US sheds light on probe into fatal Gulf of Mexico incident from 2021

After looking into circumstances surrounding an incident that resulted in a fatality aboard Fieldwood Energy’s offshore platform in the Gulf of Mexico, the U.S. Bureau of Safety and Environmental Enforcement (BSEE) has released its panel investigation report and come up with recommendations for oil and gas operators and contractors to assist in preventing such incidents in the future, improving safety and environmental protection.

BSEE’s panel investigation report on an incident from May 15, 2021, which resulted in a fatality aboard the Fieldwood Energy-operated Eugene Island Block 158, Platform #14, in the U.S. Gulf of Mexico, confirmed that Fieldwood was utilizing Island Operating Company contract employees to assist with conducting operations in the block, approximately 40 miles offshore Louisiana when the incident occurred. 

The investigative panel, which included BSEE subject matter experts, engineers, inspectors, and specialized investigators, conducted its investigation to determine the probable cause, contributing causes, and contributing factors that led to the fatality of a contracted operator conducting a pressure test on a 16-inch casing. 

In a safety alert, BSEE explained that the incident resulted in the fatality of an offshore worker two and a half years ago when an explosion occurred as two production personnel were pressure testing a 16-inch well surface casing. The explosion entailed a high-pressure release with no signs of ignition. The data obtained by the U.S. regulator during the subsequent investigation determined that personnel were using a high-pressure well to supply the pressure to the well casing.

They installed temporary test equipment that included a high-pressure hose and a digital pressure gauge, but they did not use the pressure-regulating device and pressure safety valve during the pressure test. Furthermore, the personnel first opened the surface safety valve to begin the casing pressure test on the 16-inch casing. They then opened the needle valve on the top of the source well and the needle valve on the receiving well’s 16-inch casing. The target test pressure was 250 pounds per square inch gauge (psig).

However, the production personnel were unaware of the pressure rating for the 16-inch casing at the time of the test. As they were monitoring the test pressure, the 16-inch well casing exploded, releasing fluid through a 1½-inch opening between the 36-inch drive pipe and the wellhead base plate. The resulting surface casing failed due to overpressure, fatally injuring the worker. According to BSEE, the section of grating above the casing deck was disfigured and blown upwards from the explosion while oil residue was observed on handrails, piping, and platform structure beams.

The force was so powerful that the surrounding area handrails were disfigured – a section of the handrail was blown off the platform and never recovered. The paint on the surrounding structure beams was blasted down to the bare metal. On the casing deck, the force from the explosion created a slight bend upward of the wellhead one-inch-thick base plate.

The Bureau of Safety and Environmental Enforcement’s investigation found that the production personnel had conducted a pressure test using temporary test equipment without using a pressure regulator and pressure safety valve, which resulted in the overpressure and subsequent explosion of the well’s 16-inch casing.

The probe’s findings highlight that the operator failed to develop and/or implement a hazards analysis at the facility level and a job safety analysis at the operations/task level for the activities on May 15, 2021, as required within its Safety and Environmental Management Systems (SEMS) manual.

Moreover, the production personnel failed to follow the pre-job planning safe work practice, as required within its SEMS manual. By neglecting to follow this practice, the U.S. offshore safety regulator claims that the operator compromised the safety of personnel and deviated from the established protocols outlined in the SEMS manual.

The ability to switch between output modes on the digital gauge created a potential scenario where the production operator could have inadvertently read the pressure displayed in units of bars instead of pounds per square inch.

Additionally, the operator neglected to carry out the necessary management of change (MOC) process before installing and utilizing temporary equipment, as explicitly outlined in its SEMS manual. BSEE claims that this failure to adhere to established procedures posed “a significant risk” to personnel safety and operations integrity.

Bearing in mind the findings of the investigation, the Bureau of Safety and Environmental Enforcement recommends that operators and their contractors consider ensuring that the pressure rating for all temporary equipment is verified to be compatible with specific applications prior to use; utilizing a pressure-regulating device and a pressure safety valve to protect against overpressure anytime temporary equipment is utilized where the source pressure is greater than any downstream components’ existing pressure rating.

The U.S. regulator also advises operators and contractors to think about implementing training sessions and raising awareness among personnel to enhance their proficiency in utilizing, interpreting, and accurately reading units of measurement recorded by all gauges and measurement devices, as proper understanding of how measurement devices are used is essential for maintaining safety protocols; ensuring that a hazard analysis is thoroughly evaluated during the development of pressure testing procedures, which should consider all potential hazards associated with the pressure testing operation, as including the implementation of all necessary hazard mitigation measures is deemed to be imperative.

In addition, operators and contractors are asked to consider establishing and documenting comprehensive procedures for assessing the potential hazards and risks associated with individual inactive wells. The outcome of this assessment should then be utilized to prioritize the abandonment process.

Last but not least, they are also advised to ensure that all operations and contract personnel engaged in any pressure testing activities attend and actively participate in a pre-job meeting or toolbox talk and to document the proceedings of these meetings. All operations and contract personnel should review the job safety analysis and ensure all hazards are acknowledged and policies, procedures, guidelines, contingencies, and communications are understood.

Following a thorough investigation and analysis, BSEE found a probable cause as well as multiple contributing causes and contributing factors of the fatal incident, which are detailed in the investigation panel’s report. The conclusions reached indicate that the fatality was caused by the failure to use safety devices with temporary test equipment. Therefore, the regulator highlights three recommendations to minimize the likelihood that a similar incident will occur in the future.

The first one emphasizes that the industry should use a hazard analysis to develop procedures to provide to personnel performing the operations and to enable the implementation of all necessary measures of hazard mitigation. All non-routine operations should undergo a hazard analysis by personnel with the appropriate level of expertise.

The second one underlines that the industry should consider implementing processes to assess the risk presented by individual inactive wells and use this assessment to prioritize abandonment. The third recommendation underscores that a pressure regulating device and a pressure safety valve should be installed any time temporary equipment is utilized where the source pressure is greater than any downstream components’ pressure rating.