Fremgangsmåte for tolkning av induksjonslogger i horisontale brönner

摘要

An induction logging tool is used in an inclined borehole for determining properties of subsurface formations formation away from the borehole. Measurements are made at a plurality of transmitter-receiver (T-R) distances. After correction of the data for skin effects and optionally correcting for eddy currents within the borehole, the shallow measurements (those from short T-R spacing or from high frequency data) are inverted to give a model of the near borehole (invaded zone resistivity and diameter) and the resistivity of the formation outside the invaded zone. Using this model, a prediction is made of the data measured by the mid-level and deep sensors (long T-R spacings). A discrepancy between these predicted values and the actual measurements made by the midlevel and deep sensors is indicative of additional layer boundaries in the proximity of the wellbore.