AT A GLANCE
Scope: First successful field campaign using coiled tubing to install annular PWC® isolation barrier in a single run
Where: North Slope, Alaska
When: November 2022
CLIENT CHALLENGE
HydraWell’s long standing global client required annular isolation of an existing well bore with the objective to find a more cost-effective method for use in a remote area where rig availability is extremely limited.
PWC® offers a field proven method of annular isolation, but is reliant on effective fluid displacement downhole. Traditionally this is facilitated by high circulation rates and toolstring rotation from surface.
Using coiled tubing to deploy the toolstring, provides the opportunity for rigless well abandonment. This significantly reduces the total cost of operations, but could reduce the effectiveness of fluid displacement.
HydraCT™ overcomes this to ensure the whole circumference of the annulus is cleaned and cemented effectively.
BACKGROUND
Our latest patented PWC® technology is HydraCT™, an industry first system specifically designed for coil tubing applications. HydraCT™ is a self-rotating, jet propulsion PWC tool which makes it possible to efficiently clean and subsequently cement an annulus (or annuli) without the need for rotation of the drill pipe.
Building on its PWC® track record, HydraWell applied years of experience and deep industry knowledge to transfer existing drill pipe system expertise into the development of its unique coiled tubing system.
HYDRAWELL SOLUTION
By running coil tubing as the deployment method, HydraCT™ eliminated the need for a rig to be placed over the well, significantly reducing the cost of P&A activities.
Using Computational Fluid Dynamic (CFD) modelling to support the application, the likelihood of success was confirmed as well as the confirmation that the parameters chosen were correct.
Two wells were pre-perforated and a bridge plug installed using wireline. On the first well a 2 3/8” coil tubing reel was used to ensure high flowrates could be achieved. Based on the pressure response from this operation the decision was taken to use a 2” coil tubing.
The second well was also executed according to planned parameters. Flowrates were even higher during the washing compared to the 2 3/8” coil tubing.
HydraWell completed the process in a single run, converting the tool to cement mode and successfully placing the barrier in less than 24 hours.
Our client confirmed the barrier quality by drilling out the cement in the main wellbore and logged to verify the result.
RESULTS & BENEFITS
Our first successful onshore campaign demonstrates there is no doubt the HydraCT™ technology is an ideal solution for coil tubing applications. HydraWell is leading the way to rigless operations on unmanned or smaller platforms with load capacity restrictions.
HydraCT™ eliminated the need to mobilise a rig to site and cut the need to run drill pipe to remediate the annuli without compromising barrier quality or barrier verification using established field proven PWC® techniques.
HydraCT™ achieved:
