低压致密砂岩气田开发优化研究——以苏里格气田X区块为例

Optimization Research on the Development of Low-Pressure Tight Sandstone Gas Fields—Taking Block X of Sulige Gas Field as an Example

摘要: 鄂尔多斯盆地苏里格气田属于典型的低压致密砂岩气田，储层普遍具有孔隙度低、渗透率小、非均质性强及地层压力系数低等特点，单纯依赖常规开发方式难以满足其高效开发需求。本文以盆地北部的X区块为研究对象，基于地质、测井及生产资料，建立数值模型，针对低压致密储层开发过程中单井产量低、递减快及开发效益不稳定等问题，对排水采气制度下的开发效果进行模拟分析。开展低压致密储层开采方案优化研究，并在此基础上对相关参数进行优化。研究结果表明，在低压致密储层条件下，合理的排水采气制度有助于改善井底流动条件，延缓产量递减，参考同类型气藏开发指标，通过深点注气与地面降压的协同作用(出口压力由18 MPa降至10 MPa)，可有效降低井底流压，使流入动态关系曲线与垂直举升性能曲线在低压环境下实现稳定相交，预估该气藏初步产能为4.6 × 10⁴ m³/d。该方案解决了低压井积液停产的问题，显著延长了低压致密气井的生产周期。可为类似低压致密气藏的开发方案优化提供参考。

Abstract: The Sulige Gas Field in the Ordos Basin is a typical low-pressure tight sandstone gas field. The reservoirs generally have the characteristics of low porosity, small permeability, strong heterogeneity and low formation pressure coefficient. Relying solely on conventional development methods is difficult to meet its efficient development requirements. This paper takes the X block in the northern part of the basin as the research object. Based on geological, logging and production data, a numerical model is established. Aiming at the problems such as low single-well production, rapid decline and unstable development benefits during the development of low-pressure tight reservoirs, the development effect under the drainage and gas recovery system is simulated and analyzed. Research on the optimization of the mining scheme for low-pressure tight reservoirs is carried out, and on this basis, the relevant parameters are optimized. The research results show that under the conditions of low-pressure tight reservoirs, a reasonable drainage and gas production system is conducive to improving the flow conditions at the bottom of the well and delaying the decline in production. Referring to the development indicators of the same type of gas reservoirs, through the synergistic effect of deep point gas injection and surface pressure reduction (reducing the outlet pressure from 18 MPa to 10 MPa), the flow pressure at the bottom of the well can be effectively reduced. The stable intersection of the VLP curve and the IPR curve under low-pressure conditions has solved the problem of fluid accumulation and production halt in low-pressure wells, significantly extending the production cycle of low-pressure tight gas wells. It is estimated that the initial production capacity of this gas reservoir is 4.6 × 10⁴ m³/d. It can provide a reference for the optimization of development plans for similar low-pressure tight gas reservoirs.