The Reservoir Characteristics Study on Yingshan Formation of the Ancient City-Lowuplift in Tarim Basin

The oil and gas exploration has been broken through in ordovician-Yingshan formation of the lower Paleozoic in ancient city-low uplift, in Tarim Basin. The preliminary study found that the rich oil and gas resources are mainly in karst cave of the dolomite reservoir. It is revealed that the exploration potential of the carbonate reservoir in Yingshan formation of the ordovician. So, the systematic evaluation and study on the carbonate reservoir for Yingshan formation of the Ordovician in ancient city-low uplift have been done. Based on the analysis of drilling, logging, well logging and testing data, it is found that: The reservoir spaces of carbonate reservoir of ancient city area are mainly intergranular pore, intergranular dissolved pore, karst cave, structural fracture and diagenetic fracture. The reservoir of Yingshan formation in the ancient city area is mainly crack pore-cave reservoir, secondly fracture type reservoir, and, the porosity for the third section of Yingshan formation is relative development with large thickness which should be the key exploration target. The dolomite reservoir of Yingshan formation has the characters of multi layers, thin layers vertically and the different comparison in horizon. The lower part of high-quality dolomite reservoir in Yingshan formation is an important exploration area of carbonate reservoir in ancient city-low uplift. The studies, on the micro and macro development characteristics of the carbonate reservoir of ordovician-Yingshan formation in ancient city-low uplift, provide ideas and guidance for the exploration and deployment of the carbonate reservoir.