USING A 3RD PHOTON ENERGY FOR GAMMA-RAY AND OR X-RAY COMPOSITION MEASUREMENTS IN OIL-WATER-GAS MIXTURES/

Dual energy gamma- and/or x-ray densitometry offers a powerful techniq ue for the non-intrusive monitoring of the composition of oil-water-ga s mixtures. In this paper it is shown that a third photon energy can b e used to greatly reduce the systematic errors in the watercut resulti ng from spatial and temporal variations in the mixture composition. In bubble flow, absolute systematic errors in the watercut lower than 0. 01 are attainable. The statistical uncertainty in the composition is a cceptable for practical measuring times, provided the three photon ene rgies are chosen carefully.