PROPOSED CORRECTION AND INFLUENCE OF DRILLING-FLUIDS IN X-RAY-FLUORESCENCE LOGGING

The drilling fluid in wet boreholes is a key problem in the process of XRF logging work, limiting the accuracy, precision and limit of in si tu determination of the concentrations of elements. A combination of t he mechanics in the drill hole probe (hardware) with technical methods (software) has been adopted for overcoming the influence of drilling fluids, which makes it possible for XRF logging to operate in wet hole s for determining the concentration of lower atomic number elements. F or the hardware, a short arm with a proportional counter detector (45 cm) divided from the drill hole probe (300 cm) has been designed and c onstructed which can be pushed automatically to the hole wall in the p rocess of XRF logging work. For the software, a new technical method c an be used to correct successfully the influence of a 0-6 mm water lay er on the results of XRF logging for a set of Pb-Zn wall models. (C) 1 997 by John Wiley & Sons, Ltd.