SS MTS: Subsea Monitoring - High Resolution 3D Laser Imaging for Inspection, Maintenance, Repair, and Operations

Abstract

Abstract In January 2011, 3D at Depth was awarded a RPSEA contract to bringhigh-resolution three-dimensional (3D) laser imaging technology from the labinto an underwater environment for the oil and gas industry. During theproject, CDL Inc. provided expert engineering support and materials to marinizethe system. The project included two underwater trials which demonstrated thefeasibility of utilizing high resolution laser detection and ranging (LADAR) ina subsea environment. 3D laser imaging is a powerful data collection system that provides 3-Dinformation for a specific area of interest. It is the predominate technologyfor terrestrial survey, construction, as-built analysis, and large-scaleretro-fits. The 3D laser imaging market is a mature multi-billion dollarindustry with an eco-system of software, expertise, and best practices. Developing the technology to provide high-definition subsea laser imagingenables the deep water industry to use the current state of the art in 3Dmetrology and related best practices developed for the terrestrialmarket. This paper discusses some of the theory behind subsea laser imaging andcompares this theory to the first set of underwater tests in a pool. Terrestrial laser scanners commonly produce centimeter spatial and rangeaccuracy at several hundred meter range. Due to the absorption of water, realizable deepwater systems are limited to tens of meters range depending onthe target and water conditions. To our knowledge, this is the first timesub-centimeter accuracy at greater than 6m range is demonstrated for anunderwater laser system. This technology is essential for better management of deep water assets. Thelack of timely and accurate survey-quality 3D measurements poses an integritymanagement challenge for such assets. A lack of accurate data results in eitherhigher risks or higher costs to build and maintain environmentally safeproduction and product transportation systems. The speed and precision of thetechnology developed by this project reduces operating costs for underwaterinspection, maintenance, and repair; reduces environmental risk through moreaccurate inspection; significantly improves construction practices and quality/ reliability; reduces risks to high value assets; and provides rapid access tosharable survey-quality as-built data before, during and afterconstruction.