沁水盆地煤层气水平井缝网体积压裂工艺优化研究

Optimization of Volume Fracturing Network Technology for Coalbed Methane Horizontal Wells in Qinshui Basin

从煤层气的解吸机理开展剖析,明确气井的增产是要构建立体的人工缝网,以增加更多的裂缝参与流动。为此首先分析实现人工缝网所需的压裂液体系,认为低粘度压裂液是形成大面积缝网的首要因素;其次,从施工排量、成本控制、安全风险等多方面综合考虑,选取主体压裂工艺为桥射联作;再次就所选压裂工艺进行不断优化,根据现场实际情况设计出沁水盆地南部压裂所使用的施工参数。通过现场试验应用结果表明,该工艺能够满足构建体积缝网的需要,达到了增产的目的,为沁水盆地南部高阶煤煤层气井的压裂增产提供了新思路,为高效开发煤层气提供了新方法。

By analyzing the desorption mechanism of coalbed methane,the paper clarifies that the stimu-lation of gas wells requires the construction of a three-dimensional artificial fracture network to increase the participation of more fractures in the flow.Firstly,the fracturing fluid system required to achieve arti-ficial fracture networks is analyzed,and it is considered that low-viscosity fracturing fluid is the primary factor in forming large-area fracture networks.Secondly,taking into account various factors such as con-struction displacement,cost control,and safety risks,the main fracturing process of bridge plug perfora-tion combined operation is selected.Thirdly,the selected fracturing process is continuously optimized,and the construction parameters used in fracturing in the southern part of the Qinshui Basin are designed based on the actual situation on site.The on-site test application results show that this process can meet the needs of building a volume fracture network and achieve the goal of increasing production.It provides a new idea for fracturing and increasing production of high-rank coalbed methane wells in the southern Qinshui Basin,and offers a new method for efficient development of coalbed methane.