CSA Ocean Sciences Inc. (CSA), an international marine environmental consulting and survey company, today announced the conclusion of a post drill monitoring survey (PDMS) offshore Trinidad for a local upstream oil and gas operator. The well was drilled by the operator during May to August 2022, with CSA completing the PDMS in November 2022 in full accordance with local regulatory requirements.
PDMS campaigns in waters surrounding completed wells are used to assess any temporal and/or spatial impacts to the marine environment caused by drilling discharges and to predict potential recovery times from such events. Once data are validated, the findings are then used to enhance predictive modeling and bring further support to environmental and social impact assessments (ESIAs) and environmental impact assessment (EIA) reports.
The custom PDMS program was designed and managed by a specialist field team from CSA’s Trinidad and Tobago office, who are highly experienced in running multidisciplinary survey campaigns for energy developers in these waters. The vessel and equipment were mobilized out of CSA’s Port-of-Spain location.
Factoring in the predominant direction of previously modeled drilling discharges, sediment samples were retrieved from within a 1.5 km radius of the wellsite using a Smith McIntyre grab sampler in water depths of approximately 15 m. Samples were processed, stored, and handled in accordance with international standards and local laboratory guidance before being quickly and safely shipped to laboratories for further assessment and in-depth analysis of sediment quality for hydrocarbons and macrofauna.
Sediment chemistry parameters assessed included grain size and hydrocarbons, and results were compared to sediment chemistry data available from a previous baseline environmental survey conducted in the same offshore block located on the south west coast, Trinidad by CSA in 2021. Any trends identified in the environmental baseline survey and PDMS datasets that would indicate potential levels of impact to key environmental receptors were discussed in reports.
A geophysical survey utilizing a side-scan sonar was also conducted during the program to collect seabed imagery, which was used to facilitate the verification of modeled discharge and dispersion patterns of drill cuttings and muds. The processing, interpretation, and visualization of the data was completed by CSA’s in-house geospatial and survey experts, and results were also included in the report.
“We are delighted to have successfully completed and delivered another post drill survey program for a major upstream oil and gas operator in Trinidad and Tobago and thank the operator for trusting CSA to assist in bringing scientifically robust data and analysis to the planning of their exploration and production activities,” said Candice Leung Chee, CEO of CSA Trinidad & Tobago. “This is an exciting time for the region, and amid the current uptick in demand for specialized marine survey services from developers, we look forward to ongoing opportunities to support shallow- and deep-water drilling campaigns in the region.”