Abstract: A static mixer is provided for one or more fluids flowing in a pipe, such as oil, water and gas from an oil well. The mixer comprises an element to divide the flowing fluids into at least two streams within the pipe and to deflect two of the resulting streams so that those streams rotate in opposite senses about axes parallel to the direction of flow of the fluid, the element being shaped so as to maintain movement of the flow in a substantially smooth manner. The apparatus is provided for analyzing fluid flow in a pipe comprising at least one radiation source to direct radiation through the flow, and at least one radiation detector positioned to receive from the source of radiation which has pass through the flow. The source or sources emits radiation at least at two different energies.

Abstract: The present invention is an apparatus for analyzing fluid flow in a pipe. The apparatus includes at least one radiation source to direct radiation through the flow and at least one radiation detector positioned to receive from the source or sources radiation which has passed through the flow. The radiation is emitted at least two different energies. Each detector provides a signal to a processing means. The processing means is arranged to process the signal to provide a series of chronological values. The chronological values are grouped by magnitude. The grouped chronological values are then analyzed by the analysis means.