四川盆地元坝长兴组礁滩相气藏概率体约束地质建模

四川盆地元坝长兴组气藏礁滩相储层岩相类型多样，生物礁和生屑呈离散分布，储层及物性参数非均质性强，储层构型特殊，气水关系复杂，现有建模方法难以精细表征礁滩相内部储层非均质性，不能满足气藏开发生产需求。通过对礁滩相气藏地质、物探、测井及生产动态等多学科资料研究，提出以地质模式为指导，采用礁滩相储层构型、地质及地震概率体等多信息协同约束的建模思路，分级相控-序贯指示随机模拟方法建立生物礁、生屑滩储层相模型；采用相控-序贯高斯随机模拟方法建立属性参数模型。该方法建立的模型，精细表征了礁滩相储层内部结构及属性参数非均质性特征，刻画了生物礁、生屑滩储层及属性参数的三维空间分布，为气藏的高效开发奠定了坚实地质基础。

Probability body-constrained geomodeling of reef-shoal reservoir in Changxing Formation,Yuanba area,Sichuan Basin

The reef-shoal reservoir of the Changxing Formation in Yuanba area, Sichuan Basin, is rich in lithofacies types. Organic reef and shoal bodies are distributed discretely, and the reservoir and physical parameters are highly heterogeneous. The reservoir architecture is quite bizarre, and the distribution of water cut is complicated. Given these features, the existing modeling methods can hardly characterize the heterogeneity within the reef-shoal reservoir in a high resolution manner, and cannot meet the demand of gas reservoir development and production. Based on the researches on gas reservoirs of reef-shoal facies in terms of geology, geophysical prospecting, well logging and production performance, the study put forward the idea of geological model constrained modelling, integrating multiple information, including reservoir architecture, geology and seismic probability body. The geological model of the reservoir of organic reef and bioclast shoal facies was established by hierarchical facies control and sequential indication simulation, and the attribute model by facies control and sequential Gaussian random simulation. The models constructed through the method can finely characterize the inner architecture of the reef-shoal reservoir, the heterogeneity characteristics of its physical parameters, and the 3-D distribution of the reservoir of organic reef and bioclast shoal facies and attribute parameters, laying a solid foundation for the efficient development of gas reservoirs.