–96 per cent of gas being re-injected, consumed
THE full-gas compression system aboard the Liza Destiny Floating, Production, Storage and Offloading (FPSO) vessel, which is operating in the Stabroek Block, offshore Guyana, is now operational, significantly reducing the excessive levels of flaring, as 96 per cent of the gas produced is being re-injected and consumed.
This is according to ExxonMobil Guyana, which disclosed on Friday that a team continues to perform maintenance and optimisation activities, with the aim of keeping the flash-gas compressor on-line, and minimising flaring until the arrival of the new flash-gas compressor at the end of the year.
ExxonMobil Guyana Production Manager, Mike Ryan explained that the gas compression and injection system is in place to help to manage the fluids from the oil reservoir. He explained that when the fluid is transported to the FPSO from the reservoir, the compression system separates the oil and gas, and then re-injects the gas into the reservoir.
“We are injecting, or consuming, and when I say consuming, we are using some of the gas to run our power generators offshore; we are injecting or consuming approximately 96 per cent of that gas,” Ryan said.
Just last month, ExxonMobil Guyana submitted an application to the Environmental Protection Agency (EPA) here, seeking its approval to flare beyond pilot levels, in an effort to facilitate the continued testing of a discharge silencer, a new piece of equipment for the Liza Destiny FPSO vessel.
The upgraded and repaired discharge silencer of the third-stage flash-gas compressor, and a new venturi were safely installed on the Liza Destiny, and the first phase of testing was successfully completed during the last week of June 2021.
The compressor was damaged in January, and resulted in the company having to temporarily increase gas flaring to above pilot levels, in order to maintain safe operations.
The faulty contraption was subsequently removed, and sent to Germany for immediate repairs. The repaired and upgraded components of the flash-gas compression system have been safely re-installed, with a comprehensive three-phase testing programme undertaken to ensure full safety.
The company said that the flash-gas compression system was started up on June 19 for the first testing phase, and was shut down on June 28 in order to remove temporary probes and instrumentation.
“We were able to bring the flash-gas compressor back online, in its current operating mode. And with our two main gas compressors online, and our injection gas compressors online, we’re flaring about six million standard cubic feet per day,” Ryan said.
He explained that there are a number of challenges which are preventing the company from further lowering the levels of flaring from six million to one million cubic feet per day, as the FPSO vessel is designed for and capable of doing.
“The second objective is to get the new designed machine here by the end of the year, install it, and get to that pilot level flare that we have been working so hard to get to,” Ryan said, as he disclosed that the team is consistently working to reach the objective of one million cubic feet per day.
“There is a resonance happening inside the machine; this is an extremely complex technical issue that we have all of our best efforts and experts working on it, but we need to remove that vibration, or that resonance, and the upgraded design has a number of critical features that will do that,” he said.
Ryan explained that lowering oil production would not result in a significant reduction or difference in relation to the amount of gas that is being flared, therefore, the company is trying to balance the value of the oil to the country, while at the same time minimising the gas that is being flared.
“I think we struck the right balance; we work closely with the Government of Guyana to ensure we balance all of our priorities. And our priorities are, clearly, to make sure we put people first, keep our facility safe and stable, minimise impact on the environment, and maximise the benefit of the nation,” he said.
Ryan went on to explain that there has been a “dedicated focus” on the Liza Destiny FPSO to ensure that the challenges do not repeat themselves on the Liza Unity and Liza Prosperity.
“There is a separate team, and teams working extremely hard on the Unity and Prosperity to make sure that we truly learn from these events, and that we improve. We’ve done detailed investigations on all of our issues that we had; real-time sharing with the teams, and I’m committed to ensuring that we apply those learns on each and every project going forward,” he said.