Understanding the speed and direction of ocean currents is crucial to offshore oil and gas exploration and development. The collection of in situ velocity measurements from a range of depths (sea surface to the seafloor) over time is important to understand the seasonal variability and storm conditions that occur in the offshore environment. An Acoustic Doppler Current Profiler (ADCP) measures current velocities in the water column based on the principle of the Doppler effect – a change in the frequency or wavelength of sound waves in relation to the observation relative to the source.

CSA Ocean Sciences Trinidad Limited (CSATL) is serving the needs of the energy industry in the region by providing Environmental Baseline Survey (EBS) and Environmental and Social Impact Assessment (ESIA) services to major oil and gas operators. Scientists and operational personnel collect data and samples from the offshore environment to meet local environmental regulatory requirements and to characterize the baseline marine environment prior to offshore project activities.

The CSATL team has deployed an ADCP to support a long-term study of subsea currents offshore Trinidad. Data will be processed every 3 months to support numerical modelling of current patterns and assessment of potential impacts on the marine environment. As a time series of current data is established, larger-scale circulation models will also be developed. 

Housed in a subsea mooring frame, the ADCP operates via acoustic pulses to measure the speed and direction of currents at specific locations within the water column. Three beams are emitted from the transducer to detect currents in three dimensions.

This set up provides a precise, cost-effective mechanism for the sufficient capture of current measurement data throughout the water column profile, easy system maintenance using acoustic releases, and simple data download in a relatively harsh offshore environment.