This paper describes the development and application of a dual optical probe for local volume fraction, drop velocity and drop size measurements in a kerosene-water liquid-liquid two-phase flow. A sampling tube procedure and interface tests were used to calibrate the leading optical sensor and both optical sensors for measurements of the local volume fraction and drop velocity as described in this paper. Measurements were carried out in a large-scale vertical two-phase facility mainly at the pipe centre-line to demonstrate the advantages of using optical fibres with normal cut ends in a kerosene-water two-phase flow. Finally the applicability of this probe for measurements in gas-liquid two-phase flows and gas-kerosene-water three-phase flows has also been demonstrated.

This paper describes a new optical probe system developed for measurements in liquid - liquid two-phase flows with particular reference to kerosene - water flow. The paper gives details of the optical interaction between the probe tip and the kerosene drop front and rear as well as the lay-out of the optical probe system. Static and dynamic interface tests were carried out to determine the theoretical interaction between an approaching flat interface and the probe tip. The modified probe performance in a real bubbly flow was also identified from actual kerosene drop measurements. Finally, the signal analysis procedure used is described and a comparative test of the new optical probe with X hot-wire anemometry for `bubbly' kerosene - water flow in a vertical pipe gave similar results.

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Abstract:The water-soluble polymer PAM (polyacrylamide) is used in enhanced oil recovery (EOR) operations. It is pumped into water injection wells to increase the viscosity of the injected water and in turn to direct more oil towards production wells. This EOR process is proven to be sensitive to operational well conditions such as hydrocarbon reservoir temperature, as well as the salinity of the injected water and/or formation water. These operational conditions lead to technical challenges ranging from the solubility of PAM in injection water to the behaviour of PAM inside the reservoir. To gain a clear picture of the functionality of PAM in EOR applications, this report characterizes its behaviour of in terms of degree of hydrolysis and changes in solution viscosity determined using Perkin Elmer spectrum 100 Fourier transform infrared-Attenuated total reflection (FTIR)-ATR and nuclear magnetic resonance spectroscopy ( 1 H NMR) and a Fann model 35 Couette and Cole Parmer rotational viscometer, respectively. Different shear rates were investigated to determine the effect of shear on PAM gel stability. Experiments were performed for PAM mixed with formation brine at 50, 70, and 90 • C for ageing times of up to 30 days. The results indicate that the degree of hydrolysis achieved after 30 days is much higher in saline solutions than in pure water, and that this effect is more pronounced at higher temperatures. For example, after 30 days at 50 • C, the hydrolysis level was observed to be 53%, rising to 65% at 70 • C and 75% at 90 • C in PAM mixed with brines. Similar trends were observed with viscosity, where lower viscosity was observed for samples at higher temperatures and salinities. It is thus reasonable to conclude that the degree of hydrolysis causes changes in the viscosity of the polymer gel, leading to a decline in its performance as it ages.

The objective of this work is to present a novel geometrical configuration for microbubble generators (MBGs) to improve dissolved-oxygen levels in water.Among various methodologies from the literature, Orifice and Venturi tubes have been considered as baseline cases. Experimental data from the literature are used to verify a computational fluid dynamics (CFD) case developed for a better understanding of the dynamics of MBGs. As a result, the validated CFD setup has been implemented on a modified Venturi-type generator, where air is injected coaxially with respect to the tube axis, whereas a helicoid wall at variable pitch angle is used. Results show a reduction in the mean bubble diameter distribution from the baseline Venturi tubes, particularly, at lowspeed inlet velocities. This is of interest, especially to decrease the energy requirement for most common water aeration systems.