Schlumberger Rigless Subsea Well Intervention Rigless subsea well intervention is the technology and methodology of reentering a subsea well to perform through-tubing work without a MODU, enabling coiled tubing, slickline, or wireline operations. Schlumberger is introducing two complementary rigless subsea intervention methodologies. These methodologies, Open Water Wireline (OWWL) and the Spoolable Compliant Guide (SCG), use common well control equipment accessible from a single vessel to create a step change reduction in the cost of a subsea well intervention.
Customers can now have rigless well services access to their subsea wells in water depths to 3,000 m. The addition of coiled tubing services and extension of water depth capability to 3,000 m offer added value at costs that are essentially the same as those for OWWL services deployed in shallow water depths today. Open water wireline Open Water Wireline (OWWL) enables slickline and electric-line operations services to be performed in subsea wells. To date this intervention technology has not been deployed in water depths greater than 500 m, much less the 3,000 m water depth our system is designed to operate in.
The traditional grease injection-type dynamic seal containing well pressure around the braided electric line is replaced by our streamline cable and a stuffing box-type dynamic seal system. This combination simplifies the subsea well intervention package control system and hydraulics necessary to maintain separation of the wellbore fluids from the environment. Spoolable Compliant Guide The Spoolable Compliant Guide (SCG) enables slickline, electric line, and coiled tubing intervention services to be performed in subsea wells.
Schlumberger can enable this service to water depths to 3,000 m. The patented SCG employs a flexible guide that connects a vessel to a subsea well control package. A wellbore seal protects the SCG from wellbore fluids and pressure. The guide provides motion compensation and enables injection forces from a surface coiled tubing injector to be transmitted from the vessel. These two functions allow coiled tubing, electric line, and slickline services to be rigged up and run from the vessel as if they were rigged up and run on a dry tree well from a platform.