan depression,the formation of tight gas reservoirs in low hydrocarbon generating intensity area are characterized by"long term continuous charging under hydrocarbon generation pressure,gas accumulation in large scale tight sandstone,pool control by difference in reservoir physical property,and local sweet spot",and the tight gas pools are distributed in discontinuous"sheets"on the plane.This understanding has been proved by expanding exploration of tight sandstone gas in the north Tianhuan depression.展开更多
Biogenic quartz in the Upper Ordovician Wufeng Formation to Lower Silurian Longmaxi Formation(WufengLongmaxi)shale layers in the Sichuan Basin and its periphery is qualitatively analyzed and quantitatively characteriz...Biogenic quartz in the Upper Ordovician Wufeng Formation to Lower Silurian Longmaxi Formation(WufengLongmaxi)shale layers in the Sichuan Basin and its periphery is qualitatively analyzed and quantitatively characterized by organic petrologic,mineralogic,and geochemical methods to find out the coupling effect between organic matter and quartz.(1)There are two types of biogenic quartz in the shale layers:Type I quartz is submicron quartz appearing in clusters around the organic matter.Type II quartz is in nano-scale grain size and floats in spherical shape on organic matter,with grains in point-to-point or surface-to-surface contact;this type of quartz is mainly biologic origin and slightly affected by hydrothermal activity in local parts.(2)The reservoirs in the Wufeng-Longmaxi formations is consistent in distribution with biogenic silica content in them,and mainly concentrated at the bottom of the Wufeng-Longmaxi formations,and is thinner in the Changning and Weiyuan regions,while thicker in the Fuling region.(3)The biogenic quartz in the Wufeng-Longmaxi shale worked through the entire evolution process of hydrocarbon generation.The presence of biogenic quartz can enhance the development of organic matter pores and microcracks,and can effectively preserve the organic matter pores and residual intergranular pores,forming"biological silicon intergranular pores,organic pores and micro-fractures".This would benefit later hydraulic fracturing and result in high production/stable production of well.The coupling effect between biogenic quartz development and organic matter evolution and hydrocarbon generation is a critical factor for high-quality shale reservoir development.展开更多
基金Projects 2002CB211702 supported by the National Key Basic Research and Development Program of China2006AA06Z235 by the High Technology Research and Development Program of China
文摘The rich coal-bed methane resources in the Turpan-Hami Basin are mainly located in the Shisanjianfang,Hami,Shanshan,Sha'erhu,Kekeya,Kerjian,Aidinghu inclines and the Dananhu coal-bed methane reservoirs. The big-ger coal-bed reservoirs are sitting at a depth of less than 1500 m. The coalbed methane generation,storage and confin-ing conditions of the Turpan-Hami basin can be indicated by eight key parameters. They are coal-bed thickness,coal rank,missing period,permeability,Langmuir volume,rock covering ability,structural confinement and hydrodynamic sealing environment. These parameters constitute a comprehensive appraisal index system of the coal-bed methane res-ervoir characteristics of the Turpan-Hami basin. In these parameters,the missing period of coal-bed methane is indi-cated by a stratum missing intensity factor. It reflects the relative exposure period of coal series. The results of a fuzzy comprehensive judgment showed that the Shisanjianfang coal-bed methane reservoir has the best prospects for exploita-tion and the Sha'erhu,Shanshan,Hami coal-bed methane reservoirs are next in line.
基金supported by the Science Foundation for Distinguished Young Scholars of China University of Petroleum,Beijing(No.2462020QNXZ004)the National Natural Science and Technology Major Project(No.2016ZX05034-001 and 2017ZX05035-002)。
文摘Achieving a thorough understanding of how primary sedimentary granularity drives considerable heterogeneity in internal reservoir attributes of terrigenous fine-grained deposits is of great significance.We investigated the quantitative differentiation and its corresponding driving forces of physical reservoir properties and pore-structure characteristics of silty-mud sediments in the Upper Triassic Xujiahe Formation(SW China)using a multi-method approach.The results show that the micro-mesopore volume and surface area of mudstones/shales are apparently higher than those of silty mudstones and a remarkable threefold rise in average permeability also presents.Extensively distributed bitumen pores occurring mostly along brittle mineral grains or forming clay-organic complexes make considerable contributions to shrinking microcracks.Furthermore,an evidently higher concentration of clay minerals in mudstone/shale reservoirs is primarily responsible for development of the two types of clay intercrystalline pores distributed along grain aggregates and between well-oriented platelets.These two major causes facilitate the formation of micro-bedding fractures/non-bedding micro fractures and connected fracture and pore-fracture networks,and also high-quality argillaceous reservoirs by strongly enhancing storage spaces and seepage capacities.Finally,a conceptual model is established for interpreting a differential reservoir-forming mechanism and corresponding two-sided effects on petrophysical and reservoir quality properties for continental silty-mud sediments.
基金Supported by the National Natural Science Foundation(42222208,41821002)China National Science and Technology Major Project(2016ZX05006-007)Mount Taishan Scholar Young Expert Project(201909061).
