1 Introduction The large clusters of Zn-Pb deposits in northeastern Yunnan,located in the southwestern margin of the Yangtze Block,are an important part of the Sichuan-YunnanGuizhou Pb-Zn Poly-metallic Metallogenic Tr...1 Introduction The large clusters of Zn-Pb deposits in northeastern Yunnan,located in the southwestern margin of the Yangtze Block,are an important part of the Sichuan-YunnanGuizhou Pb-Zn Poly-metallic Metallogenic Triangle Area展开更多
In order to provide basis for further exploration and deployment of volcanic gas reservoirs in the Sichuan Basin,we classified Permian volcanic rocks in this basin using drilling,mud logging,assay,logging and seismic ...In order to provide basis for further exploration and deployment of volcanic gas reservoirs in the Sichuan Basin,we classified Permian volcanic rocks in this basin using drilling,mud logging,assay,logging and seismic data comprehensively.Then,the lithological characteristics,lithofacies characteristics,lithofacies distribution and reservoir characteristics of different types of volcanic rocks were studied.Besides,the main factors controlling the development of volcanic reservoirs were determined.And the following research results were obtained.First,volcanic rocks in the Sichuan Basin can be comprehensively classified into 4 categories(i.e.,volcanic lava,volcaniclastic lava,volcaniclastic rocks and sedimentary volcaniclastic rocks),and basalt,breccia lava,tuffaceous breccia lava,tuff,sedimentary tuff are mainly developed.Second,3 types of volcanic lithofacies are extensively developed in the Sichuan Basin,including overflow facies,effusive facies and volcanic sedimentary facies.Overflow facies is mainly dominated by basalt,effusive facies is mainly composed of volcaniclastic lava,and volcanic sedimentary facies is mainly composed of tuff and sedimentary tuff.Third,volcanic reservoirs are lithologically composed of breccia lava and basalt.Breccia lava reservoirs are pore-type reservoirs of moderate porosity and low permeability with devitrified micropores and dissolution pores as main reservoir space.In basalt,fractures and dissolution pores are mainly developed,and they are porous-fractured reservoirs with lower matrix porosity.Fourth,the factors controlling volcanic reservoirs mainly include lithology,lithofacies,later fluid alteration and tectonism.Volcaniclastic lava is devitrified in the process of rapid condensation,and a great number of dispersion-shape micropores are formed to provide favorable conditions for further dissolution and pore enhancement in the later stage.Post-diagenesis effect(e.g.dissolution)and fracture development make the reservoir properties better.In conclusion,the areal distribution of volcanic reservoirs in the Sichuan Basin is mainly controlled by the lithofacies.Porous-fractured basalt reservoirs are mainly developed in the Ya'aneLeshanePingshan area in the southwestern Sichuan Basin,and pore-type volcaniclastic lava reservoirs are mainly developed in the ChengdueJianyangeSantai area.展开更多
基金supported by the Funds for the program of the National Natural Science Foundation (Noes. 41572060, U1133602)Projects of YM Lab (2011)Innovation Team of Yunnan province and KMUST (2008,2012)
文摘1 Introduction The large clusters of Zn-Pb deposits in northeastern Yunnan,located in the southwestern margin of the Yangtze Block,are an important part of the Sichuan-YunnanGuizhou Pb-Zn Poly-metallic Metallogenic Triangle Area
基金Project supported by PetroChina Company Limited Project“Research and application of key technologies for maintaining 30-billion-m^(3)gas productivity in Southwest Oil&Gas Field”(No.:2016E-0603).
文摘In order to provide basis for further exploration and deployment of volcanic gas reservoirs in the Sichuan Basin,we classified Permian volcanic rocks in this basin using drilling,mud logging,assay,logging and seismic data comprehensively.Then,the lithological characteristics,lithofacies characteristics,lithofacies distribution and reservoir characteristics of different types of volcanic rocks were studied.Besides,the main factors controlling the development of volcanic reservoirs were determined.And the following research results were obtained.First,volcanic rocks in the Sichuan Basin can be comprehensively classified into 4 categories(i.e.,volcanic lava,volcaniclastic lava,volcaniclastic rocks and sedimentary volcaniclastic rocks),and basalt,breccia lava,tuffaceous breccia lava,tuff,sedimentary tuff are mainly developed.Second,3 types of volcanic lithofacies are extensively developed in the Sichuan Basin,including overflow facies,effusive facies and volcanic sedimentary facies.Overflow facies is mainly dominated by basalt,effusive facies is mainly composed of volcaniclastic lava,and volcanic sedimentary facies is mainly composed of tuff and sedimentary tuff.Third,volcanic reservoirs are lithologically composed of breccia lava and basalt.Breccia lava reservoirs are pore-type reservoirs of moderate porosity and low permeability with devitrified micropores and dissolution pores as main reservoir space.In basalt,fractures and dissolution pores are mainly developed,and they are porous-fractured reservoirs with lower matrix porosity.Fourth,the factors controlling volcanic reservoirs mainly include lithology,lithofacies,later fluid alteration and tectonism.Volcaniclastic lava is devitrified in the process of rapid condensation,and a great number of dispersion-shape micropores are formed to provide favorable conditions for further dissolution and pore enhancement in the later stage.Post-diagenesis effect(e.g.dissolution)and fracture development make the reservoir properties better.In conclusion,the areal distribution of volcanic reservoirs in the Sichuan Basin is mainly controlled by the lithofacies.Porous-fractured basalt reservoirs are mainly developed in the Ya'aneLeshanePingshan area in the southwestern Sichuan Basin,and pore-type volcaniclastic lava reservoirs are mainly developed in the ChengdueJianyangeSantai area.
