Research On The Enrichment Condition Of The Shale Gas In The Lower Jurassic,Fuling Area,China

Sichuan basin of continental shale formation condition is complex.Organic-rich shale spatial distribution is unclear.Reservoir and gas content is also complict.Under different intervals Jurassic shale research of the Fuling area,is to explore the characteristics of different intervals enrichment conditions.Organic geochemical analysis according to Fuling area,Fuling area Lower Jurassic Dongyuemiao segment and the second Daan segment TOC abundance is mainly 1% to 2%.Lower Jurassic source rocks thermal evolution has reached the maturity to high maturity,Ro is multiple of 1% to 2%.Isotopes of hydrocarbon indicates the lower Jurassic shale gas is pyrolysis gas,oil-gas.Lower Jurassic different layers of Pr / Ph value around 1,combined with a saturated hydrocarbon aromatic organic parameters showed that the sedimentary environment is a strong reduction of lacustrine depositional environment.The second Dan segment and Dongyuemiao segment of the Fuling area is composed of micro-fractures,more performance for the direction of bedding along rigid or minerals(calcite,quartz,etc.),organic edge,the clay mineral stomatal development of micro,small amount of intergranular porosity,organic structure dense,organic matter inside biological structures stomatal development.The second Dan segment mineral content is higher than Dongyuemiao.The Daan segment and Dongyuemiao segment is mainly axial canal,generally accounting for more than50%,the percentage of Daan Village section of macro porous content is generally above 20%,the median pore diameter Da Village in 20 nm is more than Dongyue segment.The second Daan segment,the Maanshan segment and the Dongyeumiao segment porosity and permeability is higher than other strata of lower Jurassic,constitutes a self-contained and mutual dissection of reservoir-cap configuration.The Fuling area with a simple structure,stable,good storage conditions.The lower Jurassic shale gas of Fuling area enrichment process has gone through three stages: the early fast compaction buried,buried hydrocarbon mid and late uplift adjusteds.