History Lesson: Sedco 135F – IXTOC I

Compiled by: Larry Walker, Jr.

So if the Gulf Oil Blowout is going to take 3 to 10 month’s to cap, then why lie? I’m tired of the lies. If it took Red Adair nearly 10 month’s to cap IXTOC I, why would Obama think his disaster could be resolved in a few weeks? The only way that’s going to happen is through the use of military ordinance to blow the well, creating an underwater seismic event. Any thing short of this is wishful thinking.

In the IXTOC I accident the U.S. had two months to prepare the coast with booms and still failed to prevent a disaster. The Obama administration has wasted a month already. The IXTOC I dumped 3.5 million barrels into the Gulf making it the worst oil disaster ever, until now. Obama could blow the well, but he won’t. Obama could do more for the Gulf States, but he won’t. All Obama knows how to do is run his mouth (with a teleprompter), tell white lies, and make us think everything is F.I.N.E. Those who fail to learn from history are destined to repeat it. Deja Vu…

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Summary

In 1979, the Sedco 135F was drilling the IXTOC I well for PEMEX, the state-owned Mexican petroleum company when the well suffered a blowout. The well had been drilled to 3657m with the 9-5/8″ casing set at 3627m. Reports then state that mud circulation was lost (mud is, in essence, a densely weighted drilling fluid used to lubricate the drill bit, clean the drilled rock from the hole and provide a column of hydrostatic pressure to prevent influxes) so the decision was made to pull the drill string and plug the well. Without the hydrostatic pressure of the mud column, oil and gas were able to flow unrestricted to the surface, which is what happened as the crew were working on the lower part of the drillstring. The BOP was closed on the pipe but could not cut the thicker drill collars, allowing oil and gas to flow to surface where it ignited and engulfed the Sedco 135F in flames. The rig collapsed and sank onto the wellhead area on the seabed, littering the seabed with large debris such as the rig’s derrick and 3000m of pipe.

The well was initially flowing at a rate of 30,000 barrels per day (1 barrel = 42 US gallons = 159 litres), which was reduced to around 10,000 bpd by attempts to plug the well. Two relief wells were drilled to relieve pressure and the well was eventually killed nine months later on 23 March 1980. Due to the massive contamination caused by the spill from the blowout (by 12 June, the oil slick measured 180km by 80km), nearly 500 aerial missions were flown, spraying dispersants over the water. Prevailing winds caused extensive damage along the US coast with the Texas coast suffering the greatest. The IXTOC I accident was the biggest single spill ever, with an estimated 3.5 million barrels of oil released.

Aftermath

In the next nine months, experts and divers including Red Adair were brought in to contain and cap the oil well.[6] Approximately an average of ten thousand to thirty thousand barrels per day were discharged into the Gulf until it was finally capped on 23 March 1980, nearly 10 months later.[7] Prevailing currents carried the oil towards the Texas coastline. The US government had two months to prepare booms to protect major inlets. Eventually, in the US, 162 miles (261 km) of beaches and 1421 birds were affected by 3,000,000 barrels (480,000 m3) of oil.[7] Pemex spent $100 million to clean up the spill and avoided paying compensation by asserting sovereign immunity.[8]

The oil slick surrounded Rancho Nuevo, in the Mexican state of Tamaulipas, which is one of the few nesting sites for Kemp’s Ridley sea turtles. Thousands of baby sea turtles were airlifted to a clean portion of the Gulf of Mexico to help save the rare species.

Sources:

http://home.versatel.nl/the_sims/rig/ixtoc1.htm

http://en.wikipedia.org/wiki/Ixtoc_I_oil_spill

Office of Response and Restoration: IXTOC I

The Royal Society of Canada: Report on Science Issues Related to Oil and Gas Activities

Photos
1. Encyclopaedia of New Zealand
2. NOAA Photo Library
3. New Hope, PA
4. ORR Incidents Gallery