According to a Westwood Global Energy Group report issued in mid-January, the amount of money that will go toward decommissioning over the next decade is considerable—totaling about $102 billion in Western Europe alone. Report author Ian McDonald, manager with EMEA Consulting, said in just that region there are 5,600 surface wells and 2,600 subsea wells that will have to be plugged and abandoned as part of the decommissioning process. According to McDonald, innovation underway could lead to new technologies that will offer alternatives to traditional plug and abandonment (P&A) activities.
Recent reports indicated a number of companies already are moving down that path. In mid-February, Ardyne reported it had saved more than a day of rig time on a planned 3.5-day operation and improved efficiencies by 35% on a P&A job in the North Sea using its proprietary Casing Recovery Toolbox. According to the company, the product incorporates a full suite of services and bottomhole assembly (BHA) systems, which company experts have used to create downhole BHA systems for well abandonments, slot recoveries and workovers.
Meanwhile, in the Gulf of Mexico, a company called Abrado has completed the first well in a multiwell P&A campaign using its proprietary Medusa expandable casing section-milling technology. The 95⁄8-in. by 133⁄8-in. dual-string casing windows were milled out to allow traditional cement barrier placement to seal the annuli. The company is continuing to investigate, operate and validate operations with its line of downhole video cameras for pre- and post-window inspection as well as barrier placement.
Advancement is taking a different route elsewhere, funded in part by the Oil & Gas Technology Centre, based in Aberdeen. The not-for-profit, industry-led technology R&D organization is investing £1.3 million (US$1.8 million) in transformational P&A ideas with the goal of reducing decommissioning costs by 35%, a target set by the UK Oil and Gas Authority. In a recent call for ideas, the Oil & Gas Technology Centre received 48 submissions and has selected four of them for investment.
BiSN, one of the winners, is testing and verifying Wel-Lok M2M technology, which uses a modified thermite heater in conjunction with bismuth-based alloys to form a permanent barrier—an alternative to traditional elastomer seals, resins and cement. It is deployed on wireline without the need to remove tubing.
An idea submitted by the University of Strathclyde uses enzymes in a “biogrout” comprising low-viscosity nanoparticles that can repair or improve cement barriers in plugged and abandoned wells. And Heriot- Watt University is receiving funding on its plans to develop a modeling framework for well isolation design that researchers hope to use to improve risk management, increase efficiency and enhance decision- making.
The final technology selected for funding is being developed by Baker Hughes, a GE company (BHGE). BHGE is working on a plan to deliver cement logging through multiple casing strings, an improvement over existing solutions that would deliver logging behind only one casing or tubular.
With a large number of assets reaching the end of their operating lives, there is broad scope for new technology application. With luck—and a lot of hard work—these and other developing technologies will soon be fieldproven and ready for use by the offshore industry.