苏里格气田低渗透储层成岩储集相特征

研究了苏里格气田二叠系储集层的沉积相、成岩作用及微观孔隙结构,分析了成岩作用对低渗透储层储集物性的影响.研究结果表明,造成本区砂岩储层特低渗透率的主要原因是成岩期强烈的压实作用及各种自生矿物的充填和胶结作用.选用流动层带指标、孔隙度、渗透率、粒度中值、泥质含量、孔喉半径均值和变异系数7项参数,建立了遗传神经网络的学习及预测模型.采用神经网络模式识别方法,对苏里格气田二叠系进行了成岩储集相的识别.识别出了4类成岩储集相,即不稳定组分溶解次生孔隙成岩储集相、碳酸盐胶结物溶解次生孔隙成岩储集相、强压实强胶结剩余粒间孔成岩储集相和极强压实强胶结致密成岩储集相.阐述了各类成岩储集相的特征,并结合沉积相,确定了各成岩储集相的时空展布.

Characteristics of diagenetic reservoir facies of low-permeability reservoir in Sulige Gas Field

The sedimentary facies, diagenesis and micro pore structure of the Permian reservoir in Sulige Gas Field were studied. The effects of diagenesis of low-permeability reservoir on the reservoir property were analyzed. The low-permeability reservoir in this area was resulted from strong compaction, infilling and cementation of autogenetic mineral during diagenesis period. The parameters of flow zone index, porosity, permeability, median grain size, mud content, mean radius of pore-throat, and variance coefficient were used to establish the study and prediction models. The genetic artificial neural network method was applied to recognize four types of diagenetic reservoir facies in the Permian of Sulige Gas Field, including the secondary pores diagenetic reservoir facies with solution of unstable ingredients, secondary pores diagenetic reservoir facies with solution of carbonate cement, residual intergranular pores diagenetic reservoir facies with strong compaction and cementation, and tight diagenetic reservoir facies with extremely strong compaction and cementation. The characteristics of these diagenetic reservoir facies were analyzed. According to sedimentary facies, the time-space distributions of diagenetic reservoir facies were determined.