If XRF analysis is conducted on a pilot and horizontal well pair, the location of the horizontal well in a vertical stratigraphic sense can be mapped once the well is completed or as data are obtained. There are specific chemical markers which can be traced from the vertical pilot into the build section and into the horizontal which allow contacts to be mapped with respect to the well trajectory as outline in Figure A. This can be useful in predicting how a well will hydraulically fracture and produce. This same technique can be conducted in real time as drill cuttings come out of the well and survey data are collected to help with geo-steering the well.
Figure A. Cross Section of Well Trajectory and Stratigraphic Units in a Duvernay Well.