Hydraulics of Drilling With Aerated Muds Under Simulated Borehole Conditions

2010 ◽  
Vol 132 (1) ◽  
Author(s):  
L. Zhou ◽  
R. M. Ahmed ◽  
S. Z. Miska ◽  
N. E. Takach ◽  
M. Yu ◽  
...  
Keyword(s):  
Pressure Loss ◽  
Volume Fraction ◽  
Mechanistic Model ◽  
Liquid Ratio ◽  
Flow Loop ◽  
Pressure Losses ◽  
Flow Parameters ◽  
Underbalanced Drilling ◽  
Measured Flow ◽  
Gas Volume

Maintaining optimum circulation rates is important in aerated mud drilling operations. However, reliable predictions of the optimum rates require accurate modeling of the frictional pressure loss at bottom-hole conditions. This paper presents a mechanistic model for underbalanced drilling with aerated muds. Extensive experiments in a unique field-scale high pressure and high temperature flow loop were performed to verify the predictions of the model. This flow loop has a 150×89 mm2(6″×3.5″) horizontal annular geometry and is 22 m long. In the experiments, cuttings were introduced at a rate of 7.5 kg/min, representing a penetration rate of 15 m/h in the annular test section. The liquid phase flow rates were in the range of 0.30–0.57 m3/min, representing superficial liquid velocities in the range of 0.47–0.90 m/s. The gas liquid ratio (gas volume fraction under in situ condition) was varied from 0.0 to 0.38. Test pressures and temperatures ranged from 1.28 to 3.45 MPa, and 27°C to 80°C, respectively. Gas liquid ratios were chosen to simulate practical gas liquid ratios under downhole conditions. For all the test runs, pressure drop and cuttings bed height over the entire annular section were measured. Flow patterns were identified by visual observations through a view port. The hydraulic model determines the flow pattern and predicts frictional pressure losses in a horizontal concentric annulus. The influences of the gas liquid ratio and other flow parameters on the frictional pressure loss are analyzed using this model. Comparisons between the model predictions and experimental measurements show a satisfactory agreement. The present model is useful for the design of underbalanced drilling applications in a horizontal wellbore.

Modeling and Experimental Study of Newtonian Fluid Flow in Annulus

2010 ◽  
Vol 132 (3) ◽  
Author(s):  
Mehmet Sorgun ◽  
M. Evren Ozbayoglu ◽  
Ismail Aydin
Keyword(s):  
Experimental Data ◽  
Pressure Loss ◽  
Drilling Fluid ◽  
Mechanistic Model ◽  
Tangential Velocity ◽  
Petroleum Engineering ◽  
Flow Loop ◽  
Pressure Losses ◽  
Laminar And Turbulent Flow ◽  
Drilling Operations

A major concern in drilling operations is the proper determination of frictional pressure loss in order to select a mud pump and avoid any serious problems. In this study, a mechanistic model is proposed for predicting the frictional pressure losses of light drilling fluid, which can be used for concentric annuli. The experimental data that were available in the literature and conducted at the Middle East Technical University-Petroleum Engineering (METU-PETE) flow loop as well as computational fluid dynamics (CFD) software are used to verify the results from the proposed mechanistic model. The results showed that the proposed model can estimate frictional pressure losses within a ±10% error interval when compared with the experimental data. Additionally, the effect of the pipe eccentricity on frictional pressure loss and tangential velocity using CFD for laminar and turbulent flow is also examined. It has been observed that pipe eccentricity drastically increases the tangential velocity inside the annulus; especially, the flow regime is turbulent and frictional pressure loss decreases as the pipe eccentricity increases.

