Oceans-ESU - Water Pollution Remediation in Oman

Job title: Remediation and re-use of drilling wastewater in the Sultanate of Oman
Industry: Petrochemical
Clients: Petroleum Development Oman (PDO), a subsidiary of Shell International
Sites: Oil fields in the Sultanate of Oman

Oceans-ESU is currently working on a water recycling and agricultural project on the oil fields of the Sultanate of Oman. The project radically re-addresses the way the petroleum industry deals with water pollution problems.

PDO produce oil at about 140,000m³ per day, and plan to double production over the next 3 years. The oil has high water content, amounting to 400,000m³ per day. The water is saline and contains oil and heavy metals, among other materials. About 50% of it is re-injected into the oil wells by high pressure injection. The procedure is expensive, energy intensive and wasteful of water. A solution had to be sought, and PDO chose Oceans-ESU to investigate cost effective natural treatment technologies.

Oceans-ESU and PDO have installed a reed bed pilot plant to test the efficiency of the system in the environment. The system was commissioned in early 2000 and consists of 8,000m³ of reed bed and an additional 24, 000m³ of an experimental agricultural area. The system will treat 3,000m³ per day of process water.

The project will determine which reed and local plant types are resistant to the salinity and will tolerate the harsh growth conditions while providing a valuable cash crop. Salt-tolerant crops are of interest as they can be irrigated with treated water from the reed bed. In the future, based upon the findings of this study, a large area of crop plants could be irrigated with treated water from the drilling process. In a country where water is a scarce and valuable commodity, this pilot programme is attracting close scrutiny.

A number of plants have already been proven to be suitable, and these will continue to be evaluated for agricultural purposes. Alternative plants will also be investigated that can be used to provide green areas in the desert by re-using or recycling the country's precious water resources.

The system has also proven to be effective in tackling the water pollution issue at the site, with early measurements indicating a 99.9% removal of hydrocarbon contamination and 50% reduction in effluent volume through evapo-transpiration in the system.