Abstract: A well image logging tool assembly comprising at least one sensor unit, at least one spatial positioning device, and a cylindrical outer sheath that extends around and contains the sensor unit and the spatial positioning device. The sensor unit includes a solid cylindrical sensor body formed of a gamma ray shielding material and including at least one longitudinal sensor cavity extending through at least one of the top end and the bottom end of the sensor body. A window corresponds to each sensor cavity and extends through the sensor body from the outside surface thereof to the corresponding sensor cavity. A sensor assembly is disposed in each sensor cavity. Each sensor assembly includes a gamma ray radiation sensor and associated photomultiplier tube.

Abstract: A method of creating a well image log of a cased well is provided. A passive cased well image logging tool assembly including a logging tool body, a plurality of gamma ray radiation sensors and a spatial positioning device is moved through at least a portion of the wellbore at a logging speed of no greater than 750 feet per hour. Corrected gamma ray radiation data is vertically sampled at a vertical distance sampling rate of once every vertical distance sampling interval, wherein the vertical distance sampling interval is no greater than 1.75 inches. Based on the sampled data, a well image log is prepared. A passive cased well image logging tool assembly for use in a cased well is also provided.

Abstract: A method of creating a well image log of a cased well is provided. A passive cased well image logging tool assembly including a logging tool body, a plurality of gamma ray radiation sensor assemblies and a spatial positioning device is moved through at least a portion of the wellbore. Corrected gamma ray radiation data is vertically sampled. Based on the sampled data, a well image log is prepared. A passive cased well image logging tool assembly for use in a cased well is also provided.

Abstract: A method of creating a well image log of a cased well is provided. A passive cased well image logging tool assembly including a logging tool body, a plurality of gamma ray radiation sensors and a spatial positioning device is moved through at least a portion of the wellbore at a logging speed of no greater than 750 feet per hour. Corrected gamma ray radiation data is vertically sampled at a vertical distance sampling rate of once every vertical distance sampling interval, wherein the vertical distance sampling interval is no greater than 1.75 inches. Based on the sampled data, a well image log is prepared. A passive cased well image logging tool assembly for use in a cased well is also provided.

Abstract: A method of creating a well image log of a cased well is provided. A passive cased well image logging tool assembly including a logging tool body, a plurality of gamma ray radiation sensor assemblies and a spatial positioning device is moved through at least a portion of the wellbore. Corrected gamma ray radiation data is vertically sampled. Based on the sampled data, a well image log is prepared. A passive cased well image logging tool assembly for use in a cased well is also provided.