Method for completion of wells

In a well having an open borehole with a formation which is to be isolated from a lower portion of open borehole, the method comprising:

• running a string of pipe into the open borehole with an inflatable packer releasably attached to the lower end of the string;
• positioning the packer at a desired depth below said formation to be isolated;
• the packer having a radially expansible resilient sleeve sealingly connected at its ends to an interior mandrel and having passage means for permitting flow of fluid to the exterior of the mandrel into the interior of the sleeve;
• preventing flow through the mandrel into the open borehole below said packer prior to passing cement through the pipe;
• then passing cement down through the pipe string and into the mandrel with flow into the open borehole therebelow prevented through said passage means into said sleeve in an amount and under a pressure sufficient to expand the sleeve in an amount and under a pressure sufficient to expand the sleeve outwardly into tight gripping engagement with the wall of the borehole to anchor the packer to the wall of the borehole above said open borehole;
• and
• permitting the cement within the sleeve to set, and detaching the running string from the packer and removing the running string of pipe from the borehole leaving the packer in position therein to act as a plug to isolate said formation from the open borehole below the packer.