川西坳陷东斜坡致密砂岩气藏储层精细评价

Detailed Evaluation for Tight Sandstone Gas Reservoir in East Slope of West Sichuan Depression

摘要: 川西坳陷东斜坡沙溪庙组气藏为致密砂岩气藏，河道条数多，宽度小，纵向上发育多期河道，砂体厚度薄，储层致密且非均质性强，泛泛的粗线条储层评价难以指导气藏高效开发部署。为此，以小层精细划分为基础，应用沉积微相研究、砂体构型精细刻画、成岩相定量刻画成果，同时考虑储层物性、孔隙结构等参数，开展储层精细评价，落实有利储层展布区。研究结果表明：1) 该区为浅水三角洲沉积，发育分流河道、河口坝、天然堤等，其中稳定型低弯度河道砂储集性能较好；2) 储层可分为I~III类3类，I类+II类储层为相对优质储层；3) 纵向上，JS11、JS21、JS31、JS33-1、JS33-2、JS33-3等小层是I + II类优质储层发育层段，平面上主要沿主河道中心呈条带状分布。基于该研究成果开展开发部署和建产，实现了气藏高效开发。

Abstract: Detailed reservoir evaluation for tight sandstone gas reservoir in east slope of West Sichuan De-pression is the key to guide the efficient development of gas reservoirs characterized by narrow channel and multi-stage superimposition, thin sand body, tight reservoir and strong heterogeneity. Based on stratigraphic division, research of sedimentary microfacies, description of sandbody configuration, quantitative characterization of diagenetic facie, reservoir property and pore structure, the favorable reservoir is determined by comprehensive evaluation. The results show that this area is a shallow water delta with distributary channel, mouth bar, natural dike and so on, the stable low curvature channel sand has better performance. Besides, the reservoirs can be divided into three types named I, II and III, I and II are relatively high-quality reservoirs. Lastly, the sub layers named JS11, JS21, JS31, JS33-1, JS33-2 and JS33-3 are the development intervals with more high-quality reservoirs, and are mainly distributed in the center of the main channel. Based on the research results above, the development and production are carried out.