Leak Detection for Gas and Liquid Pipelines by Online Modeling

Abstract

Summary The leakage of hydrocarbon products from a pipeline not only represents the loss of natural resources, but it also is a serious and dangerous environmental pollution and potential fire disaster. Quick awareness and accurate location of the leak event are important to reduce losses and avoid disaster. A leak-detection method using transient modeling is introduced in this paper. This method is suitable for both gas and liquid pipelines, with comprehensive consideration of the transient-flow features of compressible flows and stochastic processing and noise filtering of the meter readings. The correlations for diagnosing the leak location and amount are derived on the basis of the online real-time observation and the readings of pressure, temperature, and flow rate at both ends of the pipeline. As an online real-time system, great attention has been paid to the stochastic processing and noise filtering of the meter readings and the models to reduce the impact of signal noise. It is also essential for the robust realtime pipeline observer to have the self-study and adjustment abilities needed to respond to the large varieties of pipeline configuration, pipeline operation conditions, and fluid properties. Real application cases are presented here to demonstrate this leak-detection method. For example, in the leak detection of a crude-oil pipeline of 34.5 km long and 219 mm (nominal diameter), this method located the leak at 16.6 km from the pipe-line upstream end, which is only 0.6 km away from the actual leak location.