scholarly journals CFD modeling of particle settling in drilling fluids: Impact of fluid rheology and particle characteristics

2021 ◽  
Vol 199 ◽  
pp. 108326
Author(s):  
Abdelrahman M. Awad ◽  
Ibnelwaleed A. Hussein ◽  
Mustafa S. Nasser ◽  
Hamidreza Karami ◽  
Ramadan Ahmed
Keyword(s):  
Cfd Modeling ◽  
Drilling Fluids ◽  
Particle Settling ◽  
Particle Characteristics ◽  
Fluid Rheology

Application of R/S Rheometer in Low Temperature Drilling Fluid Rheology Determination

2012 ◽  
Vol 490-495 ◽  
pp. 3114-3118
Author(s):  
Xiao Ling Jiang ◽  
Zong Ming Lei ◽  
Kai Wei
Keyword(s):  
Shear Stress ◽  
Shear Rate ◽  
Low Temperature ◽  
High Speed ◽  
Drilling Fluid ◽  
Drilling Fluids ◽  
Rheological Parameter ◽  
Fluid Temperature ◽  
Fluid Rheology ◽  
Rotary Viscometer

With six-speed rotary viscometer measuring the rheology of drilling fluid at low temperature, during the high-speed process, the drilling fluid temperature is not constant at low temperature, which leads to the inaccuracy in rheological measurement. When R/S rheometer is used cooperating with constant low-temperature box , the temperature remains stable during the process of determining the drilling fluid rheology under low temperature. The R/S rheometer and the six-speed rotational viscometer are both coaxial rotational viscometers, but they work in different ways and the two cylindrical clearance between them are different.How to make two viscometer determination result can maintain consistent?The experimental results show that, The use of R/S rheometer, with the shear rate for 900s-1 shear stress values instead of six speed rotary viscometer shear rate for 1022s-1 shear stress values.Then use two-point formula to calculate rheological parameters.The R/S rheometer rheological parameter variation with temperature has a good linear relationship,Can better reflect the rheological properties of drilling fluids with low temperature changerule

scholarly journals CFD Investigation Of Mixing Of Yield-Pseudoplastic Fluid With Anchor Impeller

2021 ◽  
Author(s):  
Poonam Prajapati
Keyword(s):  
Power Consumption ◽  
Mixing Time ◽  
Diameter Ratio ◽  
Cfd Modeling ◽  
Cylindrical Tank ◽  
Flat Bottom ◽  
Pseudoplastic Fluid ◽  
Impeller Blade ◽  
Blade Width ◽  
Fluid Rheology

The Anchor impeller, which is a close clearance impeller, produces high shear near the vessel wall and is recommended for mixing of highly viscous fluids. A thorough search of the literature suggests that few publications have beeen devoted to the computational fluid dynamics (CFD) modeling of mixing of non-Newtonian fluids with the anchor impeller. Thus the objectives of this study are (i)to generate a 3-D flow field for mixing of yield-pseudoplastic fluid in a flat bottom cylindrical tank equipped with two-and four-blade anchor impellers using CFD modeling technique, (ii) to evaluate the effects of fluid rheology agitator speed, number of blades, vessel clearance and impeller blade width on power consumption, mixing time and flow patterns, and (iii) to determine the optimum value of clearance to diameter ratio and impeller blade width to diameter ratio on the basis of minimum mixing time. The study was carried out for a yield-stress pseudoplastic fluid, using a CFD package (Fluent), to simulate the 3-D flow domain generated in a cylindrical tank equipped with two-and four-blade anchor impellers. The multiple reference frame (MRF) technique was employed to model the rotation of impellers. The rheology of the fluid was approximated using the Herschel-Bulkley model. To validate the model, CFD results for the power were compared to experimental data. After the flow fields were calculated, the simulations for tracer homogenization was performed to simulate the mixing time. The effect of impeller speed, fluid rheology, and number of impellers on power consumption, mixing time, and flow pattern were explored. The optimum values of c/D (clearance to diameter) and w/D (impeller blade width to diameter) ratios were determined on the basis of minimum mixing time.

Pectina de Citrus sinensis como viscosificante en fluidos de perforación poliméricos

2020 ◽  
Vol 7 (1) ◽  
pp. 11-22
Author(s):  
Steevenson Barreto ◽  
Luis Castillo Campos
Keyword(s):  
Citric Acid ◽  
Citrus Sinensis ◽  
Xanthan Gum ◽  
Drilling Fluids ◽  
Subsequent Stage ◽  
Experimental Laboratory ◽  
Orange Fruit ◽  
Laboratory Procedures ◽  
The One ◽  
Fluid Rheology

The present investigation was based on the experimental evaluation of the orange-based pectin (Citrus sinensis) as a viscosifier agent in polymeric drilling fluids. To develop the additive, the orange fruit peels were subjected to hydrolysis with citric acid, and then this solution was precipitated with ethanol and the resulting hydrogel was chemically and physically characterized. In the subsequent stage, fluid samples were formulated with xanthan gum and pectin to compare their performance through experimental laboratory procedures governed by API 13-B1. Finally, an Analysis of Variance was applied to determine the means that are significantly different from each other between the commercial product and the one proposed, through the Statgraphics program. In conclusion, it was obtained that pectin showed a statistically similar behavior, although inferior to xanthan gum as a viscosifier additive in polymeric drilling fluids, considering as a variant the expansion of its concentration for fluid rheology optimal development.

scholarly journals Measurement of Drilling Fluid Rheology and Modeling of Thixotropic Behavior

