Calculation Of Pressure Losses Research Articles

Real-Time Drilling-Process Optimization

This article, written by Assistant Technology Editor Karen Bybee, contains highlights of paper SPE 119650, "Real-Time Optimization of the Drilling Process - Challenges in Industrialization," by E. Cayeux, SPE, E.W. Dvergsnes, SPE, and F. Iversen, SPE, International Research Institute of Stavanger, originally prepared for the 2009 SPE/IADC Drilling Conference and Exhibition, Amsterdam, 17-19 March. The paper has not been peer reviewed. A new drilling-control system for real-time optimization and automation has been developed in an ongoing research project, which now will enter an industrialization phase. The system, which is based on application of advanced real-time process models for calculation of both hydraulic and mechanical forces, requires an extensive set of input data. Results from the calculation modules are applied directly in the drilling-control system, affecting parameters such as pipe acceleration, velocity and deceleration, and the pump-startup profile. Introduction During the last decade, computer-controlled machinery have made it possible to control the drawworks, the topdrive, mud pumps, and the iron roughneck or pipe-handling equipment from a drilling workstation by use of joysticks and keypads. Recent developments enable control of the machinery within safe-guard boundaries through application of model simulations, accounting for the effects of fluid and pipe movements in the wellbore. These new extended systems have the potential to reduce the risk of damaging the well and the downhole equipment and, subsequently, to reduce nonproductive time. For such extended systems to function properly, a more precise description of the drillstring components is required to calculate pressure losses, mechanical loads, and heat transfer. Furthermore, complete descriptions of the wellbore architecture, formation prognosis, trajectory, and drilling-fluid properties are needed for configuration of the applied models. Most of this information is not available in standard rig systems, and no standard work process has been established to make this information available before actual operations. For such systems to achieve their full potential, the necessary information must be quality controlled and made available at the right time, because an error in this information could lead to potentially serious incidents. In January 2008, a field test of a new system for automated control of the drilling process was performed on the Statfjord C platform in the North Sea. Because the system was developed through a research project, the focus up to now has been on robustness. The system now is entering the industrialization phase, with a stronger focus on system application, including the following.Sensor quality and reliability.Availability of wellbore description including information exchange between different systems.Work processes for updating well bore description and quality control of data.User friendliness.Personnel training.

Axial tunnel fans: Estimate of blade row pressure losses and validation of rational design parameters

The paper presents the calculation of pressure losses in blade rows of an impeller and directing vanes for a number of axial tunnel fans. The found rationality domains of the design parameters for fans with impeller diameters 1600, 1800, 2100, 2400 mm will allow assessment of a fan installation efficiency as early as at the design stage. Also, the author has validated the choice of an aerodynamic configuration and design parameters for the components of a fan, and calculated geometry of the fan impeller blades for subway station-to-station block ventilation.

Flow and mixing characteristics of σ-type plate static mixer with splitting and inverse recombination

A new type of demountable plate static mixer composed of σ-shaped elements was developed, which was designed to perform multi-lamination of two fluids through systematic splitting and inverse recombination. Its flow and mixing characteristics have been investigated by conducting the decolourisation reaction of iodine with sodium thiosulfate and CFD analysis. Visualized mixing patterns demonstrate that splitting and inverse recombination progress as designed in the flow of Re less than 10, where the number of mixing elements required for complete mixing increases with Re. At Re>10, secondary flows are generated due to the two- and three-dimensionally curved portion in the mixer, distorting the systematic splitting and recombination. They contribute to accelerating mixing progress through the deformation and elongation of the interfaces between the fluids to be mixed. The number of elements for complete mixing becomes maximum at Re of 10–20 and then decreases with further increasing Re. Mixing progress in the flow direction and cross-sectional mixing patterns obtained by CFD analysis show that splitting and inverse recombination do not perform satisfactorily in a shallow channel, which suggests that the aspect ratio of the mixer channel should be set around one if heat transfer is simultaneously taken into account. Based on the CFD velocity data, fluid particles disposed on the inlet cross-section at a time were traced in the mixer with the aspect ratio of one. Distributions of travelling or residence time of fluid particles reveal that the overall flow behaviour in the mixer approaches the plug flow with increasing Re as well as the number of mixing elements. The friction factor, which was obtained by applying the calculated pressure loss to the Fanning's equation, varies in inverse proportion to Re at Re<10 and its variation becomes smaller with further increasing Re.

