Process for in an arbitrary number of steps to cement an outer liner ring between a casing string and a brondboring and an apparatus for, practice of the procedure laid down

摘要

A cementing tool for providing multiple stage cementing of an oil well including a cylindrical outer case, a longitudinally sliding sleeve valve located therein, an inflatable packer assembly disposed about the outer case with annular check valve means interposed between the interior of the inflatable packer and passages communicating with the interior of the cementing tool. Annular sleeve valve means is interposed between the check valve means and the exterior of the tool and is releasable upon the application of a predetermined pressure differential across the sleeve valve means in response to the application of pressure to the interior of the tool to open the interior of the tool to the annulus between the tool and the oil well bore above the inflated packer. The inflatable packer assembly includes a relatively thin, tubular solid metallic membrane having physical properties allowing it to contain the inflatable pressure and to expand as the inflation pressure is applied to the interior of the packer. An annular resilient sealing member is formed on the exterior of the packer member to afford a fluid-tight seal between the inflated packer and the wall of the oil well bore. In one form the sleeve valve apparatus is actuated by the application of hydraulic pressure within the casing string and in an alternate form the sleeve valve is mechanically actuated by a tubing string disposed within the casing string. Various methods of operating the alternate embodiments of the cementing tool are also disclosed.