One Gas Transportation Company's Approach To Improving System Gas Balances And Dispatch Operations
Authors: Bell Donald G.W , Menazzi Ruben , Ortega Eduardo A. 
Published: December 2007

Through the implementation of state of the an electronic flow measurement equipment, Transportadora de Gas del Norte (TGN) significantly improved the metering accuracy of volumes of gas entering and leaving its pipeline system and improved its unaccounted for gas position by more than 1 percent. Telemetering of electronic flow measurement data along with the implementation of appropriate procedures supervisory control and data acquisition system (SCADA), and business information systems reduced losses in linepack by up to 11.7%. These improvements eliminated the possibility for system wide curtailments of gas volumes and substantially improved the reliability and efficiency of the TGN pipeline system, and the level of service provided to its customers and end users.

Introduction

In 1992 the privatization of the Argentine Natural Gas Industry resulted in the restructuring of the transportation and distribution systems. Eight distribution companies and two transportation companies were formed.

TGN was one of the transmission companies established through this process which owns and operates the North pipeline system consisting of 4,470 km (2,794 miles) of pipe ranging in size from 12 to 30 inch and operating at pressures from 20 kg/cm2 (284 psig) to 75.5 kg/cm2 (1074 psig). The system has 14 compressor stations with a total of 188,130 H.P. of installed compression. In 1996 TGN delivered 9.125 billion m3 (322 bcf) to seven of the eight distribution companies at approximately 186 delivery meter stations. Its current total firm service transportation contracts are abut 31, MMm3/d (1.1 bcfd). This reflects an approximate 43 percent increase since the time of privatization in 1992.

Key objectives of privatization were to provide open access, non-discriminatory service that also provided efficient, effective, safe and reliable transportation and distribution of natural gas for the end users. This brought about many technical and business challenges for the new companies formed through this process. Achieving these goals required the implementation of new technology, procedures and excellent cooperation between all of the players in the industry.

Some industry activities where this was particularly true was in the area of gas dispatching, gas balancing, and associated reporting of distribution company and large industrial user volumes entering and leaving the transmission systems.

To meet these challenges TGN worked quickly to install electronic flow measurement, telemetering, and SCADA systems in its network. TGN also worked closely with the other industry members to develop and implement agreed upon dispatch procedures.

Situation At The Beginning m Privatization.

Gas Balance. With the privatization of the gas industry it became necessary to accurately track the real time receipt and delivery of gas to the individual distribution companies and industrial users. This is necessary to ensure that differences between the volumes of gas received on behalf of each customer versus the volumes consumed. remain within reasonable tolerances. If this is not the case, over consumption during periods of high demand could result in system wide curtailments and interruptions in supply to noninterruptible markets.

Over consumption occurs when the actual demand is higher than the supply entering the system.