LEAK DETECTION METHODOLOGY 

Our significant experience in the pipeline leak detection environment has been fully exploited to supply new leak detection approaches for Oil and Gas systems. Our systems expand the capabilities of the two principal software based methodologies that analyse a pipelines physical reaction to a leak.

• What goes into a pipeline must come out (Balancing techniques)
• Pressure transients will emanate from the location of the leak when bursts occur

Balancing techniques can detect seeping leaks over extended timeframes and pressure monitoring techniques can detect large leaks very quickly. It makes sense to combine these effects to ensure the full range of leak detection capability. Although the physical reaction to a leak will never change, the way that the physical reaction is interrogated can always be improved upon.

If the instrumentation permits and if the system is not a simple one, SSL will recommend the inclusion of the simulator model to increase accuracy and reduce the false alarm rate. A simulator improves capability on pipelines with transient conditions, variable product properties and changing flow regimes which are commonly found on many pipelines worldwide. A simulator will always be used on gas pipelines.

Balance and Pressure Wave monitoring both provide a response that can be analysed to detect the presence of a leak. The simulator based balance methods produce imbalance responses in addition to important divergences between measured and calculated values of pressure and flow at key locations on the pipeline or network (UF and UP). The pressure wave method monitors the change in pressure at key locations on the pipeline and verifies the presence of a true leak by verifying the times at which the pressure changes occur.