Abstract: Ammonium nitrate shale oil explosives are provided which are effective, powerful, inexpensive, and safe. The explosives contain about 2% to 10% by weight shale oil and about 90% to 98% by weight ammonium nitrate. The shale oil can be whole shale oil or heavy shale oil containing from 0.1% to 65% by weight oil shale dust. The ammonium nitrate is preferably in the form of explosive grade ammonium nitrate prills.

Abstract: Raw oil shale is retorted to liberate an effluent product stream. Ammonia is withdrawn from the product stream and reacted to produce ammonium nitrate. Shale oil is separated from the product stream and mixed with 90% to 98% by weight ammonium nitrate to produce explosives. The shale oil can be whole shale oil or heavy shale oil containing from 0.1% to 65% by weight oil shale dust. The ammonium nitrate is preferably in the form of explosive grade ammonium nitrate prills. The shale oil is preferably heated before being mixed with the ammonium nitrate to make the shale oil more blendable.

Abstract: An improved process is provided for blasting in situ oil shale retorts, and oil and gas wells. In the process, a specially formed concrete plug is installed at a desired depth in a bottomless blast hole and an explosive charge is placed upon the plug and detonated to blast the underground formation. The plug is accurately and reliably set by lowering a canister, which releasably houses a bag support assembly supporting a bag of concrete slurry, to a desired depth into the blast hole. The bag support assembly and bag of wet concrete are subsequently dropped a fixed distance below the canister. The bag of concrete expands, dries, and hardens against the walls of the blast hole to form a permanent stationary plug across the blast hole. In the preferred process, the bag support assembly is formed by casting a concrete disc around a drainpipe, and the bag support assembly is lowered and released from the canister with the aid of an electrically powered sequencer.

Abstract: A plugging apparatus is provided to reliably plug a bottomless blast hole in underground oil shale retorts and oil and gas wells. The plugging apparatus has a special electrically powered sequencer which automatically lowers and releases a bag of cementatious slurry, supported by a drainpipe-reinforced concrete disc, from a canister to form a composite blasting plug in the blast hole.

Abstract: An in situ retort and process are provided for underground retorting of oil shale. The in situ retort is formed with at least one flame front-stabilizing layer of minute lean oil shale particles which serves as a redistribution region or grid. When the flame front is ignited and passed through the retort with a feed gas, the flame front-stabilizing layer will stabilize and enhance horizontal uniformity of the flame front to substantially minimize burning of the product shale oil.