Values Of Liquid Flow Rate Research Articles

Technique for calculating technological parameters of non-Newtonian liquids injection into oil well during workover

Technique for automated calculation of technological parameters for non-Newtonian liquids injection into a well during workover is presented. At the first stage the algorithm processes initial flow or viscosity curve in order to determine rheological parameters and coefficients included in equations of rheological models of non-Newtonian fluids. At the second stage, based on data from the previous stage, the program calculates well design and pump operation modes, permissible values of liquid flow rate and viscosity, to prevent possible hydraulic fracturing. Based on the results of calculations and dependencies, a decision is made on the necessity of changing the technological parameters of non-Newtonian liquid injection and/or its composition (components content, chemical base) in order to prevent the violation of the technological operation, such as unintentional formation of fractures due to hydraulic fracturing. Fracturing can lead to catastrophic absorptions and, consequently, to increased consumption of technological liquids pumped into the well during workover. Furthermore, there is an increased risk of uncontrolled gas breakthrough through highly conductive channels.

Gas–Liquid Flow Rate Measurement Using a Twin-Plane Capacitive Sensor and a Venturi Meter

We introduce a flow meter to monitor the flow rate of individual phases in gas-liquid flows. The meter combines pressure data from a Venturi tube and void fraction data from a twin-plane capacitive sensor. By the twin geometry of the capacitive sensor it is possible to cross-correlate the two signals and estimate gas flow rate. A simple algebraic approach, which considers no-slip condition between phases and disregards influence of gas phase, combines pressure fluctuations of the Venturi meter with the measured phase fraction to estimate liquid flow rate. The proposed meter has been tested in horizontal air-water flow loops, 1-inch and 2-inches internal pipe diameter, in permanent and transient regimes. Calculated values were compared to reference measurements. The proposed meter performs well determining liquid flow rate, independent of the flow pattern, in the whole measured range with some more discrepancies at lower values of liquid flow rate. Gas flow rate presented good agreement with reference measures whereas here mainly slug flow pattern has been investigated. RMSD% in steady-state condition was 6.5% for liquid and 20.6% for gas, being satisfactory for many applications, considering the fact the introduced flow rate meter operates without the need for any adjustment based on reference measurements or previous knowledge/assumption of the gas/vapor quality parameter, as has been usual for other similar recent developments.

Stability of nanobubbles generated in water using porous membrane system

The focus of this work was to examine the stability of gas nanobubbles in water. The generation of nanobubbles was carried out in two porous-membrane modules for two distinct values of liquid flow rate. Gas phase was nitrogen or oxygen, and the liquid phase was distilled water. Samples of nanodispersions were stored for 10 to 35 days. Half of them were stored open and other half closed to ensure or deny contact with the atmosphere, respectively. During storage Sauter diameter and zeta potential of nanobubbles were measured. Additionally, in the case of oxygen the dissolved gas concentration was measured. The result shows that stability and size of nanobubbles did not depend on whether samples were left open or closed. Obtained nanobubbles were stable for over a month and their Sauter diameter approached the value in the range 250–350 nm from different initial sizes. Additionally, the average zeta potential of nanobubbles in stable dispersions was between -10 mV and -15 mV in pure water without any frother additions. Furthermore, the discussion of reasons of stability of bubbles was carried out.

Implementation of the Finite Element Method for Simulation of Mass Transfer in Membrane Contactors

AbstractMathematical modeling and numerical simulation of gas separation by means of polymeric membrane contactors is presented. The finite element method is implemented for numerical simulation. COMSOL Multiphysics is used for simulation. Continuity equations are solved via computational fluid dynamics techniques based on the finite element method. A laminar velocity profile is applied for the solvent. Velocity distribution of the gas flow in the contactor is obtained by Happel's model. The predictions of percent CO2 removal obtained by the modeling were compared with the experimental values from literature for CO2 removal from CO2/N2 gas mixtures with amines. The modeling predictions were in good agreement with experimental data for different values of liquid flow rates.

Opposed bubbly jets at different impact angles: Jet structure and bubble properties

The structure of two colliding water jets containing small gas bubbles is studied experimentally. The effects of the separation distance between jets, as well as the orientation angle, on the spatial distribution of bubbles have been considered. Results on the global structure of the final jet and bubble properties have been obtained using a high-speed video camera, and measurements of the positions of coalescence events are presented. Jets are introduced through inclined pipes (with a diameter of 0.7 mm) into a large water tank to avoid wall effects. Inclination angle has been changed from 0° to 45° with respect to the horizontal, resulting in a 0° up to 90° impact angle between jets. Generation of bubbles is controlled by a T-junction device where a regular slug-flow is created prior to injection. Bubble sizes have been measured, and a mean diameter of around 1 mm has been obtained using high values of the liquid flow rate. In the studied range of separation distances between the bubbly jets, a more homogeneous dispersion of bubbles is created as the distance between jets is decreased and the momentum flux of each jet is increased. Higher numbers of coalescences are observed when using smaller distance between jets, and the obtained measurements revealed that the number of bubble coalescence events is reduced significantly using high values of liquid flow rates.

Development of an Effervescent Atomizer for Industrial Burners

The present work is conducted with the purpose of developing an effervescent atomizer for industrial burners that will generate a fine and steady spray in large turn-down ratio. The atomizer is fed with light heating oil (LHO) and uses air as an atomizing medium. First, a basic classification is made of the published design concepts of effervescent atomizers investigated by different researchers. Three distinct types of such atomizers are recognized. A single-hole, plain-orifice atomizer with an “outside-in” gas injection configuration was chosen for this study. The basic geometric parameters that may significantly influence atomizer performance are described. An experimental study of the effervescent atomizer was conducted to evaluate the influence of operational conditions and that of several geometric parameters on the drop size in the spray. The Sauter mean diameter of drops was measured using a phase/Doppler particle analyzer. The study covers the size and number of aerator holes, their location, and the diameter of the mixing chamber. The influence of these parameters on the spray quality was evaluated at atomizing pressures of 0.1, 0.3, and 0.5 MPa and gas:liquid mass flow rate ratio (GLR) values of 2%, 5%, and 10%. The main goal of this work is to develop a new procedure for the design of effervescent atomizers. This procedure is based on our experimental results and it is also supported by the findings of other authors. It allows for the determination of the key geometric parameters of the atomizer to achieve sprays of minimum mean drop size for defined values of liquid flow rate, air supply pressure, and GLR. The article also studies the optimization of the exit orifice size and of other parameters, such as the size of the mixing chamber (internal diameter and length), and the number, size, and position of aeration holes.

A Design Procedure for Effervescent Atomizers

A methodology for the design of effervescent atomizers is described. The objective is to achieve sprays of minimum mean drop size for any stipulated values of liquid flow rate, air supply pressure, and air/liquid ratio. Application of the method leads to optimum values for all the key atomizer dimensions, including the number and size of the air injection holes, and the diameters of the mixing chamber and discharge orifice. It also enables optimum dimensions to be determined for a convergent-divergent nozzle should such a device be fitted to the nozzle exit to improve atomization performance. Examples are provided to demonstrate the application of the recommended design procedure and to illustrate the relative importance of various flow and geometric parameters in regard to their effects on atomization quality.