Validation of the sub-channel code F-COBRA-TF: Part I. Recalculation of single-phase and two-phase pressure loss measurements

The present paper deals with recalculations of single-phase and two-phase pressure loss measurements with the advanced two-phase, three-field sub-channel code F-COBRA-TF. Thereby, experimental data of both the OECD/NRC BFBT benchmark and in-house tests in AREVA NP's KATHY loop are used. The main goal of this paper is not to focus on a special new model or correlation but to give an overview how a complete pressure loss calculation for practical purposes can be carried out being based on a simplified and straightforward method to estimate sub-channel spacer pressure loss coefficients on the one hand and an advanced sub-channel code on the other hand. The pressure loss coefficients are calculated analytically and calibrated at available measurements of total single-phase bundle pressure loss. Thus, they are not adapted to any two-phase measurement and also do not depend on the sub-channel code they are used in. The results of the recalculations of the measurements especially demonstrate the capability of a three-field code to predict both single-phase and two-phase pressure losses with high accuracy, whereas the code is not based on conventional pressure loss correlations using two-phase multipliers but rather on interfacial friction correlations for each flow regime. Thereby, the F-COBRA-TF standard models – which are usually applied for all sorts of calculations (pressure loss, void distribution, lateral mixing, critical heat flux, etc.) – were used. It was not necessary to do special code tuning with respect to certain experiments.

An engineering model of dilute polydisperse pneumatic conveying

A model for a gas-polydispersed particle flow in a pipeline is presented. The chaotically moving particles of different sizes are represented as sets of granular gases having different granular temperatures. The latter are generated due to partial momentum loss of particle–wall collisions as well as due to collisions of particles of different sizes with each other, and dissipated because of partially inelastic particle–particle collisions and also due to the particle–gas viscous friction. The model developed has been validated by comparison of the calculated pressure losses with the experimental data. The granular temperatures calculated by the model have been compared to those computed by the molecular dynamics code. A comparison is also made on the effect of polydispersity on pressure losses.

In-vivo coronary flow profiling based on biplane angiograms: influence of geometric simplifications on the three-dimensional reconstruction and wall shear stress calculation

BackgroundClinical studies suggest that local wall shear stress (WSS) patterns modulate the site and the progression of atherosclerotic lesions. Computational fluid dynamics (CFD) methods based on in-vivo three-dimensional vessel reconstructions have recently been shown to provide prognostically relevant WSS data. This approach is, however, complex and time-consuming. Methodological simplifications are desirable in porting this approach from bench to bedside. The impact of such simplifications on the accuracy of geometry and wall shear stress calculations has to be investigated.MethodsWe investigated the influence of two methods of lumen reconstruction, assuming circular versus elliptical cross-sections and using different resolutions for the cross-section reconstructions along the vessel axis. Three right coronary arteries were used, of which one represented a normal coronary artery, one with "obstructive", and one with "dilated" coronary atherosclerosis. The vessel volume reconstruction was performed with three-dimensional (3D) data from a previously validated 3D angiographic reconstruction of vessel cross-sections and vessel axis.ResultsThe difference between the two vessel volumes calculated using the two evaluated methods is less than 1 %. The difference, of the calculated pressure loss, was between 2.5% and 8.5% for the evaluated methods. The distributions of the WSS histograms were nearly identical and strongly cross-correlated (0.91–0.95). The good agreement of the results was confirmed by a Chi-square test.ConclusionA simplified approach to the reconstruction of coronary vessel lumina, using circular cross-sections and a reduced axial resolution of about 0.8 mm along the vessel axis, yields sufficiently accurate calculations of WSS.

Estimation of resistance of filter media used for Prefil Footprinter tests of liquid aluminium alloys

During the pressure filtration of molten metals, an essential parameter is the resistance of the filter medium, which is relevant to the calculation of flow velocity, pressure loss and distribution, and drag forces. The resistance has significant influences on the filtration behaviour and structure of the residual cake of inclusions retained on the filter. The Prefil Footprinter, a portable pressure filtration instrument, is usually used to determine the quality of molten aluminium alloys. To date, however, no data on the resistance of the filter medium used have been reported. The present work is an attempt to estimate the resistance. Experiments are described and analyses of flow behaviour are presented. Values of the medium resistance of the filters are determined and reported for the first time.

