Abstract

This paper describes the application of on-line two-phase dynamic simulation techniques to model the Malaysia Second LNG (MLNG DUA) Project’s pipeline network. The pipeline model is known as Trunkline Operation Model (TOM) and the on-line real plant data input is acquired from the field plant control systems via Data Acquisition and Monitoring System (DAMS).

MLNG DUA pipeline system consists of a 38″ 162 km two phase pipeline connecting the offshore gas producing fields (M1 and M3) to a riser platform at Ell Field, from where two parallel 36″ 126 km pipelines run to the Second MLNG plant at Bintulu. Liquid hydrocarbon slugs are intercepted by a finger type slug catcher upstream of the LNG plant

The capacity of the onshore slug catcher and stabilisation plant is designed to process the peak volume liquid arrival rate derived from the production forecast. The pipeline system which is designed to operate in two phase mode has a high pipeline liquid holdup in the range of 2–5 times the daily processing capacity of the onshore plant.

Under certain operating scenarios part of the liquid hold-up may be swept out, generating high rates of liquid arrival onshore. These may exceed the onshore plant capacity thereby causing disruption to gas supply. From studies made the transient can be accommodated by taking early and appropriate operational action if the liquid arrival profiles are known or can be predicted.

The paper describes how TOM and DAMS meet this operational requirement. TOM is a pipeline and process dynamic model developed by SAST (Special Analysis and Simulation Technology Ltd, London ) using the Shell TRAFLOW transient two phase flow programmes integrated within the SAST proprietory process simulation environment OTISS.

At the time of writing the Phase 2 development has just been completed and handed over to Operators.