Oil/Gas Pipeline Leak Inspection and Repair in Underwater Poor Visibility Conditions: Challenges and Perspectives

Abstract

Mechanical pressure clamps are examples of innovative tools commonly used in the oil and gas industry for arresting leaks from damaged oil and gas pipelines. However, if leaks result from pipeline rupture, clamps are not usually recommended. It is therefore obvious that inspection of the leaking pipeline is very crucial in deciding the strategy for repair. For subsea pipelines where underwater poor visibility is pronounced, this important aspect of the pipeline repair process becomes difficult to implement. The result is a repair-leak-repair cycle. This challenge is commonly found in repairs of old pipelines in unclear water conditions. Old pipelines and their vulnerability to fractures that often lead to ruptures are discussed. In this paper, the challenges and technologies available for visualisation and examination in such unclear water conditions are discussed. There appears to be a gap in the existing pipeline integrity management system with respect to inspection and repair of pipelines in unclear water conditions. This gap needs to be filled in order to minimise spills and pollution. For pipelines installed in unclear water condition, a perspective is suggested to extend the capability of existing remotely operated vehicles to employ the use of clear laminar water system or a related technique to provide integrity engineers and operators with close visual assess to inspect leaking pipelines and effect adequate repairs. This paper suggests that the use of optical eye as the main tool for examination remains valuable in managing the challenges in underwater pipeline repairs in unclear water condition.