Cleaning SSSV with well flowing
- Well type Producer
- Max. deviation 34.6 @ 6,444 ft (1,964m)
A Mexican operator was in a dilemma after debris had settled in the top area of the flow tube of the Sub Sea Safety Valve (SSSV), causing sealing problems. Despite releasing all the pressure from the control line, the flow tube did not retract completely.
The operator could now either try to repair the seal by pumping acid or by applying innovative, e-line cleaning technology. The downside of applying acid is that it requires a larger spread of equipment, the well to be shut in and the acid to be flowed back.
Based on a 100% success rate with Welltec’s e-line solutions previously in this environment, the choice was simple. Cleaning on e-line also provided the benefits of maintaining production at the normal rate as this keyhole intervention would not require the well to be shut in.
Welltec® performed careful pre-job planning with the client, including extensive valve analysis and surface tests. Based on the well characteristics, the ideal tool configuration was a Well Tractor® and Well Cleaner® Wishbone Honer (WBH) with near bit centralizer. During the offshore operation a gauge run was first performed to ensure there were no restrictions in the well before reaching the SSSV depth.
Then the entire inner profile of the SSSV was cleaned with the WBH while the well was still flowing at 2,100 BOPD. The entire operation was executed in only one hour of cleaning time. The SSSV was then function tested three times and proved to open and close normally, with a fully recovered seal.
The WBH was 100% effective and successfully recovered the functionality of the SSSV. The e-line operation generated several benefits compared to alternative methods including reduced intervention times due to faster rig up and rig down, less equipment and fewer personnel mobilized. Since Welltec could perform the operation riglessly, the operator avoided mobilizing a drilling rig in case the completion had to be removed.
This would have added 14 days to the operation, not to mention the cost of deferred production. No acid was pumped, which avoided risk of completion damage. As a result of this successful operation more interventions with the WBH are being planned to solve the seal problems in this region. Welltec’s e-line cleaning solution is now regarded as preventive maintenance instead of corrective maintenance.