Flow Control at City Gates: A Low Budget Approach

The Bolivia Brasil Gas Pipeline (GASBOL) is a pipeline extending from the gas producing fields of Rio Grande, Bolivia, to Canoas, Brazil. It distributes gas to five states in Brazil, with a total extension of 3 160 km (1,970 mi) and a rated operating pressure of 100 kgf/cm2g (1,420 psig). GASBOL is owned and operated by Transportadora Brasileira Gasoduto Bolivia-Brasil S.A., TBG, a company whose shareholders are Petrobras, AEI Ame´rica do Sul, Transredes, BBPP Holdings and Bear Ga´s. After several occurrences of flow turbine failures caused by large flow variations at some city gates, the design of new stations was modified to include a control valve upstream of the interconnection point with consumers. For operational city gates such functionality would imply delivery interruption to perform costly hot tapping procedures in order to install a flow control valve. Therefore, TBG’s engineering team was challenged to develop a cheaper and quicker solution. This paper describes TBG’s answer to that challenge, developing a low cost flow control solution at ten selected city gates along the pipeline. The stations were chosen based on several aspects such as volume capacity, line packing to the consumer, etc. The main objective is to ensure that the daily volume effectively delivered does not exceed the contracted volume, avoiding delivery failures due to imbalances caused by unplanned withdrawals, as a means to improve planning of the pipeline operational profile.