SUB-SURFACE DEPLOYMENT VALVE

摘要

A sub surface deployment valve which is particularly suitable for use in underbalanced drilling operations which can be installed through an existing tubular string comprises a radially expandable body (1) having an internal bore and a valve element (2) capable of closing off the internal bore. The deployment valve can be installed by passing the valve through the existing tubular and then radially expanding the radially expandable body of the deployment valve to form a connection resulting from the interference between the external surface of the deployment valve and the tubular string.