文摘Based on core observation, thin section examination, fluid inclusions analysis, carbon and oxygen isotopic composition analysis, and other approaches, the structural and burial evolution histories were investigated, and the diagenetic evolution process and genetic/development models were systematically discussed of the Upper Paleozoic Permian clastic rock reservoirs in the Bohai Bay Basin, East China. The Bohai Bay Basin underwent three stages of burial and two stages of uplifting in the Upper Paleozoic. Consequently, three stages of acid dissolution generated by the thermal evolution of kerogen, and two stages of meteoric freshwater leaching occurred. Dissolution in deeply buried, nearly closed diagenetic system was associated with the precipitation of authigenic clay and quartz, leading to a limited increase in storage space. Different structural uplifting–subsidence processes of tectonic zones resulted in varying diagenetic–reservoir-forming processes of the Permian clastic reservoirs. Three genetic models of reservoirs are recognized. The Model I reservoirs with pores formed in shallow strata and buried in shallow to medium strata underwent two stages of exposure to long-term open environment and two stages of meteoric freshwater leaching to enhance pores near the surface, and were shallowly buried in the late stage, exhibiting the dominance of secondary pores and the best physical properties. The Model Ⅱ reservoirs with pores formed in shallow strata and preserved due to modification after deep burial experienced an early exposure-open to late burial-closed environment, where pore types were modified due to dissolution, exhibiting the dominance of numerous secondary solution pores in feldspar and the physical properties inferior to Model I. The Model Ⅲ reservoirs with pores formed after being regulated after multiple periods of burial and dissolution experienced a dissolution of acidic fluids of organic origin under a near-closed to closed environment, exhibiting the dominance of intercrystalline micropores in kaolinite and the poorest physical properties. The target reservoirs lied in the waterflood area in the geological period of meteoric freshwater leaching, and are now the Model Ⅱ deep reservoirs in the slope zone–depression zone. They are determined as favorable options for subsequent exploration.
基金Supported by the China National Science and Technology Major Project(2016ZX05047)
文摘The Upper Paleozoic in the north part of Tianhuan depression in the Ordos Basin,NW China has lower hydrocarbon generation intensity and complex gas-water relationship,the main factors controlling the formation of tight sandstone gas and the distribution of tight sandstone gas in the low hydrocarbon generation intensity area are studied.Through two-dimensional physical simulation experiment of hydrocarbon accumulation,analysis of reservoir micro-pore-throat hydrocarbon system and dissection of typical gas reservoirs,the evaluation models of gas injection pressure,reservoir physical property,and gas generation threshold were established to determine the features of tight gas reservoirs in low hydrocarbon intensity area:(1)at the burial depth of less than 3 000 m,the hydrocarbon generation intensity ofis high enough to maintain effective charging;(2)tight sandstone in large scale occurrence is conducive to accumulation of tight gas;(3)differences in reservoir physical property control the distribution of gas pool,for the channel sandstone reservoirs,ones with better physical properties generally concentrate in the middle of sandstone zone and local structural highs;ones with poor physical properties have low gas content generally.Based on the dissection of the gas reservoir in the north Tianhuan depression,the formation of tight gas reservoirs in low hydrocarbon generating intensity area are characterized by"long term continuous charging under hydrocarbon generation pressure,gas accumulation in large scale tight sandstone,pool control by difference in reservoir physical property,and local sweet spot",and the tight gas pools are distributed in discontinuous"sheets"on the plane.This understanding has been proved by expanding exploration of tight sandstone gas in the north Tianhuan depression.
基金Supported by the China National Science and Technology Major Project(2017ZX05035)。
文摘Biogenic quartz in the Upper Ordovician Wufeng Formation to Lower Silurian Longmaxi Formation(WufengLongmaxi)shale layers in the Sichuan Basin and its periphery is qualitatively analyzed and quantitatively characterized by organic petrologic,mineralogic,and geochemical methods to find out the coupling effect between organic matter and quartz.(1)There are two types of biogenic quartz in the shale layers:Type I quartz is submicron quartz appearing in clusters around the organic matter.Type II quartz is in nano-scale grain size and floats in spherical shape on organic matter,with grains in point-to-point or surface-to-surface contact;this type of quartz is mainly biologic origin and slightly affected by hydrothermal activity in local parts.(2)The reservoirs in the Wufeng-Longmaxi formations is consistent in distribution with biogenic silica content in them,and mainly concentrated at the bottom of the Wufeng-Longmaxi formations,and is thinner in the Changning and Weiyuan regions,while thicker in the Fuling region.(3)The biogenic quartz in the Wufeng-Longmaxi shale worked through the entire evolution process of hydrocarbon generation.The presence of biogenic quartz can enhance the development of organic matter pores and microcracks,and can effectively preserve the organic matter pores and residual intergranular pores,forming"biological silicon intergranular pores,organic pores and micro-fractures".This would benefit later hydraulic fracturing and result in high production/stable production of well.The coupling effect between biogenic quartz development and organic matter evolution and hydrocarbon generation is a critical factor for high-quality shale reservoir development.
