Study On The Distribution Prediction Of Carbonate Weathering Crust Reservoir Space And Its Relationship With Oil-gas Grooming Framework

There are lots of carbonate karst reservoir formation in the north tarim area. The character of this kind of reservoir formation is better quality, large distribution area, deeper buried depth, more oil formation. Several oil-gas field which reserve is beyond hundred million has been found in lunnan, tahe and yingmaili. Through systematic analysis of the firsthand data of several important wells in the north tarim which is about drilling, logging, oil testing and combined with large number of analysis materails, core and microscope observation, this paper studies the weathered crust karst reservoir and insider karst reservoir's genesis characteristics, distribution regularities, evaluation and prediction, etc.Studies suggest that the Ordovician karst weathering crust reservoir and insider karst reservoir developed in yingshan group and yijianfang group. The reservoir matrix porosity is relatively low. The corrosion holes, corrosion expansion joints and construction joints are karst weathering crust reservoir's main reservoir space. The cracks are the main reservoir Insider karst reservoir space. The development of pure platform facies carbonate rocks, the long-term exposure and erosion caused by the Hercynian tectonic movement and late atmospheric fresh water leaching are the key factors of the formation of the north tarim weathered crust reservoir. Caledonian corrosion effect and the role of tectonic fractures are the main control factors which formed the insider karst effective reservoir in the north tarim area.With comprehensive analysis of carbonate rocks karst reservoir in the north tarim area, this paper predicts the favorable karst-type reservoir development area in the study district. In the favorable paleokarst landform and fracture development area and the congruent area which developed Caledonian fracture and beach face reservoir. Besides, near the Upper Ordovician pinch-out line and fracture developed karst reservoir. In this area, even if buried at greater depth, may also developed a larger scale, better quality reservoir.