Oceanographic equipment developed by underwater technology company Sonardyne International Ltd. will be used as part of a major US$2 million scientific study of disruptive ocean currents in the US Gulf of Mexico.

The multi-year deployment, led by the University of Rhode Island (URI)’s Graduate School of Oceanography, will monitor the Loop Current System (LCS) using Sonardyne’s Pressure Inverted Echo Sounders (PIES).

The LCS is the dominant ocean circulation feature in the Gulf of Mexico. It influences all ocean processes in the Gulf and has implications for a wide range of human and natural activities, from oil exploration to coastal eco-systems, but, knowledge of its underlying dynamics is limited. URI’s initial study aims to improve the understanding and prediction of the LCS by deploying a seabed network of PIES plus near-bottom current meters to monitor the central Gulf’s deep waters.

PIES work by transmitting an acoustic pulse from an instrument on the seabed upwards. The pulse is reflected off the water-air boundary at the sea surface and returns back down to the seabed where it is detected by the PIES. This enables an exact measurement of the two way signal travel time to be calculated. At the same instant, an accurate measurement of depth is made using highly precise internal pressure sensors. Combining data from an array of PIES instruments and near bottom current meters with historic water profile data can be used to calculate currents throughout the full water column.

A total of 25 of Sonardyne’s and URI’s own PIES and current meters will be deployed this summer, in waters down to 3,500 metres depth, with an initial data retrieval using acoustic through-water communications to a surface vessel planned for autumn 2019. Instrument recovery is scheduled for autumn 2020. The results of this study will be used to inform how best to deploy a larger array for a planned 10-year-long research campaign.

URI’s LCS study is being funded by the US National Academies of Sciences, Engineering and Medicine’s Gulf Research Programme, which was founded in 2013, as part of the legal settlements with companies involved in the 2010 Deepwater Horizon oil spill. The long term objective is to improve forecasts of the LCS in order to increase the safety of operations in the Gulf.

[blockquote author=” Professor Kathleen Donohue, URI GSO Program Director”] “Sonardyne’s PIES is a highly capable instrument, with fast seafloor to surface data telemetering capabilities, which will complement URI’s instruments and scientific expertise and will play a key role in this deployment. Sonardyne’s technical expertise in underwater acoustics, signal processing, hardware design and custom engineering are key components of the special instrumentation being deployed in this project, with a particular challenge being the retrieval of data from the seabed in near real-time.”[/blockquote],

Geraint West, Business Development Manager – Oceanographic, at Sonardyne, says “The selection of  our PIES by  the University of Rhode Island for use in this important project underlines the capability of our instrumentation to gather critical ocean observation data over long periods of time in a demanding environment. We are pleased to be working with URI on this project, which will enable more accurate predictions of the Loop Current, resulting in improved modelling to underpin safer and more efficient operations in the Gulf of Mexico.”

Pioneering subsea communications technology from Sonardyne International Ltd. has been used to stream the first live broadcast to global audiences from an underwater submersible.

International news agency Associated Press (AP) used Sonardyne’s BlueComm wireless through-water optical modem technology for the live broadcast from a two-person submersible operating in waters off the Seychelles, in the Indian Ocean. AP said that the broadcast via YouTube was “the first multi-camera live signal in full broadcast quality from manned submersibles using optical video transmission techniques, in which the pictures transmit through the waves using the electromagnetic spectrum.”

The broadcast is part of the Nekton Deep Ocean Research Institute’s First Descent expedition, which is exploring some of the world’s least explored areas of the ocean around the Seychelles, as part of a project to increase understanding and aid protection of the marine life they contain.

By using a Sonardyne BlueComm free space optical modem on the submersible, and a BlueComm receiver deployed from the hull of the Ocean Zephyr research vessel, real-time video from one of the mission’s two submersibles was able to be streamed through the water and then broadcast live across the world, enabling the general public to, in-effect, join the scientists as they explore their underwater habitats.

Next week, Sky News and Sky Atlantic, as part of Sky Ocean Rescue, which have also joined the mission, plan to broadcast three live “subsea programmes”, which will include live simultaneous broadcast from both of the mission’s two, two-person submersibles, again using BlueComm. While video transmission from a manned submersible using optical communications has been achieved before, this will be the first time it has been achieved from two, working in close proximity, which means overcoming the challenges of signal interference.

“Without BlueComm, this could not be done,” says Darryl Newborough, Sonarydne’s Technical Director. “The submersibles have no cable connection to the vessel, so they cannot send their video feed through a cable. Acoustic communications technologies work well, and over long distances, but their bandwidth is not wide enough to support live video streaming. BlueComm is the only option.”

In fact, BlueComm is the only commercially available technology that enables wireless transmission of high bandwidth data, including video, over ranges of a few tens or even hundreds of metres, at rates of up to 10 megabits per second.

Sonardyne is the official Subsea Communications Partner for the First Descent mission, which is exploring the Indian Ocean through 2019-20. The first expedition is running from March-April 2019.

Supported by 13 scientists based on the Ocean Zephyr, Nekton’s goal is to undertake at least 50 “first descents” into these waters to generate data which will support a Seychelles’ Government commitment to protect 30% of their national waters.  

Very little research has been undertaken beneath 30metres (scuba depth) across Seychelles’ vast ocean territory of 1.37 million square kilometres. The objective is to contribute to establishing a baseline of marine life and the state of the ocean in Seychelles. Research is focused from the surface into the Bathyal Zone (200m to 3000m), home to the greatest patterns of biodiversity and impact of human activities on these vital ecosystems.

Newborough adds, “We’re delighted to both be bringing the excitement of entering unexplored waters to live television audiences, but also, more importantly, helping to advance ocean exploration and, ultimately, the protection of the Seychelles’ marine environment.”

A major US oil company is set to reinforce its deepwater offshore asset integrity assurance in the US Gulf of Mexico with the aid of a sonar-based subsea leak detection system developed and delivered by underwater engineering specialist Sonardyne.

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

In this latest deployment, Sentry is being deployed under a six-month trial that will demonstrate its ability to provide real-time subsea asset monitoring. The Sentry 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-fibre strands, proving fast and accurate detection and classification of the equivalent release of 100 barrels/day of oil out to 244 metres (800 feet), a distance only constrained by the trial environment.

This was achieved within seconds of the simulated leak occurring. Sentry’s capability, however, covers 100 barrels/day mono-phase oil leaks at distances of up to 740 metres (2,427 feet). For mono-phase gas leaks, the system is capable of detecting down to just 1 barrel/day at 500 metres (1,640 feet) or 100 barrels/day (as measured at depth) at 1,000 metres (3,280 feet).

Uniquely, Sentry is able to accurately localise leaks, unlike other systems on the market. Its titanium housing and ROV-deployable design also makes Sentry an ideal choice for deepwater asset integrity monitoring.

This latest deployment follows battery-powered deployments of the Sentry system by other major international and independent operators, in the US Gulf of Mexico and offshore Papua New Guinea. Sentry has also been used in the UK, where it demonstrated its ability to detect carbon dioxide leaks from the seafloor as part of an offshore carbon capture and storage (CCS) demonstration project.

“For deep water, hard to access fields, robust field management philosophies are essential for operators to assure the ongoing integrity of their systems,” says Stephen Auld, Global Business Manager for Asset Integrity Monitoring at Sonardyne.

[blockquote author=”Stephen Auld, Global Business Manager for Asset Integrity Monitoring at Sonardyne”]Having access to reliable near real-time warning systems that are able to identify and locate sources of leak events, should they happen, is a significant benefit to both the environment and offshore exploration and production companies.[/blockquote]