The long term plan is to drill into the pipe somewhere below the BOP and plug it with cement.
How big? If they can't stop it? How big is the reservoir?
westexas on May 2, 2010 - 12:57pm
The Ixtoc case history is relevant (although the Ixtoc well was in shallow water). The well blew out in June, 1979, and they weren't able to kill the oil flow, via relief wells, until March, 1980:
incidentnews.gov
The estimated flow rate from June to March was 10,000 to 30,000 bpd.
On June 3, 1979, the 2 mile deep exploratory well, IXTOC I, blew out in the Bahia de Campeche, 600 miles south of Texas in the Gulf of Mexico. The IXTOC I was being drilled by the SEDCO 135, a semi-submersible platform on lease to Petroleos Mexicanos (PEMEX). A loss of drilling mud circulation caused the blowout to occur. The oil and gas blowing out of the well ignited, causing the platform to catch fire. The burning platform collapsed into the wellhead area hindering any immediate attempts to control the blowout. PEMEX hired blowout control experts and other spill control experts including Red Adair, Martech International of Houston, and the Mexican diving company, Daivaz. The Martech response included 50 personnel on site, the remotely operated vehicle TREC, and the submersible Pioneer I. The TREC attempted to find a safe approach to the Blowout Preventer (BOP). The approach was complicated by poor visibility and debris on the seafloor including derrick wreckage and 3000 meters of drilling pipe. Divers were eventually able to reach and activate the BOP, but the pressure of the oil and gas caused the valves to begin rupturing. The BOP was reopened to prevent destroying it. Two relief wells were drilled to relieve pressure from the well to allow response personnel to cap it. Norwegian experts were contracted to bring in skimming equipment and containment booms, and to begin cleanup of the spilled oil. The IXTOC I well continued to spill oil at a rate of 10,000 - 30,000 barrels per day until it was finally capped on March 23, 1980.
The Wikipedia article goes into more detail:
en.wikipedia.org
At the time of the accident Ixtoc was drilling at a depth of about 11,800 feet below the seafloor.(1) The day before Ixtoc suffered the blow out and resulting fire that caused her to sink, the drill bit hit a region of soft strata. Subsequently, the circulation of drilling mud was lost. Rather than returning to the surface, the drilling mud was escaping into fractures that had formed in the rock at the bottom of the hole. PEMEX officials decided to remove the bit, run the drill pipe back into the hole and pump materials down this open-ended drill pipe in an effort to seal off the fractures that were causing the loss of circulation.
During the removal of the pipe the drilling mud suddenly began to flow up towards the surface. Normally, this flow can be stopped by activating shear rams contained in the blowout preventer (BOP). These rams are designed to sever and seal off the the well on the ocean floor, however in this case drill collars had been brought in line with the BOP and the BOP rams were not able to sever the thick steel walls of the drill collars leading to a catastrophic blow out.
The drilling mud was followed by a large quantity of oil and gas at an increasing flow rate. The oil and gas fumes exploded on contact with the operating pump motors, starting a fire which led to the collapse of the drilling tower. The collapse caused damage to underlying well structures. The damage to the well structures led to the release of significant quantities of oil in to the ocean. |
