THE APPLICATION AND MECHANISM OF MULTI-MICRO-FRACTURING STIMULATION TECHNOLOGY FOR HIGH RANK CBM WELLS: A CASE STUDY FROM SOUTHERN QINSHUI BASIN, CHINA

摘要

Hydraulic fracturing is the most effective technology to increase the productivity of low permeability CBM wells and the main way to increase single well production is to increase the length of hydraulic fractures as much as possible. In order to increase single well production, multi-micro-fracturing stimulation technology is put forth by this paper. The experiments of the migration and precipitation of proppant are carried out in ideal artificial hydraulic fracture and the Multi-micro-fracturing is simulated by Meyer. The pilot comparison experiment also carried out to verify the effects of Multi-micro- fracturing on the increase of single-well production. The conclusions stated that the sanding times has great impact on the migration distance of sand in hydraulic fractures and the more the sanding times are, the longer the sand bank is. Conventional fracturing technology results in the accumulation of sand near the wellbore, however, multi-micro-fracturing technology can facilitate the further migration of sand. The three-times fracturing technology can form much longer effective fractures and larger effective stimulation volume of coal seam and can stop the hydraulic fracture penetrating into the floor slab of coal seam effectively. So the three-times fracturing technology gets gas production up to 4200m3/d, 4 times ofthat of Conventional fracturing. So multi- micro- fracturing technology can significantly improve single well production and three-times fracturing technology is appropriate for the CBM formation in Southern Qinshui Basin.