低渗透气藏压力系统划分技术

气田“压力系统”的正确划分是气藏动态分析、开发效果评价、数值模拟、动态预测、开发调整等工作的基础。靖边气田下奥陶统马五段储层具有面积大、厚度薄、低渗透和非均质性强的特征，气井关井后压力恢复慢，很难达到稳定状态，这给气藏压力系统划分和地层压力跟踪带来了较大困难。针对该气田地质特点，将建立观察井网、定点测压、压力恢复试井等多种方法相互结合，在准确求取气藏当前地层压力的基础上，综合考虑气井储层发育、流体性质、井间干扰试验、气藏生产动态特征以及地层压力分布等因素，采取由粗到细、渐进划分的原则，确定了靖边气田的压力系统，满足了气田开发研究的需要。

TECHNOLOGY OF PRESSURE SYSTEM DIVISION IN LOW-PERMEABILITY GAS RESERVOIRS

Accurate division of reservoir pressure system is an important basis for performance analysis, development appraisal, numerical simulation, production forecast and development adjustment. The Early Ordovician Majiagou-5 member reservoir of Jingbian gas field has characteristics of large area, thin layers, low permeability and serious heterogeneity, resulting in slow pressure recovery after shut-in, which led to difficulty in division of reservoir pressure system and formation pressure tracing. According to its geological characteristics, combination of building observation pattern, located pressure measurement and buildup test, etc. has been used. And reservoir development, fluid properties, inter-well interference, production performance and formation pressure distribution were all taken into consideration integrally. Therefore, pressure systems of Jingbian gas field were identified.