VIDEO: Marine Seismic Survey with Robots

Seismic surveys are the primary means by which geologists find possible places where oil or gas is hiding underground. They involve digitally processing recordings of seismic waves — essentially sound waves — to create images of rock layers.

Small robots may soon execute these surveys for Shell in open water much quicker and cheaper than is done today.

Traditional seismic imaging of rock formations below the ocean’s floor involves ships that tow air guns to send out sound waves and receivers that record their echoes. A new approach being developed instead uses small autonomous robots that could make the process quicker and cheaper.

Geoscientists are constantly improving the resolution of seismic surveys, which involve sending sound waves into the earth, recording the waves that bounce back and using powerful computers to create images of underground rock layers.

Most offshore surveys use a ship to tow the air guns that create the sound waves, as well as the receivers used to record them. But placing receivers on the seabed greatly improves the quality of recordings and sharpens the resulting image. So remotely controlled submarines are sometimes used to place receivers one by one on the ocean bottom, then retrieve them.

Now a new technique under development will use small autonomous robots to do the job more quickly and cheaply. The robots can even operate under ice, opening the Arctic to more seismic exploration. A trial using five robots is planned in 2012 in the Gulf of Mexico; another using many more is planned for 2013.

According to Shell, geoscientists will be able to launch as many as 2000 robots in a single day.  Guided by the sonar signals from the surface the battery-powered robots will be able to dive as deep as 3000 meters. They will be easily placed on their station on the seabed. Once on the seabed, the robot then deploys a sensor ready to record seismic waves.

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Source: Shell, August 22, 2012