Reservoir Evaluation Of Low Permeability Sandstone In Lower Shahai Formation Zhangqiang Depression

Qiang1block of Zhangqiang depression is located in northeast Qijiazi depression,Zhangqiang Pit, Zhangwu Basin in structure. After years of exploration, great achievementshave been made in Changbei anticline north depression. Under the guidance of "searching oilin basin", research of the south Zhangqiang basin has begun, instead of searching oil in highlylocated structural traps.The dark mudstone develops in Shahai formation Qijiazi depression,iscapable of producing oil and well preserved.Qiang1well is deploied in Qiangcan1east blockof depression structure,obtaining oil flow in lower Shahai Formation. New explorationresearch in South Zhangqiang begins.By analysing the basic material of drilling, coring, chenical examination and analysis,fornation testing and pilot production, well logging, mug logging, overall evaluation of Qiang1features of layer, depression, reservoir, microcosmic hole structure, reservoir classifyingevaluation criterion is established.1. About oil deposit feature：Single well thickness and oil reservoir distribution of theresearch area vary rapidly in space.In the flat surface, oil reservoir distribution in north andsouth block fault of Qiang1block is very different.The most in the north block(Qiang5block)is Ⅱoil reservoir group.Ⅰoil reservoir group is controlled by sand body throughgoing andphysical property,and distributes locally.Ⅰ and Ⅱ oil reservoir group develop better in thesouth block(Qiang1-4block).In vertical direction,oil reservoir distributes in lower Shahaiformation and200m range of coal formation mainly,and were gathered relatively.That iscontrolled by both sand body and physical property.It belong to structure-lithology reservoir.2. About reservoir feature：Make overall Shahai formation reservoir feature based onsystematic coring and research of reservoir petrology feature, depression feature, porestructure, physical feature.3. About logging evaluation：Establishing reservoir parameter explanation model basedon material analysing, research of reservoir productivity, electricity feature, physical featureand lithology.4. About overall reservoir classifying evaluation reacher：Reservoir classifying andevaluation is achieved by classifyig and evaluating reservoir pore throat, using conventionalMercury injection curves, and establishing physical, pore throat and electrical feature.5. Making overall reservoir feature and computing geological reserves：Overall evaluationof Zhangqiang reservoir offer research thinking and techniques for lithology and layer reservoir in other regions.