1.
n. [Formation Evaluation]
A particular combination of a spontaneous potential log and three electrical logs consisting of a 16-in. [40-cm] short
normal, a 64-in. [162-cm] long normal and an 18-ft, 8-in. [5.7-m]
lateral. With this combination, it is possible to correct for the effects of
invasion in many average
logging environments. This combination is sometimes called a conventional electrical log or
survey, or simply electrical log, and is also referred to as the ES.