Applications of a New Approach in Pipeline Leak Detection

Abstract

This article, written by Assistant Technology Editor Karen Bybee, contains highlights of paper SPE 118070, "Seeking the Hidden Threat: Applications of a New Approach in Pipeline Leak Detection," by Jack Elliott, Richard Fletcher, and Mike Wrigglesworth, Pure Technologies Limited, originally prepared for the 2008 Abu Dhabi International Petroleum Exhibition and Conference, Abu Dhabi, UAE, 3-6 November. The paper has not been peer reviewed. Prompt leak detection is an essential element of the integrity-management process for any hazardous-materials pipeline. If leaks are not detected at an early stage, they will result in progressively worse damage. Ultimately, they can grow into a far more serious failure of the pipeline if not repaired in a timely manner. Therefore, a variety of leak-detection and/or leak-prevention systems are used. Many require installation and maintenance of substantial levels of costly equipment on the pipeline. For this reason, the industry is interested in the advancement of alternative approaches in leak detection. Introduction The need for an effective method of quickly detecting leaks in hazardous-materials pipelines is clear. The economic losses resulting from undetected spills can be high: from lost product, cleanup costs, repair costs, and possible litigation. In addition to monetary considerations, the costs to the environment and local population also must be considered. In many jurisdictions, there is a legal requirement on the pipeline operator to have some form of leak-detection system in place. In the US alone during the period 2003–07, average damages from pipeline spills exceeded USD 430 million/yr. The earlier a leak is detected, the better the opportunity to limit the damage caused. Many leak-detection systems are available; however, an economical system for the detection and location of all leaks at an early stage has been elusive. Commonly used technologies are limited by the minimum leak size they can detect, inconsistencies in performance (i.e., a high rate of false alarms or missed leaks), inability to locate the leak accurately, the cost or impracticality of implementation, or a combination of these factors. A need was perceived for an easily implemented system capable of detecting small leaks before they grew to more-serious proportions, which could be incorporated into a typical pipeline-integrity-management program without the need for infrastructure changes. The full-length paper describes the development of an in-line, acoustic leak-detection system and summarizes the field work completed to date. The benefits of the new technology to the oil- and gas-pipeline industry are described. Status of Existing Leak-Detection Methods for Oil and Gas Pipelines There are a variety of methods that can detect leaks in natural-gas and petroleum-product pipelines, ranging from manual inspection to advanced satellite-based hyperspectral imaging. The various methods can be classified into internal and external systems. No single system is accepted universally as the preferred method because all have strengths and weaknesses, though some are far more commonly used than others.