基于边界元理论的气藏不稳定渗流模型研究

Research on Transient Flow Model of Gas Reservoir Based on Boundary Element Theory

邓波 陆正元 赵娜

DENGBo LUZhengyuan ZHAONa

油气藏地质及开发工程国家重点实验室·成都理工大学, 四川 成都 610059 中国石油西南油气田分公司川西北气矿, 四川 江油 621700 油气藏地质及开发工程国家重点实验室·西南石油大学, 四川 成都 610500

State Key Laboratory of Oil & Gas Reservoir Geology and Exploitation, Chengdu University of Technology, Chengdu, Sichuan 610059, China Northwest Sichuan Gas Field, Southwest Oil and Gas Field Company, PetroChina, Jiangyou, Sichuan, 621700, China State Key Laboratory of Oil & Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu, Sichuan 610500, China

川西北双鱼石区块栖霞组气藏地质条件复杂，受多期构造运动影响，气藏断裂发育、边界不规则，气井不稳定渗流模型研究难度较大。基于渗流理论基本原理，建立了在构造影响条件下，复合气藏直井考虑任意边界的不稳定渗流物理与数学模型，采用点源函数等方法求解了复合气藏直井边界元基本解，利用边界元理论建立了任意外边界复合气藏直井压力响应数学模型。通过边界离散与叠加原理思想，结合计算机编程技术，求取了不同参数影响下的气井无因次拟压力及其导数值，并绘制了相应的压力响应图版，划分了气井流动阶段并进行了影响参数分析。结合气藏试采井双鱼001-1井的实际情况及压力恢复动态监测资料，利用本文建立的模型和方法进行了现场实例运用，为后续类似复杂气藏的试井解释提供了新的手段与方法。

The reserves of gas reservoir in Permian Qixia Formation, Shuangyushi Area of northwestern Sichuan Basin is abundant, and the research on transient flow model is difficult due to the development fractures and complex boundary caused by multi-period tectonic movement. On the basis of fundamental principle of seepage theory, a composite dual-porosity physical and mathematical model for vertical well is established by considering arbitrary shape boundary, and then the fundamental and pressure response solution of vertical well in such composite model is derived by point source function and BEM. Combining the principle of superposition and computer programming techniques, the dimensionless pseudo-pressure and its derivative are obtained under different variables, and the gas flow regimes are divided and the parameters sensitives are analyzed. In the end, a field case of Well Shuangyu001—1 in Qixia Formation, Shuangyushi Area in northwestern Sichuan Basin is applied by the method proposed in this paper, and obtained an excellent agreement. It provides a new method for well test interpretation of this kind of complex gas reservoir.

10.11885/j.issn.1674-5086.2020.12.16.02