Since 1987, Helix and Schlumberger have used riser-based well access to perform interventions—including P&A, hydraulic and mechanical well interventions, well maintenance, production enhancement, and hydrate drilling—in more than 1,500 wells.
Interventions can be performed in water depths ranging from 165 to 10,000 ft [50 to 3,000 m].
By integrating the continuously evolving capabilities and extensive experience of pioneers in the sector, we support your offshore assets through proven project management, engineering, expert personnel, and world-class R&D and manufacturing centers that design and develop all the technologies required to achieve superior performance.
Schlumberger pioneered rig-based subsea well intervention, and Subsea Services Alliance is extending the operational track record, from pumping operations to multistage interventions, including coiled tubing and wireline access, through-tubing drilling, and section milling.
Interventions can be performed using your vessel of choice; alternatively, you can use one of our dedicated vessels at significantly lower cost than a drilling rig. We can perform riser-based or riserless interventions, as required.
Using a marine low-pressure riser and operating on a dead well enables all types of intervention as well as abandonment. These operations are highly complex, requiring more time to complete.
Using a high-pressure riser and operating on a live well permits most interventions, with the exception of activities such as casing milling or retrieval. These operations are faster because killing the well is not necessary.
Whether the well is geometrically challenging or environmentally harsh, our experienced well intervention teams can recommend techniques that address your challenges with minimum cost and risk. As designers, manufacturers, and operators of a range of high-pressure riser packages, we have performed rig-based interventions worldwide with equipment rated up to 15,000 psi.
Using one of our state-of-the-art intervention vessels and a high-pressure riser, we can perform most types of intervention, such as installation of pump-through plugs in subsurface safety valves, gas lift valve changeouts, sand screen repairs, sand consolidation, tubing repairs, remediation of a leaking tubing or seal failure, and choke changeouts. Fluid pumping and circulation operations are also possible.
These operations can typically use a smaller vessel compared with riser operations. All types of mechanical interventions in the well and fluid pumping are possible, except circulation. This nimble operational approach can employ our efficient and cost-effective riserless intervention and abandonment solutions on wireline and slickline, including our subsea intervention lubricator (SIL) systems for water depths up to 10,000 ft.
This is the simplest and least expensive type of intervention, typically deployed from smaller vessels with capabilities for pumping and injecting fluids into the well or flowline.
Our full suite of open-water intervention services covers the life cycle of your well. When it comes to mid- and late-life treatments, our services fully address your production enhancement needs by integrating industry-leading access systems and a complete range of fluids for scale squeezes, acid stimulation, and asphaltene and wax removal. High-rate pumping through your subsea tree is enabled via a selection of conduit types and conducted with a high degree of safety, as built into our seabed packages.