The Xujiahe Formation in Xinchang area of western Sichuan Depression has experienced multiple periods of tectonic movement superposition. The stratigraphic deformation is significant

and the whole stratum is characterized by “saddle” shape. In addition

several groups of reverse faults are developed

with different fault broken horizons and diverse fault crosscutting relationships. However

the conventional modeling methods can not accurately describe the complex structure-stratigraphic characteristics of the area

and the model is difficult to meet the actual production needs. Therefore

the VBM modeling method is used to establish the structural-stratigraphic framework model of Xu2 gas reservoir in Xinchang area. Based on the analysis of sedimentary and filling characteristics in the study area

the sequence stratigraphic framework is clarified. Then

the horizon and fault data are obtained based on seismic interpretation data and drilling stratification information to establish the model of fault frame and finely adjust the relation between sectional shape and cross section. The horizon model is used as the input data to calculate the stratigraphic thickness of each sand group

and to restore and construct the original formation model. The present structural-stratigraphic framework model can be established by accurately regulating the relation between faults and horizons by controlling the relevant parameters of them. The results show that VBM method can accurately describe complex structural model through volume conservation principle and tetrahedron grid characterization technology

and better deal with complex formation contact and fault distribution problems. The new stratigraphic framework model has higher grid quality than the traditional corner grid model

and the combination relation and sequence stratigraphic characteristics are maintained in the complex faults. This structural-stratigraphic model provides a more reliable model framework for the subsequent reservoir geological modeling.