SCSSVs are an integral part of the overall safety system of any offshore well. Since their industry adoption in the 1970s, SCSSVs have saved lives and the environment. In the Gulf of Mexico and most international locations, the local governing bodies have unanimously mandated their use.

SCSSVs types fall into one of two categories: tubing-retrievable (TR) or wireline- retrievable (WR). Both are operated by a small-diameter control line, which is located on the annular side of the production tubing. The control line is installed during completion or in a workover.

SCSSVs have been very reliable, but losing control line integrity renders them inoperable. Several techniques to repair a backside control line have been attempted in the past with inconsistent results. To avoid a workover, operators may run a storm choke or velocity valve, but these temporary solutions are less than ideal because they eliminate surface control.

The technical challenges and method to prove up a thru-tubing retrofit solution is the subject of this paper.

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