The Upper Ordovician Wufeng-Lower Silurian Longmaxi shale is widely distributed in the Sichuan Basin and its periphery,which is the key stratum for marine shale gas exploration and development(E&D)in China.Based o...The Upper Ordovician Wufeng-Lower Silurian Longmaxi shale is widely distributed in the Sichuan Basin and its periphery,which is the key stratum for marine shale gas exploration and development(E&D)in China.Based on sedimentary environment,material basis,storage space,fracability and reservoir evolution data,the reservoir characteristics of the Wufeng-Longmaxi shale and their significance for shale gas E&D are systematically compared and analyzed in this paper.The results show that(1)the depocenter of the Wufeng(WF)-Longmaxi(LM)shale gradually migrates from east to west.The high-quality shale reservoirs in the eastern Sichuan Basin are mainly siliceous shales,which are primarily distributed in the graptolite shale interval of WF2-LM5.The high-quality reservoirs in the southern Sichuan Basin are mainly calcareous-siliceous and organic-rich argillaceous shales,which are distributed in the graptolite shale interval of WF2-LM7.(2)Deep shale gas(the burial depth>3500 m)in the Sichuan Basin has high-ultrahigh pressure and superior physical properties.The organic-rich siliceous,calcareous-siliceous and organic-rich argillaceous shales have suitable reservoir properties.The marginal area of the Sichuan Basin has a higher degree of pressure relief,which leads to the argillaceous and silty shales evolving into direct cap rocks with poor reservoir/good sealing capacity.(3)Combining shale gas exploration practices and impacts of lithofacies,depth,pressure coefficient and brittle-ductile transition on the reservoir properties,it is concluded that the favorable depth interval of the Wufeng-Longmaxi shale gas is 2200~4000 m under current technical conditions.(4)Aiming at the differential reservoir properties of the Wufeng-Longmaxi shale in the Sichuan Basin and its periphery,several suggestions for future research directions and E&D of shale gas are formulated.展开更多
In recent years,with the advancement of geothermal heating engineering technology,the projects and scale of geothermal heating have continued to grow.At present,geothermal development and utilization projects are most...In recent years,with the advancement of geothermal heating engineering technology,the projects and scale of geothermal heating have continued to grow.At present,geothermal development and utilization projects are mostly researched on economic evaluation methods,main control factors of benefits and case analysis of project benefits.Post-evaluation of economic benefits can provide strong support for improving existing projects,adjusting projects under construction,and guiding proposed projects,but there are few studies on post-evaluation of economic benefits of completed geothermal heating projects.In order to improve the economic benefits of geothermal heating projects and change extensive management to intensive management,this paper studies the post-evaluation principles,methods and evaluation indicators of the economic benefits of hydrothermal geothermal heating projects,and take the geothermal water heating project of S community in Xianyang City as an example to carry out the post-evaluation research on economic benefits.Through research,it is suggested to carry out post-economic evaluation of geothermal utilization projects that have been completed and run for 3 to 5 years.In order to do a good job in the post-evaluation of economic benefits,the evaluators should continue to track the progress of the project,collect and analyze various historical data in a timely manner,and select a variety of methods for prediction,comparison and mutual correction.In order to fully reflect the benefits of geothermal heating,the indirect benefit evaluation of energy conservation and emission reduction of geothermal heating projects will be strengthened in the future.展开更多
基金granted by the National Science and Technology Major Project of the Ministry of Science and Technology of China (Grant No. 2017ZX05036002–001)National Natural Science Foundation of China (No. 41202103, 41872124)SINOPEC Ministry of Science and Technology Project (Grant No. P17027–2)
文摘The Upper Ordovician Wufeng-Lower Silurian Longmaxi shale is widely distributed in the Sichuan Basin and its periphery,which is the key stratum for marine shale gas exploration and development(E&D)in China.Based on sedimentary environment,material basis,storage space,fracability and reservoir evolution data,the reservoir characteristics of the Wufeng-Longmaxi shale and their significance for shale gas E&D are systematically compared and analyzed in this paper.The results show that(1)the depocenter of the Wufeng(WF)-Longmaxi(LM)shale gradually migrates from east to west.The high-quality shale reservoirs in the eastern Sichuan Basin are mainly siliceous shales,which are primarily distributed in the graptolite shale interval of WF2-LM5.The high-quality reservoirs in the southern Sichuan Basin are mainly calcareous-siliceous and organic-rich argillaceous shales,which are distributed in the graptolite shale interval of WF2-LM7.(2)Deep shale gas(the burial depth>3500 m)in the Sichuan Basin has high-ultrahigh pressure and superior physical properties.The organic-rich siliceous,calcareous-siliceous and organic-rich argillaceous shales have suitable reservoir properties.The marginal area of the Sichuan Basin has a higher degree of pressure relief,which leads to the argillaceous and silty shales evolving into direct cap rocks with poor reservoir/good sealing capacity.(3)Combining shale gas exploration practices and impacts of lithofacies,depth,pressure coefficient and brittle-ductile transition on the reservoir properties,it is concluded that the favorable depth interval of the Wufeng-Longmaxi shale gas is 2200~4000 m under current technical conditions.(4)Aiming at the differential reservoir properties of the Wufeng-Longmaxi shale in the Sichuan Basin and its periphery,several suggestions for future research directions and E&D of shale gas are formulated.
文摘In recent years,with the advancement of geothermal heating engineering technology,the projects and scale of geothermal heating have continued to grow.At present,geothermal development and utilization projects are mostly researched on economic evaluation methods,main control factors of benefits and case analysis of project benefits.Post-evaluation of economic benefits can provide strong support for improving existing projects,adjusting projects under construction,and guiding proposed projects,but there are few studies on post-evaluation of economic benefits of completed geothermal heating projects.In order to improve the economic benefits of geothermal heating projects and change extensive management to intensive management,this paper studies the post-evaluation principles,methods and evaluation indicators of the economic benefits of hydrothermal geothermal heating projects,and take the geothermal water heating project of S community in Xianyang City as an example to carry out the post-evaluation research on economic benefits.Through research,it is suggested to carry out post-economic evaluation of geothermal utilization projects that have been completed and run for 3 to 5 years.In order to do a good job in the post-evaluation of economic benefits,the evaluators should continue to track the progress of the project,collect and analyze various historical data in a timely manner,and select a variety of methods for prediction,comparison and mutual correction.In order to fully reflect the benefits of geothermal heating,the indirect benefit evaluation of energy conservation and emission reduction of geothermal heating projects will be strengthened in the future.