During precommissioning, fluorescent dye may be injected into the pipeline during the flooding phase so that any leaks are more easily detected. Models in our LEAKlog LR series of long range fluorometer sensors are available for all the regularly used fluorescent tracers, including ultra-violet sensors, which can also detect hydrocarbons. The sensors can detect very small quantities of tracer dye, even in highly turbid conditions where traditional ‘black light’ technology is too insensitive. Typical detection level when immersed in a leak plume is better than 1 ppb of dye, while maximum detection range of a significant leak can be up to 10 metres.

Research into the typical signals emitted by high pressure leaks led to the development of a highly sensitive directional ultrasonic detection sensor. Background noise such as from an ROV is filtered out, so that only the ultrasonic signals in the band of interest are monitored and analysed. The LEAKlog PA1 acoustic sensor operates alongside existing LEAKlog sensors, thus providing a multi-stage detection process. It is also ideal for situations where the use of fluorescent dyes is either unfeasible or not permissible.

When there is a temperature differential between the sea water and the contents of a pipeline, the fast response LEAKlog T1 temperature probe can be used to detect small thermal plumes rising from the leak source. The probe can provide an absolute temperature output, or an ultra-sensitive temperature gradient output. Typical differential temperature sensitivity is in the order of millidegrees.