直井助排技术在煤层气下倾多分支水平井上的应用研究

Research and Application on the Technology of Dewatering Vertical Well in Downdip CBM Multi-Lateral Horizontal Well

煤层气多分支水平井目前已经在沁水盆地南部樊庄区块得到规模应用。开发初期,方案设计并未考虑到该问题,导致部分水平井分支下倾,不利于煤层中水的排出,难以形成有效的降压面积,开发效果差。通过引入微破裂四维向量扫描监测技术,确定产量的主要贡献分支,在资源动用程度低的区域部署助排直井,协同降压,区域盘活,实现了井组产量的稳步上升,进而提高了资源动用程度。

CBM multi-lateral horizontal well was widely applied in Fanzhuang Block in Qinshui basin. At the initial stage of the development, the problem was not considered in the design plan, which led to the downdip branches of horizontal wells, and not conductive for the water discharge in the coal beds. It is difficult to form an effective depressurization area that lead to a poor CBM development effect. By introdu- cing the Micro Fracture Four-dimensional Vector scanning and monitoring technology, determining the main branches which makes contribution to the gas production, dewatering vertical wells are distributed in the areas where the resources was in a low development level. The dewatering vertical well helps to de- crease the pressure and make CBM production of the well group to raise steadily. It can also improve the development extent of CBM resources.