A large number of in-situ volcanic reservoirs have been discovered from the Meso-Cenozoic rift basin group in eastern China.Based on drilling results in combination with geological and geophysical analysis,a case stud...A large number of in-situ volcanic reservoirs have been discovered from the Meso-Cenozoic rift basin group in eastern China.Based on drilling results in combination with geological and geophysical analysis,a case study from the Early Cretaceous Xujiaweizi fault-depression shows that the formation mechanism of in-situ volcanic reservoirs is characterized by"fault-controlled body,body-controlled facies,facies-controlled reservoir,and reservoir-controlled accumulation".In other words,deep faults control the volcanic eruption type,volcanic body,and gas reservoir distribution;the volcanic body determines the spatial distribution of volcanic facies and volcanic gas reservoir size;the volcanic facies control reservoir physical properties and effective thickness of gas formation;the volcanic reservoir properties control gas reservoir type and gas productivity.The result is useful to guiding the discovery of in-situ volcanic gas reservoirs in faulted basins in both theory and practice.展开更多
There are widespread Mesozoic–Cenozoic terrestrial volcanic activities in East China,and they produced favorable geologic factors for the volcanic reservoirs.To reveal the spatio-temporal evolution of regional volcan...There are widespread Mesozoic–Cenozoic terrestrial volcanic activities in East China,and they produced favorable geologic factors for the volcanic reservoirs.To reveal the spatio-temporal evolution of regional volcanisms and their tectonic setting,we subdivide Mesozoic–Cenozoic volcanic activities into 6 volcanic cycles(Ⅰ–Ⅵ),and summarize the temporal-spatial distribution,rock association and tectonic setting of each cycle.The Cycle I forms a post-orogenic intraplate bimodal volcanic association.The cyclesⅡandⅢinclude arc volcanic associations formed in compressional and extensional subduction environments,respectively.The CycleⅣcontains a post-orogenic arc bimodal association.The CycleⅤis a basaltic association of tholeiite series under initial rift setting,and the CycleⅥis basaltic association of alkaline series under typical rift setting.The volcanic strata between each cycle are bounded by regional unconformity.The above 6 volcanic cycles correspond to 6 sequential stages of tectonic evolutions from the Early Jurassic post-orogeny,the Mid-Jurassic–Cretaceous subduction of the paleo-Pacific Plate to the Cenozoic marginal rifting.According to the geological characteristics of volcanic reservoirs in different volcanic cycles,it is put forward that the CycleⅤis the major formation period of volcanic reservoirs in East China and should be the focus of exploration,and that the volcanic reservoirs of the CycleⅣare also worthy of attention.展开更多
基金supported by the National Basic Research Program of China(Grant No.2009CB219308)
文摘A large number of in-situ volcanic reservoirs have been discovered from the Meso-Cenozoic rift basin group in eastern China.Based on drilling results in combination with geological and geophysical analysis,a case study from the Early Cretaceous Xujiaweizi fault-depression shows that the formation mechanism of in-situ volcanic reservoirs is characterized by"fault-controlled body,body-controlled facies,facies-controlled reservoir,and reservoir-controlled accumulation".In other words,deep faults control the volcanic eruption type,volcanic body,and gas reservoir distribution;the volcanic body determines the spatial distribution of volcanic facies and volcanic gas reservoir size;the volcanic facies control reservoir physical properties and effective thickness of gas formation;the volcanic reservoir properties control gas reservoir type and gas productivity.The result is useful to guiding the discovery of in-situ volcanic gas reservoirs in faulted basins in both theory and practice.
基金supported by the State Key R&D Project of the Ministry of Science and Technology of China(No.2016YFC06002010).
文摘There are widespread Mesozoic–Cenozoic terrestrial volcanic activities in East China,and they produced favorable geologic factors for the volcanic reservoirs.To reveal the spatio-temporal evolution of regional volcanisms and their tectonic setting,we subdivide Mesozoic–Cenozoic volcanic activities into 6 volcanic cycles(Ⅰ–Ⅵ),and summarize the temporal-spatial distribution,rock association and tectonic setting of each cycle.The Cycle I forms a post-orogenic intraplate bimodal volcanic association.The cyclesⅡandⅢinclude arc volcanic associations formed in compressional and extensional subduction environments,respectively.The CycleⅣcontains a post-orogenic arc bimodal association.The CycleⅤis a basaltic association of tholeiite series under initial rift setting,and the CycleⅥis basaltic association of alkaline series under typical rift setting.The volcanic strata between each cycle are bounded by regional unconformity.The above 6 volcanic cycles correspond to 6 sequential stages of tectonic evolutions from the Early Jurassic post-orogeny,the Mid-Jurassic–Cretaceous subduction of the paleo-Pacific Plate to the Cenozoic marginal rifting.According to the geological characteristics of volcanic reservoirs in different volcanic cycles,it is put forward that the CycleⅤis the major formation period of volcanic reservoirs in East China and should be the focus of exploration,and that the volcanic reservoirs of the CycleⅣare also worthy of attention.
