Automatic tool with adaptive suspension system for high-quality inspection of underwater risers

Purpose The inspection of flexible risers is a critical activity to ensure continuous productivity and safety in oil and gas production. The purpose of this paper is to present the design and development of a novel automatic underwater tool for riser inspection that fits the most commonly used riser diameters and significantly improves inspection quality and reduces its operating costs. Design/methodology/approach The mechanical and electronic design of the inspection system is discussed, as well as its embedded sensors and control system. The tool is equipped with a suspension system that is able to adapt to the riser diameter and negotiate obstacles on the pipe wall. Numerical simulations were carried out to analyze the mechanical design, and a hardware-in-the-loop simulation was developed for tuning the control system. Further, experimental results are presented and discussed. Findings Experimental tests in laboratory tanks and shallow seawater have confirmed the effectiveness of the tool for detailed real-time inspection of underwater pipelines. Practical implications The use of the proposed tool will potentially reduce the time and costs for riser inspection, currently performed by divers or high-cost ROVs. Originality/value The authors present a reliable tool able to perform automatic inspections up to 250 m deep in less than 30 min, equipped with a high-definition visual inspection system, composed of full-HD cameras and lasers and a suspension mechanism that can negotiate sharp obstacles in the pipe wall up to 25 mm high. The tool uses a comprehensive control system that autonomously performs a full inspection, collecting sensors data and returning safely to the surface. Its robust design can be used as basis for several other nondestructive techniques, such as ultrasound and X-ray.