Correlation of well sections in the Eastern Donbass using geophysical methods

Correlation was carried out to find small-amplitude fault disturbances. The regions of tectonically disturbed rocks in borehole sections were determined from the apparent resistance and the natural radioactivity which are lower than in the undisturbed case, from the maximum positive anomalies in the gamma-gamma log and cavernometry diagrams. The amplitude of the disturbances was determined from the change of size of the normal interval between two marked horizons (generally limestone) between which the disturbance appears. A reliable correlation of log diagrams is possible because of the sufficient sequential stability of the sections. Examples for disturbances with amplitudes of 5-11 m are given