Drift-Flux Parameters for Three-Phase Steady-State Flow in Wellbores (2004)

Drift-Flux Parameters for Three-Phase Steady-State Flow in Wellbores H. Shi; H. Shi Stanford University Search for other works by this author on: This Site Google Scholar J.A. Holmes; J.A. Holmes Schlumberger GeoQuest Search for other works by this author on: This Site Google Scholar L.R. Diaz; L.R. Diaz Stanford University Search for other works by this author on: This Site Google Scholar L.J. Durlofsky; L.J. Durlofsky ChevronTexaco ETC Search for other works by this author on: This Site Google Scholar K. Aziz K. Aziz Stanford University Search for other works by this author on: This Site Google Scholar Paper presented at the SPE Annual Technical Conference and Exhibition, Houston, Texas, September 2004. Paper Number: SPE-89836-MS https://doi.org/10.2118/89836-MS Published: September 26 2004 Cite View This Citation Add to Citation Manager Share Icon Share Twitter LinkedIn Get Permissions Search Site Citation Shi, H., Holmes, J.A., Diaz, L.R., Durlofsky, L.J., and K. Aziz. "Drift-Flux Parameters for Three-Phase Steady-State Flow in Wellbores." Paper presented at the SPE Annual Technical Conference and Exhibition, Houston, Texas, September 2004. doi: https://doi.org/10.2118/89836-MS Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex Search nav search search input Search input auto suggest search filter All ContentAll ProceedingsSociety of Petroleum Engineers (SPE)SPE Annual Technical Conference and Exhibition Search Advanced Search AbstractDrift-flux models represent multiphase flow in wellbores or pipes in terms of a number of empirically determined parameters. Because of the lack of data for two and three-phase flow in large-diameter inclined pipes, existing parameters are commonly based on small-diameter pipe experiments, which can lead to significant errors when the models are applied to wellbore flows. In this work, we use recent large-diameter experimental data for the determination of drift-flux parameters for oil-water-gas flow. The parameters are computed through application of an optimization procedure. It is shown that gas holdup in three-phase systems can be estimated using a two-phase flow model by viewing the system as an effective gas-liquid system, with oil and water comprising the 'liquid' phase. This approach is, however, generally inaccurate for the determination of oil and water holdups, in which case the effect of gas must be taken into account. Specifically, for pipe inclinations away from horizontal, even small amounts of gas can act to eliminate the slip between oil and water. As the pipe deviation approaches horizontal, however, oil-water slip persists, even in the presence of gas. We develop and apply a unified two and three-phase flow model to capture this gas effect. The new model is shown to provide much more accurate predictions for oil and water holdups in three-phase systems than were achievable with previous models.IntroductionDrift-flux modeling techniques are commonly used to represent two and three-phase flow in pipes and wellbores. These models are well-suited for use in reservoir simulators because they are relatively simple, continuous, and differentiable1,2. Drift-flux models require a number of empirical parameters. Most of the parameters used in current simulators were determined from experiments in small diameter (5 cm or less) pipes and may therefore not be appropriate for large diameter wellbores3,4.In recent work5, we described a new research program, which includes experimental and modeling components, aimed at the determination of drift-flux parameters for large-diameter deviated wells. The experimental work entailed water-gas, oil-water and oil-water-gas flows in a 15 cm diameter, 11 m long plexiglass pipe at 8 deviations ranging from vertical to 2 degrees downward. Unique steady-state holdup data were measured using several different experimental techniques6. Our previous work provided optimized drift-flux parameters for two-phase water-gas and oil-water flows. Here we extend the analysis to three-phase flows.Even though the simultaneous flow of oil, water and gas is very common in wellbores and pipelines, systems of this type are not fully understood. Most of the studies to date have focused on horizontal or near-horizontal flows7–12. Açikgöz et al.7 classified the observed 10 flow patterns in a horizontal 1.9 cm pipe into two categories: oil-based and water-based flows, depending on which phase is dominant in the liquid. No three-layer stratified flows were observed in their experiments. Following the work of Açikgöz et al., Lahey et al.8 used the same experimental facility to collect three-phase holdup data. These data were then used to determine the drift-flux parameters C0 and Vd for each of the 10 flow patterns. They found that the values of C0 and Vd could be significantly different from one flow pattern to another and, as expected, the drift velocities were quite small compared with those in vertical flows. It is, however, clear that general simulation models are still lacking for three-phase stratified flows13. The state of three-phase flow modeling is even less developed for deviated pipes and wells.Because comprehensive three-phase flow models are lacking, one treatment for three-phase flow is to combine oil and water into a single 'liquid' phase and to then model the system as a two-phase liquid-gas flow. In this treatment, the slip between oil and water is ignored and a homogeneous mixture is assumed for the liquid phase. Some studies indicate that this simple treatment can lead to significant errors in phase holdup predictions10,14, while other observations suggest that this approach is valid15,16. In this work, we will use our experimental data and model to clearly quantify the range of validity of this approach. Keywords: prediction, holdup data, artificial intelligence, gas holdup, drift-flux parameter, fraction, production monitoring, holdup, optimized parameter, upstream oil & gas Subjects: Well & Reservoir Surveillance and Monitoring, Production logging This content is only available via PDF. 2004. Society of Petroleum Engineers You can access this article if you purchase or spend a download.