Method for Calculating Pressure Losses in an Upward Cocurrent Flow

In an upward cocurrent gas-liquid flow in a vertical tube, the dependence of the pressure gradient on the gas velocity is known to be extremal. At a certain gas velocity w = w0, the pressure gradient takes the minimal value ϕ = ϕ0. It is also known that stable modes of upward cocurrent flow, which are of the greatest practical importance for adsorption processes, occur at w ≥ w0. By analyzing a large body of primary experimental data obtained by various researchers over a wide parameter range, corrections are made to a known relation between the pressure gradient and the gas velocity in a column. An algorithm for calculating the pressure loss is developed.

Modeling Nonsteady‐State Regimes of Dilute Pneumatic Conveying

AbstractThe nonsteady‐state gas‐particle flows in pipelines are considered. Chaotically moving particles are described as granular gas characterized by granular temperature. This temperature dissipates because of partially inelastic particle collisions with the wall, with each other and also because of the particle viscous friction with gas. The energy losses on a microscale are translated into the pressure losses on a macroscale. The model developed is validated for both steady‐state and nonsteady‐state regimes by comparing calculated pressure losses with experimental data. A detailed numerical study of the nonsteady‐state flows shows that the pipe wall roughness is a major parameter affecting the pressure drop. Flow regimes for different particle elastic properties, particle sizes, and solids loading are studied.

Coolant Flow Distribution and Pressure Loss in ONAN Transformer Windings—Part I: Theory and Model Development

A comprehensive resistance network-based hydraulic model for mass flow distribution and pressure loss in disk-type oil-cooled transformer windings with zigzag cooling flow passages is presented. The number, size, and location of the horizontal ducts and fluid properties are considered variable, and the distribution of mass flow rates is determined by associated pressure losses, including the so-called minor losses. Axisymmetry of the winding geometry is taken into consideration, and the pressure loss calculation is based on the discretization of flow domains in order to tackle the nonuniformity of the cross-sectional area in the horizontal ducts and to provide easy coupling with thermal analysis for the cooling of winding disks. Successive under relaxation method is used for numerical convergence.

Pressure Loss Calculation Software-2002

We would like to introduce you new pressure loss calculation software for piping system, which is the renewed and updated version from one of last year and easier to use. We would like to explain to you mainly additional features from the previous one here, not the same features. The previous software calculated fluid pressure loss based upon virtual installation of valves and elbows on a fixed piping system.There had been some differences from the actual piping system with this way, which sometimes created difficulties in handling. The new software was programmed to solve this problem. You can design plane and lateral drawings automatically by selecting piping materials from the menu and calculate pressure loss by setting fluid conditions at the piping system.Thus, there is no restriction for number of piping system patterns. Users can specify as many piping system patterns as possible.Also you can check pressure losses at the specific locations by clicking mouse at any points of the piping system. You can print out the whole piping system to verify it clearly. We hope that this new software will be of great help to you.

Analysis and Multidisciplinary Optimization of Internal Coolant Networks in Turbine Blades

The theoretical methodology, conceptual demonstration, and validation of a fully automated computer program for the inverse design and optimization of internal convectively cooled three-dimensional axial gas turbine blades is presented. A parametric computer model of the three-dimensional internal cooling network was developed, including the automatic generation of computational grids. A boundary element computer program was written to solve the steady-state, nonlinear heat conduction equation inside the internally cooled and thermal barrier coated turbine blade. A finite element algorithm was written to model an arbitrary network of internal coolant passages for the calculation of the internal pressure losses, flow rates, effects of centrifugal pumping, heating of the coolant fluid, and heat transfer coefficients from the thermal model of the solid to the coolant fluid. The heat conduction and internal flow analyses were strongly and iteratively coupled to account for the heat balance between the blade and the coolant fluid. A system of evolutionary optimization algorithms was used to modify the internal cooling configuration and internal heat transfer enhancements (boundary-layer trip strips and pedestals) to achieve the objectives of increased cooling effectiveness and greater durability against oxidation, corrosion, and creep. The computer-automated design and optimization system was demonstrated on the second high-pressure turbine blade row of the Pratt and Whitney F100 engine. The internal cooling optimization on the product definition of this blade yielded a 5% increase in average cooling effectiveness, with only a marginal increase in coolant flow rate, in addition to having the same corrosion life and a doubling of the creep life.

