Notices served

Notice 315465968 served against Centrica Energy Storage Limited on 20/11/2025
Notice Type	Improvement Notice
Description	You have failed to follow the arrangements in your Rough 47/3B Safety Case section 3, sub-section 6.1, with the result that you failed to maintain well B12 in accordance with your procedures within the Operations Maintenance System, in particular, the 12 Monthly Wellhead and Xmas Tree Integrity Testing, 47/3B procedure Ref. CSL-OMS-00408 Rev. 5.0 dated 18/08/2025. On the 29th October 2025, your procedure was not followed as it calls for Xmas Tree valves to be inflow tested using well pressure when it is over 20 Barg (290 psig). At time of testing, the B12 well pressure was approximately 600 psig. For well pressure less than 20 Barg, the same procedure instead calls for the Xmas Tree valves to be pressure tested between the gates via a Model "D” fitting. This incorrect pressure test method was being used on the well B12 injection wing valve when the o ring on the Model “D” fitting failed and an attempt was made to replace it. Replacing the o ring on the Model “D” fitting during testing is not part of your procedure. At 09.21 hrs, the removal of the Model “D” fitting, for o ring replacement, resulted in a potentially uncontrolled hydrocarbon gas release from the well B12 and the consequential partial down manning of 24 persons from the Installation by a Search and Rescue helicopter.
Compliance Date	31/05/2026	Revised Compliance Date
Result	Complied with
Breaches involved in this Notice

Location of Offence
Address	Rough 47/3B/Centrica Energy St Woodland House Woodland Park HESSLE HU13 0FA	Region
		Local Authority
		Industry	Extractive and utility supply industries
		Main Activity	06100 - EXTRACTION OF CRUDE PETROLEUM
		Type of Location	Fixed Attended
HSE Details
HSE Group	EDU6OFFS	HSE Directorate	Energy Division
HSE Area		HSE Division