Enhanced Subsea Hydrocarbon Leak Detection with Broadband Active Acoustic Sensor System (L-BAS)

The objectives of this project is to develop and demonstrate next generation active acoustic Leak detection system of hydrocarbons with Broadband Acoustic (L-BAS). Methane exists in various phases (gas, liquid and solid) dependent on the surrounding temperature and pressure. Methane turns into solid phase at low temperature and/or large pressure and thus changes its acoustic properties. Varying currents will change the behaviour of hydrocarbons when distributed in midwater. Sudden change of phase from gas to solid may also cause clogging to subsea infrastructure, and all together, these factors increase the complexity in acoustic detection of these contaminants. In this project, we will first theoretically clarify the expected characteristics of hydrocarbons. In succession, we will test this assessment towards measurements in controlled experiment. This will be used as basis for development of a monitoring system that can operate at deep water. We will solve the challenges through a partnership of Norwegian partners. A pilot of L-BAS will test the system through a demanding offshore demonstration. The innovation and the basis for value creation in this project is based on: - Improved cost-efficiency of monitoring through opening of the observation window (360° with radius> 500m), and thereby reducing number of units required and thus the capex per location - Extreme acoustic sensitivity with focus on solving the most challenging leakage conditions including CH4. - Flexible technology that eases operations, ensures HES, reduces costs, and thus provide a basis for increased exploitation and reduced greenhouse gas emission - Autonomous operation safegurding monitoring over long periods without impact on sensitivity or other basic specification. - Flexibility in operational water depth - Measurement available in close to real time - Leak detection software robust towards false alarms. We have carried out theoretical assessment of the expected acoustic reflectivity of the hydrocarbons going through the various phases. We have built and tested the equipment for validating these assessments. We have demonstrated that this equipment, which releases and measures the acoustic properties of our targets, is working as planned. The pilot unit has been built qualified and in operation in the sea monitoring an oil and gas field since November 2019, with Equinor.

The scientific work has led to development of a commercial product which is actively being marketed internationally as well as in Norway. I has also led to the possibility for further research and development in the area of acoustic leak detection with international clients.