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Gulf of Mexico Region

Losses of Well Control - 2001

March 1, 2001 - Forest Oil Corporation

Remarks: On March 1, 2001, during an attempt to weld the casing head of a slip-on wellhead, gas flow was noticed coming from the +10 valve. Later, unsuccessful attempts were made to stop flow, which was then coming from the drive pipe/surface casing annular region. The gas flow eventually ignited and caused extensive damage to the platform. The well bridged-over and kill operations were completed. There were no injuries. For more information see Outer Continental Shelf (OCS) Report MMS 2001-084.

April 2, 2001 - Newfield Exploration Company

Remarks: After opening the SCSSV and recording zero pressure, the crew attempted to pump 2 barrels of seawater into the perforations through the gravel pack assembly. The tubing pressure increased to 3500 psi with no leak-off. It was assumed that the perforations were either blocked by a sand bridge or by a mechanical failure of the gravel pack assembly. The crew bled the tubing pressure to zero with no indication of build-up on the tubing. The flapper type SCSSV was opened, but the crew was unable to lock it open due to clearance problems between the wellhead and support beams in the well bay. To secure the well, the crew installed a back-pressure valve in the tubing, removed the tree, installed a BOP stack, and then replaced the back-pressure valve with a two-way check valve to facilitate testing the BOP. After the BOP was tested, the crew removed the two-way check valve. Shortly after removal of the two-way check valve, the crew noticed gas bubbles in the tubing. A landing joint assembly was run into the hole, and seawater pumping operations were initiated. The tubing pressure increased to 1100 psi after pumping 1 barrel of seawater. The crew bled the pressure to zero, but the SCSSV was in the closed position with 1100 psi on the bottom side. The driller began pulling on the tubing and working the pipe up and down. Eventually the tubing parted, and 500 feet of tubing and the master bushing from the rotary table were blown from the hole into the derrick. The crew evacuated the rig floor, and activated the BOP from a remote location. The well was shut-in by closing the blind rams. The crew commenced well control operations.

April 4, 2001 - Matrix Oil & Gas, Inc.

Remarks: A jack-up boat with a coil tubing unit was rigged up on the well. The coil tubing crew was preparing to run a mill on a downhole mud motor in the well. The subsurface safety valve was leaking when the reel crew attempted to bleed off pressure to test the valve. Thinking that the valve had trash in it, the crew pumped 5 barrels of water downhole to clean the valve. The supervisor instructed the crew to cycle the valve three times and close it. At this time the valve appeared to hold. When the bottomhole assembly (BHA) was lowered into the well, the BHA tagged the closed surface safety valve, which was closed by mistake. When the surface safety valve was opened, the BHA was blown out of the lubricator and into the water. It was later determined that the surface safety valve was cycled three times and then closed instead of the subsurface safety valve. This led the supervisor to believe that the subsurface safety valve was holding. After the incident, the operators discovered that the needle valve on the subsurface safety valve was closed. The control line had pressure on it, so this caused the downhole valve to be blocked open.

Remarks: Preliminary reports indicate that the well initially flowed through the diverter, but the flow ceased. A water boil developed 20 feet from the platform with a mud plume and a small sheen. The incident is under investigation by MMS.

May 24, 2001 -- BHP Petroleum (Americas) Inc.

Remarks:  The crew had run in the hole with a tool string to begin logging when a leak developed in a connection between the wireline pump-in sub and a 2-inch molded “Y”. The leak could not be isolated from the wellbore without shutting in the gate valve on the tree. All non-essential personnel were evacuated from the Jack-up boat and the platform, and the electrical wireline was retrieved. After the tools were above the SCSSV, the pressure was bled to 0 psi into the production system. When the BOP’s and the pump-in sub were dismantled, the crew found that a seal was cut out.

July 6, 2001 – Tri-Union Development Corporation

Remarks:  Preliminary reports indicate that the operator was in the hole with a work string and overshot washing over the gravel pack assembly, when they took a kick. They tried to bullhead into the hole. The shear pin on the mud pump PSV sheared and the well began flowing through the PSV. The platform was evacuated. A crew reboarded the platform later and closed the TIW valve and secured the well. This incident is under investigation by MMS.

July 13, 2001 – William G. Helis Company

Remarks:  Preliminary reports indicate that while the crew was making a connection, the well began to flow through the drill pipe. They stabbed the TIW valve, and closed the annular preventer and pipe rams. The well continued to flow through the drill pipe, and began to flow through the casing valve on the casing head below the BOP. The rig was evacuated with one person missing. The well was blowing dry gas from the drill pipe and water, sand, and gas from the wellhead assembly. On July 17, 2001 they began drilling a relief well from the Marine 304 rig. On July 25, 2001 the well was still blowing dry gas through the drill pipe and gas and water from the wellhead. This incident is under investigation by MMS.

Remarks: After the well was perforated, it was surged-in while pulling out of the hole. The well began flowing while the crew was picking up screens to run in the hole. The screens were across the BOP’s at the time and had to be dropped into the well. The BOP’s were closed, shutting-in the well. The crew then killed the well by circulating mud with

Remarks: Preliminary reports indicate that the drill string penetrated a salt body, which caused a kick. During kill operations a sudden discharge of drilling fluid occurred, resulting in synthetic fluid being discharged into the water. MMS is investigating the incident.

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Last Updated: 06/24/08, 03:07 PM