Sedimentary And Reservoir Characteristics Of The Ma-5_1-4 Subsection Of The Tao 2 Block In The Sulige Gas Field

Based on the research of sedimentary and reservoir characteristics of the M51-4 submember of Tao 2 area of the Sulige gas field; with the guidance of sedimentary petrology, theory of carbonate reservoir geology, structural geology; combine the drilling, well logging and production test date, analysis by observe the rock core in the field and describe the microsection indoors, this thesis is mainly produced M51-4 layer deposition microfacies and reservoir characteristics detailed research and analysis.We can conclude that the study area M51-4 formation is intact by contrast the regional symbol of correlation and completeing the stratigraphic division of M51-4 submember in study area. This has laid a good foundation for the study of sedimentary facies. Through observing the core and the logging analysis of the M51-4 submember, The M51-4 submember of the region of interest is the evaporated tidal flat facies of continental sea carbonate in Early Ordovician. Including three subfacies (supratidal zone, intertidal belt and sublittoral zone) and nine microfacies. One of the most favorable sedimentary microfacies for reservoir development in the study area M51-4 submember is the gypsum dolomitization flat in the supratidal zone. It always appears in M513 and M54la, and has a large range.It can conclude from the reservoir lithology, physical property, electric prorerty and gas analysis that the main reservoir of M51-4 submember of study area is dolomite dissolution, and crystalline dolomite and crack-microporous dolomite. For the weather-worn, the main reservoir and trap of M513 and M522 always get obstructed by the erosional depression that make the gas and water relatively independent. Compared with the Eastern regions of sulige, due to tectonic actio, M54la is easier producing water.Finally, according to the effective reservoir, gas test results, and other indicators of production, and consider the factors of sedimentary facies, palaeogeomorphology, structure and so on. High quality reservoirs are mainly located in the formation intact, it has a favorable sedimentary facies and good reservoir space.There are three range of profitability:I is 66.2km2, Ⅱ is 131.1km2, III is 199.97km2.There is 25.09km2 profitability acreage in the area.It can be concluded through this thesis:in the Ordovician weathering crust of carbonate reservoirs, at the supratidal zone and intertidal belt zone, the gypsum dolomitization flat is the main reservoir distribution area, and the structure and diagenesis of the reservoir are formed a certain impact.