Pivotree has tested a full-scale prototype of its integrated subsea production tree and vessel mooring system.
Inventor and managing director Chris Merrick said the technology could make development of marginal and stranded oil and gas fields both profitable and sustainable.
The design of the 44-mt prototype is said to combine traditional subsea tree technology with innovations that allow it to swivel, providing 360-degree mooring capability for offtake vessels.
Merrick said the Pivotree and FPSO concept requires no additional infrastructure such as spread moorings, platforms, flowlines, pipelines and manifolds.
“All that extra equipment is taken out of the design, which means upfront capex drops significantly and time to first oil is much faster," he said. “Once the well is drilled and completed, the FPSO can self-install the Pivotree flexible riser and swivel assembly upon entering the field. No additional equipment or construction spreads, such as crane vessels, are required to start production."
There is also no subsea infrastructure to decommission at the end of field life.
“Being reusable and having a smaller physical footprint means less equipment to install and maintain during installation, operation and decommissioning, further increasing Pivotree’s environmental credentials," Merrick added. “Once production is finished, the Pivotree can be removed and redeployed to another location quickly and efficiently with minimal seabed disturbance.”
The concept is designed to operate initially on fields of less than 25 MMbbl, in water depths ranging from 50-500 m. It suits tankers weighing typically less than 50,000 deadweight metric tons.
Other applications could include early production assessment for difficult-to-appraise reservoirs; extending the life of aging facilities to defer decommissioning costs; and re-injecting CO2 into offshore reservoirs for permanent storage.
The company has identified multiple fields globally that could benefit from the use of the technology, including in the UK North Sea, Norway, Brazil and Malaysia—all of which have large numbers of stranded oil fields.
To date, Pivotree has signed sales agreements/MoUs with IPB Petroleum for the Gwydion oil and gas discovery in the WA-424-P offshore Western Australia, and with Harvester Energy for Block 29/7b (Curlew A) and Block 22/12b (Phoenix) in the Uk central North Sea.
In addition, the technology is under consideration by Sea-Quester Offshore for injecting CO2 from Perth’s Kwinana Industrial Area into the offshore Perth reservoir.
Earlier this year, Malaysian oil and gas services company Olio Group invested in Pivotree.
Marcus Christian, Pivotree’s executive director and co-founder, expected DNV to grant technology quality certification shortly. “We have engaged with customers in Australia and internationally, with a pipeline of more than 30 operators and explorers,” he said.
