The fluid evolution and reservoir formation model of the ultra-deep gas reservoirs in the Permian Qixia Formation of the northwestern Sichuan Basin are investigated by using thin section,cathodoluminescence,inclusion ...The fluid evolution and reservoir formation model of the ultra-deep gas reservoirs in the Permian Qixia Formation of the northwestern Sichuan Basin are investigated by using thin section,cathodoluminescence,inclusion temperature and U-Pb isotopic dating,combined with gas source identification plates and reservoir formation evolution profiles established based on burial history,thermal history,reservoir formation history and diagenetic evolution sequence.The fluid evolution of the marine ultra-deep gas reservoirs in the Qixia Formation has undergone two stages of dolomitization and one phase of hydrothermal action,two stages of oil and gas charging and two stages of associated burial dissolution.The diagenetic fluids include ancient seawater,atmospheric freshwater,deep hydrothermal fluid and hydrocarbon fluids.The two stages of hydrocarbon charging happened in the Late Triassic and Late Jurassic–Early Cretaceous respectively,and the Middle to Late Cretaceous is the period when the crude oil cracked massively into gas.The gas reservoirs in deep marine Permian strata of northwest Sichuan feature multiple source rocks,composite transportation,differential accumulation and late finalization.The natural gas in the Permian is mainly cracked gas from Permian marine mixed hydrocarbon source rocks,with cracked gas from crude oil in the deeper Sinian strata in local parts.The scale development of paleo-hydrocarbon reservoirs and the stable and good preservation conditions are the keys to the forming large-scale gas reservoirs.展开更多
Based on the outcrop,drilling and seismic data,the sedimentary successions,evolution and hydrocarbon exploration potential of the Neoproterozoic rift basin in the northern Tarim were firstly analyzed.Due to assembly a...Based on the outcrop,drilling and seismic data,the sedimentary successions,evolution and hydrocarbon exploration potential of the Neoproterozoic rift basin in the northern Tarim were firstly analyzed.Due to assembly and breakup of the Rodinia supercontinent,the Tabei paleocontinent and the Tarim paleocontinent were developed in the Tarim craton with an EW-trending back-arc rift basin between them during Neoproterozoic time;very thick marine clastic rocks,carbonate rocks and volcanic rocks(including tillite)were deposited in the Kuruktag and Aksu area of the northern Tarim,which experienced deep sea,bathyal sea and littoral sea environments with transitional delta and ice-sea.During the Early Cryogenian and the Late Ediacaran,the northern rift basin evolved from the deep sea to the littoralneritic sea,while the lithology changed from clastic rocks to carbonate rocks.According to the field and production data,the formation and preservation of the source rocks and reservoirs indicate a good exploration potential of the Neoproterozoic rift basin.展开更多
基金Supported by the Special Project of National Key R&D Plan(2017YFC0603106).
文摘The fluid evolution and reservoir formation model of the ultra-deep gas reservoirs in the Permian Qixia Formation of the northwestern Sichuan Basin are investigated by using thin section,cathodoluminescence,inclusion temperature and U-Pb isotopic dating,combined with gas source identification plates and reservoir formation evolution profiles established based on burial history,thermal history,reservoir formation history and diagenetic evolution sequence.The fluid evolution of the marine ultra-deep gas reservoirs in the Qixia Formation has undergone two stages of dolomitization and one phase of hydrothermal action,two stages of oil and gas charging and two stages of associated burial dissolution.The diagenetic fluids include ancient seawater,atmospheric freshwater,deep hydrothermal fluid and hydrocarbon fluids.The two stages of hydrocarbon charging happened in the Late Triassic and Late Jurassic–Early Cretaceous respectively,and the Middle to Late Cretaceous is the period when the crude oil cracked massively into gas.The gas reservoirs in deep marine Permian strata of northwest Sichuan feature multiple source rocks,composite transportation,differential accumulation and late finalization.The natural gas in the Permian is mainly cracked gas from Permian marine mixed hydrocarbon source rocks,with cracked gas from crude oil in the deeper Sinian strata in local parts.The scale development of paleo-hydrocarbon reservoirs and the stable and good preservation conditions are the keys to the forming large-scale gas reservoirs.
基金supported by the project of PetroChina(2014A-02).
文摘Based on the outcrop,drilling and seismic data,the sedimentary successions,evolution and hydrocarbon exploration potential of the Neoproterozoic rift basin in the northern Tarim were firstly analyzed.Due to assembly and breakup of the Rodinia supercontinent,the Tabei paleocontinent and the Tarim paleocontinent were developed in the Tarim craton with an EW-trending back-arc rift basin between them during Neoproterozoic time;very thick marine clastic rocks,carbonate rocks and volcanic rocks(including tillite)were deposited in the Kuruktag and Aksu area of the northern Tarim,which experienced deep sea,bathyal sea and littoral sea environments with transitional delta and ice-sea.During the Early Cryogenian and the Late Ediacaran,the northern rift basin evolved from the deep sea to the littoralneritic sea,while the lithology changed from clastic rocks to carbonate rocks.According to the field and production data,the formation and preservation of the source rocks and reservoirs indicate a good exploration potential of the Neoproterozoic rift basin.
