Simultaneous gamma ray measurement of formation bulk density and casing thickness
 A method for simultaneously measuring the formation bulk density and the thickness of casing in a cased well borehole is disclosed. Low energy gamma rays are emitted into the casing and formation in a cased borehole. Two longitudinally spaced detectors detect gamma rays scattered back into the borehole by the casing and surrounding earth materials. The count rate signals from the two detectors are appropriately combined according to predetermined relationships to produce the formation bulk density and the casing thickness, which are recorded as a function of borehole depth. 
Halliburton Company
G E
G01V E21B
inventional inventional
Harry D. Kenneth J. Dan M.
Smith, Jr. Smith Arnold