BiSN sets largest wel-lok™ plug in the world for a super major operator in the Gulf of Mexico
An operator in the Gulf of Mexico had a previously abandoned subsea well that was facing abandonment challenges. A permanent, gas-tight seal was needed inside 36” conductor pipe that could be deployed rigless with a quick turnaround. BiSN was contacted to provide a solution that would protect the environment and reduce operator cost.
Acting in collaboration with the super major operator and team partners, BiSN was able to successfully seal the well using a liftboat and remote operated vehicles to deploy the tool.
This deployment considerably exceeds the world’s largest bismuth plug record set previously (by BiSN) for the Aker BP Valhall campaign in 2020.
Summary video of BiSN setting the largest bismuth alloy plug in the world.
Sealing inside the 36″ conductor necessitated a record-breaking and unprecedented tool in terms of size and weight, given the volume of bismuth alloy needed. The tool had to contain more alloy and thermite than any previous BiSN tool, considerably surpassing the prior record set. Moreover, the tool had to be deployable without a rig, which added to the operational complexity.
The application of wel-lok™ technology in this use case had already been field proven, however the size of the seal required posed material challenges and had never been attempted before.
The weight of the tool required BiSN to expand its own internal operations and equipment to accommodate the weight of the tool and ensure safety for BiSN staff and partners during production and deployment.
Comparison of a typical Seal Through Casing (STC), the previous Aker BP STC, and the Tubing Seal (TS) tool used in Project Atlas.
To give some real world comparison, once complete, the tool weighed approximately the same as a humpback whale.
BiSN produced a Wel-Lok™ Tubing Seal (TS) using 10,000 kg of bismuth alloy, 2,000 kg of thermite, and a total weight of 20,000 kg. Prior to deployment, a drift and scraper run was completed to ensure the placement of the tool in the open conductor.
The TS tool was then deployed from a liftboat and guided into the conductor using remote operated vehicles (ROV). A timer activated system was used to start the thermite reaction, which melted the bismuth alloy from the tool. The bismuth alloy flowed into the well, completely filling the cross section of the pipe. The chemical reaction heater was removed from the molten alloy, leaving a solid, metal-to-metal seal in the pipe.
After the bismuth alloy had solidified, which causes expansion, ROVs observed the well for 20 hours with no evidence of further gas migration.
BiSN Engineering and Quality Control inspect the complete heater.
BiSN set the world’s largest bismuth plug in the Gulf of Mexico and created a V0 gas-tight seal for the super major operator.
The wel-lok™ TS tool after being successfully deployed in the Gulf of Mexico.
BiSN provided the customer with a reliable solution for permanent abandonment. This eliminated the complexity of traditional abandonment alternatives while providing the long-term reliability of bismuth alloy. Because bismuth alloy can form an effective seal with a shorter plug length, this could be deployed in the shallow conductor without requiring significant workover, representing significant cost savings for the operator.
BiSN was able to help the operator reduce HSE risks, operation time, and cost. The reliability of the bismuth plug also benefits the environment by providing a permanent seal for millennia.
wel-lok™ Tubing Seal (TS) tool preparing to be deployed from the liftboat.
Learn about the process of creating the largest bismuth plug in the world, delivered only by BiSN’s wel-lok™ technology.
When the super major operator first approached BiSN, the challenge was immediate – how to stop gas migration in a previously abandoned subsea well and set a wel-lok™ plug inside a 36″ conductor pipe?
BiSN engineers and operations staff worked together with the operator to draw up plans for the largest wel-lok™ plug ever created, significantly larger than BiSN’s previous deployment of wel-lok™ technology in the North Sea for AkerBP.
A solution was arrived at to create a Wel-Lok™ Tubing Seal (TS) tool and deploy from a third party liftboat.
BiSN Founder and CEO Paul Carragher briefs the engineering team on the challenge.
BiSN designs and manufactures each tool it produces, from the chemical reaction heater to the bismuth alloy used in wel-lok™ technology.
To create a wel-lok™ technology tool, BiSN engineers and manufacturing crew collaborate to create a permanent seal in wells to protect the environment forever. This involves the following stages:
Click to watch the R&D, testing, planning and manufacturing phases of the world’s biggest wel-lok™ tool.
BiSN chemical reaction heaters are powered by controlled thermite reactions. At BiSN we create our own proprietary thermite blend to power wel-lok™ technology.
In order to create an effective seal for the operator, BiSN technicians created more than 2,000kg of thermite.
The BiSN team with the thermite created for Project Atlas.
BiSN’s wel-lok™ technology uses a bismuth alloy to produce a V0 gas-tight wel-lok™ plug for operators. The alloy is produced in house at both our Houston and Warrington facilities by experienced alloy technicians.
In order to cast a tool of this size, 10,000kg of alloy was created to satisfy the operator’s needs. This required a full 3 days of alloy production and 2 full days of casting the alloy onto the tool.
The BiSN team with the completed wel-lok™ Tubing Seal (TS) tool at the Houston Technology Centre.
To deploy the tool and stop gas migration in the well, BiSN worked with the operator to coordinate a liftboat and remote operated vehicles. This required overcoming several logistical challenges to ensure a smooth deployment.
The deployment was conducted in 4 stages:
Click to watch the deployment phase of the world’s biggest wel-lok™ tool in the Gulf of Mexico.
The wel-lok™ TS (Tubing Seal) was developed to overcome the shortcomings of traditional methods, using bridge plugs and cement during well abandonment. It is typically run on electric line but can be deployed on a slick line or coil tubing as well. It can pass through small restrictions such as damaged or crushed tubing, yet still create the gas tight seal. It has a higher expansion ratio than conventional plugs, higher pressure ratings than inflatable packers and gas blocking abilities that cement cannot match.
Dive deeper into BiSN and learn more about our performance barrier technologies.
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