基于致密砂岩储层气水渗流阻力系数的产能新模型  

A new productivity model based on gas-water seepage resistance coefficient for tight sandstone reservoirs

作　　者：张建中 高树生 熊伟[1,2,3] 叶礼友 刘华勋[2,3] 朱文卿 杨懿[1,2,3] 牛文特[1,2,3] ZHANG Jianzhong;GAO Shusheng;XIONG Wei;YE Liyou;LIU Huaxun;ZHU Wenqing;YANG Yi;NIU Wente(University of Chinese Academy of Sciences,Beijing 101408,China;Institute of Porous Flow&Fluid Mechanics,Chinese Academy of Sciences,Langfang,Hebei 065007,China;PetroChina Research Institute of Petroleum Exploration and Development,Beijing 100083,China)

机构地区：[1]中国科学院大学 [2]中国科学院渗流流体力学研究所 [3]中国石油勘探开发研究院

出　　处：《天然气工业》2023年第1期177-187,共11页Natural Gas Industry

摘　　要：致密砂岩储层气水两相渗流规律复杂,实验难度大、目前的两相渗流方程具有一定的局限性。为此,在常规气水相渗测试实验的基础上改进流程,实现了不同压力条件下的气水两相渗流模拟,通过数学分析从系数拟合和减少参数2个角度出发建立了2个渗流阻力系数数学模型,并采用数值模拟的方法验证了2个数学模型的正确性与适用性,然后推导出新的产能方程。研究结果表明:①不论是水驱气还是气驱水过程,同一块岩样在高孔隙压力条件下的渗流阻力系数都比常压实验条件下的数值都要大,说明高孔隙压力对于气水两相渗流有一定的影响;②孔隙压力的持续增大对于气水两相渗流阻力的影响变小,气水两相的渗流能力在一定阶段后并不随孔隙压力的增大而发生明显变化;③不论是纯水驱、水驱气还是气驱水过程,渗流阻力系数与孔隙压力之间都有着较好的对数关系,与渗透率之间则为反比关系;④从系数拟合和减少参数2个角度出发建立了2个渗流阻力系数数学模型,进而推导了全新的产能方程,气井实例计算的IPR曲线与传统方程计算结果基本一致。结论认为,渗流阻力系数消除了实验岩样几何尺寸与驱替速度的影响,推导的致密砂岩气藏新的产能计算模型可靠、准确,该认识对于高效合理开发致密砂岩气具有重要意义。The gas-water two-phase seepage law of tight sandstone reservoirs is complex,the experiment is difficult,and the current two-phase seepage equation has some limitations.In this paper,the gas-water two-phase seepage simulation under different pressure conditions is realized by modifying the procedure on the basis of the conventional gas-water relative permeability test.Then,two mathematical models of seepage resistance coefficient are established by means of mathematical analysis from the perspectives of coefficient fitting and parameter reduction,and their correctness and applicability are verified by means of numerical simulation.Finally,a new productivity equation is derived.And the following research results are obtained.First,the seepage resistance coefficient of the same rock sample under a high pore pressure is larger than that under an atmospheric pressure,no matter in the process of water flooding gas or gas flooding water,which indicates that high pore pressure has a certain influence on gas-water two-phase seepage.Second,with the increase of pore pressure,its effect on gas-water two-phase seepage resistance reduces.After a certain stage,the gas-water two-phase seepage capacity does not change obviously with the increase of pore pressure.Third,there is a good logarithmic relationship between seepage resistance coefficient and pore pressure,and an inverse relationship between seepage resistance coefficient and permeability in the process of pure water flooding,water flooding gas or gas flooding water.Fourth,two mathematical models of seepage resistance coefficient are established from the perspectives of coefficient fitting and parameter reduction.Then a new productivity equation is derived.The calculated IPR curve of gas well is basically consistent with the calculation result of the traditional equation.In conclusion,the seepage resistance coefficient eliminates the influence of sample geometrical size and displacement velocity in the experiment,and the derived new productivity calculation model of tigh

关 键 词：致密砂岩气 渗流阻力系数 孔隙压力 渗透率 数学模型 产能方程 

分 类 号：TE312[石油与天然气工程—油气田开发工程] TE328