Self-consistent log interpretation method

摘要

Responses of subsurface formations adjacent a well borehole are obtained from a number of types of well logs. The well logs typically include a resistivity log, a gamma ray log, a density log, a neutron log and an induction or electromagnetic wave log. Parameters of interest are determined in evaluating whether the subsurface formations are of interest for petroleum contents by a non-linear programming technique based on the log responses obtained. The parameters of interest are maintained self-consistent, i.e. their contribution to log measurements is based on the same value for the parameter in its effect on each log in which they produce a response.