Modeling of pressure losses on friction in three-layer laminar flows

2003 ◽  
Vol 3 ◽  
pp. 208-219
Author(s):  
A.M. Ilyasov
Keyword(s):  
Pressure Loss ◽  
Gas Flow ◽  
Mutual Influence ◽  
Fluid Model ◽  
Immiscible Liquid ◽  
Laminar Flows ◽  
Pressure Losses ◽  
Flow Parameters ◽  
Interphase Boundaries ◽  
Closing Relations

In this paper we propose a model for determining the pressure loss due to friction in each phase in a three-layer laminar steady flow of immiscible liquid and gas flow in a flat channel. This model generalizes an analogous problem for a two-layer laminar flow, proposed earlier. The relations obtained in the final form for the pressure loss due to friction in liquids can be used as closing relations for the three-fluid model. These equations take into account the influence of interphase boundaries and are an alternative to the approach used in foreign literature. In this approach, the wall and interphase voltages are approximated by the formulas for a single-phase flow and do not take into account the mutual influence of liquids on the loss of pressure on friction in phases. The distribution of flow parameters in these two models is compared.

scholarly journals Proposal of a stage-by-stage design method and its application on a multi-stage multiphase pump based on numerical simulations

2021 ◽  
Vol 13 (1) ◽  
pp. 168781402098731
Author(s):  
Yi Shi ◽  
Hongwu Zhu
Keyword(s):  
Volume Fraction ◽  
Design Method ◽  
Oil Field ◽  
Stage Design ◽  
Multiphase Pump ◽  
Flow Parameters ◽  
Multi Stage ◽  
Comparison Results ◽  
Third Stage ◽  
Gas Volume

Rotodynamic multiphase pumps are usually equipped with many compression units to provide sufficient boosting pressure for the transportation of production fluid in gas oil field. It is a challenge to maintain pump performance while flow parameters in each stage vary due to the compressibility of gas-liquid phase. In this article, a stage-by-stage design method is proposed to improve the boosting capability of a multiphase pump. Variations of flow parameters in each stage are investigated based on computational fluid dynamics (CFD) numerical simulation. Available methods to determinate main impeller geometry parameters of impeller are discussed. The stage-by-stage design method is applied on a five-stage multiphase pump when the inlet gas volume fraction (GVF) are 30% and 50% separately. The second stage is modified base on its corresponding inlet flow parameters when inlet GVF is 30% while the second and third stage are modified when inlet GVF is 50%. Flow parameters, pressure distribution and velocity distribution are compared between the original pump and modified pump. Differential pressure of the modified pump increases by 53.72 kPa and 58.57 kPa respectively when inlet GVFs are 30% and 50%. The feasibility of the stage-by-stage design method is verified through the comparison results.

Modeling of Newtonian Fluids in Annular Geometries With Inner Pipe Rotation

2010 ◽  
Author(s):  
Mehmet Sorgun ◽  
Jerome J. Schubert ◽  
Ismail Aydin ◽  
M. Evren Ozbayoglu
Keyword(s):  
Axial Velocity ◽  
Pressure Loss ◽  
Tangential Velocity ◽  
Flow Characteristics ◽  
Newtonian Fluids ◽  
Flow Loop ◽  
Eccentric Annulus ◽  
Pressure Losses ◽  
Proposed Model ◽  
Pipe Rotation

