The measurement of component ratios in multiphase systems using γ-ray attenuation

Methods are described for determining the in situ volume fractions of materials flowing in pipelines. By using a number of discrete γ-ray energies the method can be extended in theory to cover as many different types of material as required. In practice, clearly defined γ-ray energies are required and the materials must have substantially different absorption coefficients. Results are presented for oil-air, oil-water and air-water mixes and for the oil-air-water combination. The theoretical and practical results agree well. Applications are presented for homogeneous, annular, and stratified flow patterns. It is concluded that the described method is a simple and accurate way of determining the in situ volume fractions at any given instance in multiphase pipelines. (author)