The full gas compression system on the Liza Destiny Floating Production Storage and Offloading (FPSO) vessel is now operating, ExxonMobil said in an update on Friday.
OilNOW understands that the team continues to perform maintenance and optimization activities with the aim of keeping the flash gas compressor on-line and minimizing flaring until arrival of the new flash gas compressor at the end of the year.
“All systems are currently online,” said Mike Ryan, Production Manager at ExxonMobil Guyana. “We are…using some of the gas to run our power generators offshore. We are injecting and consuming approximately 96% of that produced gas.”
He said with the machine back online in its current operating mode there are a total of six gas compressors that are helping to take the gas from the low pressure all the way to the high or injection pressure.
Ryan reminded that there will always be a small percentage of flaring on the FPSO as part of the normal operations of the vessel.
“The reason we leave a little bit of flare there at all times is really a safety feature,” he said.
The flare/blowdown system, he pointed out, is there as a safety device to ensure that the crew is protected and safe offshore.
“So, because of our current operating mode and we are still optimizing the system, we’re flaring in the range of 6 million cubic feet per day,” the Production Manager stated.
He pointed out that some challenges and technical issues with the current gas compressor design prevent the level of flaring to be taken to just under 1 million cubic feet.
“The team has addressed them systematically and very effectively. We did have an issue with what we call the discharge silencer and that’s on the output of the third stage flash gas compressor,” Ryan said. “We were able to repair that and upgrade that as well as install a venturi, and that is upstream or just before the discharge silencer.”
He said the production rate on the FPSO is being maintained in the 120,000 to 125,000 barrels of oil per day range.
“We’re looking at the amount of gas that comes in, and in order to control that, you keep the level of production steady. So really, our focus is on steady, safe operations,” he said.
