ExxonMobil should have been able to limit harmful gas flaring
Dear Editor,
In the last Sunday Stabroek in an article headlined: `Exxon to begin reinjecting gas into well’, the head of the local Environmental Protection Agency; Mr. V. Adams, claimed that Exxon will begin the transition to using gas for injection purposes
[https://www.stabroeknews.com/2020/05/17/news/gu yana/exxon-to-begin-reinjecting-gas-into-well/].
According to Mr. Adams this will happen after venting, flaring, and polluting the atmosphere with over two billion cubic feet of associated and not free gas, to the environment. It is hard to understand why ExxonMobil lacked the necessary planning to avoid, or mitigate this type of unacceptable operational behaviour in this infant Liza Phase I project, knowing that the asset was expected to produce large volumes of associated gas from project initiation.
Associated-not-processed gas is a significant and well known source of greenhouse gas emissions and airborne contaminants that has proven difficult to mitigate over the years. A non-processed vented and flared gas, such as the case of Liza Phase I, can result in incomplete combustion which produces a variety of volatile organic compounds, polycyclic aromatic hydrocarbons, and organic/inorganic contaminants; Sox, Cox, NOx among
many others, adversely impacting and threatening both wildlife and human existence.
This type of irresponsible behaviour by major operators was also experienced in Nigeria [https://www.dw.com/en/gasflaring-continues-scorching-niger-delta/a46088235]. Along 55+ years, associated gas venting and flaring in the Nigeria’s Niger Delta has been responsible, for a number of crimes against society and the environment, in terms of energy, human health, natural environment, socio–economic environment and sustainable development.
Since December 19, 2019 the Liza field has been producing at an increasing Gas Oil Ratio (unit volume of gas per unit volume of crude oil produced) from >330 standard cubic feet per standard barrel (Scf/Stb) to current >600 Scf/Stb. This means that the volume of gas incoming with the daily production has almost doubled since the beginning of production. Our own estimates suggest that total cumulative associated gas produced, flared and vented to the atmosphere totals between 2.300 and 3.100 million cubic feet (between 2.3 and 3.1 billion cubic feet of gas).
A confusing statement was made by
Mr. Adams mentioning that “now that they [ExxonMobil] have learned and redesigned equipment, we do have a high degree of confidence that we won’t have this prolonged flaring”, when according to the available field development plan for Liza phase I, a total of 17 wells were drilled, consisting of 8 producers, 6 water injectors, and 3 gas injectors, meaning that Exxon knew since the project inception, that a large volume of gas was expected to be produced during Liza Phase I production.
As per confirmed information, both the Liza and Payara reservoirs as well, are preferentially volumetric, meaning they have little or no additional/significant pressure support besides fluid & rock expansion, demanding during production acceleration additional pressure support via gas/water injection from project inception, necessary to reduce gas emissions, preserve the reservoir energy, and maximize recovery.
Technically speaking there is no fundamental reason why ExxonMobil did not comply with its commitments, knowing the potential damage to the environment and the people, these massive gas emissions could cause.
Yours faithfully, Millan Arcia Einstein