Critical DHSV remediation with ShiftLok hybrid solution

Well type

Producer

Max. temperature

25°C / 77°F

ShiftLoK hybrid solution

From concept to deployment in 10 days

Background

Following a coiled tubing (CT) clean-out operation utilizing proppant and gel, sulfide stress cracking and the introduction of a corrosive environment within the CT string led to fragmentation downhole.

Subsequent fishing attempts with CT resulted in further coil breakage, with high pull forces inadvertently resulting in damage to the downhole safety valve (DHSV) area, also depositing pieces of the internal conductor cable.

Downhole camera imaging revealed that approximately 50 cm of conductor cable was tangled and lodged within the DHSV, rendering it inoperable and compromising the well barrier.

Under normal circumstances, a dimpling operation to lock the DHSV open – and regain access – relies on an open starting position. It was at this point that Welltec^®became involved, and began planning remediation of the two main challenges:

Recovery of the obstructing conductor cable
Re-establishing access through a mechanically inoperable DHSV

Operation

Wire recovery

After performing a camera inspection to assess the downhole obstruction, Welltec determined that the Wellgrab CLAW was ideally suited to retrieve the tangled conductor cable. The tool was deployed over two successful runs, recovering approximately 50 cm of cable in total (30 cm in the first run and 20 cm in the second), clearing the path for further intervention.

DHSV remediation – ShiftLoK deployment

To address the inoperable DHSV, Welltec developed a hybrid solution integrating a mechanical shifting feature with the Well Key^® Dimple Tool. Dubbed ‘ShiftLoK’, the new tool was designed to shift the DHSV flow tube and lock the flapper in an open position through dimpling — all in a single run.

Pre-deployment testing: The procedure was validated through rigorous surface testing to ensure performance offshore.
Successful manipulation and dimpling: After shifting the DHSV flow tube into an open position, a total of 10 dimples were created to ensure it remained locked open.
Post-operation validation: A follow-up camera inspection confirmed both the success and integrity of the dimples.
Real-time adaptation: Operational adjustments were made offshore to ensure continued alignment with downhole conditions.

With the DHSV now firmly locked open, the client's intervention program could safely resume.

Achievements

This high-stakes operation showcased rapid innovation and cross-disciplinary expertise from Welltec, who developed, tested, and deployed the ShiftLoK solution within just 10 days. The successful cable retrieval and DHSV remediation restored well access and resolved a primary well barrier failure, allowing the operator to move forward with planned interventions.

Working single-run DHSV shifting and dimpling solution delivered from concept to the field in only 10 days.
Successfully recovered damaged conductor cable in two runs using the Wellgrab CLAW.
Shifted and dimpled a hydraulically compromised DHSV in a single run.
Re-established well integrity and enabled further intervention activities.
Demonstrated agility and technical range across multiple downhole challenges.