Omani state oil firm tackles water quality, emissions

MINA AL FAHAL, OMAN//John Malcolm, the managing director of

(PDO), is well aware that oil companies have poor reputations for environmental stewardship, but he is determined that Oman's flagship oil and gas producer will clean up its act.

Last year, the government-controlled company signed a contract to create a "giant farm" to grow reeds for treating waste water from its oil operations, he told reporters gathered for

.

Following the successful completion of a pilot project using natural reed beds at Oman's Nimr oilfield, the company is planning to grow reeds on 2.4 million square metres of land. The expanded beds would be capable of treating 45,000 cubic metres per day of processed water from local oilfields, Mr Malcolm predicted.

PDO has been trying to maintain its oil output by using a number of techniques to stimulate production from aging fields. One of the most extensively used is a "water flood" process, in which water is pumped into oil reservoirs to push out the oil. When it re-emerges from producing wells, the water is not exactly fit to drink, and could contaminate the environment with oil residue and toxic chemicals if left untreated.

A number of PDO's other environmental projects are aimed at reducing the company's carbon footprint.

"All oil and gas companies produce carbon emissions. PDO is no exception," Mr Malcolm said. "We burn fuel gas to generate power, to drive [gas] compression systems, to heat our crude for transport, and we drive almost 260 million kilometres per year."

To address the emissions problem, PDO is using solar photovoltaics to power equipment, lighting and surveillance systems in remote locations. Closer to populated areas, it uses waste heat from power stations to produce steam for the "thermal enhanced oil recovery (EOR)" projects on which the company increasingly relies to exploit deposits viscous "heavy oil".

Like treacle, heavy oil flows more readily when heated up, so PDO and other heavy-oil producers pump steam into underground deposits of sticky crude to raise temperatures in the reservoirs.

PDO is also piloting a solar concentrating trough system, using an array of curved mirrors to focus sunlight onto water-filled pipes. That produces steam for an EOR project. The solar installation could produce as much as 100 tonnes of steam daily based on 10 hours per day of sunshine.

"We are hoping to be the first in the world to do this," Mr Malcolm said. "If successful, this technology could be used at thermal EOR projects with solar-generated steam being injected during the day and conventional steam at night."

In partnership with Oman's ministry of environment and climate affairs, PDO is also investigating the feasibility of carbon capture and storage applications and seeking carbon-trading opportunities.