Permanently Plugging Deepwater Wells Challenges Standard Operating Procedures

Plugging Wells

After a well has produced its last oil and gas, it must be plugged and abandoned (P&A). The phrase suggests it will remain sealed forever. “What we want when we abandon a well is we never want to come back to it,” said Don Stelling, president of Chevron Environmental Management Company. Compared with the 30- to 40-year life expected of most facilities, “it is a difficult engineering standard.”

And it will be getting more difficult. The wells of the future include many in stormy seas and deep water, magnifying the cost of what the United States Bureau of Safety and Environmental Enforcement (BSEE) describes on its website as “safely plugging the hole in the Earth’s crust.”

Estimating the scale of this work is a highly inexact exercise. There are many interdependent variables affecting cost and demand.

Based on the wells that will someday need to be decommissioned, the value of the market could exceed USD 250 billion using current methods, said Martial Burguieres, vice president of marine well services for Wild Well Control, which does plugging and abandonment work. Actual demand will depend on what operators can afford and regulators require.

One sure thing is that the number of wells needing to be permanently plugged will continue to rise.

“As long as they are drilling new wells. The backlog of wells to be plugged and abandoned is humongous,” said Bart Joppe, global business development manager for plug and abandonment at Baker Hughes.

A key variable in the volume of work done is the cost per well. P&A work is the most expensive component when shutting down an offshore field. Reducing that expense is critical in places where oil companies are experiencing decommissioning price shock, such as the North Sea or offshore California, and in the deep waters of the US Gulf of Mexico.

“P&A is a massive problem. There are huge cost overruns,” said Brian Twomey, managing director of Reverse Engineering Services, which offers decommissioning advice and classes.

Changing Rules

Operators are also having to adapt to changing rules over the past 5 years in Norway, the United Kingdom and the US. “Regulation is becoming more stringent and the volume of work is going up,” Joppe said. “We have seen customers screaming over large increases in costs and in the volume of work. We have definitely gotten more requests for new technology.”

At the top of the technology wish list are ways to work on wells without paying for a drilling rig and riser, and tools capable of dependably doing jobs faster because even the “lighter” intervention vessels command hefty day rates. There is also more attention paid to the materials used to create lasting barriers to ensure wells never leak, because the cost of going back to fix a leaking deepwater well is punishingly high. (See sidebar on well cementing.)

Without new methods to reduce the cost, the expense of plugging and abandoning difficult wells offers a strong argument for postponing the work.

“A lot of operators will not admit it, but there is nothing in the budget to provide money for these wells” at current prices, which are both high and hard to predict, Burguieres said. “Drilling rigs should be drilling. We can handle this.”

That assertion will be tested in the Gulf of Mexico, which is a proving ground for new deepwater removal approaches. The BSEE’s “idle iron” rule sets a deadline requiring that inactive wells be plugged and production equipment be removed.