SFT criticism doesn't reflect Hydro efforts

October 17, 2002, 01:00 CEST

"SFT's comments about our will to implement measures on produced water discharges is misleading both in regards to what we have done and to the momentum of the current process we've started in co-operation with SFT," says Hydro Oil & Energy information director Hege Marie Norheim.

Hydro actively works to reduce discharges of produced water from petroleum platforms in the Norwegian offshore sector - and adamantly rejects the Norwegian Pollution Control Authority (SFT) assertion that Hydro may "lack the will to get discharges down."

A law passed in 1997 by the Norwegian Parliament mandates all oil companies operating in Norway to submit a comprehensive plan in June 2003 for how they will reach zero harmful discharges by 2005.

Hydro is preparing such a plan for its platforms in the Norwegian offshore sector.

"The plan is supposed to be submitted eight months from now... SFT itself determined that. Hydro has met with SFT all along and we've not been given any reason to believe they were dissatisfied with our work so far. The criticism is surprising, blunt and badly timed," she asserts.

Hydro and Statoil count the highest number of offshore operations and subsequently have the highest volumes of produced water - residual water after oil and gas production which occurs naturally in subterranean petroleum reservoirs. Aging oil and gas operations - which produce comparatively higher volumes of water - has caused produced water discharges to rise an estimated 20 percent per year, according to SFT.

"It will be extremely expensive for the companies to do something about discharges, which is enough of a reason some companies haven't yet determined how to bring discharges down," said SFT petroleum activities sector chief Marie Nordy on Norway's national broadcast network NRK Tuesday night.

Different technologies

"Hydro is working with different technologies for reducing harmful natural compounds from produced water discharges, as well as reducing production chemical use and completely phasing out some harmful chemicals," explains Toril Røe Utvik, environmental section head in Hydro Exploration and Production Norway. "We have already implemented new technology which reduces discharges of oil with produced water on several platforms and are evaluating technology that uses condensate from platforms to extract dissolved oil components from produced water discharges."

Another option studied is reinjecting produced water back into the reservoir. "Reinjection technology is already implemented on six of our 12 platforms," she says.

The subsea Troll Pilot system on the Troll field - which separates water from oil and gas and sends it back into the reservoir - is a good example of Hydro's proactive efforts, remarks Norheim. "We've had one year of great success with Troll Pilot and see this technology as a forerunner for 'invisible' platforms placed on the seabed in the future."

Smart well advantage

"Hydro has a big advantage rarely mentioned regarding the zero discharge goal in 2005 - smart well technology," says Ruben Schulkes, section leader at Hydro's Oil & Energy Research Center in Porsgrunn. "This is a technology where we equip our wells with sensors and valves. The valves can be shut when a well segment starts to produce water.

"This ensures that we prevent or reduce the production of water thereby reducing the total volume of water which reaches the platform. Preventing water production is one of the most effective means of reducing produced water discharges. Hydro is one of the world's leaders in applying smart well technology... accounting for some 30-40 percent of all smart wells installed worldwide. In particular, we've had positive experiences with the application of smart well technology on the Oseberg field."