Sedimentary Facies Analysis And Its Influence On Reservoirs In Hangjinqi Area Lower Shihezi Formation

It possesses the basic geological conditions of favorable reservoir in Hangjinqiarea.With the exploitation in low permeability reservoir and unconventional oil and gasresources, Hangjinqi area has become the main target area.It plays an important rolethat finding out the characteristics of sedimentary facies of the area and influence onreservoir in favorable reservoir evaluation in the area.In this paper, under the guidance of basic knowledge of geology, access to manyreferences and production research, gather information of more than40single wellsand9wells core observation, analyze more than300pieces and100data on theporosity and permeability, also on the basis of the regional tectonic background,according to the sedimentary petrology characteristics and well logging facies analysisin Hangjinqi area, this paper has carried on the division of sedimentary facies in LowerShihezi Formation. And through the sedimentary facies analysis of single well andwells, in accordance with the though of point-line-plane sedimentary facies analysis,the plane sedimentary facies evolution figure is drew and three-dimensional model isestablished. Research has shown that alluvial fan facies, fluvial facies, delta facies,developed in the early Lower Shihezi Formation in Hangjinqi area, and fluvial facies,delta facies developed in the upper strata.On the basis of the research of sedimentary facies,further analyzing thecharacteristics of reservoir property in the area. Research has shown that: the averageporosity of P1x1-P1x3is10.73%, the average permeability is3.452x10-3μm2;Thedevelopment of porosity in P1x1and P1x3is better, P1x2is medium; the permeability inP1x2and P1x3is better, P1x1is poorer. Results suggest that it develops medium porosityand low permeability reservoirs in Hangjinqi area Lower Shihezi Formation.Through the research of sedimentary facies and reservoir characteristics inHangjinqi area Lower Shihezi Formation, it analyzes deeply the control factors ofsedimentary reservoir physical property. According to the development of sedimentary facies controlled by different hydrodynamic conditions, studying the influence ofsedimentary facies to reservoir physical property from the detrital composition maturity,the relationship between rock grain size, sorting,shale content and porosity andpermeability, basic rock facies etc. several aspects. Research shows that influenced bythe hydrodynamic conditions, the sedimentary facies with high quartz content, lowshale content, coarse grain size sediments generally develop favorable reservoir.Braided river channel, braided channel, beach, point bar, distributary channel basicallycontrol the favorable reservoirs in the study area Lower Shihezi Formation.