fax 01-972-952-9435. AbstractThe paper illustrates the improvements in logging while drilling (LWD) images and subsequent formation evaluation by utilizing a new methodology for depth and survey measurements correction. LWD depth measurements are often considered inaccurate and therefore not as reliable for well-to-well correlations, correlations to offset data acquired with wireline measurements and formation layer thickness determinations. The reasons for these inaccuracies generally originate from the traditional practice that LWD depth is purposely made equal to the driller's depth, which is a static pipe length measurement made by tape at surface.There is almost always a difference between the actual measured depth (MD) of the LWD sensor downhole and this static pipe measurement because downhole, the drillpipe is subject to an environment that is not representative of the derrick, such as, varying drilling mechanical conditions and temperature changes. We demonstrate the applications of the method, which allows dynamic driller's depth correction for the effects of drillstring weight, downhole friction, weight on bit, thermal expansion, residual rig heave, and tide.Another significant inaccuracy source is a standard practice of calculating borehole position from stationary survey points typically taken every 90 ft using minimum curvature method. Neglecting complex borehole shape between survey stations leads to a systematic error in determining the borehole position. We consider using continuous inclination and azimuth measurements along with stationary surveys to correct these errors.We provide comparisons of LWD images before and after the depth and survey corrections to illustrate how the measurement errors affect formation dips interpreted from the images. We demonstrate how improved accuracy allows
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