Planning, Design and Optimization of CT Intervention for the First Successful Multistage Fracturing Completion with Sand Control System in the Region

Abstract

Abstract For the first time in the region, a multistage fracturing completion technology that enables simultaneous fracturing and controlled sand production was successfully installed. After the fracturing operation was conducted through frac ports in multiple zones, coiled tubing (CT) intervention was needed to shift the frac ports closed and then open the production sleeves located within the sand screens. It was necessary to use the appropriate shifting tools and utilize the downhole parameters to ensure the shifting operation success. CT was first utilized to mill the frac balls and associated seats after the fracturing operation, and this was followed by CT intervention to close the frac ports and open the sand control production sleeve. CT providing real-time downhole parameters was utilized during the shifting operation as its downhole weight provided the ability to apply required surface forces to shift the respective well accessories. Additional benefits were gained by utilizing the depth correction and obtaining the required differential pressure across the shifting tool in real-time ensuring tool functionality at optimum parameters. The success of the innovative multistage completion operability depended on the successful implementation of shifting operations to close the frac ports and open the production sleeves with sand screens. Therefore, it was very important to select and deploy the appropriate shifting tools that can be trusted to actuate each of the respective well accessories. A series of yard tests were conducted to understand the hydraulically operated shifting tools. After the successful yard tests, during the design phase, each of the shifting operation steps were elaborated with the respective contingencies, and it was confirmed that the CT equipment utilized for the job can provide the required surface and downhole weights. The hydraulically activated shifting tools operation during the actual CT intervention was optimized using the CT by providing real-time downhole measurements of depth correction, tension, compression and pressures. The downhole measurements helped in repeating the shifting step as needed and helped in confirming that the respective well accessory is shifted. During the intervention, two frac ports were shifted close. Whereas, there were two production sleeves with screens shifted open. The use of the two different hydraulically activated shifting tools during the shifting operations for the first successful multistage fracturing with sand control completion system will be detailed. The paper also describes the full benefits of monitoring downhole parameters during shifting operations enabling the tools to operate at optimum conditions and ensuring the shifting is conducted successfully.