The paper presents a study of the design and development of a Hydraulically Expanded Tubular System (HETS) Internal Patch and Wireline Running Tool by READ Well Services, and qualification testing of the patch for oil and gas well applications. The HETS Internal Patch solutions enable tubing or other leaking downhole equipment to be repaired, or provide a method of strengthening corroded or damaged completion equipment.
The process involves expanding a metal sleeve (using hydraulic pressure) into the existing tubing to provide a continuous lining with a permanent seal. The restriction in the well is minimal (only the thickness of the patch) unlike straddle type solutions. A typical patch could be 5 mm (0.2”) thick. This allows the maximum possible production and for tools to be run through the patch for ongoing well maintenance requirements.
For a number of years HETS solutions, and their deployment systems, have been available to suit tubing sizes of 7” and larger. A Joint Industry Project (JIP) was created to downsize the technology to suit smaller sizes of tubing. READ Well Services and 5 major oil and gas sponsors used the inherent scalability of the available HETS technology and developed the SlimHETS system to provide a means of deployment for Internal Patches to suit 4 ½” to 5 ½” tubing. The deployment system was also required to be compatible with a tractor to suit high angle or horizontal wells. The project was created to develop, manufacture and test the the wireline deployment system and to design, manufacture and qualify corresponding Internal Patches.
The SlimHETS Internal Patch represents a new development for well design and offers significant advantages over alternative solutions. These advantages are further described in the paper.