At a fraction of the cost of conventional tools, Coretrax, the wellbore clean-up and abandonment specialist, is increasing its stock of CX-Enviroplugs to meet demand for a safe, simple and significantly cost-effective solution for big bore cement plug placement.
Confidently setting an environmental barrier for plugging and abandonment (P&A) operations has traditionally been limited to complex and costly mechanical bridge plugs and inflatable devices.
With a patent pending, eight CX-Enviroplugs have so far been run across Norwegian and UK P&A projects in the North Sea. The most recent was completed in the Southern North Sea for a major, independent European operator. It is particularly suited to wells requiring an environmental barrier to prevent the leakage of oil-based mud.
“The CX-Enviroplug is a unique offering for those looking to undertake efficient and reliable well P&A at considerably less cost and is available for all as part of our range of abandonment products and services,” says Cherish Bodman, Operations Coordinator with Coretrax. “It essentially removes the complexity and restraints associated with other environmental barriers, which can be over-engineered for what is a relatively simple procedure.”
Originally designed to act as a simple base for cement, the tool has been enhanced to allow the option of pressure testing in larger ID casing. Available in a range of sizes up to 20 inches, the three-finned tool, which allows accurate self-centralisation, now incorporates a compression set element. The design is also able to pass through a smaller wellhead restriction.
The plug is typically run on the drill pipe. Once at depth, a ball is dropped, and pressure applied to shear out the disconnect sub. This leaves the lower section of the disconnect sub and the plug downhole. Once released, an open-ended disconnect sub is left and cementing can take place simultaneously. The disconnect tool utilised on the CX-Enviroplug is also suitable for other applications.
Manufactured from drillable materials, the CX-Enviroplug also boasts a one-way valve and bypass ports across the plug to prevent surging when running in hole. The inclusion of a compression set elastomer in the design allows for a pressure test of up to 1,000 psi to be achieved.
“There are approximately 3,650 development wells awaiting P&A along with many partially suspended or partially abandoned wells that require final abandonment and this represents nearly half of the estimated total decommissioning costs. Providing a solution that is cost-efficient, competent and safe is paramount as operators look to reduce decommissioning costs by more than a third. Deploying the CX-Enviroplug as an environmental barrier can realise that saving,” adds John Fraser, Global Business Development Director at Coretrax.