COILED TUBING FRACTURING MULTISTAGE TOOL STRING AND UTILIZATION METHOD

摘要

A coiled tubing fracturing multistage tool string and a utilization method thereof. A joint (1), a releaser (2), a centralizer (3), a spray gun (4), a balance valve (5), a bottom packer (6), a friction joint (7), a collar locator (8) and a guide shoe (9) are connected to form the tool string. The joint (1) and a connecting tube are connected at the top of the whole tool string. The spray gun (4) and the balance valve (5) are positioned above the bottom packer (6). The balance valve (5) isolates the internal channels of the upper string (601) and lower string (611) of the bottom packer (6) when the tool string is seated, and the balance valve (5) communicates the internal channels of the upper string (601) and the lower string (611) of the bottom packer (6) when the tool string is lifted. Due to the arrangement of the balance valve (5) and the bottom packer (6), when the fracturing tool string is lifted after modification of one target stratum, a sealing element of the balance valve (5) is in an opening position and the upper string (601) and the lower string (611) of the bottom packer (6) are communicated, so that pressure is balanced and work time is shortened.