Protective device for RF applicator in in-situ oil shale retorting
 In the in-situ retorting of oil shale using radio frequency electrical energy, an applicator is inserted into a borehole and energized at a radio frequency. A protective device protects the applicator from expansion of the oil shale formation. The protective device includes an end plate attached to the applicator and a plurality of elements surrounds the applicator and is in contact with the end plate so as to prevent the oil shale formation from contacting the applicator. 
Texaco Inc.
E
E21B
inventional
Kerry D. Herbert A. Richard H.
Savage Rundell Vinton