Increasing Value Through Reducing Differences Between LWD and Wireline Depths

Bolt, Harald (Depth Solutions Ltd.)



Along-hole depth is the most fundamental subsurface measurement made in our business. Driller's depth, the basis of logging while drilling (LWD) data registration, and wireline logged depth are the primary sources of along-hole depth data. These are rarely congruent. This paper sets out a methodology that can be applied to both wireline and drill pipe along-hole depth measurement (Driller's Way-point Depth, DwpD) and provides an uncertainty calculation that results in True Along-hole (TAH) depth. The result is a reduction in differences between drill pipe and wireline depth measurements, increasing confidence in along-hole depth measurements and increasing well data value. A field data set is reviewed that showed up the similarities and the differences between DwpD and the wireline corrections.