https://www.maritime-executive.com/features/deep-sea-explorers-the-world-of-seismic-survey-vessels

You have to find the oil before you can drill.

By Kathy A. Smith

The work of marine seismic survey companies is becoming more and more critical as the world’s recoverable oil and gas reserves continue to be a concern. The search for new carbon deposits ranges farther and farther offshore, and deeper and deeper beneath the surface, often in harsh, inhospitable climates. According to most estimates, seismic activity is expected to grow 10 percent this year with business picking up in the Gulf of Mexico and the Arctic continuing to be a hot exploration frontier.

Where Are the New Reserves?
“There are an estimated 380 billion barrels of undiscovered oil and gas north of the Arctic Circle that remain to be found, of which 84 percent is expected to occur in offshore areas,” says Peter Zickerman, Executive Vice President and Head of Strategic Investments for seismic explorer Polarcus in Dubai. “Until the world finds alternative energy sources, the quest to find new oil reserves and maximize extraction from existing fields remains paramount.” Fast-growing Polarcus doubled its fleet in 2011 from three to six vessels and expects growth of 15 to 20 percent this year. It’s particularly strong in Ice Class and the Arctic and committed to reducing its environmental footprint while maintaining a cutting-edge, green seismic fleet.



All of its Arctic-ready vessels are double-hulled and feature numerous environmentally-conscious features, including high-spec catalytic converters, low-sulfur fuel, and advanced ballast and bilge water cleaning systems. The ships’ innovative Ulstein X-Bow® design reduces the pitch/heave acceleration through the water, giving a comfortable ride while decreasing “slamming,” the wave/hull noise that interferes with the acoustic source used in acquiring seismic data. They also have an SPS (Special Purpose Ships) class notation for better stability and evacuation routes and will soon have Triple E (Environmental & Energy Efficiency) DNV accreditation.

The ships are equipped with up to 14 streamers for gathering subsurface data through hydrophones. A survey vessel shoots with an air gun and measures the interval between the sound wave’s hitting the ocean floor and bouncing back to the surface. As Zickerman explains with a hypothetical scenario, 10 to 12 eight-kilometer streamers can be towed between six and 12 meters below sea level at a speed of four and a half to five knots. With the separation between the streamers at about 100 meters each, the display becomes one of the world’s largest moving objects, the equivalent of 1,200 football fields. “By pulling multiple streamers you get a three-dimensional image of the subsurface. So we acquire the data, and the client ultimately interprets it and decides if they want to drill. That’s the only real way to explore before you can even consider drilling,” he says.

Places like the Gulf of Mexico and Northwest Europe, which have been explored several times over, require companies to constantly fine-tune their data-gathering techniques to find hydrocarbons through deeper and more complex geology. “Planning starts with geological objectives,” explains Zickerman, “and the right plan provides the geological solution, not just the technology itself, and that’s been our breakthrough.”

Two newbuilds with ICE-1A superclass notation are nearing completion. Remarkably for a company founded just four years ago, Polarcus has been given 100 percent of all the Arctic work in Greenland so far this year for companies like Shell. “We are expecting that the Arctic will open up more aggressively, driven by the petrodollar,” adds Zickerman. “With our ice class vessels, we have the ability to extend the Arctic season and operate responsibly in very sensitive areas.”

Obs dette er en gammel artikkel selv om det står 29.12.2019 på siden. Ble selv litt lurt :-)
Men leteområdene ligger der enda.