In general terms, pipelines are (mostly) underground conduits used for transporting materials including water, waste products, oil and gas.
April 24, 2014 By Mike Burzek
In general terms, pipelines are (mostly) underground conduits used for transporting materials including water, waste products, oil and gas. The Canadian petroleum and natural gas industry uses pipelines extensively for transporting hydrocarbons. For emergency personnel, it is important to understand the basic characteristics of pipelines and what they carry. It is also useful to know some pipeline jargon to better understand why certain control procedures are necessary.
The petroleum industry in Canada has a remarkable safety record when it comes to pipeline-related incidents. High safety standards and strict regulations for pipeline design, construction and operation go a long way to ensure failures are prevented and risks mitigated. Many of the hydrocarbon-based products processed and used by the industry are classified as hazardous by Transport Canada; these substances can be readily identified by cross-referencing the supply labels or placards with the corresponding information provided in the Emergency Response Guidebook.
When responding to pipeline-related emergencies, it is useful to understand a few essential terms and their meanings so personnel can be better prepared. For example, a section of pipeline is referred to as a segment; this term identifies a specific length of pipe between control points or shut-off valves. Obviously, the larger the diameter and the length of pipe, the greater the volume of product it will contain; emergency evacuation zones are primarily determined by this information. These segments of pipe have to be bled down – that is, the pressure in the pipe must be reduced – whenever a major leak or failure is detected. Reducing pressure in some large-diameter natural gas pipelines can take several hours.
It is important to know that pipelines are classified as either transmission or distribution, the key difference being the standard operating pressure. Distribution lines typically operate at less than 100 psi, whereas transmission pipelines can operate at several hundred psi. Distribution networks of piping are more commonly included within the broader utilities category and are generally located in or near urban centres, supplying natural gas to a large customer base. Distribution lines are generally much smaller than transmission lines, are constructed with different materials, and carry clean, dry methane gas. A chemical called mercaptan is added to the gas carried in distribution lines, giving it a pungent odour that is easily detected at low concentrations. On the other hand, transmission pipelines transport raw products and contain higher concentrations of liquids. And remember, raw natural gas generally has no detectable odour.
There are many pipeline safety control measures required by regulations. Some of these features include protective material referred to as a jacket on the outside of the pipe; cathodic protection, a technique that reduces the risk of static discharge; remote sensors; computer-controlled high- and low-pressure alarms; an emergency shutdown (ESD); and pipeline cleaning/inspection gauges (referred to as PIGs). It is useful to know that all transmission pipelines are required to have manual shut-off valves at designated places. These valves are located at a pipeline riser, the small section of pipeline that is above ground and barricaded or fenced in. Pipelines are also marked by warning signs indicating the product in the pipe and a 24-hour emergency contact number for the company or owner.
Although major pipeline-related emergencies, such as the explosion and fire in Otterburne, Man., on Jan. 25, are rare in Canada, it is imperative for industry and emergency response services to recognize the need to be prepared. One of the most common causes of pipeline failures is third-party damage, usually from heavy equipment. Other causes of failure include stress fracturing from flooding, from landslides, or from the pipe itself over-pressuring; corrosion; weaknesses in the steel or weld due to age or wear; and manufacturing defects. Most of the serious pipeline incidents in Canada occur in remote places, posing limited risk to public safety. When pipelines are close to populated areas, emergency planning zones are predetermined and identified for response personnel in the company’s emergency response plan.
Responder safety must always be the highest priority. It is important that responders learn how pipelines are operated, the products they transport and common types of incidents – pipeline companies can provide this information – so that emergency personnel have practical knowledge prior to responding to an actual event. Knowledge is not only power, put protection as well.
Mike Burzek is the director of public protection and safety for the BC Oil and Gas Commission. He lives in Fort St John, B.C., and can be reached at firstname.lastname@example.org
Print this page