Chuan West Region, In Charge Of The Upper Triassic Xujiahe To Be Sec Reservoir Characteristics And Reservoir Prediction

Xujiahe layer-4 is the main pay oil formation of chongxi area in middle Sichuan, well drilled show of Xujiahe layer-4 in many well displays favorable gas(oil) exploration potential in this area ,but it is attached less important and researched relatively not enough. Based on the xujiahe layer-4 research of the lithology, sedimentary, structure and physical property characteristic ,This text ,which combined with the integrative prediction through the analysis of the production test , log and seismic information , aims to avail well reservoir and gas(oil) distributing area .The researches of sedimentary facies and reservoir characteristics indicate that the Xujiahe layer-4 reservoir pore spaces was dominated by residual primal intergrain and ingrain infrasonic corrosion pores ,the reservoir type was defined as fracture- porosity reservoir, reservoir type mainly belongs to type Ⅲ or type Ⅱ -Ⅲ .which heterogenic is strong and has obvious characters of low pore and especially permeability , the reservoir physical property is mostly influenced by the aggradations ,compaction ,cementation and conformation, it mostly develops in the sub-environment of the littoral mere, and form primarily sedimentary microfacies following: arenaceous beach dam, gravel dam ,storm stone .the crack develops also but is disequilibrium in this area,Through the analysis of log reservoir identify method, it is considered that the xujiahe layer-4's reservoir primarily should be the middle and nether, there are comparatively steady in portrait and are flaky in the plane. in the seismic reservoir prediction ,we analyses reservoir's seismic response characters through 2D seismic forward model which was based on the lithology and reservoir characteristics in this region ,then pick out the seismic inversion key to this area compared with other inversion method ,during the course of reservoir prediction .firstly ,we choose the nature Gamma inversion to identify lithology and eliminate mud stone, then , depending on the reservoir show character of low wave impendence ,we make full use of wave impendence inversion method to distinguish the reservoir and un-reservoir. Finally, we predict the distributing rule of porosity in portrait and nether according to the correlation between the reservoir wave impendence and porosity value. ultimately we consider that the reservoir develop best among the xi-56 well and xi-49-1 and xi-13-1 and gongxinchang structure .at the same time ,we identify the crack by use of the correlation analysis method and find that the gobbet strong correlation unconventionality is the main exhibition form of crack, which develop mainly in the structural distortion ,near the fault and the fault disappearing belt,According to the researches of the log identify,seismic reservoir and the crack prediction, we know that not only the reservoir thickness and porosity are both high but also the crack develop between the south of xi-56 well and xi49-l well near in this area , so infer that it should be the favorable area of high production gas (oil) .