METHOD AND APPARATUS FOR POSITIONING DOWNHOLE TOOL IN A CASED BOREHOLE

摘要

An apparatus and method to locate a collar of a downhole casing are described. The apparatus includes a housing (203). The apparatus also includes a first type of sensor (205) disposed in the housing, the first type of sensor operating in the frequency domain, and a second type of sensor (207) disposed in the housing, the second type of sensor operating in the time domain. The apparatus further includes a gamma ray detector (230) disposed in the housing.