PAC Losses of Well Control, 2004

Investigation:	Completed	Activity:	Exploration
Lease:	G10744	Event(s):	Explosion / Loss of Well Control / Pollution (5.4 bbl condensate and oil)
Area:	Eugene Island	Operation:	Drilling
Block:	277	Cause:	Equipment Failure / Human Error
Rig/Platform:	Platform A / Ensco 60	Water Depth:	23 feet

Remarks: In February 2004, the jack-up rig ENSCO 60 was engaged in drilling operations for EPL on Eugene Island Block 277 Well A-3 BP (the “Well” or “A-3 BP”). The Rig was in place next to the EI-277 “A” Platform. Drilling operations were being conducted with the rig cantilevered over the Platform and the Well was being drilled using an available slot on the Platform.

On 9 February 2004, the well had reached a target depth for the setting of the intermediate string, and logs had been run. Approximately 11,285 feet of 9-5/8 inch casing was run and cemented.

While waiting on cement, pressure built up on the 9-5/8 inch by 13-3/8 inch intermediate by surface casing annulus (the Annulus), reaching 1,225 psi on the driller’s gauges. The pressure then began to decline, reaching a gauge reading of 0 psi on both of the driller’s gauges after a period of hours. With the driller’s gauges reading 0 psi, 3,000 psi pressure was observed on a secondary gauge monitoring the same annulus pressure. Shortly thereafter, an explosion occurred, followed by a rising cloud of gas, water, oil, sand, and debris, which enveloped the rig floor over the top of the wind walls. The rig was evacuated and flow eventually ceased. Operations then commenced to secure the well. During and after the event, a sheen was observed trailing from the platform with pollution estimated to be 5.4 barrels (bbl) condensate and oil. See OCS MMS 2005-007.

Investigation:	Completed	Activity:	Development/Production
Lease:	G02853	Event(s):	Loss of Well Control
Area:	East Cameron	Operation:	Workover
Block:	23	Cause:	Equipment Failure / Human Error
Rig/Platform:	Platform Well No. CA-1	Water Depth:	30 feet

Remarks: During January 2004, contract technicians arrived on the platform to assess the wellhead equipment, repair the actuator, and replace a wing valve. On February 15, 2004, a lift boat arrived on location to begin well work. Coiled tubing equipment, operated by contractor personnel, was rigged-up and run in hole. Nitrogen was injected down the tubing to wash and clean out the sand to the target depth of 10, 391 feet. As the intended target depth was neared, the well started to flow. Wellhead pressure rapidly rose to 2,300 psi after the choke manifold was closed. At approximately 0200 hours on the morning of February 17 nitrogen was observed leaking from around the wellhead, below the BOP stack. The rig crew started pumping seawater as the kill fluid, and non-essential personnel were evacuated by 1100 hours. Well Control experts arrived by 1430 hours, and the wellhead pressure was reduced to 0 psi by the next day. There were no injuries and no pollution associated with this LWC. The injection fitting port on the wellhead that is used to inject a plastic energizer for the wellhead seal assembly failed. The failed port, together with a missing wellhead seal assembly, allowed for the LWC. See OCS MMS 2005-075.

Investigation:	Completed	Activity:	Development/Production
Lease:	G19822	Event(s):	Loss of Well Control / Spill (2.5 bbls condensate-completion fluid emulsion)
Area:	Ship Shoal	Operation:	Completion
Block:	358	Cause:	Equipment Failure
Rig/Platform:	/A	Water Depth:	419 ft.

Remarks: After perforating the well, the circulation valve above the packer which is used to circulate out the annulus, failed in the open position. The well came in and gas, sand, and condensate flowed into the well from the open perforations. This valve failure and a large sand influx prevented the unseating of the packer. The gas acted as a carrier and sanded up the wellbore which stopped the normal circulation pathway. The condensate had a chemical reaction with Zinc Bromide completion fluids that were already in the wellbore and created an emulsion. This emulsion flowed onto the shale shakers and essentially plugged the shakers. At this point the emulsion flowed over the shale shakers into the shunt line then into the water.

Investigation:	Completed	Activity:	Exploration
Lease:	G18278	Event(s):	Loss of Well Control / Pollution (11 bbl crude oil)
Area:	MC	Operation:	Drilling
Block:	722	Cause:	Human error
Rig/Platform:	Noble Max Smith	Water Depth:	3855 ft.

Remarks: While drilling on Tuesday, October 19, 2004, at approximately 0530 hours, the BOP system was activated when a kick was detected. Circulation was started to get the well back under control. Slow pump rates were used to prevent exceeding the Formation Integrity Test.

On Thursday, October 21, 2004, the well was considered stabilized and the Hydrill was opened at approximately 1500 hours while circulating. A gas bubble entered the riser and at approximately 2150 hours it was necessary to put the well on the diverter. This resulted in the discharge of approximately 160 barrels (bbls) of drilling fluid into offshore waters. Of the 160 bbls discharged, it is estimated that approximately 11 bbls was entrained crude oil.