Use of Computer Vision for Monitoring of Slow Varying Displacements on Subsea Structures

Abstract

Structural monitoring of subsea structures is very common in the oil and gas industry. Monitoring may be performed to keep track of e.g. position, movements, loads and fatigue accumulation. Well growth of subsea wells is a slow process, and traditional accelerometer-based monitoring is not feasible. The objective of this paper is to present the camera-based monitoring campaign of the subsea wellheads on the Norwegian continental shelf. The paper gives a brief introduction to the issue around well growth and how that potentially can lead to fatigue issues. Further we give an overview of the theory behind marker-based monitoring and explain how this is used in practice by presenting experience from a measurement campaign where 2 different battery powered camera kits operated subsea for 5 months. This to enable establishment of the fatigue integrity of the subsea wellheads. The paper will show how the experience from this campaign has been used to create a new and improved camera kit for more efficient monitoring of similar issues in the future. The technology can be used in a wide range of subsea applications for monitoring slowly variating relative displacements.