Publisher Summary The aim of dip measurements, or dipmeter logs is to determine the angle to the horizontal and the azimuth referenced to magnetic north and geographical north of the dip of the planes cut by the well. The tool consists of at least three electrodes mounted on pads in a plane perpendicular to the axis of the tool and situated at angles of 120° (3-pad tool) or 90° (4-pad tool) to each other. Schlumberger has put into use a new method of dip computation based on the mathematical recognition of patterns. Hence the program is called “Pattern Recognition” (P.R.). Its commercial name is GEODIP. The results of computer processing of data recorded in a well are presented in various forms, mainly using a line printer or a plotter. Dip measurements are fundamentally used to define regional or structural dips, but also to detect structural dip anomalies associated with structural deformation such as faults, folding, etc.