Downhole chemical cutting tool.

摘要

A downhole chemical cutting tool having an anchoring system employing interchangeable slip arrays (38) of progressively larger outside diameters that can be used economically to adjust the range of the anchoring system. The range can be further adjusted by utilizing interchangeable slip expansion mandrels (44). This anchoring system both anchors and centralizes the chemical cutting tool. The cutting tool includes a slip shaft (32) that provides fluid communication between the propellant section (24) and chemical section (26), thence to the slip piston (36) that receives the interchangeable slip arrays (38). The slip shaft and slip piston are threadedly connected to a set coiled tension spring (34). Interchangeable slip expansion mandrels (44) connected to the slip shaft (32) below the slip arrays are constructed with ball bearings (44a) on the surface that receives the slip arrays expanding the slip segments into a gripping engagement an usually large angle as the slip piston is actuated by the application of fluid pressure during the cutting operation. The interchangeable slips are configured so that the gripping teeth (38k,j,i,h) will simultaneously engage the internal surface (110) of the wellbore pipe being cut. During the cutting operation the application of fluid pressure activates the slip assembly and discharges the chemical cutting fluid from the chemical section into the fluid jet section of the tool at high temperature and velocity. After the release of fluid pressure the slip assembly reliably releases the tool due to the large angle of engagement of the slip segments.