PHOTON ENERGY SELECTION FOR DUAL-ENERGY GAMMA-RAY-ABSORPTION AND OR X-RAY-ABSORPTION COMPOSITION MEASUREMENTS IN OIL-WATER-GAS MIXTURES/

Dual energy gamma- and/or X-ray absorption techniques can be used to m onitor the composition of oil-water-gas mixtures in pipes. Criteria fo r the selection of the two photon energies and their relative intensit ies are developed, that maximise the precision of the mixture composit ion determination. A correction for the effects of pressure and temper ature changes is presented. Changes of the salinity of the water and v ariations of the mixture composition in time and in space, even in the case of bubble Bow, are shown to deteriorate the results.