ULSEL. A well log recorded with the use of a modified long normal electrode configuration mounted on a 5,000-foot bridle. The AM spacing can be made 75, 150, 600, or 1,000 feet. Differences between the measured resistivities and anticipated resistivities calculated from conventional resistivity logs indicate nearby resistivity anomalies. Used to define the distance to a salt dome flank. May have important application in locating salt overhangs or casing in nearby well bores.