July 03, 2022

In the fall of 1966, USSR used nuclear explosive for the first time to control a well that had been burning for three years in Uzbekistan.
In December 1963, while drilling gas Well No. 11 in the Urta-Bulak gas field in Southern Uzbekistan about 80 km southeast of Bukhara, control of the well was lost at a depth of 2450 m. This resulted in the loss of more than 12 million m3 of gas per day through an 8-inch casing, enough gas to supply the needs of a large city. Formation pressures were about 270-300 atmospheres.
Over the next three years, many attempts were made using a variety of techniques to cap the well at the surface or to reduce the flow and extinguish the flames.
Finally, in the fall of 1966, a decision was made to attempt closing the well with the use of a nuclear explosive. It was believed that a nuclear explosion would squeeze close any hole located within 25-50 m of the explosion, depending on the yield. Two 13 1/2 inches deviated wells were drilled simultaneously.
They were aimed to come as close as possible to Hole No. 11 at a depth of about 1,500 m in a 200 meter-thick clay zone. This depth was considered sufficient to contain the 300-atmosphere pressure in the gas formation below. The location for the explosive in the selected relief well was cooled to bring it down to a temperature the explosive could withstand. A special 30-kt nuclear explosive developed by the Arzamas nuclear weapons laboratory for this event was ran in hole and stemmed. It was detonated on September 30, 1966.
Twenty-three seconds later the flame went out, and the well was sealed.
A few months after the closure of the Urtabulak No. 11 hole, control was lost on another high-pressure well in a similar nearby field, the Pamuk gas field.
This time, a special explosive developed by the Chelyabinsk nuclear weapons laboratory was used. It had been designed and tested to withstand the high pressures and temperatures in excess of 100°C expected in the emplacement hole. It also was designed to be only 24 cm in diameter and about 3 m long to facilitate its use in conventional gas and oil field holes.
The second success gave Soviet scientists great confidence in the use of this new technique for rapidly and effectively controlling gas and oil wells.
In April 1972 a 14-kt nuclear bomb was detonated to seal a gas well in the Mayskii gas field about 30 km southeast of the city of Mary in Turkmenistan.
In July 1972, another runaway gas well in eastern Ukraine, 65 km southwest of Kharkiv, was sealed with a nuclear explosion.
The last attempt to use this application occurred in 1981 on a well in the Kumzhinskiy gas deposit in the northern coast of Western Siberia near the mouth of the Pechora River, 50 km north of the city of Nar’yan Mar. Reports indicated that due to the wrong position of the relief well, the explosion failed to seal the blowout.
Of the Soviet attempts to extinguish runaway gas wells, the Ministry for Atomic Energy of Russia reports that all the explosions were completely contained, and no radioactivity above background levels was detected at the surface of the ground during post-shot surveys.
(Sources: Pravda, Wikipedia, Milo B. Nordyke/Princeton University – Image: Atomic bomb lowered in a relief well in the USSR)