An article on Software Based Pipeline Leak Detection - What is Piping

An article on Software Based Pipeline Leak Detection

Introduction:

Pipelines used as bulk carriers of crude oil and natural gas

Used in water distribution systems

Results of Leakages include: Loss of product, Environmental hazards, Loss of life

Pipeline Configurations:

Figure showing pipeline networks
Fig. 1: Figure showing pipeline networks

Methods of leak detection:

Hardware Method: This method is used to detect leaks with instrumentation outside the pipeline.

Software Method: This method uses different instruments to monitor internal parameters (such as pressure, flow, temperature) that infer product release.  It is also known as computational pipeline monitoring (CPM).

Hardware Method:

  • Acoustic Emissions
  • Fiber Optic Sensing
  • Vapor Monitoring
  • Multi-hop Sensor Wireless Network*

Advantages:

  • Good sensitivity to leak
  • Very accurate in leak locating

Disadvantages:

  • System costs are usually high
  • High complexity of installation

Software Methods-Balancing System :

  • Balancing Systems: Uses the principle of mass conservation

Mass Conversion Equation

Types of Balancing systems:

  • Volume Balance
  • Compensated Mass Balance
  • Model Compensated Mass Balance

Advantage:

  • It is simple to implement
  • Cost effective

Disadvantage:

  • Can be affected by instrument error
  • High rate of false alarms

Software Method – Pressure Analysis:

Gradient Intersection method

  • This method uses SCADA (Supervisory Control and Data Acquisition) values to calculate the theoretical hydraulic profile or baseline of the pipe
  • The presence of a leak can be determined from a specific deviation or combinations of several deviations from the baseline

Advantages: Estimation of leak location can be determined

Disadvantages:

  • Dependent on instrument sensitivity.
  • Smaller leaks typically take longer time to detect.
  • Does not give magnitude of leak

Software Method – RTTM:

Real Time Transient Modeling (RTTM) involves computer simulation of pipeline conditions using advanced fluid mechanics and hydraulic modeling.

Basic equations used in RTTM are:

Basic Equations of RTTM
Fig. 2: Basic Equations of RTTM

Advantages:

  • It takes into account the configuration of the pipe as well as the product characteristics.
  • Very fast in detection and location

Disadvantage:

  • It is a complex way of leak detection
  • The RTTM method costs much more than the other methods
  • Requires many instruments, controller training and maintenance.
  • Errors in instrument calibration could raise false alarms

Generalized Likelihood Ratio:

  • This is a statistical method modeled after the flow conditions in the pipeline
  • A mathematical model that describes effects of leaks and biases on the flow process is used.
  • Can detect leaks in pipeline branch, location in the branch and magnitude of the leak.
  • Can identify various types of gross errors
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1 thought on “An article on Software Based Pipeline Leak Detection”

  1. I found it very interesting when you talked about the gradient intersection method of pressure analysis for pipes. My friend is working to join the industry and wants to learn all he can about using the software as well as hardware to determine the locations of leaks and other issues and how to fix them. Thank you for the information about how this method can determine the presence of a leak from a specific deviation or combinations of several deviations from the baseline.

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