In heavily fractured carbonate reservoirs, wells often suffer heavy losses while running lower completion. To avoid any unexpected flow-back, continuous pumping is required. Failure to do this will result in flow-back of the reservoir fluid into the completion string and could reach the surface, leading to a major well control risk. Integrated Pressure Activated Valve (PAV) with Autonomous Inflow Control Valve (AICV) offers a unique solution to manage well control risks, allowing safe deployment of lower completion in such challengeable situations.
The PAV module is mounted in series between the screen and AICV housing and will be a part of a lower completion. PAV-AICV system remains closed while RIH, ensuring no fluid can flow through it in either direction. Once the completion reaches the target depth and other pressure-activated completion tools are set/tested, then the PAV is triggered by applying the design pressure in the tubing. PAV will open once activated pressure is reached, and open when the pressure is released, establishing the flow path between the reservoir and tubing via AICV.
The qualification test of the AICV-PAV integrated system involves multiple functions and pressure tests. The test results prove the reliability and robustness of the PAV to get activated at the design pressure window. This paper will describe in detail the operating principle along with the testing results of the AICV-PAV system. During the deployment of completion, the AICV-PAV system acts as a well barrier between the reservoir and the completions system and prevents reservoir fluid to enter the completion string. This will result in reducing the well-control risk significantly while deploying the completion string, especially in a fractured or faulted reservoir. Furthermore, this system allows all formation treatment fluids to be fully circulated through the end of the completion string, thus eliminating the requirement of an inner string. Furthermore, it also allows setting liner hanger packer and hydraulically set mechanical packers. This will result in saving rig time in running extra runs and further reducing cost/risks as well as increasing operational efficiency. Once the PAV module is open, it stays in an open position and normal AICV functionality is established. The system is field ready and will be deployed for a major operator in the Middle East.
PAV module incorporated with AICV provides pressure integrity in the liner for lower completion installation. This ensures an optimized lower completion installation in challenging situations, especially with well control issues. This paper will describe the newly developed AICV-PAV system operating principle, functionality and discuss in detail the various testing results.