Gulf of Mexico Region

Loss of Well Control – 2005 (4 total)

8-March-2005 – Hunt Oil Company

Remarks:  On 3/8/05, a lock down screw on the 16" cagins head flange blew out and began flowing a 3/4" stream of mud and water.  The 9 5/8" casing had been set and cemented.  After 3 1/2 hours of waiting on cement it was noticed that the annulus wanted to flow.  They did several mud pumping jobs but well still wanted to flow.  They decided to pump cement.  They were 80% thru the job when the lockdown screw failed and well began flowing mud and water.  Flow was determined to be 100% salt water.  All 48 persons aboard rig were evacuated to nearby rig.  Well was secured on March 11, 2005.

Probable Cause:  The probable cause of the accident was equipment failure.  The lockdown dog in the wellhead flange blew off during annular squeeze. It was not certain if the lock down dog blew off or became unscrewed because of sand erosion on the flange while the annulus was flowing.

Damage:  The wellhead, choke and kill hose, manifold and valves were plugged with cured cement.  Damage was estimated at $308,500.

28-May-2005 – W & T Offshore, Inc.

Remarks:  While drilling the surface hole on well D-5 feet measured depth and true vertical depth, an unknown shallow gas formation was encountered, and the well was immediately placed on diverter. The well flowed gas, mud and sand for 1.5 hours and eventually bridged over. All non-essential personnel were evacuated to the Mariner Tide with no injuries. No pollution was observed while the well was on diverter. A total of 13 personnel remained on board the drilling rig (Pride Florida) to monitor the well.

30-November-2005 – W & T Offshore, Inc.

Remarks:  Initial report states that after setting the 13-inch casing and pumping cement, the well started to flow on the back side up the 13.375-inch surface casing through the 18-inch conductor annulus and was placed on diverter system.  The well flowed intermittently on the diverter and the rig was abandoned. Well control team of Boots & Coots was on site on December 2, 2005.  There were ongoing plans to secure well.

01-December-2005 – Chevron USA.

Remarks:  While drilling gas slowly came up the drive pipe through the drill pipe annulus. Decision was made to weight up the mud and drill head.  Well became unstable and released a pocket of gas. The well was shut in and diverted.  All non-essential personnel were evacuated from the rig.  Well under control but still burping.  Non-essential personnel were returned to rig.  On December 2, 2005, the drill pipe got stuck.  Approval was obtained to set 20 –inch conductor casing at a shallower depth than originally planned.

Last Updated: 10/19/09, 11:52 AM