Occurring on Ekofisk 2/4 X, this was also the most serious incident in the series, which began when a box weighing 70-80 kilogram fell to the deck of the same platform on 5 January. And on 7 January, a load of 400-500 kilograms had tipped over and dropped on Ekofisk 2/4 J. Two people were in the area, but nobody was injured on this occasion or the one before. When the third incident occurred, the 2/4 X drilling and wellhead platform – which became operational in 1998 – was shut down for maintenance.
The drilling equipment was undergoing its five-year recertification, with corrective maintenance also taking place on a cementing unit to make maximum use of the shutdown.
Cement is used in wells for various applications, including fixing the casing, forming a downhole plug or finally plugging borehole and reservoir section when abandoning a well. In order to cement long casing runs, the mixing system must be able to handle large volumes of cement. Powerful pumps are also used to squeeze the cement into place behind the casing. The cement handling system is normally owned, used and maintained by a service company under contract.An investigation of the accident was conducted by the Petroleum Safety Authority Norway (PSA) to identify what went wrong on this occasion.
Owned and operated by Halliburton, the cementing unit on 2/4 X had two diesel engines which drove the cement pumps. A water-cooled exhaust unit was installed on either side of these engines. The coolers had long been having problems with leaks, forcing Halliburton to make several repairs. It had therefore decided to replace them on both engines.
Temporary lifting equipment was installed in advance, and the work of demounting the first cooler went well. But problems arose when the second came to be lowered. Because it was incorrectly suspended, the cooler was dragged sideways, the strain became too high, the fastenings gave way and the load fell to the deck. In falling, it hit the mechanic’s left leg and inflicted a deep gash right above his knee.
Although this injury was fortunately only minor, the PSA took a serious view of the incident. In its view, a fatal accident could have occurred under slightly different circumstances.[REMOVE]Fotnote: Petroleum Safety Authority Norway, Gransking av hendelse med personskade på Ekofisk 2/4-X 13.1.2006, Investigation report, 13 January 2006.
Five serious nonconformities from the regulations were identified in its investigation report, including a lack of leadership on the platform. ConocoPhillips was also found to fall short on preparations for maintenance, expertise in using the lifting equipment, planning, and training in applying its procedures.
The drilling supervisor had gone ashore and not been replaced. A coordination meeting had also been cancelled, so that many people on the platform lacked an overview of what was happening.Other comments included a cramped worksite, where equipment in the way had not been removed. Expertise in assembling and using the temporary lifting equipment was also inadequate. Clearance had not been given for the actual lifting operation. A safe job analysis (SJA) form should have been completed in advance. Nor was the area cordoned off during the lift.
The PSA was satisfied with the response to the accident. The control room was notified immediately, the nurse arrived quickly with a stretcher team, and the injured mechanic was swiftly put on a helicopter and flown to hospital.[REMOVE]Fotnote: Petroleum Safety Authority Norway, Gransking av hendelse med personskade på Ekofisk 2/4-X 13.1.2006, Investigation report, 13 January 2006.Ekofisk Growth start-up with 2/4 MPlatform removal on Edda in 2006