‘Produced water’ is a major challenge for Oman

The 3rd edition of Produced Water Middle East will be held in Oman in October — underscoring the Sultanate’s increasingly important role in the produced water space in the region.
Produced water is typically referred to as naturally occurring water that is extracted from the subsurface along with oil and gas. But unlike potable or other types of surface or groundwater, produced water must be suitably and safely disposed of because it is contaminated with hydrocarbons, hydrogen sulphide (H2S) and potentially toxic heavy metals as well. Consequently, it must either be treated if used for oilfield or industrial consumption, or disposed of in deep aquifers — options that are prohibitively expensive given the prodigious volumes involved, say experts.
The two-day forum, which will be held during October 23-24, 2019 at Sheraton Oman Hotel — Muscat, has been organised by Global Water Intelligence (GWI), a UK-based leading publisher and events organiser serving the international water industry. The event is supported by Petroleum Development Oman (PDO) and Oman Water Society (OWS), among a host of service providers as well.
“As oil producers look to increase their output from aging wells, and with capital expenditure on Produced Water projects expected to double in the next five years, it is more important than ever that professionals working within the region stay abreast of emerging trends, industry best practice, new technologies and approaches for produced water treatment. The event combines keynote speeches, technical papers, and unrivalled networking opportunities,” said GWI in a curtain-raiser on the event.
In the Sultanate, produced water is evolving into a formidable challenge for hydrocarbon producers, chiefly PDO — the nation’s largest producer of oil and gas. The majority government-owned energy firm is projected to boost its output of produced water to an estimated 1 million cubic metres per day in 2019 as part of its routine operations. This is roughly equivalent to the volume of potable water that the Public Authority for Water (PAW) — the principal supplier and distributor of potable water in the Sultanate —handles per annum.
PDO, by far the biggest source of produced water, currently has a strategy in place to manage this prodigious output averaging 910,000 cubic metres/day presently. Around 55 per cent of this output is used for pressure maintenance, while a further 300,000 m3/day is disposed of into deep formations in a process termed as deep water disposal (DWD).
Over the past decade, PDO has embarked on a number of green and other innovative solutions for produced water disposal. One such initiative is the award-winning Nimr Reed Beds project, which is operated on PDO’s behalf by Bauer Nimr. The latter currently treats around 115,000 cubic metres/day of produced water by developing wetlands in the desert based on the cultivation of a species of temperature and salinity resistant reeds. Since it was established in October 2010, around 260 million cubic metres of produced water has been processed via the reed beds project, resulting in the greening of a 10.5 sq kilometre desert area. The project has also contributed to the recovery of around 2.1 million barrels of oil from the produced water.
This year, PDO plans to channel a further 60,000 cubic metres per day of produced water away from energy-intensive Deep Water Disposal schemes to the environment-friendly reed bed project in Nimr in the south of the country.