MY name is Robert McChane. I am a Senior Project Manager for Northern Plains Natural Gas Company. Northern Plains, a subsidiary of Enron, is the managing partner of the Northern Border Pipeline System (NBPL). The Northern Border System is an 822 mile, 42", 1435 Psig pipeline that extends from the Montana/Saskatchewan border to near Ventura, Iowa, in the northeast part of the state. On September 20, Northern Border celebrated its Tenth Anniversary. The current system includes three compressor stations, each with a single 20,000 horsepower 9s turbine/centrifugal compressor package installed. The capacity of the system is in the 1.4 Bcfd range. An additional four compressor stations, each with the single 20,000 horsepower compressor package, are scheduled to come on line November 1. The Northern Border system will also be extended via the purchase of Natural Gas Pipeline's 147 mile, 30", 1,050 Psig pipeline system. This system begins at the present NBPL terminus near Ventura and extends to Natural's Compressor Station #109, south of Des Moines, Iowa. The pipeline was constructed by Natural in 1990. The capacity of the 42" system, with the additional compression, will be in the 1.7 Bcfd range. The capacity of the 30" system is in the 400 MMcfd range. Last January 14, we conducted a successful field performance test of a 20,000 horsepower turbocompressor package at Compressor Station #lO (CS #lo). The test took less than a day to complete, from calibration of -linstruments to the final calculations that verified vendor's compliance with their field performance guarantee. Previous field tests had taken up to four days to complete and required voluminous calculations to verify vendor's compliance. CS #10 was commissioned in October of 1991. It was the third compressor station added to the system and the first since Northern Border went into service in September of 1982. The initial decision to add CS #10 was made in 1990. Manufacturers and packagers (hereinafter vendors) of nominal 20,000 horsepower turbocompressor equipment were requested to provide quotations for the turbocompressor package. The vendors were notified that all performance parameters requested would have to be guaranteed. The purpose of the guarantees was to add validity to the economic analysis of the competing packages. The performance guarantees would be based on the expected operating conditions of the package. Six operating points were submitted for use in the design of the compressor wheel, a design point, a rated point and fouradditional points to expand and enhance the wheel's capability from surge to choke. The design point was the expected compressor conditions at contract flow assuming winter design conditions. The rated point was the expected station conditions with the flow maximized using winter design conditions.

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