Robert S. Burton, Grand Junction;
Sten I. Rundberg, Debeque; James V.
Vaughn, Debeque; Thomas P.
Williams, Debeque; Gregory C.
Benson, Grand Junction, all of Colo.
Occidental Oil Shale, Inc., Grand
 Appl. No.: 119,857
 Filed: Feb. 8, 1980
 Int. C1.3 E21B 43/243; E21B 36/02
 U.S. CI 166/260
 Field of Search 166/57, 59, 260, 302
 References Cited
U.S. PATENT DOCUMENTS
2,188,737 1/1940 Hixon 166/59
2,668,592 2/1954 Piros et a! 166/272
2,853,136 9/1958 Moore et al 166/266
2,902,270 9/1959 Salomonsson et al 166/59 X
3,204,696 9/1965 De Priester et al 166/59
3,254,721 6/1966 Smith 166/59
3,315,745 4/1967 Rees, Jr 166/59
3,680,636 8/1972 Berry et al 166/302
3,990,835 11/1976 Burton 431/353
4,136,737 1/1979 Howard et al 166/251
4,137,968 2/1979 Howard et a! 166/53
Primary Examiner—Stephen J. Novosad
Attorney, Agent, or Firm—Christie, Parker & Hale
A technique is provided for igniting an in situ oil shale retort having an open void space over the top of a fragmented mass of particles in the retort. A conduit is extended into the void space through a hole in overlying unfragmented formation and has an open end above the top surface of the fragmented mass. A primary air pipe having an open end above the open end of the conduit and a liquid atomizing fuel nozzle in the primary air pipe above the open end of the primary air pipe are centered in the conduit. Fuel is introduced through the nozzle, primary air through the pipe, and secondary air is introduced through the conduit for vortical flow past the open end of the primary air pipe. The resultant fuel and air mixture is ignited for combustion within the conduit and the resultant heated ignition gas impinges on the fragmented mass for heating oil shale to an ignition temperature.
14 Claims, 5 Drawing Figures