Rigless Tubing Repair Using Permanent and Retrievable Patches at Prudhoe Bay, Alaska

Abstract

TX 75083-3836, U.S.A., fax 01-972-952-9435. AbstractIn Prudhoe Bay, Alaska, non-rig tubing repairs have become a viable alternative to rig workovers (RWO's) to provide an economic remediation for wells with production tubing by "A" annulus communication. Electricline (EL)-set patches can eliminate tubing communication at a significant cost savings and are particularly attractive in areas where RWO cost is significant, such as offshore, remote, or arctic locations. The advantage of tubing patch repair over a conventional RWO is that there is no need to pull tubing, resulting in the well being returned to service faster. Typical patch deployment costs are less than 5% of the costs for tubing replacement with a RWO. To date, 263 permanent and retrievable tubing patches have been set in 181 wells at Prudhoe Bay. This paper discusses the history of conventional tubing patches at Prudhoe Bay, recommended pre-patch diagnostics, and the use of 3-D advanced caliper viewing software. The paper also provides a systematic approach for the design and deployment of conventional tubing patches.