To remind, the incident occured on March 14, 2020, when the unintentional disconnection of the LMRP occurred during a drilling operation on the Maria field in the Norwegian Sea, where Wintershall Dea is the operator.
Drilling was not underway in hydrocarbon-bearing layers of the well, which meant no danger existed of discharges from the reservoir to the natural environment.
Following, the well was isolated by the shear ram in the blowout preventer. Since the weight of the drilling mud included a riser margin for the section, the barriers remained intact. Most of the oil-based drilling fluid in the riser was drained to the sea.
It is reported that the incident could have led to serious damage, as the BOP would cut the string and shut in the well. The PSA concluded that the incident could have caused material damage to the facility and its equipment. Yet, it caused the discharge of 49.9 cbm of drilling fluid from the riser to the sea/natural environment. The drill string was cut and had to be fished out of the well.
Except the incident, the investigation has identified several underlying causes for the West Mira incident. These relate primarily to reduced situational awareness and assessment of risk, procedures and compliance with these, use of analyses, management of change, design of the facility, cost cuts and concentration on efficiency.
Concerning regulatory breaches, the investigation identified four non-conformities with the regulations, in regards to procedures and compliance with procedures, risk understanding and prioritisation of risk-reduction solutions, learning lessons from incidents and preventing recurrences, and deficiencies in meeting the operator’s see-to-it responsibility.
It is stated that the last of these concerns relates to operator company Wintershall Dea. It was given a deadline of 17 September to explain how this non-conformity with be dealt with. The three others relate to Seadrill. They coincide to a great extent with identified non-conformities following an earlier incident on West Mira in January 2020.
According to the PSA, the deadline for compliance with the order is set to 15 October 2020.