We learn from the past in order to prevent the bad incidents to be happened. This time we would like to discuss about Sedco 135F – IXTOC I Blowout and Oil Spill. The Sedco 135F was perforating and drilling the IXTOC I well in 1979 for PEMEX, which is a petroleum company in Mexico owned by the state at the time when the well underwent an eruption. Through a drilling, the well had been dug up to 3.6 km with the 9-5/8″ casing set at 3.6 km. It has been vindicated by various studies that there was a failure in mud circulation (essentially mud is a massive and heavy weighted drilling fluid which is utilized as a lubricant for the drill bit, helps in cleaning the drilled rock from hole and present a column of hydrostatic pressure as a prevention from influxes), hence a consensus was reached that it is the best to pull the drill string & plug the well. The absence of mud column’s hydrostatic pressure triggered an unconstrained and liberal circulation of oil & gas to the surface, and this was what happened when the crew was working with drillstring’s lower part. The BOP was shut on the pipe however it was unable to chop the chunky drill collars, permitting oil and gas to come up to the surface where it burned and inflamed the Sedco 135F. The rig broke down and drowned on top of the wellhead space on the seabed, cluttering the seabed with debris like the rig’s derrick & 3000m of pipe.
Sedco 135F – IXTOC I Blowout