Showing papers on "Multiphase flow published in 1976"

Multidomain multiphase fluid mechanics

Abstract: A set of multiphase field equations—conservation of mass, momentum and energy-based on multiphase mechanics is developed. Multiphase mechanics applies to mixtures of phases which are separated by interfaces and are mutually exclusive. This is in contrast to the field equations of mixtures based on continuum mechanics which directly applies to molecular mixtures where the phases coexist at the same points in space. Based on the multiphase mechanics formulation, additional terms appear in the field equations when the physical size of the dispersed phase (bubble or droplet) is many times larger than the inter-molecular spacing:These terms are the' inertial coupling due to virtual mass and the additional viscous coupling due to unsteadiness of the flow field. These physical effects as well as the continuum inertia! coupling terms were neglected in many other two-phase calculations. By including this inertial coupling term, the onedimensional multiphase equations are found to give real characteristics. Furthermore, the sum of momentum equations of all phases reduces to the momentum equations of the mixture as should be expected.

The Vertical Multiphase Flow of Oil and Gas At High Rates

Abstract: This paper presents a method for calculating the pressure-depth profile for a well flowing oil and associated gas at a stabilized rate. It is primarily designed for flow rates in excess of about 5,000 B/D in large-diameter tubing, casing, or casing annuli. The flowing mixture density is obtained from laboratory-derived data for the particular crude. Using a two-phase Reynold's number and an equivalent roughness height for annular flow, friction factors are obtained from published sources and the pressure traverse equation is evaluated. From the test data available from 41 high-rate wells in the Middle East, the calculated pressure drops are in error by an average of --0.84 percent, with a standard deviation of 2.06 percent.

Some unsteady parallel flows of particulate suspensions

Abstract: Analytical and numerical solutions are obtained for five unsteady parallel flows of particulate suspensions which exhibit boundary-layer characteristics. The governing equations are based on a continuum theory of particulate suspension behavior. An attempt is made to infer some of the pertinent features of two-phase and multiphase boundary-layer flows from the solutions.

Geohydrological environmental effects of geothermal power production: Phase IIA. Final report. [Using reservoir simulators]

Abstract: Results are presented for the second year (Phase IIA) of a three-year research effort to develop and validate computer simulators whereby field information for a specific liquid- or vapor-dominated geothermal system can be used to predict reservoir performance and subsurface environmental effects due to production and reinjection of geothermal fluids. During the first year (Phase I), separate codes were developed for describing the multiphase multidimensional unsteady flow of steam and water in a heterogeneous geologic setting without rock deformation; and for calculating the response of a multidimensional rock matrix to prescribed pore pressure changes without consideration of fluid flow. These codes have now been coupled to produce a fully active geothermal reservoir simulator for simultaneous treatment of fluid flow and ground movement effects. Calculations are presented for a five-spot production/injection pattern which show the numerical techniques employed to be free of grid orientation problems. Reservoir calculations simulating pressure drawdown and buildup well tests are presented. Effects of in-formation flashing and salt precipitation on well deliverability were studied; flashing near the wellbore and above the production horizon were both evaluated. Application of the reservoir simulator to a two-dimensional vertical model of the Wairakei geothermal system has successfully reproduced the total fluidmore » production history over time interval 1953 to 1967. The ground surface subsidence history of the field is examined in terms of the calculated two-phase fluid flow and the local geology. A separate abstract was prepared for the appendix, entitled ''Tests on Cores from the Wairakei Geothermal Project, Wairakei, New Zealand.''« less

Erosive Wear Testing

Abstract: Fluid-induced erosion, single and multiphase flow induced, is considered according to the various phenomena involved. The basic damage mechanisms are considered and described. The various types of erosion testing devices are described and compared.

Non-equilibrium radiation from viscous chemically reacting two-phase exhaust plumes

Abstract: A knowledge of the structure of the rocket exhaust plumes is necessary to solve problems involving plume signatures, base heating, plume/surface interactions, etc. An algorithm is presented which treats the viscous flow of multiphase chemically reacting fluids in a two-dimensional or axisymmetric supersonic flow field. The gas-particle flow solution is fully coupled with the chemical kinetics calculated using an implicit scheme to calculate chemical production rates. Viscous effects include chemical species diffusion with the viscosity coefficient calculated using a two-equation turbulent kinetic energy model.