April 2019, Vol. 246, No. 4

Tech Notes

Sonar Leak Detection Deployed by Oil Major in Gulf of Mexico

A major U.S. oil company is reinforcing its deepwater offshore asset integrity assurance in the Gulf of Mexico with the aid of a sonar-monitoring system developed and delivered by subsea engineering specialist Sonardyne International Ltd. 

The Sentry Integrity Monitoring Sonar (IMS), has been deployed on the seafloor at more than 6,500 feet (2,000 meters) water depth. The system, which can be installed short-term or permanently, is able to detect, classify and localize subsea releases of hydrocarbons from either the seafloor or oil and gas field production infrastructure. 

The sonar head, which is mounted on a seafloor lander, is connected into an existing power and communication umbilical to a floating production facility. During operation, inbuilt intelligence using algorithms developed by Sonardyne continuously assess the sonar data gathered by Sentry and generate near real-time automatic alerts of any hydrocarbon seeps detected in the water column. 

As part of the trial deployment, simulations of an oil plume in the water were created, using nitrile-fiber strands, proving fast and accurate detection and classification of the equivalent release of 100 bpd of oil out to 800 feet (244 meters), a distance only constrained by the trial environment.

This was achieved within seconds of the simulated leak occurring. Sentry’s capability, however, covers 100 bpd mono-phase oil leaks at distances of up to 2,427 feet (740 meters). For mono-phase gas leaks, the system can detect 1 bpd at 1,640 feet (500 meters) or 100 bpd (as measured at depth) at 3,280 feet (1,000 meters). 

This latest deployment follows battery-powered deployments of the Sentry system by other major international and independent operators, in the U.S. Gulf of Mexico and offshore Papua New Guinea.