Gas network planning as mechanism to achieve better supply and optimization of investment
Authors: Sanfeliu J.M. , Herbalejo D. 
Published: December 2007

The gas network planning through the utilization of simulators constitutes a tool of tremendous potential for the decision making, since from a known situation permits to generate growing demand scenes and to select the most convenient technical-economic alternative of supply, assuring better delivery.

This paper describes the project faced, in that sense, by Gas Natural BAN in order to achieve a complete knowledge of the initial operative situation and to have the solutions for the future operation of approximately 250 regulating stations and more than 16,000 km of gas pipelines, high and medium pressure, where at the beginning of the exploitation operations important problems of quality in supply were experienced during the winter peaks.

Introduction

The gas network planning, starting from the models validation, permits to know the current capacity of the distribution systems, to detect critical points and to determine, in advance, the complementary works needed to achieve the appropriate quality in supply, in a growing demand context, which implies the optimization of the investments to be made for the improvement of the gas network, and also permits an adequate analysis of the expansions, based on market studies.

This method was not carry out in the gas distribution system of the Argentine Republic, therefore it was defined as an essential objective to be fulfill.

For this assignment Gas Natural BAN counts on the software "SICAR", developed by itself, that runs in PC and has a wide range of alternatives to analyze the results of the calculations. Furthermore, this software has an important graphic interface with a digitized cartographic system, that permits an adequate geographical location.

The paper that we present describes: the initial problems, the stages that we accomplished to achieve the modelling of a system that involves 1,000,000 of clients supplied through 16,000 km of gas pipelines and more than 250 regulating stations, which major part interacts between itself, and the simulation of base stages and of medium or long term to achieve quality in service with optimized investments.

This implies the generation or updating of the standardized drawings, georef digitizing of pipelines and cartography, review and topological adaptation, monitorings in field, load of the demand information, until arriving to the models validation of the current situation and simulation to 1,3 or 5 years from then, according to the available data of the market or the critical situation of the pipelines, where the necessary reinforcements are specifically determined. It is complemented with experiences (for example about the importance of the geographical referencing in the process of digitizing, or the flexibility of the software to incorporate vectorialmente cartography and texts) and the presentation of some plans in which the principal parameters arise from the studies of the gas network simulation, are shown.

Initial Problems Of The Exploitation Operations

In order to give a proper idea of the project magnitude and the information handled, we have to say that our gas distribution system consists of more than 15,000 km of medium pressure lines (1,5 bar) and more than 1000 km of high pressure lines (60, 45, 25 and 10 bar).

The two transport companies (Transportadora de Gas del Sur and and Transportadora de Gas del Norte) that operate in the Argentine Republic deliver the natural gas to our high pressure system. From there, more than 1,000 companies (mainly industries) are supplied and 250 regulating stations; 230 of those are the injection points to the medium pressure lines of the distribution system, which mainly supplies natural gas to residential and commercial consumption (1,000,000 of customers). Transfer points to Metrogas, gas distribution company adjacent to our distribution area, has to be added.