Reservoir Of Comprehensive Evaluation On Chang4+5in HuanJiang Area

HuanJiang oilfield is located in HuanXian of QingYang, Its tectonic units the Tianhuan Depression covering an area of3371km2Chang4+5oil layer is the pich structure westward from west to east gradually and locally developed nose like structure from south to north.This article fully use core, well logging and abundant of static and dynamic data and reservoir geology, reservoir sedimentology, reservoir well logging theory to research micro sedimentary facies for Chang4+5oil layer, summarizes controlling factors of sandbody distribution, analyzes preserving capability of the reservoir,reservoir heterogeneity and reservoir evaluation. Main understandings for Chang4+5oil layer of HuanJiang region.(1) According to the principle of strati graphic correlation, Chang4+5oil layer of Huanjiang region would be separated into two oil sub-layer which including Chang4+5i,Chang4+52.(2) It is river-delta sedimentary environments, delta front subfacies is developed. It will union area geology background, distinguishes out three kinds of micro sedimentary facies including subsea distributary channel, subsea distributary channel flank and interdistributary bay. The subsea distributary channel is mainly reservoirs in study area.(3) The sandstones are mainly lithic arkose, high maturity for texture. Sandstone spreads northwest to southwest like banding, which is controlled by micro facies of subsea distributary channel in delta system.(4) Porosity types of the reservoir:predominantly intergranular pore and feldspar dissolution porosity, secondly debris dissolved pore, intergranular dissolution pore and locally developed fissure which weak porous structure..Diagenesis types:mainly compaction, cementation and dissolution. We analyze the aeolotropism of reservoir,from inside,interlayer and plane.The Formation Sensitivity is velocity sensitivity-free, medium low-medium high water sensitivity, medium high-strong acid sensitivity, low-medium low alkali sensitivity. And show some weak lipophilic.(5) Utilize storage coefficient, stratigraphic coefficient and flow unit analysismethod, combined with the clustering analysis method, the reservoir can be dividedinto four categories: Ⅰ, Ⅱ, Ⅲ, Ⅳ. Lithology is pure for Ⅰ and Ⅱ,mainly fine sandstone.Ⅲ consist siltstone and fine sandstone, generally oil-poor. Ⅳ is Non-reservoir.