Flow in annular geometries, i.e., flow through the gap between two cylindrical pipes, occurs in many different engineering professions, such as petroleum engineering, chemical engineering, mechanical engineering, food engineering, etc. Analysis of the flow characteristics through annular geometries is more challenging when compared with circular pipes, not only due to the uneven stress distribution on the walls but also due to secondary flows and tangential velocity components, especially when the inner pipe is rotated. In this paper, a mathematical model for predicting flow characteristics of Newtonian fluids in concentric horizontal annulus with drill pipe rotation is proposed. A numerical solution including pipe rotation is developed for calculating frictional pressure loss in concentric annuli for laminar and turbulent regimes. Navier-Stokes equations for turbulent conditions are numerically solved using the finite differences technique to obtain velocity profiles and frictional pressure losses. To verify the proposed model, estimated frictional pressure losses are compared with experimental data which were available in the literature and gathered at Middle East Technical University, Petroleum & Natural Gas Engineering Flow Loop (METU-PETE Flow Loop) as well as Computational Fluid Dynamics (CFD) software. The proposed model predicts frictional pressure losses with an error less than ± 10% in most cases, more accurately than the CFD software models depending on the flow conditions. Also, pipe rotation effects on frictional pressure loss and tangential velocity is investigated using CFD simulations for concentric and fully eccentric annulus. It has been observed that pipe rotation has no noticeable effects on frictional pressure loss for concentric annuli, but it significantly increases frictional pressure losses in an eccentric annulus, especially at low flow rates. For concentric annulus, pipe rotation improves the tangential velocity component, which does not depend on axial velocity. It is also noticed that, as the pipe rotation and axial velocity are increased, tangential velocity drastically increases for an eccentric annulus. The proposed model and the critical analysis conducted on velocity components and stress distributions make it possible to understand the concept of hydro transport and hole cleaning in field applications.

scholarly journals Gas turbine outlets: test results

2020 ◽  
Vol 4 (394) ◽  
pp. 121-128
Author(s):  
Nikolay N. Ponomarev
Keyword(s):  
Experimental Study ◽  
Gas Turbine ◽  
Pressure Loss ◽  
Total Pressure ◽  
Mutual Influence ◽  
Engineering Calculation ◽  
Total Pressure Loss ◽  
Flow Section ◽  
Pressure Losses ◽  
Flow Parameters

Object and purpose of research. The object of this work is gas turbine outlet consisting of axial-radial diffuser with the struts and the volute. The purpose is to create a methodology for engineering calculations, taking into account the mutual influence of the diffuser and the volute. Materials and methods. Experimental study of the flow in the models of outlets by measuring total and static pressure in characteristic sections. Calculation of integral and averaged flow parameters in measurement sections. Visualization of boundary flows. Based on the experimental results, development of regression models for the correction factors to be applied in the theoretical model, with selection of relevant factors. Main results. An experimental study of 23 variants of models with a total volume of 112 experimental points (modes) was carried out. On the basis of the experiment, methodology and program for engineering calculation of total pressure losses in the outlets were developed. It was found that the installation of guide blades and radial ribs in the diffuser in order to reduce local expansion angles with the ultimate purpose of mitigating total pressure losses actually does not lead to this result due to the because the flow in the diffuser becomes asymmetric due to its interaction with the volute. Visualization of boundary flows in the diffusers and the volutes has been performed, which makes it possible to identify the locations of separations causing increased pressure losses. Conclusion. An engineering method for calculating the total pressure loss in gas turbine outlet has been developed. The technique makes it possible, taking size restrictions into account, to select the geometry of the flow section that ensures minimum total pressure loss.

Hemodynamics of the Fontan Connection: An In-Vitro Study

1995 ◽  
Vol 117 (4) ◽  
pp. 423-428 ◽  
Author(s):  
Young H. Kim ◽  
P. G. Walker ◽  
A. A. Fontaine ◽  
S. Panchal ◽  
A. E. Ensley ◽  
...  
Keyword(s):  
Pressure Loss ◽  
Superior Vena ◽  
Fontan Operation ◽  
Vena Cava ◽  
In Vitro Study ◽  
Magnetic Resonance Images ◽  
Flow Loop ◽  
Pressure Losses ◽  
The Right

The Fontan operation is one in which the right heart is bypassed leaving the left ventricle to drive the blood through both the capillaries and the lungs, making it important to design an operation which is hemodynamically efficient. The object here was to relate the pressure in Fontan connections to its geometry with the aim of increasing the hemodynamically efficiency. From CT or magnetic resonance images, glass models were made of realistic atrio-pulmonary (AP) and cavo-pulmonary (CP) connections in which the right atrium and/or ventricle are bypassed. The glass models were connected to a steady flow loop and flow visualization, pressure and 3 component LDA measurements made. In the AP model the large atrium and curvature of the conduit created swirling patterns, the magnitude of which was similar to the axial velocity. This led to an inefficient flow and a subsequent large pressure loss (780 Pa). In contrast, the CP connection with a small intra-atrial chamber had reduced swirling and a significantly smaller pressure loss (400 Pa at 8 l.min) and was therefore a more efficient connection. There were, however, still pressure losses and it was found that these occurred where there was a large bending of the flow, such as from the superior vena cava to the MPA and from the MPA to the right pulmonary artery.

