CPC G01V 5/06 (2013.01) [E21B 49/00 (2013.01)] | 10 Claims |
1. A fast forward method for gamma-ray logging of highly-deviated and horizontal wells, comprising the following steps:
step S1: based on an effective detection space of a gamma detector, in the effective detection space, obtaining a one-dimensional equivalent longitudinal contribution coefficient (varying with a distance between a formation and the center of the detector) of a gamma-ray flux received by the gamma detector under the condition of a straight well;
step S2: converting an integral of a gamma-ray flux received by the detector under the condition of a deviated well into an equivalent integral of the gamma-ray flux of a same space under the condition of the straight well; and
step S3: performing fast forward for gamma-ray logging of highly-deviated and horizontal wells under the condition of parallel sedimentary formations by using the obtained equivalent integral under the condition of the straight well, and then obtaining a forward value of a measurement point according to the one-dimensional equivalent longitudinal contribution coefficient, where the deviated well refers to a well whose wellbore is non-orthogonal to the formation, and the straight well refers to a well whose wellbore is orthogonal to the formation.
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