Duong Ngoc Hai

Theoretical modeling of the carbon dioxide injection into the porous medium saturated with methane and water taking into account the CO2 hydrate formation

In this work the mathematical model is constructed and the features of the injection of warm carbon dioxide (with the temperature higher than the initial reservoir temperature) into the porous reservoir initially saturated with methane gas and water are investigated. Self-similar solutions of the one-dimensional problem describing the distributions of the main parameters in the reservoir are constructed. The effect of the parameters of the injected carbon dioxide and the reservoir on the intensity of the CO 2 hydrate formation is analyzed.

Body parameters with application of optimal differential variation method in super cavity model

When a slender body moves very fast through water at sufficient speed the cavity phenomena is happened. In a cavity model the bodys lengths and cavitator diameter are determined by the differential variation optimal method so that the velocity of body is maximum.

A numerical model for water-oil flow in naturally fractured reservoirs

This paper describes the development of a three-dimensional , two-phase model for simulating the flow of water and oil in naturally fractured reservoirs. The model is based on the dual porosity approach. Main flow in the reservoir occurs within the fractures with local exchange of fluids between the fracture system and matrix blocks. A new formula for matrix/fracture fluid exchange rate is proposed based on an extension of the equation developed by Kazemi to account the gravity effects. This formula allows to eliminate the matrix pressure in the pressure equation for fractures and makes the solution algorithm easier. Some example calculations are presented to validate the model. These include a comparison of the results of this paper with previous results , showing the gravity effects and applicability of the model for field-scale problems.

Experimental results of gaslift process

In the paper, the investigation results of periodical gas-lift flow s in vertical pipes using experiment method are presented. The experiment facilities consist of flow measurement equipment, gas and fluid supplier facilities, tubing system. To study the influence of medium physical and dynamical characteristics on the process efficiency, two liquid-gas systems are used, namely, water-air and spindle oil-air. The objects of investigation are to obtain data from tests conducted in some conduits and to analyse the influence of system physical, geometrical and etc. parameters such as: initial liquid height in the conduits, gas inj ected volume, conduit diameter, conduit configuration and etc. on the considered process.

The theoretical research of an upward two-phase flow with phase's changes in a vertical well

By methods of mechanics of multiphase systems the mathematical model describing an upward gas-and-oil flow in a vertical well is constructed. The model considers phase’s changes, deposition of oil paraffin on the elevating column’s walls of the well, influence of an installation of electrical centrifugal pumps on parameters of the gas-and-oil flow, and also heat exchange of the well with surrounding rock. It is shown, that at the using of an installation of electrical centrifugal pumps and variation of its metering characteristic, depth of its setting, it is possible to achieve the optimum temperature mode on all the well’s height and to prevent by it formation of paraffin deposits.

Waves reflected by solid wall in the mixture of liquid with vapour bubbles

The liquid and gas mixtures are met in many natural and industrial processes. In the paper the results of investigation of waves reflected by solid wall of the stationary shock waves with moderate intensities or the transient pulses propagated in the mixture of liquid with vapour bubbles are presented. The effect of initial conditions, shock strength, size of the bubbles and volume fraction of vapour phase on the behaviour of the waves reflected by solid wall is studied.

Shock adiabat analysis for the mixture of liquid and gas of two components

The liquid and gas mixture is met in many natural and industrial pro~ cesses. In the paper, the investigation results of shock waves, propagated in the liquid and two-component gas (one component is neutral, the other is condensed) mixture, are presented. The influence of the relative gas ratios , initial gas volume, wave intensity etc. on the main wave characteristics, is analyzed and illustrated as examples for two mixtures. The first is a mixture of water and gas (air and water vapour) . The second is a mixture of crude oil and gas (one component is soluble, the other is insoluble).

A three dimensional non-hydrostatic model for turbulent air flow

A finite-volume code is developed to compute the turbulent airflow over small-scale complex terrain. A pressure-correction algorithm is ·used to solve the threedimensional non-hydrostatic flow equations . The turbulent transport is simulated by the kE: model using some modifications suitable for atmospheric boundary-layer application. As an example, the model is used to simulate the flow-field around a cubical building. The same flow as a towing-tank experiment of USEPA was simulated using our code. These simulations show that, the model was capable of simulating recirculation zones behind the building. The results of calculation are also compared with available measurement data.

Some initial experimental results on the conditions of free water layer formation in horizontal pipes

This paper presents an experimental facility conducted in Hanoi Institute of Mechanics to investigate multiphase How pattern in the pipes. First and foremost, it ts used to define the conditions of water layer formation in the horizontal pipe. · I· Experimental results have been . obtained in stainless steel pipes ~f three different diameters (24.6mm; 30.8mm and 40.5mm) with white spindle oil N° 10 and water. They have been shown in the form of water layer maps.

Rheological properties of emulsion of crude oil and water

In the paper the rheological properties of crude oil of White T iger oil-field (Vietnam) and its emulsion with sea-water, including measurement results and analytical approximation formulae for wide range of pressure, temperature and water concentration, are presented. As it is known, the crude oil of White Tiger oil-field is a high-paraffin and high-viscous oil. At the low temperature (T ~ 40°C) it behaves as non-Newtonian fluid of Bingham-Shvedov group. Therefore, beside the effective viscosity, the effective dynamic shear stress is also measured and approximated. The rheological properties of crude oil and emulsion of crude oil and water are also measured and approximated for the case when the mixture contains 0.1% chemical reagent ES-3363.