Application of Multiphase Flow Methods to Horizontal Underbalanced Drilling

Abstract Multiphase flow can be present in all aspects of underbalanced drilling. This paper outlines the ways in which multiphase flow pressure loss calculations can be used by drilling engineers in the design and optimization of underbalanced drilling operations. Then, detailed field measurements for several horizontal wells drilled underbalanced with coiled tubing are used to evaluate the application of existing pressure loss calculation methods to this unique application. Introduction Underbalanced drilling (UBD) is rapidly gaining popularity in the oil and gas industry. The Alberta Energy and Utilities Board ID94–3(1) defines underbalanced drilling as follows: "When the hydrostatic head of a drilling fluid is intentionally designed to be lower than the pressure of the formation being drilled, the operation will be considered underbalanced drilling. The hydrostatic head of the drilling fluid may be naturally less than the formation pressure or it can be induced. The induced state may be created by adding natural gas, nitrogen, or air to the liquid phase of the drilling fluid. Whether induced or natural, this may result in an influx of formation fluid which must be circulated from the well and controlled at surface." Benefits of Underbalanced Drilling Maintaining the pressure in the wellbore below the reservoir pressure allows reservoir fluids to enter the wellbore while UBD operations proceed, thus preventing flow of drilling fluids (and associated solids) into the formation, thereby minimizing or even eliminating formation damage. This is of particular importance in the drilling of horizontal wells as the formation is exposed to the drilling fluids for an extended period of time. Although formation damage reduction is the most widely recognized benefit of underbalanced drilling, several additional benefits are outlined below: Increased Penetration Rates Underbalanced drilling can achieve higher rates of penetration due to reduced "chip holdown" and decreased hydrostatic pressure at the bit face. Reduction in "chip holdown" refers to easier removal of drilled solids from the vicinity of the drill bit due to the flow of drilling and reservoir fluids, thus allowing the bit to drill into fresh rock continuously. The decreased hydrostatic pressure at the bit face reduces stress in the rock being drilled, allowing it to fail more easily. The experience of drilling engineers(2) familiar with UBD is that the rate of penetration can be increased by between three and ten times that of conventional drilling. Minimal Lost Circulation Underbalanced drilling gives better control in situations where fractured, low pressure, or high permeability formations may lead to the loss of drilling fluids and the associated problems that can cause. Evaluation While Drilling Data acquired in real time during underbalanced drilling operations allow for both the short term on site optimization of the UBD operation, and the longer term assessment of the well's potential. On site, the data acquired can be used to optimize drilling parameters such as the well's horizontal length, vertical depth, and orientation. Other data that can be obtained, useful both on site and long term, include fluid properties, productivity, and geological interpretations of the formation.

Pressure Loss and Separation Characteristics Calculation of a Uniflow Cyclone with a CFD Method

CFD simulations of separation devices are frequently carried out with simple models and boundary conditions due to cost and processing time limitations. In the present paper, calculations of pressure loss and separation efficiency of an uniflow cyclone have been performed on the basis of CFD simulations and compared with experimental data. It is shown that simplifications often made to reduce the computing effort significantly limit the prediction quality.

Contribution to solution of pressure losses of heat exchanger

This paper tells deals withe the calculation of pressure losses of heat exchangers and its individual parts. Local and length pressure losses in circular sections and also sections of different shape are dealt with. There are different alternatives of tubular heat exchangers connection. Liquid and gaseous heat carrying agents and various coolants can be used. It is possible to dimension pumps or ventilators by this calculation. Operation and investing charges also depend on that.

The design of sewage sludge pumping systems

A project has recently been undertaken to improve the way in which sewage sludge pipeline systems are designed. A new, more accurate method of calculating pressure losses has been developed which r...

Predictive methods for two-phase flow pressure loss in tee junctions with combining conduits

This paper discusses several predictive methods for two-phase flow pressure loss calculation in tee junctions with combining conduits. A semi-empirical approach has been followed utilizing three different models for the prediction of the pressure drop at the junction. The models are referred to as “loss coefficient model”, “contraction coefficient model” and “momentum coefficient model”. The results were compared with experimental data that were measured in a refrigerant flow loop.

