Numerical Comparison of Pressure Points Analysis and Transient Model Leak Detection and Location Systems

Abstract

This study offers the basis and numerical application of the pressure points analysis (PPA) technique and transient model (TM) leak detection and location systems (DLS). The study numerically compared the PPA technique and the TM leak (DLS) method on a crude oil transmission pipeline. The PPA technique used pressure differentials derived from the pipeline’s upstream, midstream, and downstream pressure sensors to find and locate leaks. In contrast, the TM method used measurements of temperature, flow, and pressure at the pipeline’s inlet and outlet ends and differences in the continuity and law of conservation of momentum equations to derive equations that pilot the system to find and quantify leaks on the pipeline. The static parameters employed for both models were extracted from the pipeline (commercial steel) configuration and the Nigeria Bonny Light Crude Oil properties. The dynamics parameters applied in both models were obtained from SCADA (Supervisory Control and Data Acquisition) system. The models were used separately to detect and locate leak incidents on a straight horizontal pipeline of length 5km and diameter 0.3556m conveying Nigeria bonny light crude oil from Heritage Energy Operational Services Limited into the Trans-Forcados Pipeline (TFP). However, the Leak located by the PPA technique at 2781.2m from upstream is 30.07m after the actual Leak. In comparison, the same Leak located by the TM method is 15.10m behind the actual position, as discovered after excavation during pipeline leak remedial activities. Although both leaks (DLS)) are not accurate, the results show that the TM method is more précised regarding leak location than the PPA technique. On the other hand, the PPA technique can detect leaks faster than the TM method. Both methods are not expensive, and since they give an accurate narrow range of the section of the pipeline in which the Leak is found, they are complementary. Hence, it is recommended and advisable for an establishment to adopt both methods simultaneously for leak confirmation and to know the section of the pipeline to be excavated and replaced.

Keywords

• flow
• pressure points analysis
• transient model
• leak detection
• inlet
• outlet
• scada