Abstract
Well abandonment is as much a part of the oil and gas industry as drilling and production yet is seems to receive the least amount of consideration. Operators spend months and even years planning how they will drill and complete a well but often don't think about how they will abandon it until production has ceased. As such, they tend to rely on traditional methods and materials, doing it the same way it has always been done and yielding the same results which are often not desirable. Recently, more operators have chosen to spend more time planning well abandonments than ever before. Perhaps this is because the requirements for well abandonment have increased or because, unlike drilling and production, any money spent on well abandonment comes straight off the bottom line without the opportunity to recuperate during production. Either way, this increase in visibility has led to a search to abanon wells more efficiently and cost effectively.
One of the ways to achieve this is by looking at alternative sealing materials, such as bismuth. Since 2015, bismuth alloy tools have been delployed over 80 times to seal wells at various stages of the well's life with 60% of the tools run for well abandonment. Bismuth alloys are also being considered as possible alternative barriers to cement by multiple regulatory agencies.
