Novel Dip Picking Approach using “Expert Dip” in HAHZ Well and Influence on Structural Modelling

Abstract

Summary In this era of automation, manual dip analysis method is evolving as more and more technology is seeping into geological interpretation. Since advent of image log in horizontal wells, low angle bed boundaries which are near-parallel to wellbore and traceable on borehole images for several tens of feet, can hardly be attributed with dips as conventional approach of mathematical sinusoid fails to well-fit bedding features resulting inaccuracy of dip interpretation. This leads to loss of information and restricted interpretation in terms of bedding dips specially in horizontal or highly deviated sections of image. Recently, a new approach has been introduced to trace such bed boundaries in horizontal wells. Quality indicators are also available to ensure proper tracing and hence more accurate dip computation. Instead of the conventional sinusoidal algorithm, this technology contours the lithological boundaries and provides true dip and azimuths of these beds at every desirable sampling interval. This case study shows applicability of the methodology and its implementation in image based high resolution structural analysis of high-angle/horizontal (HAHZ) wells. After comparison with conventional results it is evident that this new way of working with HAHZ well images has an edge over conventional dip analysis method.