非均布导流下页岩气藏压裂水平井产量模拟

Production Simulation of Fractured Horizontal Well with Non-uniform Space Distribution of Fracture Conductivity in Shale Gas Reservoir

杨兆中 廖梓佳 李小刚 朱利勇 陈浩

YANGZhaozhong LIAOZijia LIXiaogang ZHULiyong CHENHao

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 中国民用航空飞行学院空中乘务学院, 四川 德阳 618307

State Key Laboratory of Oil&Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu, Sichuan 610500, China Air Crew Institute, Civil Aviation Flight University of China, Deyang, Sichuan 618307, China

现有的页岩气压裂井产能预测模型假设导流能力在缝长方向均匀分布，导致预测结果存在较大偏差。为提高压裂气井的产量预测精度，基于源汇思想和势的叠加原理，考虑压裂裂缝缝内导流能力的非均匀分布特征，建立了气井水力压裂后的非稳态产量预测模型，并通过数值方法对压裂水平井的产量进行了模拟。研究表明，与常规导流均匀分布的模型相比，缝内导流的非均匀分布对产量产生较大影响；在无因次导流能力较小时，强化近井地带裂缝导流能力的凹型分布等布局方式，有利于提高压后产量；随着无因次导流能力的增加，产量增幅逐渐降低；由于气层的供给能力有限，在无因次导流能力较高时，导流能力出现“过剩”，不同的导流能力分布方式下的产量接近。

The universal assumption in existing production prediction models of fractured horozontal well for shale gas reservoir is the evenly distribution of fracture conductivity. Therefore, there is a large deviation between the prediction production and real production. In order to improve the accuracy of production prediction for fractured gas well, a new model has been established based on point sink and superposition principle with consideration of the characteristic of non-uniform distribution of fracture conductivity. Numerical simulation studies show that the non-uniform distribution of fracture conductivity has a greater impact on production compared with the conventional model. Intensifying the fracture conductivity at nearside of wellbore with concave distribution could improve the yield after hydraulic fracturing when the dimensionless conductivity is small. With the increase of dimensionless conductivity, the increasing amplitude of yield decreases. Due to the limitation of supplying capacity of gas reservoir, the yield of gas well is similar under different patterns of conductivity distribution when the fracture conductivity reaches a certain level.

10.11885/j.issn.16745086.2020.03.09.01