Natural gas well production network state-space model development and validation for process control

Abstract

A transient state-space nonlinear model is developed for a natural gas system fed from multiple gas wellheads. The dynamic models are developed by making use of the spectral element method for pipeline spatial discretization. Wellhead models are integrated into the pipeline models by making use of suitable boundary conditions based on the characteristic compatibility method. The models are validated against a large scale natural gas well production network. The validation shows that the model has a good prediction performance based on a low normalized root-mean-square error of at most 5.08% and a high Pearson correlation coefficient with measured plant data of at least 0.94. The good prediction response of the developed transient models makes them suitable for use in model-based optimal control of natural gas well production networks. The resulting dynamic model can be easily adapted to a gas network of any configuration due to its modular form.