Of the more recent discussions in the decommissioning industry, one which is currently gathering pace is the environmental, social, and economic impact that decommissioning programs will have in the Gulf of Mexico.

The process of identifying and quantifying both the environmental costs and benefits of the removal and management of pipelines, jackets, wellheads, and sediment deposits is a complex task.

We now need to ask the question as to whether a Complete Removal of the asset will provide a greater benefit to the environment and public compared to a partial removal (i.e., rigs to reefs).

“Ultimately we need to understand how the environment has adapted to the presence of steel structures and drill cuttings on and below the seabed” said Joseph Nicolette, Principal and Global Ecosystem Services Director at Ramboll ENVIRON, Inc. ”Inevitably, the ecology will adapt to the new conditions and in many cases has thrived”.

Drawing the line between costs and benefits

“A big challenge here is identifying how much of the structure can or should be removed. We need to assess what option will provide the greatest benefit, or least negative impact on environmental, social, and economic conditions; removing the entire structure or leaving certain components in place”.

“In many instances, structures have proved beneficial to the ecological condition of the site and have increased the number and variety of fish in the area. This in turn, may translate to improved recreational and commercial opportunities”.

“This in itself poses another significant question to Decommissioning Program Leads in the region; where does it make sense to draw the line? Identifying the breaking point between positive and negative impacts on environmental, social, and economic conditions is a complex task”, Joseph indicated.

The Net Environmental Benefit Analysis

“We’ve developed an enhanced “Net Environmental Benefit Analysis (NEBA)” approach that can assist operators facing decommissioning option decisions, the purpose of which is to help identify the break-point between options where option costs (i.e., risks, impacts, and monetary costs) may outweigh benefits” Joseph added.

“The analysis is a holistic approach that takes into account how various options can affect, using quantifiable ecosystem service metrics, ecological, social, and economic values. The use of quantified metrics provides a level of clarity to stakeholders that otherwise may not be apparent in qualitative parameter assessments".

“We can evaluate the range of decommissioning options for the jacket, pipelines and associated structures, sediment/cutting deposits, and adjacent habitats. We look not only at ecological populations, but we also incorporate other values such as greenhouse gas emissions, long-term waste management, human health, safety and risk, benthic habitat, structural habitat, residual contamination, ecological risks, commercial and recreational fisheries to name several”.

“We can use the methodology at a semi-quantitative level to screen potential options, then proceed to a more quantitative valuation approach once we have narrowed the number of options to consider”. Each case is a site by site consideration based upon many factors.

“In a recent case, we were able to identify a specific point in the Decommissioning process where a Partial Removal option would be more beneficial to the local environment and the public when compared to the Complete Removal” option.

In a final analysis, each of the individual components are assessed and quantified individually, then brought together in a holistic manner; what changes will a decommissioning program effect on the local environment?

In some cases, certain components or structures are the building blocks of future production, essentially providing a service to the local ecology and the public.

LARP (Louisiana Artificial Reef Program) donated structures by year and deployment method (2009-2013):

Benefits of partial removal

“Those who consider that removal of the entire structure is the only option for decommissioning, may not be considering the overall impacts of an action on the environment and therefore, may not be making an informed decision.”

Aside from ecological benefits, there are also significant benefits to the Operators themselves; millions could be trimmed from decommissioning projects not only in the Gulf of Mexico, but throughout the world.

Some of these savings could be incorporated into further restoration projects that can be designed to provide benefits to offset potential risks associated with leaving part of a structure and/or residual contamination to remain in place.

Joseph stated that “the NEBA approach he employs helps operators to understand the risks, benefits, and tradeoffs associated with various alternatives for decommissioning.

This approach incorporates quantified values and can be integral to the development of a preferred decommissioning strategy as it is systematic, scientifically and technically based, defendable, and non-arbitrary, therefore being transparent to stakeholders”.

Reducing environmental impact and costs

At a time of low oil prices, the opportunity to reduce Decommissioning costs, as well as the risk to human life, would be highly welcomed by the industry.

The process of identifying the “break-point” of removal is a complex task, but does present the potential for a WIN-WIN solution for the oil companies, the public, and the environment; costs and risk are severely reduced, whilst the public benefits from improved environmental values.

Tom Campbell, Esq., a Partner in the Environment, Land Use & Natural Resources Section of the international law firm of Pillsbury Winthrop Shaw Pittman LLP said that “many offshore platforms have become valuable aquatic habitat that should not be removed. The NEBA framework allows that value to factor into societal decision-making to allow informed decommissioning decision-making by regulators and the regulated community. Properly used, NEBA can inform both the technical and legal processes”.

“As an industry, we’re always striving to reduce our impact on the Environment, and such innovations clearly demonstrate that stakeholders are driving towards sustainability” added DecomWorld Director Phil Chadney.