(Photo: "Workers on the LLOG 115A platform inspect the fire tubes adjacent to the heater treater")
WASHINGTON, DC -
The Bureau of Safety and Environmental Enforcement today released the report of its panel investigation into a Nov. 12, 2016 fire at LLOG Exploration Offshore, L.L.C.’s Grand Isle Block 115 “A” Platform in the Gulf of Mexico. The panel, including BSEE subject matter experts, engineers, and investigators, investigated the fire incident to determine the cause and contributing factors of the incident.
On the day of the incident, three Wood Group operators, contracted by LLOG, suffered burn injuries as a result of a fire that began in the vicinity of a heater treater on LLOG’s platform.
BSEE’s panel made several recommendations to reduce the likelihood of similar events in the future, including the recommendation that operators conduct proper hazard analyses when opening process vessels and tanks, and that operators use portable gas detectors when operating in the vicinity of fired vessels.
To read more about the panel investigation, including BSEE’s recommendations, the full report can be found here.
A memo from BSEE leadership in response to the report can be found here.
A Safety Bulletin has been sent to offshore operators and can be viewed here.
BSEE's National Investigations Program is administered by its Safety and Incident Investigations Division in Washington, D.C. Panel investigations, an integral tool for safety improvement, are chaired by division and regional staff, and conducted in coordination with region and district staff.
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Executive Summary
On November 12, 2016, three Wood Group Operators contracted by LLOG Exploration Offshore, L.L.C. (LLOG) at their Grand Isle Area (GI) Block 115 “A” platform (the platform) suffered burn injuries while preparing to eliminate an emulsion pad that formed in the platform’s heater treater. The injuries occurred due to a fire that began in the vicinity of the heater treater when a flammable gas mixture migrated into the area and reached a heat source, completing the necessary requirements for ignition and sustainment of fire.
Since resuming production in March 2016 following structural modifications, excessive basic sediment and water (BS&W) caused frequent issues with maintaining production on the platform. In early November 2016, LLOG installed a steam unit, which resolved some of their BS&W issues. However, on the day of the incident, a mechanical malfunction occurred to the steam unit, resulting in an excessive emulsion pad in the heater treater that prevented LLOG and Walter Oil & Gas (WOG) from producing sales quality oil. To address this issue, crews usually drained the emulsion pad from the heater treater to one of the oil tanks on the cellar deck below, and then used a bucket to batch treat the emulsion with a chemical emulsion breaker.
The crew involved in the incident was preparing to troubleshoot the emulsion pad when the fire occurred. They made no attempt to isolate the heater treater, nor did they secure the fire tube burners. Without draining the emulsion pad, one operator, located adjacent to the heater treater flame arrestors on the platform’s main deck, prepared to batch treat the dry oil tank using a hose from a chemical tank on the main deck to the dry oil tank located on the cellar deck below. Another operator opened a hatch on the top of the dry oil tank to receive the hose. This action released a flammable vapor cloud that extended upward to the main deck.
Within a minute of the hatch being opened, the operator on the main deck, as well as another operator who had just walked up to him, described witnessing a flame coming from the general location of the heater treater flame arrestors. The flame ignited the existing flammable vapor cloud in the vicinity of the heater treater flame arrestors.
The operator preparing to batch treat was engulfed in flames, but managed to escape the fire by running toward the southwest corner of the platform. The operator on the cellar deck felt the flame around him before closing the hatch and jumping down to safety. The operator who had just arrived fell backward, got up, pushed the platform emergency shutdown (ESD) button and announced the fire over the radio. Both operators on the top deck, as well as other personnel on shift throughout the platform, responded to assist with extinguishing the fire. Individual accounts indicated that the fire lasted anywhere from a few seconds to several minutes.
The three injured operators suffered a combination of first and second degree burns to their hands, arms and face; the most severe of which were to the operator preparing to batch treat. Platform personnel assisted with first aid treatment while the Person-in-Charge (PIC) called for evacuation of the injured employees to a hospital on shore. All three were treated and released within two days of the incident.
The Bureau of Safety and Environmental Enforcement (BSEE) convened a panel to conduct an investigation into the cause(s) of the incident and issue a report of its findings, conclusions and recommendations. The panel, comprising BSEE professionals, identified the following direct and indirect incident-causal-factors that may have contributed to the direct causation and totality of the incident:
Direct Cause
The fire occurred when a flammable gas mixture, which was released through the thief hatch on the dry oil tank, migrated into the left fire tube of the heater treater, where it contacted either the left fire tube flame or the left burner pilot flame. This flame likely propagated through a gap in the mating flange between the left flame arrestor housing and the heater treater, igniting the flammable gas mixture in the surrounding atmosphere.Indirect Causes
- Personnel failed to sufficiently mitigate hazards.
- Lack of sufficient engineering controls
- The gap in the flame arrestor/heater treater mating flange was likely caused by improper installation and/or assembly of the mating flange.
Contributing Factors
- Failure to follow OEM recommendations, industry recommended practices, and industry standards.
- Personnel failed to adhere to permitting requirements.
- The hazard analysis performed for the work to eliminate the emulsion pad was insufficient, as the incident crew not only neglected to perform a JSA, but also failed to hold a pre-job safety meeting.
- The improper use of PPE resulted in injuries that may not have occurred had proper PPE procedures been followed.
- Daily safety meeting failed to sufficiently address operations and hazards on the day of the incident.
- Insufficient supervision.
- Poor communication.
- Unfavorable environmental conditions.
- Equipment failure
The BSEE Panel makes recommendations in an effort to further promote safety, protect the environment, and conserve resources on the U.S. Outer Continental Shelf (OCS). The following listing contains some of the key recommendations identified as a result of the investigative findings detailed within this report:
- Consider the location(s) of fired elements relative to potential gas releases when performing facility-level hazard analyses.
- Consider the use of permanent containment systems for vessel draining and chemical treatment.
- Consider conducting visual inspections of natural draft burners, ensuring airtight integrity between flame arrestors and fire tubes.
- Consider the use of a portable gas detector when operating in the vicinity of fired vessels.
- Consider increasing operator supervisory presence when using contractor-employed supervisory personnel during non-routine operations.
- Consider ensuring production SOPs are used for site specific equipment and/or conditions.
- Ensure operators are familiar with, and adhere to, OEM instructions regarding start-up, operations, maintenance, and inspection of fired vessels and associated safety devices.
- Consider instituting applicable industry standards into inspection programs, SOPs, and SWPs.
- Ensure all contractor personnel engaged in production operations are knowledgeable regarding operator SWPs.
- Ensure that all company, contractor, and visiting personnel properly wear PPE where the potential exists for thermal exposure from fire, and that the PPE selected for the job reflects the probable and possible hazards of the job.