Offshore Test Measures Electrical Potential of Subsea Pipelines

Kawasaki Heavy Industries, Ltd. developed the world’s first autonomous underwater vehicle (AUV) with a robot arm for subsea pipeline inventions known as the Subsea Precise Inspector with Close Eyes (SPICE). Photo courtesy of Kawasaki.

Kawasaki Heavy Industries, Ltd. (Kobe, Japan) announced the successful completion of its joint offshore verification test with French energy supermajor TotalEnergies (Paris La Défense, France) to measure the electrical potential of subsea pipelines during close-range inspections. The test was conducted off Awaji Island (Hyogo Prefecture, Japan) using an autonomous underwater vehicle (AUV).

Leveraging its long-accumulated submarine and industrial robot technologies, Kawasaki has developed the world’s first AUV with a robot arm for subsea pipeline inventions known as the Subsea Precise Inspector with Close Eyes (SPICE). The SPICE AUV was developed in response to growing demand for subsea pipeline maintenance in offshore oil and gas fields.

In a 2020 verification test, conducted under the Joint Technical Development Support Program for Offshore Oil and Natural Gas Fields1 by DeepStar2 and the Nippon Foundation Ocean Innovation Consortium, SPICE achieved stable pipe-tracking performance, demonstrating high capability as a platform for close-range subsea pipeline inspections.

Following this favorable outcome, Kawasaki decided to launch a joint research project proposed by TotalEnergies to integrate its electrical potential measurement technology, Light Touch Cathodic Protection (LTCP), with SPICE. This made the AUV capable of measuring the electrical potential gradient of a pipeline, thus allowing for the detection of potential coating defects.

Kawasaki and TotalEnergies successfully completed a joint offshore verification test to measure the electrical potential of subsea pipelines during close-range inspections. Photo courtesy of Kawasaki.

From October 2020 to February 2021, the basic design was completed, and various integrated simulations were performed. Then, beginning in August 2021, SPICE received more detailed design modifications in order to incorporate LTCP. These preparations enabled the verification test off Awaji Island from August 30 through September 2, resulting in the successful measurement of the electrical potential of subsea pipelines.

For this offshore test, simulated pipes and a corrosion protection system were placed on the seabed under the supervision of TotalEnergies. In the test, SPICE utilized its pipe-tracking capability and highly precise, autonomously controlled robot arm to successfully perform measurements of electrical potential. With its newly integrated measurement device, the robot arm checked the state of protection of the pipelines against corrosion inferred by the measurement of the electrical potential. The success of the outcome suggests that SPICE can achieve automation and reduce operational time in close-range subsea pipeline inspections currently performed by remotely operated vehicles.

“LTCP had demonstrated its repeatability of establishing the effectiveness of the cathodic protection system in a controlled test environment, and there was a need to deploy the technology in close proximity to the pipe under inspection,” says Andy Gower, R&D Subsea Robotics Project Leader for TotalEnergies.

“SPICE, with the ability to deploy sensors at a controlled distance, enabled LTCP to demonstrate repeatable performance,” Gower adds. The potential for additional sensors to be deployed at the same time should enable other non-destructive test sensors and techniques, providing enhanced data of aging pipeline and allowing integrity threats to be assessed with more detail. The future trend of subsea robotics is for highly maneuverable sensor platforms, and the performance of LTCP integrated with SPICE provides an effective solution to determine the performance of the cathodic protection system in an operational context.”

“We have combined self-own technologies of underwater vehicle and industrial robot to develop a AUV with an arm called SPICE,” says Noriyuki Okaya, Manager of Development & Design Section for the AUV department at Kawasaki. “By using the arm, we are confident in accurately positioning the sensor to the target where proximity is required.”

“We are very pleased to receive the great opportunity of this joint offshore verification sea trial from TotalEnergies,” Okaya concludes. “In this sea trial, we could obtain useful inspection data in combination with LTCP and also could demonstrate the ability of SPICE as a pipeline proximity inspection platform, continuing from 2020. We will continue to develop it in search of further possibilities.”

In 2021, Kawasaki received an order from Modus Smart Subsea Services, a UK-based offshore solutions provider, for the commercial model of SPICE, which will be an upgraded version of the model used for the verification test.

Kawasaki says that it is currently working on production and test runs for its commercial SPICE model, along with other underwater AUV equipment, in order to meet growing market demand. The project includes the following:

  1. A support program promoting the technological development of Japanese companies int eh offshore oil and gas sector, jointly administered by the Nippon Foundation and DeepStar. Kawasaki was selected as a participant in the program in FY2019 in order to pursue applications for autonomous underwater robots in offshore oil fields.
  2. An international offshore marine technology development consortium comprising major oil companies engaged in the exploration, development, and production of offshore oil and natural gas around the world, along with universities, research institutes, and other organizations involved in offshore development.

Source: Kawasaki Heavy Industries, Ltd.,

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