A New Approach to Barrier Verification

Abstract

Abstract Objectives/Scope Verification and testing of a wellbore barrier, in older assets has proven to be challenging. Even more so when the well has structural issues, indemnities or weak spots in the barrier envelope, that limits the possibility to get a positive pressure verification of the barrier with an applied surface pressure. The paper will air on the operational use of this novel test method and the tools used, to allow an in well verification of any type of barrier to secure the well for a repair or a upcoming P/A operation. A pilot job case history will be included to illustrate use of the principles. Methods, Procedures, Process Find a suitable location with necessary support and strength in the well. If installing a mechanical barrier by means of a bridge plug as the primary barrier, we will monitor the installation forces in the anchoring and sealing sequence. This individual signature will be verified towards a nominal base line signature towards a library of thousands of collected installation profiles. Any abnormality can trigger a release and possible relocating of the barrier. A second verification barrier will then be installed above the primary barrier. When both installation signatures are accounted for, we can pressure test the installed barriers. This is done with a pressure inflow tool, where we introduce a calculated predetermined pressure drop between the installed primary barrier and the verification barrier. By monitoring this pressure alteration vs. the pressure above the verification barrier, we can determine if we have a verified barrier. Results, Observations, Conclusions We now have the Primary Barrier verified in the direction of flow (negative pressure test). And verification barrier as the secondary barrier (verified with a positive pressure test). If a dual barrier is requested, you can leave the verification barrier as secondary barrier. Novel/Additional Information Pressure manipulation is done with existing and proven technology and is re-usable after re-setting at surface. By monitoring this pressure alteration, we can verify the installed primary and verification barrier in one run. This without any time-consuming pressure manipulating from surface.