Response of dual laterolog and fast correction for layer thickness and shoulder bed in horizontal wells

Abstract

On the basis of horizontal well modeling with three layers, the 3D finite element method is used to simulate the response of dual laterolog in horizontal wells. The modeling results show that the response of the dual laterolog is obviously influenced by the borehole position in the target formation. When the borehole position varies, the dual laterolog response of nonthick formation changes. Under conditions of different layer thicknesses and/or different borehole positions, the responses of dual laterolog in horizontal wells are different from that in vertical wells. The deep and shallow resistivity of the dual laterolog exhibits an apparent amplitude difference for the noninvaded zone in horizontal wells. On the basis of the 3D numerical simulation results, the correction charts of dual laterolog responses for layer thickness and shoulder bed are generated, and a fast calculation method for resistivity correction in horizontal wells is proposed. The correction results from proposed method agree well with those from 3D numerical computation. The fast correction method is rapid and effective in layer thickness and shoulder bed correction. Key words: horizontal well, dual laterolog, log response, layer thickness/shoulder bed, correction method