Leak Detection Technologies for Continuous Monitoring of Subsea Production Templates

Abstract

Abstract Subsea leakages from underwater production facilities may have significant environmental and economical consequences. There are a wide range of different technologies available for detection of subsea leakages, depending on the type of application and approach to leak detection. The two most common approaches to direct subsea leak detection are inspection/surveying, where sensors are attached to mobile units such as ROVs, and continuous monitoring, where the sensors are permanently installed at the seabed. For the latter case, there are several different types of leak detection technologies depending on whether templates or pipelines are to be monitored. While most subsea facilities are monitored by flow measurement devices which can typically detect leaks of above a few percent of overall flow, this paper addresses direct methods of leak detection, suitable for smaller leaks. The Norwegian Oil Industry Association (OLF) has initiated a series of projects on subsea leak detection, where the purposes are to obtain an overview of the different types of leak detection systems available, and to determine the practical applicability and functionality of these systems. An important issue in this regard is to experimentally test the leak detection systems with both gas and oil leakages under realistic conditions. This paper presents results from comparative, experimental tests of five different leak detection systems suitable for continuous monitoring of subsea templates, where the purpose of the tests was to elucidate the strengths and limitations of the different detection principles.