2019 ◽  
Vol 29 (1) ◽  
pp. 1-11 ◽  
Author(s):  
Hans Joakim Skadsem ◽  
Amare Leulseged ◽  
Eric Cayeux
Keyword(s):  
Shear Rate ◽  
Drilling Fluid ◽  
Drilling Fluids ◽  
Rheological Characterization ◽  
Pressure Losses ◽  
Rate Step ◽  
Thixotropic Behavior ◽  
Pump Pressure ◽  
Static Conditions ◽  
Fluid Rheology

Abstract Drilling fluids perform a number of important functions during a drilling operation, including that of lifting drilled cuttings to the surface and balancing formation pressures. Drilling fluids are usually designed to be structured fluids exhibiting shear thinning and yield stress behavior, and most drilling fluids also exhibit thixotropy. Accurate modeling of drilling fluid rheology is necessary for predicting friction pressure losses in the wellbore while circulating, the pump pressure needed to resume circulation after a static period, and how the fluid rheology evolves with time while in static or near-static conditions. Although modeling the flow of thixotropic fluids in realistic geometries is still a formidable future challenge to be solved, considerable insights can still be gained by studying the viscometric flows of such fluids. We report a detailed rheological characterization of a water-based drilling fluid and an invert emulsion oilbased drilling fluid. The micro structure responsible for thixotropy is different in these fluids which results in different thixotropic responses. Measurements are primarily focused at transient responses to step changes in shear rate, but cover also steady state flow curves and stress overshoots during start-up of flow. We analyze the shear rate step change measurements using a structural kinetics thixotropy model.

CFD Modeling of Hydraulic Behavior of Oil- and Water-Based Drilling Fluids in Laminar Flow

2019 ◽  
Vol 34 (03) ◽  
pp. 207-215
Author(s):  
Sneha Sayindla ◽  
Bjørnar Lund ◽  
Jan David Ytrehus ◽  
Arild Saasen
Keyword(s):  
Laminar Flow ◽  
Cfd Modeling ◽  
Drilling Fluids ◽  
Hydraulic Behavior ◽  
Water Based

scholarly journals CFD Investigation Of Mixing Of Yield-Pseudoplastic Fluid With Anchor Impeller

2021 ◽  
Author(s):  
Poonam Prajapati
Keyword(s):  
Power Consumption ◽  
Mixing Time ◽  
Diameter Ratio ◽  
Cfd Modeling ◽  
Cylindrical Tank ◽  
Flat Bottom ◽  
Pseudoplastic Fluid ◽  
Impeller Blade ◽  
Blade Width ◽  
Fluid Rheology

The Anchor impeller, which is a close clearance impeller, produces high shear near the vessel wall and is recommended for mixing of highly viscous fluids. A thorough search of the literature suggests that few publications have beeen devoted to the computational fluid dynamics (CFD) modeling of mixing of non-Newtonian fluids with the anchor impeller. Thus the objectives of this study are (i)to generate a 3-D flow field for mixing of yield-pseudoplastic fluid in a flat bottom cylindrical tank equipped with two-and four-blade anchor impellers using CFD modeling technique, (ii) to evaluate the effects of fluid rheology agitator speed, number of blades, vessel clearance and impeller blade width on power consumption, mixing time and flow patterns, and (iii) to determine the optimum value of clearance to diameter ratio and impeller blade width to diameter ratio on the basis of minimum mixing time. The study was carried out for a yield-stress pseudoplastic fluid, using a CFD package (Fluent), to simulate the 3-D flow domain generated in a cylindrical tank equipped with two-and four-blade anchor impellers. The multiple reference frame (MRF) technique was employed to model the rotation of impellers. The rheology of the fluid was approximated using the Herschel-Bulkley model. To validate the model, CFD results for the power were compared to experimental data. After the flow fields were calculated, the simulations for tracer homogenization was performed to simulate the mixing time. The effect of impeller speed, fluid rheology, and number of impellers on power consumption, mixing time, and flow pattern were explored. The optimum values of c/D (clearance to diameter) and w/D (impeller blade width to diameter) ratios were determined on the basis of minimum mixing time.

Recovery boiler sootblowers: History and technological advances

TAPPI Journal ◽  
2015 ◽  
Vol 14 (1) ◽  
pp. 51-60
Author(s):  
HONGHI TRAN ◽  
DANNY TANDRA
Keyword(s):  
Cfd Modeling ◽  
Computing Systems ◽  
The Past ◽  
Technological Advances ◽  
Recovery Boilers ◽  
Computational Fluid Dynamics Cfd ◽  
Recovery Boiler ◽  
Steam Parameters ◽  
Insight Into ◽  
Deposit Removal

Sootblowing technology used in recovery boilers originated from that used in coal-fired boilers. It started with manual cleaning with hand lancing and hand blowing, and evolved slowly into online sootblowing using retractable sootblowers. Since 1991, intensive research and development has focused on sootblowing jet fundamentals and deposit removal in recovery boilers. The results have provided much insight into sootblower jet hydrodynamics, how a sootblower jet interacts with tubes and deposits, and factors influencing its deposit removal efficiency, and have led to two important innovations: fully-expanded sootblower nozzles that are used in virtually all recovery boilers today, and the low pressure sootblowing technology that has been implemented in several new recovery boilers. The availability of powerful computing systems, superfast microprocessors and data acquisition systems, and versatile computational fluid dynamics (CFD) modeling capability in the past two decades has also contributed greatly to the advancement of sootblowing technology. High quality infrared inspection cameras have enabled mills to inspect the deposit buildup conditions in the boiler during operation, and helped identify problems with sootblower lance swinging and superheater platens and boiler bank tube vibrations. As the recovery boiler firing capacity and steam parameters have increased markedly in recent years, sootblowers have become larger and longer, and this can present a challenge in terms of both sootblower design and operation.

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