Prediction of Dispersion Viscosity of Oil/Water Mixture Flow in Horizontal Pipes

Abstract

SPE Members Abstract A pipe viscometer facility was constructed to investigate the flow of oil-water dispersions in horizontal pipes. Pressure drop, liquid mass flow rate, mixture temperature, Pressure drop, liquid mass flow rate, mixture temperature, input water fraction, and mixing intensity data were obtained for 490 oil-water tests. Mixture velocities ranged from 2.5 to 15.5 ft/sec, while input water fractions ranged from 0.0 to 0.35. Mixture temperatures ranged from 60 degrees F to 90 degrees F. A refined oil with a viscosity of 85 cp at 80 degrees F was used. Data analysis showed that when the phase inversion point was reached, mixture viscosities were considerably higher than the viscosities for single-phase oil. Also, the frictional pressure gradients were found to be strongly dependent on whether oil or water was the continuous phase of the dispersions. phase of the dispersions. A model was developed for the prediction of the oil-water mixture frictional pressure gradient in horizontal pipes. The model assumes homogeneous flow and a power-law rheological behavior for the dispersion. The application of the model to the design of a non-Newtonian pipeline system is also presented. Introduction Of all the multiphase flow phenomena encountered in pipeline operations, one of the most common but least pipeline operations, one of the most common but least understood phenomena is the flow behavior of two immiscible liquids, particularly oil and water. The accurate prediction of apparent viscosity of an oil-water mixture is needed because this value is very crucial in evaluating the frictional pressure drop for pipeline design purposes. The increased difficulty is because oil-water purposes. The increased difficulty is because oil-water mixtures exhibit non-Newtonian rheological behavior. Thus, their apparent viscosities cannot simply be calculated using standard weighted mixing rules. The most widely recognized rheological model, which can approximately describe the flow behavior of an oil-water mixture system, is called the "power-law "model. The "power-law" stress-strain relationship can be expressed as: (1) If n' is equal to unity, the equation will describe the Newtonian behavior, and K' will be equal to the constant viscosity,. For a typical oil-water system, n' will usually be less than unity, and Eq. (1) will describe pseudoplastic behavior (shear thinning). It is also possible for an oil-water system to have n' greater than unity, resulting in dilatant behavior (shear thickening). This paper investigates the behavior of hydrodynamically stable dispersions of an oil-water system flowing in a horizontal pipe. The study involves gathering experimental pipe flow data of dispersions at different water fractions. The behavior of the apparent mixture viscosity as a function of flow rate, temperature, water fraction, and droplet size of the dispersed phase is studied, and the relative importance of various parameters that affect the dispersion inversion point is determined. A model is proposed for the design of a non-Newtonion pipeline system. This model is based upon the two major pipeline system. This model is based upon the two major assumptions that the flow pattern is homogeneous, and the rheological behavior obeys the "power-law" model. The appropriate scale-up procedure is also suggested for a proper extrapolation of non-Newtonian experimental data proper extrapolation of non-Newtonian experimental data acquired in small-diameter pipes to full-scale pipeline conditions. PREVIOUS STUDIES PREVIOUS STUDIES Most oil-water flow studies have been devoted to development of methods for pipeline transportation of heavy crude oils. The introduction of water into a heavy-oil pipeline usually results in one of the following configurations;a mixture of oil droplets finely dispersed in water,a stratified oil-water system, P. 427

Pressure drop in three‐phase oil–water–gas horizontal co‐current flow: experimental data and development of prediction models

“…In fact, there was a marked difference between the profiles found from rheological analysis and for flowing pipe systems. [8,27,28] Arirachakaran [29] suggested a correlation between oil viscosity µ o and transition point f oi but in this work the relation was sometimes shown to fail. [19] Pan et al .…”

Experimental investigation of oil–water two-phase flow in horizontal pipes: Pressure losses, liquid holdup and flow patterns

“…They found that the holdup was altered from the input volume fraction at a minimum flow rate and increased slip ratio. This trend, according to Charles et al (1961) and Martinez et al (1988), was due to the liquid that was in contact with the pipe. It was likely to accumulate in the tubes at a slower velocity.…”

“…Soleimani et al (2000) found that the holdup was influenced by the input volume fraction at the minimum flow rate as well as the increase in slip ratio. This trend, according to Charles et al (1961) and Martinez et al (1988), was due to the contact between the liquid and the pipe, and the liquid was likely to be accumulating in the pipe at a slower velocity. When oil and water travelled concurrently in a pipe, oil was found to travel faster than water causing a slippage between the phases.…”

Application of a radial basis function neural network to estimate pressure gradient in water–oil pipelines

“…The input parameters used in this work are oil slip velocity, water slip velocity, pipe diameter, pipe roughness and oil viscosity which are collected over 994 data point from experimental works of Trallero [20], Yipping et al [57], Nadler et al [58], Martinez et al [59], Angeli et al [6], Elseth [1], Lovick and Angeli [34], Chakrabarti [4], Rodriguez [3], Al-Wahaibi [60], Liu et al [61] and Al-Yaari et al [62] .…”