Inspection Of Risers Research Articles

RPA POSITIONING ERROR INFLUENCE ON CLOSE RANGE PHOTOGRAMMETRY FOR INDUSTRIAL INSPECTION

Abstract. In oil and gas offshore platforms, special pipelines as flexible risers make the connection between the ocean floor structures and the platform in extreme environmental and operational conditions. Periodic inspections are necessary to assess their integrity. As industrial climbing for inspection is expensive, extremely dangerous and time consuming, qualitative visual inspection with Remotely Piloted Aircraft System (RPAS), also known as drones, are being successfully applied for remote inspection of offshore flares and risers in a much safer, quicker, and cheaper way. These experiences motivate the 3D photogrammetric inspection of risers using RPAS, considering restrictions like layout of the inspected structures and surroundings and inability to prepare the scene. In this paper, taking advantage of the position information provided by the RPAS, the reconstruction and scale of the test scene were made using only GNSS data, GNSS and scale bars, RTK, and RTK and scale bars. Calibrated artifacts were used to evaluate the results and they include a PVC pipe with artificial defects simulating a riser, a pyramidal pattern with four spheres, and scale bars. The results showed that, as expected, the worst results are for GNSS data with error standard deviations of 0.35 mm compared with 0.20 mm or less for other options. For the sphere’s artifact, relative maximum sphere spacing errors are 9.3% for GNSS, 1.9% for RTK and 0.26% using scale bars. In any case it was possible to identify the defects in the pipe with good quality and with much more detail compared with a climbing inspection.

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.

TARGETLESS PHOTOGRAMMETRY NETWORK SIMULATION FOR INSPECTION PLANNING IN OIL AND GAS INDUSTRY

Abstract. The oil and gas offshore industry demands regular inspections of components and structures that are subjected to extreme operational and environmental conditions. In this context, risers are pipelines that transport mainly oil, gas, water, and cables between submarine structures and the surface offshore platform, in the portion not touching the ocean floor. The emerged part of these risers is typically inspected by industrial climbing, which is a very time-consuming activity, has high operational costs, is dangerous and has a strong dependence on inspector skills. Remotely Piloted Aircraft Systems (RPAS) have been recently used for visual inspection of risers, however, no quantitative or geometrical evaluation has been conducted using this kind of image acquisition yet. An image-based measurement technique, such as close-range photogrammetry, can provide a 3D reconstruction using images, but a series of requisites is mandatory to achieve good results as image acquisition sequence, overlap, camera positioning network, spatial resolution and object texture in non-prepared and targetless scenes. The analysis of different image acquisition strategies using a real RPAS is too difficult because it demands a lot of time, good weather, daylight, and a scene similar to where risers are installed. An alternative is to use simulation. In this paper a ROS/Gazebo simulation is described and used to create a realistic textured 3D virtual environment of the platform, risers and RPA, providing a fast and low-cost solution to simulate different RPA trajectories for photogrammetry image acquisition in targetless scenes. These trajectories are evaluated by comparing the measured risers through photogrammetry to its CAD/simulated model. Since the scene is not prepared, the RPA position/orientation or a stereo vision setup can be used to set scale to the measurement result. The best trajectory found during simulations was also evaluated in a real experiment.

A Service Robot for Subsea Flexible Risers

This article presents the development of a remotely operated vehicle (ROV) for the underwater inspection of subsea flexible riser, proposing effective solutions for the associated robotic manipulation system. Novel, underactuated end-effectors have been conceived and developed to firmly hold the robot on the riser during locomotion or operation, without affecting riser's integrity. By using these end-effectors, the robot is able to move along the riser, like an inchworm does, and rotate around the riser at any angle. In principle, the current design could operate up to 2,000 m sea depth with minor modifications. In this study, the service robot carries and deploys digital radiographic equipment for the volumetric inspection of flexible risers. Several preliminary tests, as well as a series of underwater tests, prove the robot's encouragingly positive performance.

NEWSDESK: Phased array inspection system facilitates successful installation of bar finishing facility; Sustainable engineering – ECUKguides the profession; Online condition monitoring system helps manage remote pumping station; Development of an underwater radiography inspection system for inspection of flexible risers

NEWSDESK: Phased array inspection system facilitates successful installation of bar finishing facility; Sustainable engineering – EC^UKguides the profession; Online condition monitoring system helps manage remote pumping station; Development of an underwater radiography inspection system for inspection of flexible risers

Automated radiographic inspection of flexible risers: a feasibility study

Flexible risers are flexible pipes used to bring oil from oil wells deep underwater to the surface, where it can be processed by Floating Production, Storage and Offloading (FPSO) installations. Flexible risers consist of a number of layers of steel and polymer that have a complex structure and some layers are shielded by others, making non-destructive testing particularly difficult. This paper presents some experimental radiography of a sample flexible riser. Both single-wall and double-wall techniques were used with X-rays and gamma rays with both computed radiography imaging plates and an amorphous silicon flat-panel detector. The layer of the riser that is of particular interest is the pressure armour, which is the layer designed to withstand the infernal pressure. It is a layer that is particularly difficult to inspect, as it is shielded by a metallic layer on both sides. The resulting images were used to develop an image processing technique designed to detect separations in the pressure armour, which is also presented here. The technique is based on the use of the Hough transform to detect non-structural lines in the image. This technique has been tested on a defect simulated by image processing and an artificial defect introduced to the flexible riser sample. The technique was found to be successful in detecting the artificial defect in a set of images, with only 4% of misclassification, which were all false positive results.