The Nimr water treatment plant (NWTP) project is located in the south of Muscat in Oman. The temperatures in the region can be as high as 60°C in the summer months, making it a harsh environment to work in. This water treatment project was co-executed by Bauer Environment and Petroleum Development Oman (PDO). The plant came online in late 2010 and has been treating water since 18th December 2010. The Nimr oilfield requires 250,000 m³/d of water to be managed to keep oil production going. Deep disposal wells were the main option but the Nimr WTP can address the issues of loss of revenue from oil left in produced water, stricter environmental regulations, highenergy costs and the carbon footprint associated with disposal wells.
The Nimr WTP is designed to treat 45,000 m³/d, which is less than a fifth of the daily volume of produced water generated by the oilfield. It is a build-ownoperate (BOO) project under a 20-year operation and maintenance contract. This is a unique model, for which BAUER designed and built the facility and is now operating it. BAUER has taken full liability for managing the water from the oil and gas producer. The composition of the produced water from the Nimr oilfield is brackish, with total dissolved solids (TDS) ranging between 7,000 mg/l and 8,000 mg/l. The oil in the water is higher than 400 mg/l in average.
The plant layout includes a pipeline, which enters the NWTP system and leads to an oil and water separator. The water is then distributed into a wetland facility where it is channeled through four wetland terraces by gravity feed. The overall area of the wetland is 2.3 million m². Finally, there are evaporation ponds used for salt recovery in order to reuse the salt for drilling operations in the oilfields of Oman. The figures below show the gravity flow reed bed.
Nimr Water Treatment Plant Oman