Damaged Control Line Solution to Sustain Functional Downhole Safety Valve and Avoid Completions Recovery

Abstract

An Oil & Gas company experienced an issue with communication to the Sub surface safety valve (SSSV). To address this issue, a unique solution was developed to avoid the need for a workover and restored surface communication with the SSSV.

One of the offshore wells in United Arab Emirates developed a blockage in the Control Line (CL), leading to an inoperational SSSV. As a result, it became necessary to close the well. This situation would normally continue until a completion workover could be scheduled.

An alternative solution was implemented in this well and restored production through the SSSV without the need to perform a workover.

After collecting data such as wellhead details, SSSV profile, and production history, a custom Safety Valve communication system was designed and installed. The Lower Master Valve was modified to allow an in-tubing control-line communication, which in turn located the retrofit SSSV. The old CL was also isolated as part of this operation.

Over two stages of operation, the wellhead modification was performed and the installation of a replacement surface controlled SSSV, wet connect, CL, and CL hanger was completed. The system was then tested successfully prior to handing the well back to production.

The installation of this system saved the cost of rig mobilization and completion recovery as a barge was utilized to install this system as opposed to a workover rig with all the associated additional resource and costs. Supported by flow modeling prior to design and installation, the installed system maintains its integrity while the well is producing at normally expected flow rates. This is a retrofit solution that can be engineered to suit any well with various combination of wellheads and downhole completion accessories. The system follows oilfield standards as required for a safety-valve barrier. It can be used to extend the production duration of the mature wells before an expensive workover operation becomes necessary. The type of wellhead penetration used does not affect the functionality of the existing wellhead valves.

Installation of this system saved the cost for a workover rig, replacement completion equipment, and brought a previously shut-in well into production. This system provides a significantly safer alternative compared to the restrictive storm-choke devices and ultimately brings the well back online, while adhering to industry standard definitions for surface-controlled SSSVs.