中江气田沙溪庙组气藏高效开发面临着河道精细刻画、高产富集模式建立、开发技术政策制定、工程压裂改造技术配套4大难点。针对窄河道砂采用多域多属性精细刻画及储层精准预测技术,对多期叠置河道砂空间展布特征刻画效果较好,实现了最薄8 m、最窄50 m河道砂的刻画,且河道砂的沉积时间顺序也非常清晰,采用基于射线参数域的改进三参数叠前反演技术实现了薄层高精度定量预测,储层厚度、孔隙度预测误差均低于10 %;通过建立烃源岩断层与河道砂有效搭配模式,古今构造高或古构造高、今构造低,同时储层物性好的区域有望获得气井高产、稳产;采用井组立体部署、井型优选及水平井优化设计等技术,极大提升了窄河道致密砂岩气藏储量动用程度,同时节约了投资成本;采用地质工程一体化水平井分段压裂改造技术,单井测试产气量稳步提升,改造效果提高至实施前的10.6倍。所形成的窄河道致密砂岩气藏高效开发技术实现了中江气田的高效勘探开发,建成了年产气量超10×10⁸ m³的中国石化川西第一大气田。

Efficient development of Zhongjiang gas reservoir is faced with four difficulties: the meticulous channel depiction, the establishment of high-yield enrichment mode, the formulation with development technology policy, and corresponding engineering fracturing technology. For the narrow channel sand bodies, the multi-domain and multi-attribute fine description and accurate reservoir prediction technology are used, and the spatial distribution characteristics of multi-stage and overlapping channel sand bodies are well described. It can depict the channel sand bodies of the thinnest 8 m and the narrowest 50 m, and the sedimentary time sequence of each channel sand body is also very clear. An improved three-parameter pre-stack inversion technique based on ray parameter domain is used to realize the high-precision quantitative prediction of thin-layer, the predicted error of reservoir thickness and porosity is less than 10 %. By establishing an effective combination model of source rock fault and channel sand, with high ancient and modern structures or high ancient and low modern structures, and good reservoir physical properties, it is expected to obtain high and stable production of gas wells in these areas. By using the techniques of 3D deployment of well groups, well pattern optimization and horizontal well optimization design, the production degree of tight sandstone gas reservoir in narrow channel is greatly enhanced, and the investment cast is saved. By using the integrated horizontal well fracturing technology, the single well test gas production is steadily increased, and the transformation effect is increased to 10.6 times before implementation. High-efficiency development technology of tight sandstone gas reservoir formed by narrow channel enables efficient exploration and development of the Zhongjiang Gas Field, the largest gas field of Sinopec in western Sichuan, with an annual gas production of more than 1 billion cubic meters.