The Resistance to Air Flow of Farm Building Ventilation Components

The static air pressure change (pressure drop) across a variety of ventilation components used in agricultural buildings was measured. Twenty-one ventilated wall claddings and ten roof ventilation arrangements were tested. The pressure drops across these items were measured at air approach speeds between 0·05 and 1·7 m/s. Despite the low Reynolds number of the air flow involved, pressure drops varied with the square of air velocity. This allows the pressure drop characteristics of the items measured to be described by a pressure loss coefficient, k. The values of k for the various items tested are given. The use of k, which simplifies the calculation of pressure losses in complex ventilation paths, is described.

Effect of wall roughness in turbulent pipe flow of a pseudoplastic crude oil: An evaluation of pipeline field data

An equation for estimating the thickness of the laminar sublayer in turbulent pipe flow of pseudoplastic fluids was developed. This equation was used to classify the turbulent pipe flow into two regions: smooth wall and rough wall turbulence. The roughness Reynold number was used to determine the smooth wall turbulence and rough wall turbulence regions. To verify the validity of the present analysis, the developed equations were used to quantify the effect of wall roughness of the Hungarian Alygo pipeline on pressure loss calculations. Excellent agreement was obtained between the friction factors calculated from the correlations of Clapp (1961) and Szilas et al. (1981), and the field data of the Hungarian Algyo pipeline.

Friction Factors For Yielldless Fluids In. Turbulent Pipe Flow

Abstract A new equation relating the friction factor to the generalized Reynolds number and rheological characteristics of non-Newtonian yieldless fluids was developed under turbulent pipe flow conditions. The rheological behaviour of yieldless fluids was described by the generalized approach developed by Metzner and Reed. Statistical error analysis were used to determine the accuracy of the developed equation. To verify the validity of tire present analysis, a comparison was made between published experimental friction factors and those cal culated from the developed equation, Dodge and Metzner, and Desouky and El-Emam correlations. A comparison was also made between field measurements and calculated ones, The results showed that the developed equation provided a more accurate estimation of friction factor. Introduction Transportation of non-Newtonian yieldless fluids in a pipeline under turbulent conditions requires a precise method to determine the pressure loss. The yield less fluids include pseudoplastic and dilatant fluids. In view of several correlations developed for calculating pressure loss in a pipeline handling pseudoplastic or dilatant fluids, there are two approaches: power-law and generalized correlations. Shaver and Merrill(1), Tomita(2), Ciapp(2), Torrance(2l, Bogue and Metzner(3), Hall (5), Murthy and Zandi(5), and Szilas, Bobok and Navratil(6) had developed correlations applied for power-law fluids. The power-law model is one of rhe twenty blown rheological models of pseudoplastic and dilatant fluids(7). As for the second approach, odge and Metzner(H) developed a generalized correlation for time-independent fluids. The data used to determine the constants of their correlation were from power-law and viscoelastic fluids(2). Lord, Hulsey and Melron(9) developed a generalized approach for ime-independent viscous or viscoelastic fluids. Hall(5) drew attention to the actual variation in the exponent of the correlation proposed by Lord, Hulsey and Melton and cautioned against scale-up over too extensive a range. A recent generalized correlation and short method for all types of pseudoplastic were developed by Desouky and El-Emam(7), and Desouky(10). These authors indicated excellent agreement between calculated and experimental friction factors over values of 5000 to 60 000. In the present analysis, a generalized equation for friction factors of pseudoplastic and dilatant fluids were derived under turbulent pipe flow conditions. The twenty, known rheological models of pseudoplastic and dilatent fluids were expressed through the use of the generalized approach developed by Metzner and Reed(11). Equation Development An equation relating the friction factor to the generalized Reynolds number and characteristics of pseudoplastic and dilatant fluids was derived. The maximum velocity was determined by equating the point velocities on both sides of the bounding surface of the turbulent core and the laminar sublayer. For an incompressible fluid under steady stare, isothermal and fully developed conditions, the flow equation in Z-direction is given by: Equation (1) Available In Full Paper. Integrating equation (1) with respect to r, the following equation is obtained Equation (2) Available In Full Paper. The relationship between laminar shear stress and shear rate for pseudoplastic and dilatant fluids(2) is given by: Equation (3) Available In Full Paper. The apparent viscosity (μapp) can b