DOF Subsea, working with Sonardyne, 2G Robotics and Seatronics, has released a new underwater surveying technique in which ROV-mounted and mapping operations are conducted while the vehicle is in motion.

The technology makes it possible to simultaneously survey multiple horizontal or vertical flanges.

“The solution generates high-resolution engineering models from which accurate measurements can be instantaneously and repeatedly captured,” according to DOF Subsea. “This is critical for successful fabrication and installation of spools and jumpers, and brings enormous cost and time saving benefits.”

It is the result of the combination of Seatronics’ 2G Robotics ULS 500 Pro Laser, Sonardyne’s SPRINT acoustically aided inertial navigation sensor and DOF Subsea’s exclusive Metro software. The technology was demonstrated at The Underwater Center in Fort William in the U.K.

“We believe that using this combination of technology to provide a full metrology solution is an industry first,” said DOF Subsea’s Colin Cameron. “We can save days on traditional metrology work and provide much higher quality data. This in turn brings savings to the operations teams running the projects.”

Other benefits as outlined in the release:

  • Subsea intervention is not required before metrology;
  • No subsea bracketry, control spheres or metrology aids are required;
  • The modular system can be fitted to an ROV for dynamic data acquisition or mounted onto a tripod for static data acquisition;
  • Less time is needed to gather survey data, ultimately lowering vessel costs, compared to traditional techniques; and
  • Data are delivered within six hours of acquisition.

With prior dimensional control information, hub position and orientation can be inferred using laser scan data, DOF Subsea said. In addition, the 3-D model can serve as an as-built model of the subsea installation and the surrounding area.

Pieter Jansen of Geomatics Global called the technology “a much welcome and needed approach in an economically hard hit oil and gas industry.”