Oil spill unlikely but response plan critical for Exxon-led Yellowtail project

Location of the Yellowtail Project Development Area within Stabroek Block (Source: Environmental Impact Assessment)
Location of the Yellowtail Project Development Area within Stabroek Block (Source: Environmental Impact Assessment)

While a large oil spill is seen as being an unlikely outcome of the ExxonMobil-led Yellowtail Development Project, an environmental study has recommended that the company be required to commit to regular response drills, simulations and exercises as part of needed preparations in the event of a worst case scenario.

The consultants who prepared the Environmental Impact Assessment (EIA) and the Environ-mental Impact Statement (EIS) for the project have recommended that national authorities consider embedded controls, mitigation measures, management plans and oil spill preparedness as conditions of issuing an environmental authorization for the project, which is expected to pose only minor risks to Guyana’s environmental and socioeconomic resources, while potentially offering significant economic benefits to the citizenry.

They agreed that multiple controls have been embedded into the project design to prevent a spill from occurring, and that a large spill that affects the Guyana coastline and/or other regional coastlines is “unlikely.” However, they said “given the sensitivity of many of the resources that could potentially be impacted by a spill (e.g., Shell Beach Protected Area; marine mammals; critically endangered, endangered, and vulnerable marine turtles; and Amerindian, fishing, and other communities reliant on ecosystem services for sustenance and their livelihood), we believe it is critical that EEPGL commit to regular oil spill response drills, simulations, and exercises—and involve appropriate Guyanese authorities and stakeholders in these activities, document the availability of appropriate response equipment on board the FPSO, and demonstrate that offsite equipment could be mobilized for a timely response.”

EEPGL – Esso Exploration and Production Guyana Limited – is Exxon’s local affiliate, which on behalf of itself and its co-venturers Hess Guyana Exploration and CNOOC Petroleum Guyana Limited, has sought an environmental authorization from the Environmental Protection Agency (EPA) for the project, which is the fourth project development in the eastern half of the offshore Stabroek Block.

By way of a public notice, the EPA yesterday announced that the EIA and the EIS for the project have been submitted and it invited members of the public to make written submission upon reviewing them. The EPA had determined based on an initial assessment that an EIA was required for EEPGL’s application for environmental authorization. It is intended to provide the factual and technical basis required by the EPA to make an informed decision on EEPGL’s application.

The EIA “was prepared by a team of consultants, including Environmental Resources

Management (ERM), an international environmental and social consulting firm with a local registration in Guyana and extensive experience in the preparation of EIAs for offshore oil and gas development projects; SLR Consulting (SLR); and the Guyanese consultancies

Caribbean Engineering & Management Consultants Inc. (CEMCO), the University of Guyana

Centre for Study of Bio-logical Diversity (CSBD), and Leon Moore Nature Experience (LMNE).”

It states that the area that will be developed as part of the project is located approximately 203 kilometers (approximately 126 miles) northeast of the coastline of Georgetown, Guyana.

It says the project will consist of the drilling of approximately 41 to 67 development wells (including production, water injection, and gas re-injection wells); installation and operation of Subsea, Umbilicals, Risers, and Flowlines equipment; installation and operation of a Floating Production, Storage, and Offloading (FPSO) vessel in the eastern half of the Stabroek Block; and project decommissioning.

The initial production is expected to begin by end of 2025–early 2026, with operations continuing for at least 20 years. It is noted that the Project is expected to employ up to 540 persons during development well drilling, approximately 600 persons at the peak of the installation stage, and 100 to 140 persons during production operations.

According to the EIA, the planned activities of the Project are predicted to have negligible residual impacts on most physical resources (air quality, marine geology and sediments, and marine water quality)—with potential moderate residual impacts on greenhouse gas (GhG) emissions, no impacts on coastal biological resources, negligible to minor residual impacts on most marine biological resources (with potential moderate residual impacts on special status marine fish), and negligible to minor residual impacts on socioeconomic resources—with largely positive impacts on socioeconomic conditions and employment. It explains that these predictions are based on the fact that the bulk of the project activity will occur approximately 203 kilometers (approximately 126 miles) offshore, and the project will capture and re-inject associated natural gas (that which is not used as fuel on the FPSO) back into the targeted Project reservoirs, treat all required wastewater streams prior to discharge to the sea, have a very small physical footprint and use Marine Mammal Observers and “soft starts” during seismic surveys to reduce the potential for auditory injury to marine mammals.

‘Unlikely’
Although a large marine oil spill is considered unlikely and the probability of reaching the Guyana coast is low, given the sensitivity of many of the resources that could be potentially impacted by a spill, it was concluded that preparation for spill response is warranted. Unplanned events, such as a potential oil spill, the EIA says, are considered unlikely to occur because of the extensive preventative measures employed by EEPGL. Nevertheless, EEPGL has conducted oil spill modeling to evaluate the range of likely spill trajectories and rates of travel in the unlikely

event of a spill. The EIA says the location of the project offshore, prevailing northwest currents, the medium nature of the Yellowtail and Redtail fields’ crude oil, and the region’s warm waters would all help reduce the severity of a spill. It further says stochastic modeling of an unmitigated subsea release of crude oil from a loss-of-well-control event indicates a less than 5 percent to 40 percent probability of oil reaching the Guyana coast, without taking into consideration the effectiveness of any oil spill response, and the low likelihood that such a spill would occur, while modeling of an unmitigated 2,500-barrel (400 m3) release from an FPSO offloading spill indicates no impact to the Guyana coast.

“Although the probability of an oil spill reaching the Guyana coast is low, a subsea release of crude oil from a loss-of-well-control event would impact marine water quality, marine sediments, and marine biological resources found near the well. Marine turtles and marine mammals would be particularly susceptible to impacts from an oil spill due to the need to surface to breathe and the resulting inhalation risks,” it notes.

Additionally, it says baleen whales feed near the surface where oil would be entrained, so an oil spill could foul their baleen plates and expose them to ingestion of oil as well as inhalation of volatized hydrocarbons. Further, should spilled oil reach the coast in Region One, it says the risks of oiling nesting beaches could pose inter-generational risks to marine turtles. Other physical and biological resources, such as air quality, seabirds, marine fish, and marine benthos could also be impacted but the EIA notes that current speeds in the Project Development Area regularly exceed 1 meter per second and spilled oil would travel rapidly to the north and/or west, depending on the season.

The EIA also says a spill could potentially impact Guyanese fisherfolk if commercial fish and shrimp resources were impacted. The magnitude of this impact would depend on the volume and duration of the release as well as the time of year at which the release were to occur.

Regardless of seasonal trends in abundance or spatial distribution among the major taxonomic groups, the EIA says effective implementation of the Oil Spill Response Plan (OSRP) would reduce this risk by reducing the ocean surface area impacted by a spill and thereby reducing potential exposure of these species to oil.

Oil spill modeling indicates that transboundary impacts could potentially occur for the largest spill scenarios considered and the unmitigated modeling results for these scenarios indicate there is the potential for oil to reach portions of a number of countries in the Caribbean. “Potential impacts on resources and receptors in these other countries would be similar to those for Guyana,” it notes, while adding that there are some additional resources that could potentially be affected.

The EIS and EIA are available on the EPA’s website and can also be copied at the EPA’s office, the National Library in Georgetown and the Regional Democratic Council offices in all 10 administrative regions.