影响川东石炭系气藏气井产能的地质因素

GEOLOGICAL FACTORS AFFECTING GAS WELL DELIVERABILITY OF THE CARBONIFEROUS GAS RESERVOIRS IN EAST SICHUAN

介绍了气井产能的确定方法及地质参数的选择与计算方法 :采用初始二项式无阻流量、稳定产量及初始采气指数作为气井产能评价的指标 ;1 0项参数分别是①储层有效厚度 ;②储层孔隙度 ;③储容系数 ;④好储层的储容系数 ;⑤与断层的距离 ;⑥与断层距离开方的倒数 ;⑦视褶皱强度系数 ;⑧构造面最大主曲率 ;⑨横向剖面线曲率 ;⑩纵向剖面线曲率。分析了影响气井产能的地质参数特征 ,完成了气井产能与地质因素的相关分析。在气井产能与地质因素的图论聚类分析的基础上 ,对气井作了分类 ,提出了两种不同模式的高产井的观点 ,即 :①储层厚度大、孔隙度中等、视褶皱强度系数中等的高产井 ;②储层厚度中等、孔隙度高、视褶皱强度系数大的高产井。

The methods of determining gas well deliverability and of choosing and calculating geological parameters are introduced in the paper.The initial binomial open flow capacity,stable production and primary gas productivity index are adopted as the criteria of evaluating gas well deliverability.The parameters are:①reservoir effective thickness;②reservoir porosity;③reservoir volume efficiency;④fair pay′s reservoir volume efficiency;⑤distance to the fault;⑥reciprocal of the square root of the distance to the fault);⑦apparent fold strength coefficient;⑧maximum principal curvature of structural plane;⑨transversal section line curvature;and ⑩ longitudinal section line curvature.The characteristics of the geological parameters affecting gas well deliverability are analyzed and a correlation analysis of the gas well deliverability with the geological parameters is finished.On the basis of graphic cluster analysis of the gas well deliverability with the geological factors,the gas wells are classified and two models of high production wells are proposed,including①the wells in a reservoir with large thickness and medium porosity and a medium apparent fold strength coefficient;and ② the wells in a reservoir with medium thickness and high porosity and a large apparent fold strength coefficient.