The. Xujiaweizi Trap Of Yingcheng Sec Stratigraphic Depositional Model

Integrating the theory and methods of stratigraphic sequence, sedimentology,seismic stratigrphy and logging geology with the exploration technology ofglutinite subtle reservoir, this thesis applies seismic, well logging and coredata to classifying and correlating the K₁yc₄ conglomerate layer in Xujiaweizi Rift,establishes depositional model through in-depth analysis and study, and predictsfavorable reservoir zone, which is of great value to explore natural gas and deploywells in the future.According to the lithology, electricity and their combination of theseventy-eight cat wells or appraisal wells, and sedimentary cycles of the strata,this thesis also correlates and analyzes sedimentary cycles for K₁yc₄ in XujiaweiziRift, and divides K₁yc₄ strata into upper and lower sedimentary cycles. On the basisof former studies, it, combing analysis of lithology, individual-well facies andcontrastive analysis of logging data interpretation and seismic data, classifiesK₁yc₄ strata into six types of sedimentary facies: braided delta facies developedin Xingcheng region, fan delta facies developed in the west fault-terrace,alluvial fan facies in Weishen4 borefild, fluvial facies and lacustrine deltafacies developed in the south land, and lacustrine facies in the middle of rift,and presents four depositional models of the upper and lower cycles in K₁yc₄formation.Based on the analysis of physical property in eastern Changde region, thethesis, combining sedimentary facies and seismic data, predicts the favorablereservoir facies belt in Xujiaweizi Rift. The result shows that braided delta frontand fan delta front are favorable blocks;Xingcheng region is favorable block withthick conglomerate deposit, vast area of distribution, which belongs to braideddelta front subfacies;In Weishen5 borefild, the favorable block is consideredas fan delta facies.