- To provide a solution to BP for plug and abandoning a subsea well
- BP required a method to latch onto their tubing hanger (provided by FMC), unlocking it, and then retrieve it to surface using the existing Expro subsea landing strings, which had been configured for an alternative tubing hanger
- Functionality required to the tubing hanger running tool, tubing isolation valve, and surface-controlled subsurface safety valve (SCSSV), as well as a method of sealing the annulus with the BOP annular bags
- Local teams in Angola presented a suitable technical solution to BP, proposing significant cost savings by delivering the project in-country - a first for a project of this nature for the Expro team
- Modifications of the existing system to allow for control of the FMC tubing hanger running tool (THRT) and tubing hanger functionality included: modification of the spacer sub (shortened to allow for space out); new HMI software package; riser control module modification; re-piping of the landing string
- Global expertise network: support from Expro Group Engineering team in the UK for approval of documentation to ensure relevant equipment, system drawings and procedures were updated; machining complete in-country to reduce turnaround time for the client
- Additional challenges which were overcome included: known trapped gas below the tubing hanger at the time of retrieval; defining the collapse pressure of shear sub hoses; running PDG-line cable and connectors through B18 subsea test tree; using only annular bags to seal around ported annular slick joint - spaceout does not allow for pipe rams to close on integral slick joint; redesign of the secondary THRT unlatch system
- The project was delivered within 80 days, which was critical due to the management of the Block 31 Project running concurrently
- The Expro team in Angola delivered primary and back-up electro-hydraulic (EH) landing strings on time and performed a successful abandonment with zero NPT and a job performance report score of 99.25%
- Significant cost savings: Expro's in-country team were fundamental in enabling BP to deliver this project while making savings of up to 50% from the original budget
- Commendation from BP senior management team to Expro as a "leader in service quality"
- BP have subsequently chosen Expro to deliver additional projects due to in-depth knowledge, expertise and track record of working with the operator