A modeling and analytical solution for transient flow in natural gas pipelines with extended partial blockage

• The physical and mathematical models of partially plugged gas pipes are presented.
• A novel, analytical solution for pipelines with extended partial blockages is obtained.
• The calculated results agree with the professional software results.

Modeling analysis of pipeline systems is a significant means of effective system management and control; however, analytical solutions to the transient flow in natural gas pipelines with partial, extended blockages remain an enduring challenge in the oil and gas industry. Based on a variable diameter pipeline in series, a physical model and a simplification suitable for a natural gas trunk pipeline, this paper proposes a novel, analytical solution to the problem. The Sturm-Liouville theory and Fourier transform have been adopted to solve the mathematical model. Finally, an analytical solution is derived, and the pressure distribution of a plugged natural gas pipeline is presented. The accuracy of the calculated, analytical solution is verified using a standard industry software package. The model and analytical solution presented in this paper can be used for additional blockage detection and characterization analysis.