Research On The Clastic Reservoir Evaluation Of Denglouku Formation In The Shiwu Fault Depression

The Shiwu fault depression is a big one in the fault depression layer systems of Songliao basin, which lied in southeast margin of the Southeast uplifted area. The preexisting exploration practice and study had indicated that the deep layers of the Shiwu fault depression also have major prospecting potentiality. But the former priority converged on downwarping layer and the exploration study degree of deep layers was lower relatively.On the basis of researches and knowledge in the past, many respects about Denglouku formation in the Shiwu fault depression have been intensively studied in this text such as the reservoir petrology characteristics, sandbody distribution characteristics, diagenetic types and its stages division, reservoir pore types and evolution, physical property characteristics, and its influence by diagenesis etc. by observation of drill cores and taking rock samples, and using some analytic testing technologies such as polarizing microscope, casting slice, scanning electron microscope and cathodoluminescence etc., combining the theories of sedimentology, petrology and reservoir evaluation. After comprehensive analysis and evaluation, the profitable areas are found out finally.The results indicate that clastic reservoir of Denglouku formation mainly are arkose, feldspathic litharenite and lithic arkose, and the interstitial material mainly are carbonate and shale. The reservoir physical property of Denglouku formation is better, which mainly are mid porosity and high permeability to low porosity and low permeability. The main diagenetic types of the reservoir are compaction, cementation, metasomatosis and dissolution. The clastic reservoir of Denglouku formation mainly is in period of middle diagenetic stage. Different diagenesis has different influence on reservoir physical property. Dissolution is constructive diagenesis, and compaction and cementation are unfavorable diagenesis for reservoir. But early carbonate cementation rejected the development of compaction on definite degrees, which was favour of dissolution and become secondary porosity by acidic water. Dissolution improve reservoir physical property extremely, means that the solution of carbonate cement and aluminum silicate minerals which unstable in acidic water.After the comprehensive analysis and evaluation of Denglouku formation reservoir using method of weighted mean, it is considered that the best reservoir may be exist in east area of Houwujiahu gas field and the area between Houwujiahu gas field and Bawu gas field, comprehending the distributed feature, tectonic feature and the studied results of diagenesis.