The density log measures the electron density of a formation. The logging device is a contact tool that emits gamma rays from a source. Emitted gamma rays collide with formation electrons and scatter. A detector, located a fixed distance from the tool source, counts the number of returning gamma rays. The number of returning gamma rays is an indicator of formation bulk density. The litho-density tool (LDT) also provides a photoelectron (P<sub>e</sub>) cross section curve, an independent indicator of lithology. | The density log measures the electron density of a formation. The logging device is a contact tool that emits gamma rays from a source. Emitted gamma rays collide with formation electrons and scatter. A detector, located a fixed distance from the tool source, counts the number of returning gamma rays. The number of returning gamma rays is an indicator of formation bulk density. The litho-density tool (LDT) also provides a photoelectron (P<sub>e</sub>) cross section curve, an independent indicator of lithology. |