The primary objective of the campaign, which covered four operators in Australia and New Zealand, was to decommission or desuspend aging subsea wells in challenging deepwater environments. These wells faced issues such as parted tubing, uncertain cement integrity, and harsh weather conditions. Traditional rig-based interventions prove costly and inefficient, with high day rates, complex logistics, and frequent operational complications. The operators sought a safer, compliant, and economically viable solution to achieve permanent abandonment or production reentry while minimizing project timelines and maximizing operational efficiency.
The SLB-Helix Energy Solutions Subsea Services Alliance deployed the Helix Q7000 semisubmersible vessel, equipped with advanced intervention hardware and integrated services, to tackle the diverse P&A challenges. The vessel's intervention riser system (IRS) and tension frame allowed operations to continue within a wider weather window, reducing downtime. The Q7000's unique tension frame and skidding system ensured rapid switching between coiled tubing and wireline setups, reducing traditional multiday transitions to just hours. Specialized tools and techniques, such as coiled tubing pump-and-pull cement placements and Epilogue™ dual-string barrier evaluations, streamlined the process and achieved faster abandonment timelines. The project provided valuable insights into subsea P&A techniques, with lessons learned applied progressively from one well to the next. For one operator, operational efficiency improved by up to 55% from the first well. The integrated approach fostered improved collaboration and long-term cost savings, setting a precedent for future P&A campaigns in the region.
For more information, read SPE-224106-MS.
