Well pressure integrity is a primary concern during offshore operations. Without proper control, barriers can significantly impact safety and production activities. Once a well barrier is unable to deliver pressure control, correcting the pressure integrity problem as quickly as possible becomes a priority. This paper describes a case where, in a conventional gas lifting oil well, a downhole packer leaked during production and significantly reduced hydrocarbon production.
A conformance system was introduced to a Gulf of Thailand operator. The conformance system's rigid setting fluids are a new generation solution for plugging or temporarily isolating specific zones. The system was engineered to help ensure conformance would set at the right angle and temperature under specific well conditions. High-pressure resistance, low solution viscosity, and zero shrinkage are advantages of using the system to recover well pressure barriers.
The conformance operation was performed using an electric line (e-line) punched target below the downhole packer inside production tubing to help establish conformance injectivity. Once the rate was confirmed, the conformance solution was squeezed to target the zone using coiled tubing (CT). CT was an important component of the solution necessary for cleaning as thoroughly as possible. Conformance pressure was confirmed under controlled conditions. The design only allowed a few hours for the solution to build up compressive strength, so a pressure test was performed from the "A" annulus, and the well could hold 1,500 psi.
The recovery of well pressure integrity successfully addressed the well control issue for the entire life of the well and restored hydrocarbon production from an inability to produce to production of 200 B/D. Using this system, a workover of the rig was not necessary to recomplete the well by replacing the downhole packer and risking hydrocarbon exposure during workover operations. This conformance solution was ideal for correcting the packer leaking problem.