ExxonMobil says treated production water discharge safer than reinjection

Last Updated on Wednesday, 26 August 2020, 17:50 by Denis Chabrol

ExxonMobil  says it prefers to discharge treated production water into the Atlantic Ocean offshore Guyana instead of re-injecting it into the Liza Phase One well.

President of ExxonMobil Guyana, Alistair Routledge explained that the water is treated on the vessel and “what is discharged causes no damage to the environment.” “It’s treated to international standards and it’s no harm at all,” he added.

In the context of reported preferences for the production water from the Payara well to be re-injected into the reservoir, Mr. Routledge warned that doing so could possibly cause some problems. “There are some potential risks to doing that. There are some chemistry issues between the produced water and the reservoir fluids into where we would inject which can cause problems, potentially raising fractures in that part of the reservoir,” the ExxonMobil official said.

Noting that there is a “quite complex balancing acts,” he said treatment of water for re-injection could cause more air-emissions from the treatment facilities.

The Guyana government has hired a team of experts to review the Payara Development Plan before ExxonMobil is given the go ahead with making its final investment decision.

ExxonMobil hopes to eventually ramp up production from the Liza Phase One reservoir  to 120,000 barrels per day. Payara is expected to come on stream in 2025 with 220,000 barrels per day from the yet to be built Floating Production, Storage and Offloading (FPSO) vessel named Prosperity.