The biggest gas well blowout in Indonesia happened in 1978 when the CII-2 well in the Arun field was being drilled. This blowout is also the biggest in Southeast Asia ever.
About The Super Giant Arun Gas Field
The Arun field is a supergiant gas field. It had 16 trillion cubic feet of original gas in place and was discovered in 1971 by Mobil Oil in Aceh, Sumatra.
The Arun gas reservoir had abnormally high temperatures and pressure of 178 degrees C and 7100 PSIG respectively. The reservoir is made up of carbonate rock located at 10,000 feet in depth.
Due to its high pressure, porosity, permeability, and reservoir thickness of about 500 feet, the Arun gas wells were extremely productive. Each well could produce more than 100 MMSCF of gas per day.
The highly productive Arun field produced over 3000 MMSCF of gas per day for more than 10 years. The produced natural gas was fed into the Arun LNG plant to recover the condensate and liquefy the gas.
The field is estimated to have produced over 14 trillion cubic feet of natural gas and 840 million barrels of condensate.
As a retrograde gas reservoir with no water drive, Mobil Oil took extreme care to manage the reservoir to achieve the highest gas recovery possible. Steps, such as gas reinjection, were taken to manage the reservoir pressure. As the reservoir and wellhead pressures eventually declined, gas compressors were used to boost gas production.
The now-depleted Arun reservoir is a great candidate for storing captured CO2 as it has no water influx and is at low pressure.
The Arun LNG Plant
The Arun LNG plant was built to monetize the huge amount of the discovered gas. It is the first LNG plant built in Indonesia and Southeast Asia.
Initially, the Arun LNG plant consisted of three LNG trains that started to operate in August 1978, September 1978, and February 1979 respectively.
Two trains were later added to the plant in October 1983 and January 1984 respectively.
All five trains produced a total of 55,000 M3 per day of LNG and 115,000 barrels per day of condensate.
The LNG plant eventually had six trains. The sixth train was completed in November 1984.
Up till 1999, Indonesia produced one-third of the LNG in the world.
A major problem in processing Arun gas is that the gas has a large percentage of mercury reacts with aluminium in the cryogenic system to form an amalgam.
After 36 years in operation, the Arun LNG plant was finally shut down in 2014.
The Gas Well Blowout
The massive blowout in the Arun field happened in 1978 when the CII-2 well in the Arun field was being drilled.
The blowout killing efforts were led by Red Adair. Initially, the well control team attempted to kill the well from the top. However, it failed.
Finally, the blowout was killed by drilling a directional well and then pumping a huge amount of acid followed by heavy mud into the bottom of the CII-2 well.
The blowout was so huge and due to the extremely high reservoir pressure, more than fifty high-pressure and high-volume pumps, and one hundred pump operators and engineers were brought in from several countries to kill it.
The photo above, courtesy of Pete Hackney, showed another Arun well, CIII-8, that blew out two years later in 1980. You can see the rig drilling a directional well that would intersect the blowing-out well to kill it.