Simulation Of Diagenesis History And The Prediction Of The Favorable Exploration Areas In Tight Oil Reservoirs

Commercial oil flows were discovered in the tight reservoirs of the Lucaogou Formation, Malang-Tiaohu Sag, Santanghu Basin, has good exploration prospects. However, Unconventional oil and gas Accumulation and Conventional oil and gas reservoirs are different in Reservoir formation mechanism, distribution characteristics, petroleum entrapment, Enrichment characteristics, Evaluation methods and Exploration Technology. Santanghu basin’s geology is extremely complex, tight oil’s Reservoir formation mechanism and distribution characteristics are not entirely clear, exhaustive study is needed in order to get a breakthrough. In order to study the distributing characteristies of the tight oil, this paper started with the research of the reservoir rock characteristic and physical property characteristic of Lucaogou Formation, then performing numerical modeling of diagenesis, the research recovered the burial and geothermal history, by studying the effects of diagenesis and Sedimentary Processes on the porosity and permeability of the reservoirs, We evaluated the reservoir, we predict favorable exploration area by combined with Source rocks research. we will lay a solid foundation for the exploration and development of tight oil. The study results showed that the lithology of Lucaogou Formation reservoir mainly contains calcareous clay, calcite dolomite and the tuffaceous mudstone; Commercial oil wells mainly located in the early diagenetic stage A1 to the late middle diagenetic stage A21. Lucaogou Formation reservoir began to tight from Jurassic to Cretaceous, then entered Expulsion Threshold from Cretaceous to Paleogene. Lucaogou Formation reservoir is mainly controlled by diagenesis and facies, Commercial oil wells mainly located in Conventional reservoir and class I tight reservoir(porosity≥7%), Low yield oil wells mainly located in class II reservoir and class III reservoir. the favorable exploration area of tight oil exploration in Lucaogou Formation are controlled by source rock and Reservoir, the most favorable exploration area in Member 2 of Lucaogou Formation are in the northern area of Malang sag.