TECHNOLOGY
The 250Hz dynamic subsea laser scanner DLS-500
Subsea Lasers: Rising to the Challenge of Riser Integrity Management This summer, Savante deployed their fastest and most advanced subsea laser tooling aboard a WROV to conduct a 3D SLAM scan of a dynamic production riser, confirming the location and condition of buoyancy elements used to maintain the catenary of a production riser. As 2016 draws to a conclusion, the oil and gas industry remains laser-focused on the difficult task of cutting costs at every conceivable level; all whilst protecting, maintaining and ensuring security of infrastructure, environment and personnel. Underwater inspection, maintenance and repair (IMR) operations, conducted by diver or remotely operated vehicle are an essential component of an asset integrity management system yet are inherently commercially risky. At the lowest level of complexity an IMR survey consists of nothing more than a general visual inspection (GVI) record of an asset using a video camera. Whilst cheap; this can largely be insufficient and ineffective in addressing subsequent questions typically raised by asset-integrity managers.
of integration, ease of measurement and precision. Savante’s latest laser technology achieves scanning rates exceeding 250Hz in a simple manipulator-mounted tool and combines HD visual recording with precision 3D data that delivers decision-making clarity for asset integrity managers. Critically, this can be delivered dynamically on a moving-target, moving-platform basis without the need to extend the duration of survey in field. Dr. Thomson, founder of Savante Subsea, said: “The main benefit of subsea laser scanning is that it can be integrated seamlessly into any GVI campaign at low cost but delivers an enormous increase in capability and measurable content. Laser scanning retains the advantages of a GVI quoted in DNV-RP-F206 of being fast, low cost and able to cover large areas.
“Laser scanning dramatically overcomes the traditional criticisms of a GVI; namely ‘measurements not accurate, subjective and labour intensive’. Laser scanning delivers essential 3D measurement data that is vital in guiding the forward actions of asset integrity managers. Our capacity to deliver this at the front-end of an inspection campaign can deliver significant cost-savings to the operator, particularly when it eliminates the need for a follow-up investigation.” Manipulator-mounted DLS-500 during integration with WROV
The applications for lasers in the subsea environment are endless and growing to match the prevalence and diversity found in the onshore construction industry. Whether used for alignment, scaling, range-finding or creating full 3D models of subsea assets; lasers are now setting the underwater standard for speed, accuracy, ease
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Subsea UK News | November 2016
The resulting buoyancy element position data was used as part of a hydro-dynamic modelling study to determine the maximum applicable loading forces anticipated during extreme environmental conditions of monsoon season and confirm safe operation of the riser. This project was driven by the requirements of a classification society. The DLS-500 will be show-cased at the upcoming Subsea Expo exhibition in February 2017.