The study of patterns of closely spaced dip computations throughout the length of continuous dipmeter surveys is producing greatly increased geological information in Mississippi wells. Structural dip (or regional dip if no structure is present) is the basic dip shown by the dipmeter. Superimposed on the basic dip are the dips resulting from faults, unconformities, and local depositional features. These are generally greater than structural dips and in random directions.

Faults are most commonly shown by the increasing dip in the drag zone as the bore-hole approaches the fault plane from the downthrown side. Complex faulting over shallow ridges or domes may be recognized by the change in dips between faulted blocks. Buried bars are detected in wells drilled on the steep slopes by the decreasing dips exhibited by the successively younger beds deposited above them. Other changes in dip indicate the location of unconformities, most of these being reasonably easy to recognize, since they appear at the same general position in the geological column. Cross-bedding shows as erratic dips within sands.

It is emphasized that detailed geological interpretations of the dipmeter survey require numerous closely spaced computations studied in relation to the well log.

End_of_Article - Last_Page 1601------------