Alberta EUB issues findings on BP Canada ethane well fire investigationA structural defect leading to failure of the elbow on a wellhead connector line has been pinpointed by the Alberta Energy and Utilities Board (EUB) as the cause of last summer's ethane well fires that occurred at the BP Canada plant site in Fort Saskatchewan, Alberta (ELW September 10, 2001).
In its investigation report, made public last week, the Board concludes that unusual forging defects-undetectable by conventional testing methods-caused the elbow on a line connecting two wellheads that service the ethane storage cavern to fail. The failure of this elbow resulted in a release of ethane product to atmosphere, creating an ethane vapour "plume" which ignited through contact with overhead power lines on the plant site.
The fire, which burned from August 26 to September 3, 2001, was contained on-site, and there were no injuries to plant personnel or members of the public. The main environmental impacts of the incident included emissions of soot and other particulate matter from the fire in its early stages. In addition, notes the report, there was a small release of brine (salt) water into the North Saskatchewan River during early fire control efforts.
The Board's investigation also found that the measures taken by BP and affected industries to minimize the effects of the incident on industry operations were appropriate. BP's ethane storage cavern has been out of operation since the fire and will remain so until the EUB approves a resumption of operations.
Since the incident, the report notes that the company has also implemented equipment design changes which will effectively ensure that a similar incident will not recur. Notably, the two-inch line between BP's wells 103 and 103A has been eliminated, and a similar line on another of its caverns has been taken out of service.
In its report, the EUB says it intends to propose regulatory changes which would require an approved emergency response plan-including effective ignition criteria-for all natural gas liquids (NGL) cavern storage facilities. Such changes will be preceded by consultations with appropriate public parties, government agencies, and industry.
The EUB Post-Incident Report on the BP Canada Company Ethane Cavern Well Fires may be viewed on the Board's Web site, www.eub.gov.ab.ca.