[ Alloys ]
[ Alloys ]
New record for largest bismuth plug
In 2023 BiSN , a supplier of downhole sealing solutions and technology to the global oil and gas industry , eclipsed its own record for the largest bismuth plug with a deployment in the Gulf of Mexico .
Text & images by BiSN
A permanent , gas-tight seal was required for a well with a 36 ” OD experiencing gas migration . In previous campaigns with Aker BP in Norway , BiSN had set the record for permanently sealing a 30 ” OD well in the North Sea . To seal a well of this size , BiSN scaled its Wel-lok technology and operations to meet the needs of both the size of the tool and the production timeline requested by the operator . With potential environmental damage to be considered , it was essential to meet the timeline required by the operator . The Wel-lok tool required more than 10,000kg of bismuth alloy and 2,200kg
What is Bismuth ?
Bismuth is a chemical element with the symbol Bi and atomic number 83 . It is a dense , silvery-white metal with a pinkish tint . Bismuth is known for its distinctive appearance and physical properties , including its low toxicity , low thermal conductivity , and high electrical resistance . Most importantly , bismuth has a unique property where it expands upon solidification , making it particularly useful for downhole applications and in the formation of seals and barriers .
Pictured prior to deployment in the Gulf of Mexico is the largest bismuth plug , which was produced by BiSN to provide a permanent , gas-tight seal for a well that was experiencing gas migration .
of thermite , bringing the total weight to over 20,000kg .
Offshore rigless deployment As the well had already been sealed using cement but was still experiencing gas migration , BiSN needed to deploy the plug without using a rig while avoiding any potential environmental damage . An innovative deployment method was applied using a liftboat and remoteoperated vehicles ( ROV ). Once the tool was activated by timer , the bismuth alloy flowed , filling and sealing the cross-section of the conductor pipe in under an hour . Upon solidification , the alloy expanded , creating a mechanical gas-tight seal . The burn time took approximately 55 minutes , resulting in significant environmental benefits and cost savings for the operator . ROVs continued to observe the well for 20 hours with no evidence of further gas migration . “ The success of this tool really speaks more about the flexibility and varied applications of BiSN ’ s Wel-lok technology , the size is just part of the story ,” said Paul Carragher , CEO of BiSN . “ We ensured a permanent seal giving the supermajor operator peace of mind , saving them time as we were able to deploy from a liftboat , and costs as a rig wasn ’ t necessary .”
So far , the technology has been commercially applied to 11 different applications , including water shut-off , cement repair , packer repair , and plug and abandonment .
How does it work ? Bismuth alloy is deployed using a standard wireline and is so straightforward that it requires no special licences or handling permits . A modified thermite heater creates a chemical reaction with the bismuth alloy . It melts and takes on a viscosity similar to water , flowing into the area requiring sealing and forming a gas-tight seal as it cools . With a density ten times higher than water , it can also displace any wellbore fluids . The BiSN technique using the modified thermite heaters takes just minutes to melt the alloy , which then cools and is ready for pressure testing within one hour . To see a demonstration , visit https :// bisn . com / bisn-video-portfolio /.
About BiSN
Founded in 2010 , BiSN ’ s unique Performance Barrier Technologies allow operators to solve unwanted downhole flow issues once and for all by sealing across the life of the well to assure uptime , improve production , extend well life , protect the environment , and , ultimately , abandon safely .
44 Stainless Steel World March 2024 www . stainless-steel-world . net