a mobile automatic installation for conducting geophysical tests in wells (well logging). It consists of borehole instruments and probes, which are sensors of geophysical parameters; surface equipment, which makes possible analog or digital recording of the readings of the borehole instruments and probes; special logging cable, by means of which the borehole devices are connected to the surface equipment; and winches for hoisting and lowering operations in the borehole.
An automatic well-logging unit is usually mounted on one or two vehicles; in the latter case the surface measuring equipment is installed in the laboratory vehicle, and the winch, cable, and borehole devices are installed in a separate, self-propelled hoisting vehicle. Serial well-logging units perform all types of geophysical operations in wells up to 7, 000 m deep, recording as many as four or five different parameters in a single lowering and hoisting operation. Portable well-logging units are used for testing wells that are located in inaccessible areas.
V. M. DOBRYNIN