Software for well correlation by log data support: principles, realization, examples.

The problem considered is a detailed well correlation by log data, related to oilfields with a developed borehole grid. A special software is designed, with automatic correlation procedure for log intervals of 50-100 m wide as a main part of it. In the result of the procedure each well gets a mark, alignment on which provides the maximal correlation of given log intervals in a horizontal direction. Well marks are used to compute correlation surface, while the latter is found to be very close to stratigraphical surface on the appropriate depth. A number of correlation surfaces, obtained by this way through vertical intervals in 25-50 m define a directing skeleton for log data interpolation in 3D space. Research of interpolated data by tools of 3D visualization allows the geologist to reveal all essential features of the ancient sedimentation environment. In the process correlation surfaces are used to present interpolated data in a paleoreconstructed view. After the research manual well correlation turns to simple fixing of notion obtained.