Abstract
A plug needed to be set in a well located in the Norwegian Continental Shelf to shut off an existing production interval, followed by the opening of several pre-installed reservoir control sliding sleeves, in order to optimise oil production from the well. It was suggested by the service company that such a two- run operation could be combined into a single run to save time and cost.
An electric line deployed solution was designed to ensure high accuracy and control across the combined operation, providing power to both the plug setting and sleeve shifting tools, along with real- time command and toolstring status readout at surface. The combined setting and shifting functionality required the use of a through-wired shifting tool to enable real-time activation of the plug setting tool, which was positioned below. A bi-directional shifting tool was used, which, in conjunction with a bi- directional stroker, would enable sliding sleeve shifting in both directions, if required, during the operation. Furthermore, its dogs were retractable on command to ensure no inadvertent shifting occurred while traversing the multiple sleeve positioned in the well.
Pre-job system integration testing was done at the service company location using a mock up completion comprised of two sleeves rigged up with a tubing joint in a horizontal set-up. This tested that there was no incompatibility between the plug setting and sleeve shifting components of the combined tool string, and that no inadvertent tool hang up occurred within the completion.
The toolstring was run in hole, depth correlated and the plug set and released. Subsequent correlation was then done for the sleeve section. The real-time control and surface readout of stroker force and position enabled a precise sleeve shifting operation, and all sleeves were shifted successfully as per requirements.
The stroker also provided a means of pulling the plug when it got inadvertently stuck whilst running to set depth and the electric line winch was unable to pull the string free. Multiple release subs were also positioned in the toolstring to enable independent recovery of the plug and stroker assembly if required. In addition, a memory pressure/temperature gauge was run, which provided further validation of sleeve shifting upon download and analysis. A tractor was used to convey the toolstring across the highly deviated section of the well.
This single-run combined service solution delivered flawless operation with considerable time savings.
