Gas Transportation Cost Dividends From Internally Coated Pipe and Station Automation

The Alberta-California gas pipeline is coated internally throughout most ofits length with a thin film of epoxy resin, the purpose of which was primarilyto provide a smooth internal surface and reduce compressor station horsepower requirements. Three of the compressor stations installed on the line are automated and arecontrolled remotely by a single "set point" signal from the central dispatch office. This paper evaluates the benefits that have been realized from these two factors. Pipeline flow efficiency factors are reported and compared with thosefor uncoated portions of the line, and compressor station operating and maintenance costs on the line are compared with costs usually experienced insimilar manned stations. Both of these effects are then related to costs of transportation, and the net effect of each is reported. Introduction The Alberta – California pipeline system extends from gas fields in theeastern foothills region of Alberta through the southeast corner of British Columbia across the international border in Idaho, and through Washington, Oregon and northern California to Antioch on San Francisco Bay – a total ofsome 1,600 miles, including gathering laterals. It carries gas purchased in Alberta by Alberta and Southern Gas Co. Ltd. to markets served by the Pacific Gas & Electric Co. throughout northern California, and to the Canadian Montana Pipeline Co. at the Alberta-Montana border. In addition, gas purchasedby the Westcoast Transmission Company Limited from fields in Alberta is carriedby the line and delivered to the El Paso Natural Gas Co. near Spokane, Washington, as well as to local utility companies along the route of the linein British Columbia, Idaho, Washington and Oregon. The main line is 36 inches in diameter throughout its length and, with thefour compressor stations installed at the time the line was built, the systemis capable of delivering some 460 MMcf/D to the San Francisco Bay area, about160 MMcf/D to El Paso at Spokane and about 36 MMcf/D to Canadian Montana.