Void fraction measurement by an ultrasonic transmission technique in bubbly gas-liquid two-phase flow is developed. Numerical modelling of the experiment is conducted by using an equivalent bubble method and also by Monte Carlo simulations. Comparison of experimental and numerical results shows agreement for small void fraction conditions (e g < 0.20).

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this article begins on the next page F F JCPT91-06-02 OPERATIONS Measurement of steam quality using a neutron densitometer PAK T. WAN* AECL Research Whiteshell Laboratories Pinawa, Manitoba ABSTRACT The needfor reliable and cost-effective methods to monitor steam quality at the wellhead of steam-injection projects has @ted for many years. A neutron densitometer, based on the principle of thermal neutron transmission, has been designed and calibrated to measure steam quality at the wellhead. The meter is non-intrusive, portable and safeforfield use. By combining the meter with a flow measuring device, such as a flow nozzle, the steam quality and mass flow rate at the wellhead can be determined This paper describes the principle of operation of the neutron densitometer for monitoring steam quality Because of the large m= attenuation coefficient of thermal neutrons in water, thermal neu-trons are well suited for measuring the high void fraction (or low liquidfraction) conditions that awt at the steam qualities of interest. T7ze neutron densitometer haspreviously been calibratedfor high-presmre test conditions. This paper also describes the results of re-cent low-prewure calibration tests. The range of test conditions studied were pr@res of I MPa to 6.5 MPa, flow rates of 0.25 kgls to 2.5 kgls, and steam qualities of 0. I to 0. 9 in 0. 051 m and 0. 076 m (2 in. and 3 in. nominal) schedule-80 pipes. Both horizon-tal and vertical flow configurations were tested. Introduction Steam injection is one of the most widely used enhanced recovery tec@ques available today for heavy oil. When the injected steam is condensed to water in the petroleum reservoir, the latent heat of vaporization heats the surrounding heavy oil, thereby reducing its viscosity. It is possible with reasonable temperature increases, to reduce the viscosity of some crudes to one-hundredth or one-thousandth of their former values. Once the heavy crudes are heated, they can be pumped to the surface by conventional equipment.The need for reliable and cost-effective nwffiods to monitor steam quality at the wellhead of steam-injection projects has existed for many years. Steam is produced from a steam generator typically at 0.7 to 0.8 quality. This steam is usually injected simultaneously into several wells through a distribution network. Depending on the quabv, mass flow rate, junction geometry, operating pres-sure and pipe size, the distribution of steam into different wells can be highly uneven, resulting in uneven heat input to the petroleum reservoir.Several investigations(i-3) have been conducted to study different tec@ques for measuring steam quality at the wellhead. The *Now with Nuclear Safety Department, Ontario Hydro, Toronto, Ontario Insight Tm steam-quality monitoring system, developed by AECL Research in partnership with two major oil companies, is a neu-tron densitometer that operates on the principle of thermal neu-tron transmission to measure steam quality. It has been calibrated to measure steam quality for a wide range of two-phase flow con...

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