A Performance Analysis Of Alberta's Pipelines

Abstract

Abstract Historic pipeline failure data has been compiled from reports to the Energy Resources Conservation Board by operators. The performance of pipelines used in the oil and gas industry is reviewed in this paper with the use of failure statistics. An analysis of failure rates and Trends shows that each pipe line type has leading causes of failure. By indicating the areas of greatest fault or least concern on pipelines, statistics direct the investigation of pipeline performance. The widely accepted engineering technique of using evaluation and analysis of failures co identify necessary changes in design, construction, and operation of structures can be readily applied to pipelines. Introduction One of the first cross-country pipelines in Alberta was constructed in 1912 for the transmission of natural gas from Bow Island to Calgary. At the time, the 275-kilometre, 406-millimetre diameter pipeline was the longest line in the world. The tale has been told that the day's events surrounding the ceremonious pipeline start-up did not unfold as expected. During pressurization of the gas line to 2000 kilopascals, a blowout occurred in a slough at DeWinton. The introduction of a natural gas supply to the City of Calgary was delayed somewhat while the line was coupled and pressurized again. Today, pipelines span the countryside in an extensive network, which resembles a field of spaghetti, moving many types of products through lines constructed of steel, cast iron, aluminum, concrete, asbestos cement, plastics and fibreglass. Over 220 000 kilometres of pipelines, within the oil and gas industry, including some 90 000 kilometres of gas distribution lines, have been constructed and placed in operation throughout Alberta (Fig. 1). As with much service equipment and structures, pipelines require an adequate level of operating and maintenance practices. Despite this, during a minimum 40-year service life, a pipeline may fail from any number of causes. A failure, which in general terms includes any leak or break however small or large, is usually a stable event and its extent is limited to a localized area of the pipe. The economic and orderly development and continued safe operation of pipelines used in the production of oil and gas resources within the province is regulated by the Energy Resources Conservation Board. Pipeline failures in Alberta, without limitation of cause magnitude or consequence are reported to the Board by the operators. Data is collected as it relates to the transmission of crude oil and oil products, sweet natural gas, sour natural gas(1), multiphase fluids(2), salt water, and fresh water. The information compiled on each failure includes a description by one of 18 failure causes (Table 1), date of occurrence geographic location, and some general pipe specifications and operating conditions. During the past few years, the Board has reviewed pipeline failures on a regular basis and major trends identified have formed the basis of some changes in policy direction. In some instances, the failure statistics have provided background assistance for engineering decisions.