Abstract:

Gas reservoir in Es³ interval of Qiaokou structure is characterized by its great buried depth,long gas-bearing interval,poor physical property,great change longitudinally and transversally,low productivity of gas bearing strata and unstable pressure.It is believed,by analyzing structure of litho-composition,sedimentary facies belts,physical property,overburden,structure and hydrocarbon evolution,that sedimentary facies is the main factor among several controlling factors,gravitational flow channel sandbody and physical property of fan-braided channel in the sublacustrine fan is not good but also buried in mudstone of hydrocarbon genetic depression which is favorable for hydrocarbon trapping and accumulating to reservoir.Therefore,it is necessary to stress the importance of next step exploration by strengthening a carefully study of sedimentary facies,analyzing those favorable sedimentary facies by combining seismic data with data of well-logging,predicating reservoir.

Key words: Qiaokou structure, Es³ interval, characteristic of gas reservoir, sedimentary characteristic, sedimentary facies, controlling factor