灰色关联网格化综合评价普光气田储层

Integrated evaluation of reservoir for Puguang Gas Field with gray correlation gridding

实践证明,勘探开发效果及成败的关键是对储层的认识是否符合客观实际。由于影响储层特征的因素是复杂的、多方面的,只有对储层进行综合评价,并将储层综合评价工作贯穿在勘探开发的全过程中,才能对储层逐步做出逼近真实地质情况的判断,从而为勘探开发部署、油气资源评价、开发动态分析、油藏工程研究、油藏数值模拟,以及开发方案的调整奠定可靠的地质基础。由于普光气田碳酸盐岩储层分布受沉积相、成岩作用、断裂系统等多种因素控制,使得储层孔隙结构复杂、非均质严重,增加了开发难度。为精细评价储层,准确刻画优质储层的分布,首先引入储层厚度、孔隙度、渗透率、沉积微相指标及裂缝指数等多种评价参数,建立地质模型;然后采用灰色关联法确定权系数,并在地质模型中归一化网格计算评价指数,通过对这些指数加权求和确定各网格综合得分;最后根据综合得分与产能的关系式确定各网格的储层类型,精细刻画了储层间的差异及优质储层的空间展布规律。

It has been found that the key of success or failure in exploration and development is whether the reservoir study is corresponding to the objective reality. Because the factors which affect reservoir characteristics are complex and versatile, only through a comprehensive evaluation of reservoir and running through it in the whole course of exploration and development, can we succeed in making the judgment which approaches the true geological situation progressively, and lay a reliable geological foundation for the deployment of exploration and development, oil-gas resources appraisal, development dynamic analysis, reservoir engineering research and reservoir simulation as well as the adjustment of development plan. The distribution of carbonate reservoir in Puguang Gas Field is controlled by many factors, such as sedimentary facies, diagenesis and faulting system, which causes the complicated reservoir pore structures and serious heterogeneity and increase the development difficulty. Various evaluation parameters, such as reservoir thickness, porosity, permeability, sedimentary microfacies index and fracture index, are introduced and a geological model is established in order to estimate the reservoirs and to portray the distribution of high-quality reservoir accurately. Weight factors are determined through the use of gray correlation method and the evaluation index of grid computing is normalized in the geological model, which determines the comprehensive score of each grid by the weighted summation of these indexes. The reservoir types of each grid are defined and the difference among reservoirs and the spatial distribution rules of highquality reservoir are described according to the relational expressions of comprehensive score and productivity.