煤层气洞穴完井技术

CBM Cave Completion Technology

摘要:

煤层气洞穴完井技术既是一种裸眼完井技术，又是一种增产技术，在适宜的地层该技术能够大大提高近井地带的渗透率，从而提高煤层气的采收率。该技术在美国圣胡安盆地的高渗煤层取得了巨大的成功，但是在其它区域并没有像圣胡安盆地那样效果明显，究其原因对该技术的增产机理及煤层适应性的认识还有一定的差距。分析了洞穴完井技术的增产机理及洞穴完井的煤层适用条件，对洞穴完井技术的储层选择、井身结构、工艺流程及设备配套进行了详细论述，并介绍了国内的现场试验情况及取得的一些有益经验，为该技术以后的推广应用奠定基础。

Abstract:

CBM cave completion technology is not only a kind of open hole completion technology, but also a stimulation technology, which can greatly improve the permeability of the near well zone in the appropriate formation, so as to improve the recovery rate of coal-bed methane. This technology was applied in the high permeability coal seam of San Juan basin in the U.S. with great success, but there is no such obvious effect in other areas. The main reason is that there is certain gap in the understanding of the mechanism of the stimulation technology and reservoir adaptability. In this paper, the stimulation mechanism of the cave completion technology and the applicable conditions of coal seam in cave completion are analyzed; the reservoir selection, well structure, process flow and equipment matching are discussed in detail. The field tests situation and some useful experience obtained in China are introduced, which lay the foundation for the popularization and application of this technology.