CSA Ocean Sciences Inc. (CSA) has been providing marine environmental expertise to clients in the U.S. and internationally for more than five decades. CSA provides the offshore energy industry with environmental, geophysical, and geotechnical services to support life of field activities, from permitting through decommissioning.

CSA’s long-term expertise involves providing Environmental and Social Impact Assessments (ESIAs) for operators and regulators during exploration, development, and operational phases. An increase in decommissioning activities has offered renewed opportunities to serve the industry’s needs in the latter phases of the life of field.

Subsea infrastructure often supports diverse benthic communities as shown in this image, and domestic and international best practices and regulatory requirements often allow for these unique habitats to remain undisturbed. This consideration requires careful evaluation of the lowest level of environmental impact associated with decommissioning.

In the Eastern Mediterranean, CSA analysts are examining proposed plugging and abandonment (P&A) plans for multiple wells and associated linear subsea infrastructure. This effort includes the development of a comparative assessment, which considers environmental, societal, and economic aspects of decommissioning. CSA’s conclusions identify preferred P&A alternatives that offer the lowest level of environmental impact, employ well known technical procedures, and have the lowest costs.

In the deep waters offshore northern Mexico, a second comparative assessment is being conducted by CSA analysts, including a Net Environmental Benefit Analysis (NEBA) approach designed to examine potential future abandonment strategies. This analysis, conducted prior to construction of the project, is part of the Mexican regulatory process to ensure that all phases of the project are considered by oil and gas operators. CSA’s role in the study includes evaluation of various alternatives for proposed construction, operation, and maintenance of an offshore facility. The study includes integration of modeling results in terms of ecosystem services. This study will inform an ESIA to be prepared by CSA for submittal to the Mexican regulatory authorities.