Industry-First Subsea Ultrasonic Flowmeter – Case Study
Based on a unique customer requirement, Aquip’s Engineering team worked in partnership with Oceaneering to develop a ROV-installable subsea ultrasonic flowmeter.
The flowmeter was to be used to determine gas injection flow rate to an individual well offshore in Australia.
A non-invasive subsea flow measurement tool was developed for model validation and calibration. This innovative solution provided a suitable alternative to the only other option being a costly workover of the rig.
The customer was aware their pipe was leaking and had attempted to rectify the leak using sealant. The sealant was unsuccessful due to an unknown gas flow that appeared to be too high based on their inability to measure gas injection to a well.
The customer needed to monitor the pipeline floor but there is no current technology as the subsea well was some 300 metres below the ocean.
Aquip supplies FLEXIM meters that can measure flow but they are not designed for underwater environments.
Working with Oceaneering, Aquip’s technical team successfully marinised an ultrasonic flowmeter and made it ROV-installable. For this to be possible, the flowmeter had to be fitted with a safe and reliable attachment mechanism.
Project was turned around in an 8-week period with our team undertaking full FAT testing.
The flowmeter identified that the choke indicator was incorrect. When the flowmeter was installed and the choke “closed”, it was found the choke needed to be closed in two positions for the flow to return to zero.
The customer was then able to inject the correct rate of sealant based on the gas flowrate and seal the leak.
This was the first time an ultrasonic flow meter has been used in an offshore subsea application to measure gas or liquid.
Customers are now able to non-invasively verify choke positions, validate flow on permanently installed flow meters and flow assurance models by measuring gas or liquid flow on existing infrastructure.