考虑压裂区渗透率变化的页岩气井产能评价

Evaluation on productivity of shale gas well considering change of permeability
in fractured zone

任飞 王新海 任凯 李清泉 王珊珊 张磊 王宇

中国石油大学（北京）石油工程学院，北京 102249 中国石油大学（北京）非常规天然气研究院，北京 102249 中国石油塔里木油田公司，新疆 库尔勒 841000

College of Petroleum Engineering, China University of Petroleum, Beijing 102249, China Research Institute of Unconventional Gas, China University of Petroleum, Beijing 102249, China Tarim Oilfield Company, PetroChina, Korla 841000, China

为掌握页岩气的生产动态特征，进行页岩气的高效合理开发，文中在考虑近井地带压裂区渗透率变化的条件下，建立了页岩气的渗流模型，并给出了相应的有限差分数值模型。通过编程求解，研究了压裂区渗透率不同变化方式及压裂半径对页岩气产量及稳产时间的影响。结果表明：压裂区渗透率呈指数递减时，页岩气产量最高，稳产时间最短；渗透率为线性递减时，产量次之，稳产时间次之；渗透率为常数时，产量最低，稳产时间最长。在压裂区平均渗透率与压裂区半径乘积为常数的情况下，随压裂半径的增大，页岩气产量减少。

In order to understand the production performance characteristics of shale gas, shale gas should be developed efficiently and reasonably. Based on the consideration of permeability change in fractured zone near wellbore, the mathematical model of shale gas was established. Relevant numerical model of finite difference was given. The influence of different changing ways of permeability and fracturing radius in fractured zone on the production of shale gas was studied through programming. The result indicates that with exponential decline of permeability in fractured zone, shale gas well has the highest production and the shortest stable production time. With linear decline of permeability in fractured zone, production and stable production time take the second place. With constant permeability in fractured zone, shale gas well has the lowest production and longest stable production time. When the product of radius and average permeability in fractured zone is constant, the production of shale gas reduces as the radius of fractured zone increases.

10.6056/dkyqt201305025