Regulations for offshore drilling operations


The oil and gas industry in Nigeria has always tried to meet the challenges of providing environmental protection. Admittedly, the exploitation of oil and gas reserves has not been without some ecological side effects including oil spills, and air and water pollution.

Drilling fluids and drill cuttings are the largest waste streams generated in global drilling operations. Regulations ensure minimal damage is done to the environment and protect marine life offshore.

These protections are not limited to Nigeria; most oil and gas countries have similar legislation and regulations to protect the environment. There are also regional legislations like OSPAR, Helsinki, Barcelona and Kuwait, and international groups such as the International Finance Corporation and the World Bank Group also has the Environmental, Health & Safety Guidelines for Offshore Oil & Gas Development. All these are efforts aimed at protecting the environment along with workers health and safety.

The Department of Petroleum Resources (DPR) is the regulator of the oil and gas industry in Nigeria. The Environmental Guidelines and Standards for the Petroleum Industry in Nigeria (EGASPIN) outlines environmental and safety standards that must be complied with by oil operators.

The DPR evaluates and monitors the discharges into the environment from exploration, production, terminal operations, hydrocarbon processing, oil transportation, and marketing operations. Since 1991, the EGASPIN has been updated and revised to be at par with international best practices and advancements in drilling waste management technology, including zero discharge for inland and offshore shallow waters. This includes water less than 12 nautical miles distance from shoreline and in water depth of less than 200 feet.

In these zero-discharge zones, discharge is prohibited of whole and spent drilling fluid, drill cuttings, deck drainage, and well treatment waste. Discharges are permitted where the distance from shoreline is greater than 12 nautical miles or the water depth greater than 200 feet under certain conditions.

Water-based drilling fluids and cuttings discharge is allowed if the fluid and cuttings pass the sheen test and discharge is approved by DPR. For synthetic-based drilling fluid cuttings, the oil on cuttings (OOC) must be treated to less than 5 per cent before discharge. Low toxic, mineral-oil-based cuttings may be discharged if treated to less than 1 per cent OOC.

How Nigeria compares with Africa

Some of the newer oil producing countries in West Africa do not have regulations. In those countries, operator discretion and corporate global standards drive the present practices. Ghana – Environmental Protection Agency (EPA) is Ghana’s regulatory authority. Offshore Oil & Gas Development in Ghana Guidelines for Environmental Assessment and Management, issued in 2012, outlines the regulation for the country. Non-aqueous drilling fluid cuttings shall not be discharged to sea in water depths less than 500 m. Group III non-aqueous drilling fluid with polycyclic aromatic hydrocarbons (PAHs) level than 0.001% and total aromatic content less than 0.5 per cent is preferred for use at water depth beyond 500m. The discharge limit is 2 per cent oil on cuttings. Group II non-aqueous drilling fluid discharge limit is 1 per cent oil on cuttings at water depths beyond 500m. Group I non-aqueous drilling fluid is prohibited in regulated areas. Cameroon, Equatorial Guinea, Ivory Coast, Liberia, Benin, Togo, Senegal, Mauritania, Mozambique, Tanzania & Namibia have no set or clear environmental regulations for oilfield discharge. Operator discretion drives the present practices, which is stipulated in their Environmental Impact Assessment.

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This Day, 19 March 2021