A major operator in the Middle-East faced a casing integrity issue on a well drilled in 2015, due to several leaking production casing connections determined through analysis of a number of data sets including pressure test results, casing connection torque turn charts and caliper logs.
Potential remedial solutions were limited to those that did not involve directly remediating the production casing as the number of suspect connections made these solutions high risk. Potential solutions were also required to meet a V0 “gas-tight” pressure integrity requirement to meet the need for gas lift production as well as provide a post remedial ID suitable to deploy the upper completion equipment through. Lastly, any solution identified was to have a high probability of success through existing qualification testing and field deployments.
The solution identified and selected was an expandable tubular technology called “Expandable Steel Patch”, deployed with a deformable element hydraulically inflated, called “Inflatable Packer”. When pumped from surface into this high-pressure balloon, the outer diameter increases, applying a force inside a steel pipe. This pipe, the Expandable Steel Patch, is pushed against the casing and stressed above the material plastic limit. The deformation is permanent. An outer skin of elastomer creates both a gas tight seal and anchoring in order to lock the patch in place and restore the integrity of the covered section. The final expanded ID of the patch is sufficiently large to allow standard upper completion equipment to be deployed through the patch.
This paper will highlight the application limitations that had to be met, the solution selection process and the operational deployment of a record five expandable patches in a single wellbore. Deployment results and technology experience will be reviewed.