Dynamic Processes During Pulsed Gas Injection Into Liquid Column

2016 ◽  
Author(s):  
P. D. Lobanov ◽  
O. N. Kashinsky ◽  
A. S. Kurdyumov ◽  
N. A. Pribaturin
Keyword(s):  
Liquid Metal ◽  
Gas Phase ◽  
Gas Injection ◽  
High Amplitude ◽  
Metal Alloy ◽  
Dynamic Processes ◽  
Flow Parameters ◽  
Liquid Metal Alloy ◽  
Inner Diameter ◽  
Gas Volume

An experimental study of dynamic processes during pulsed gas injection into quiescent liquids was performed. Both water and low melting temperature metal alloy were used as test liquids. Air and argon were used as gas phase. The test sections were vertical cylindrical columns 25 and 68 mm inner diameter. Measurements of flow parameters during gas injection were performed. Water – air experiments were performed at room temperature, the temperature of liquid metal alloy was 135 deg C. Time records of pressure in the liquid and in gas phase above the liquid were obtained. Measurements of liquid temperature and level of liquid surface were performed. It was shown that at pulse gas injection into liquid metal high amplitude pressure fluctuation may arise. Also the fluctuation variation of the free surface of the liquid may appear which are connected with the oscillations of the gas volume. Experimental data obtained may be used for verification & validation of modern CFD codes.

scholarly journals Turbulence model performance for ventilation components pressure losses

2021 ◽  
Author(s):  
Karsten Tawackolian ◽  
Martin Kriegel
Keyword(s):  
Reynolds Number ◽  
Turbulence Model ◽  
Pressure Loss ◽  
Low Reynolds Number ◽  
Turbulence Models ◽  
Reynolds Numbers ◽  
Test Case ◽  
Pressure Losses ◽  
Loss Coefficients ◽  
Near Wall

AbstractThis study looks to find a suitable turbulence model for calculating pressure losses of ventilation components. In building ventilation, the most relevant Reynolds number range is between 3×104 and 6×105, depending on the duct dimensions and airflow rates. Pressure loss coefficients can increase considerably for some components at Reynolds numbers below 2×105. An initial survey of popular turbulence models was conducted for a selected test case of a bend with such a strong Reynolds number dependence. Most of the turbulence models failed in reproducing this dependence and predicted curve progressions that were too flat and only applicable for higher Reynolds numbers. Viscous effects near walls played an important role in the present simulations. In turbulence modelling, near-wall damping functions are used to account for this influence. A model that implements near-wall modelling is the lag elliptic blending k-ε model. This model gave reasonable predictions for pressure loss coefficients at lower Reynolds numbers. Another example is the low Reynolds number k-ε turbulence model of Wilcox (LRN). The modification uses damping functions and was initially developed for simulating profiles such as aircraft wings. It has not been widely used for internal flows such as air duct flows. Based on selected reference cases, the three closure coefficients of the LRN model were adapted in this work to simulate ventilation components. Improved predictions were obtained with new coefficients (LRNM model). This underlined that low Reynolds number effects are relevant in ventilation ductworks and give first insights for suitable turbulence models for this application. Both the lag elliptic blending model and the modified LRNM model predicted the pressure losses relatively well for the test case where the other tested models failed.

scholarly journals Effect of the Gas Volume Fraction on the Pressure Load of the Multiphase Pump Blade

