Abstract: The lack of systematic research on the principal of T3x gas containing strata,sand division and correlation in Guanan gas field largely constrains the Guannan gas field exploration in the overall planning,deployment,and the exploration success rate.Under the guidance of the theory and technology of the high-resolution sequence stratigraphy,according to the identification symptoms of the sequence interfaces and lakeflood sedimentation,combining the comprehensive analysis of outcrops,rock cores,well logs and seismic interpretation,six middle-term,twenty-two short-term,sixty-nine supershort-term base-level cyclic sequences are recognized in Xujiahe formation,Guannan gas field.On the basis of the above studies,the vertical sequences,facies associations,lithologic components,structural types and stacking patterns are discussed in detail.The application of these differentgrade base-level cycle sequences to the stratigraphic division and isochronal correlation,the foundation of sequence stratigraphic framework and the sand body distribution regularity are probed into in the light of these sequence characteristics,which provide a scientific basis for the next exploration.

Key words: high-resolution sequence stratigraphy, base-level cycle, sequence interface, Xujiahe formation, Guannan gas field