CBM Cave Completion Technology

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.