Analyze rock and mud to detect the presence of oil.
Measures sonar, electrical, or radioactive characteristics of earth formations in oil- or gas-well boreholes to evaluate productivity of oil- or gas-bearing reservoirs, using sonic, electronic, or nuclear measuring instruments: Signals HOISTING ENGINEER to lower instruments into well, observing oscillograph and meters on control panel to verify operating condition of instruments. Turns dials on control panel to adjust instrument for specified recording and starts recording device when instruments reach bottom of borehole. Prints copies of recorded graphs in truck darkroom [DEVELOPER]. Interprets graphs for customer to indicate identity, porosity, oil- or gas-bearing content, and productivity of geological formations. Measures borehole diameters, direction of borehole, and inclination of geological strata, using microcalipers, directional indicators, and dipmeters. May be designated according to measuring instruments used as Acoustical Logging Engineer; Nuclear Logging Engineer.