Processes ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 650
Author(s):  
Guangtai Shi ◽  
Dandan Yan ◽  
Xiaobing Liu ◽  
Yexiang Xiao ◽  
Zekui Shu
Keyword(s):  
Flow Rate ◽  
Static Pressure ◽  
Volume Fraction ◽  
Pump Impeller ◽  
Impeller Blade ◽  
Multiphase Pump ◽  
Pressure Load ◽  
Gas Volume Fraction ◽  
Power Capability ◽  
Gas Volume

The gas volume fraction (GVF) often changes from time to time in a multiphase pump, causing the power capability of the pump to be increasingly affected. In the purpose of revealing the pressure load characteristics of the multiphase pump impeller blade with the gas-liquid two-phase case, firstly, a numerical simulation which uses the SST k-ω turbulence model is verified with an experiment. Then, the computational fluid dynamics (CFD) software is employed to investigate the variation characteristics of static pressure and pressure load of the multiphase pump impeller blade under the diverse inlet gas volume fractions (IGVFs) and flow rates. The results show that the effect of IGVF on the head and hydraulic efficiency at a small flow rate is obviously less than that at design and large flow rates. The static pressure on the blade pressure side (PS) is scarcely affected by the IGVF. However, the IGVF has an evident effect on the static pressure on the impeller blade suction side (SS). Moreover, the pump power capability is descended by degrees as the IGVF increases, and it is also descended with the increase of the flow rate at the impeller inlet. Simultaneously, under the same IGVF, with the increase of the flow rate, the peak value of the pressure load begins to gradually move toward the outlet and its value from hub to shroud is increased. The research results have important theoretical significance for improving the power capability of the multiphase pump impeller.

Annular Frictional Pressure Losses During Drilling—Predicting the Effect of Drillstring Rotation

2014 ◽  
Vol 136 (3) ◽  
Author(s):  
Arild Saasen
Keyword(s):  
Rheological Properties ◽  
Pressure Loss ◽  
Drilling Fluid ◽  
Axial Flow ◽  
Drilling Fluids ◽  
Unstable Flow ◽  
Pressure Losses ◽  
Shear Dependent Viscosity ◽  
Water Based ◽  
Dependent Viscosity

Controlling the annular frictional pressure losses is important in order to drill safely with overpressure without fracturing the formation. To predict these pressure losses, however, is not straightforward. First of all, the pressure losses depend on the annulus eccentricity. Moving the drillstring to the wall generates a wider flow channel in part of the annulus which reduces the frictional pressure losses significantly. The drillstring motion itself also affects the pressure loss significantly. The drillstring rotation, even for fairly small rotation rates, creates unstable flow and sometimes turbulence in the annulus even without axial flow. Transversal motion of the drillstring creates vortices that destabilize the flow. Consequently, the annular frictional pressure loss is increased even though the drilling fluid becomes thinner because of added shear rate. Naturally, the rheological properties of the drilling fluid play an important role. These rheological properties include more properties than the viscosity as measured by API procedures. It is impossible to use the same frictional pressure loss model for water based and oil based drilling fluids even if their viscosity profile is equal because of the different ways these fluids build viscosity. Water based drilling fluids are normally constructed as a polymer solution while the oil based are combinations of emulsions and dispersions. Furthermore, within both water based and oil based drilling fluids there are functional differences. These differences may be sufficiently large to require different models for two water based drilling fluids built with different types of polymers. In addition to these phenomena washouts and tool joints will create localised pressure losses. These localised pressure losses will again be coupled with the rheological properties of the drilling fluids. In this paper, all the above mentioned phenomena and their consequences for annular pressure losses will be discussed in detail. North Sea field data is used as an example. It is not straightforward to build general annular pressure loss models. This argument is based on flow stability analysis and the consequences of using drilling fluids with different rheological properties. These different rheological properties include shear dependent viscosity, elongational viscosity and other viscoelastic properties.

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