川西坳陷新场地区须家河组受多期构造运动叠加,地层起伏较大,总体呈“马鞍”形特征,同时发育多组逆断层,断穿层位各异,断层交切关系多样。常规的建模方法不能精确表征该区复杂的构造-地层特征,模型难以满足实际生产需要。因此,采用VBM建模方法对新场须二气藏进行了构造地层模型建立。依据地震解释数据和钻井分层信息,获取须二段层面和断层控制数据。建立断层框架模型,精细调整断面形态和断层交切关系。以层面数据为输入数据,计算每一砂组的地层厚度,恢复并构建原状地层模型。利用断层与层面的相关参数控制,精准调控断层与层面之间的关系,实现现今构造-地层格架模型的建立。结果表明：VBM方法通过体积守恒原理和非结构化网格表征技术,对复杂构造模型能够做到精准刻画,较好处理复杂的地层接触和断层展布问题。新建立的地层格架模型相比传统角点网格建立的模型具有更高的网格质量,且保持了复杂断层处的断层组合关系以及层序地层特征,为后续的储层地质建模提供了更可靠的模型框架基础。

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.