An Overview of Well Logging

The French translation of the term well logging is carottage ´electrique,∗ literally “electrical coring,” a fairly exact description of this geophysical prospecting technique when it was invented in 1927 [1, 2]. A less literal translation might be “a record of characteristics of rock formations traversed by a measurement device in the well bore.” However, well logging means different things to different people. For a geologist, it is primarily a mapping technique for exploring the subsurface. For a petrophysicist, it is a means to evaluate the hydrocarbon production potential of a reservoir. For a geophysicist, it is a source of complementary data for surface seismic analysis. For a reservoir engineer, it may simply supply values for use in a simulator.