Coiled tubing deployed inflatable stimulation tool

摘要

A resettable well stimulation tool is lowerable into a well bore on a length of tubing through which pressurized fluid may be forced into the tool to inflate a packer portion carried by the tool and then discharge a stimulation fluid into a portion of the well bore sealed off by the packer portion. During the inflation cycle of the tool pressurized fluid is forced downwardly into an annular tool body inflation chamber that communicates with an inflatable packer carried by the tool body. A perforated tube member coaxially carried in the inflation chamber serves to vertically distribute the inflation pressure along the length of the packer and assure its even inflation. In a straddle packer embodiment of the tool inflation and stimulation passages extend internally through the tool and are sealingly separated by an internal crossover structure, with the inflation passage being in communication with upper and lower packer members. The internal inflation passage eliminates the previous necessity of communicating the upper and lower packers with inflation tubing externally coiled around the tool body. A longitudinally intermediate portion of the tool body has a telescoping expansion joint portion to compensate for the longitudinal forces exerted on the body by inflation of the packers. The expansion joint is biased, by both mechanical spring pressure and internal fluid pressure, toward a retracted position thereof.