Modelling of Drilling Fluid Thixotropy

2018 ◽  
Author(s):  
Eric Cayeux ◽  
Amare Leulseged
Keyword(s):  
Shear Stress ◽  
Shear Rate ◽  
Time Dependence ◽  
Rheological Properties ◽  
Drilling Fluid ◽  
Time Dependent ◽  
Drilling Fluids ◽  
Shear Rates ◽  
Pump Flow Rate ◽  
Drilling Operations

Drilling fluids are visco-elastic materials, i.e. they behave as a viscous fluid when subject to a sufficient shear stress and like an elastic solid otherwise. Both their elastic and viscous properties are time-dependent, i.e. drilling fluids are thixotropic. Because of thixotropy, it takes a finite time before the effective viscosity of a drilling fluid attains an equilibrium when the fluid is subject to a change of shear rate. This effect is visible when one changes the applied shear rate in a rheometer, as the fluid will gradually adapt to the new shearing conditions. When the velocity of a drilling fluid changes, for instance due to a change in pump flow rate, movement of the drill string, or change of flow geometry, the fluid will exhibit a time-dependent response to the new shearing conditions, requiring a certain time to reach the new equilibrium condition. Unfortunately, the time-dependence of the rheological properties of drilling fluids are usually not measured during drilling operations and therefore it is difficult to estimate how thixotropy impacts pressure losses in drilling operations. For that reason, we have systematically measured the time-dependence of the rheological properties of several samples of water-based, oil-based and micronized drilling fluids with a scientific rheometer in order to capture how drilling fluids systems respond to variations of shear rates. Based on these measurements, we propose to investigate how one existing thixotropic model manages to predict the shear stress as a function of the shear rate while accounting for the shear history and gelling conditions. Then we propose a modified model that fits better, overall, with the measurements even though there are still noticeable discrepancies, especially when switching back to low shear rates.

Development of Digital Twins for Drilling Fluids: Local Velocities for Hole Cleaning and Rheology Monitoring

2021 ◽  
Author(s):  
Mehrdad Gharib Shirangi ◽  
Roger Aragall ◽  
Reza Ettehadi ◽  
Roland May ◽  
Edward Furlong ◽  
...  
Keyword(s):  
Machine Learning ◽  
Rheological Properties ◽  
Drilling Fluid ◽  
Training Data ◽  
Drilling Fluids ◽  
Hole Cleaning ◽  
Digital Twins ◽  
Wide Range ◽  
Drilling Operations ◽  
Cuttings Bed

Abstract In this work, we present our advances to develop and apply digital twins for drilling fluids and associated wellbore phenomena during drilling operations. A drilling fluid digital twin is a series of interconnected models that incorporate the learning from the past historical data in a wide range of operational settings to determine the fluids properties in realtime operations. From several drilling fluid functionalities and operational parameters, we describe advancements to improve hole cleaning predictions and high-pressure high-temperature (HPHT) rheological properties monitoring. In the hole cleaning application, we consider the Clark and Bickham (1994) approach which requires the prediction of the local fluid velocity above the cuttings bed as a function of operating conditions. We develop accurate computational fluid dynamics (CFD) models to capture the effects of rotation, eccentricity and bed height on local fluid velocities above cuttings bed. We then run 55,000 CFD simulations for a wide range of operational settings to generate training data for machine learning. For rheology monitoring, thousands of lab experiment records are collected as training data for machine learning. In this case, the HPHT rheological properties are determined based on rheological measurement in the American Petroleum Institute (API) condition together with the fluid type and composition data. We compare the results of application of several machine learning algorithms to represent CFD simulations (for hole cleaning application) and lab experiments (for monitoring HPHT rheological properties). Rotating cross-validation method is applied to ensure accurate and robust results. In both cases, models from the Gradient Boosting and the Artificial Neural Network algorithms provided the highest accuracy (about 0.95 in terms of R-squared) for test datasets. With developments presented in this paper, the hole cleaning calculations can be performed more accurately in real-time, and the HPHT rheological properties of drilling fluids can be estimated at the rigsite before performing the lab experiments. These contributions advance digital transformation of drilling operations.

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

Characterization of the Rheological Behavior of Drilling Fluids

2020 ◽  
Author(s):  
Eric Cayeux ◽  
Amare Leulseged
Keyword(s):  
Shear Rate ◽  
Rheological Behavior ◽  
Drilling Fluid ◽  
Drilling Fluids ◽  
Shear Rates ◽  
Operation Conditions ◽  
Fluid Systems ◽  
Different Temperatures ◽  
The One ◽  
Shear Stress Response

Abstract It is nowadays well accepted that the steady state rheological behavior of drilling fluids must be modelled by at least three parameters. One of the most often used models is the yield power law, also referred as the Herschel-Bulkley model. Other models have been proposed like the one from Robertson-Stiff, while other industries have used other three-parameter models such as the one from Heinz-Casson. Some studies have been made to compare the degree of agreement between different rheological models and rheometer measurements but in most cases, already published works have only used mechanical rheometers that have a limited number of speeds and precision. For this paper, we have taken measurements with a scientific rheometer in well-controlled conditions of temperature and evaporation, and for relevant shear rates that are representative to normally encountered drilling operation conditions. Care has been made to minimize the effect of thixotropy on measurements, as the shear stress response of drilling fluids depends on its shear history. Measurements have been made at different temperatures, for various drilling fluid systems (both water and oil-based), and with variable levels of solid contents. Also, the shear rate reported by the rheometer itself, is corrected to account for the fact that the rheometer estimates the wall shear rate on the assumption that the tested fluid is Newtonian. A measure of proximity between the measurements and a rheological model is defined, thereby allowing the ranking of different rheological behavior model candidates. Based on the 469 rheograms of various drilling fluids that have been analyzed, it appears that the Heinz-Casson model describes most accurately the rheological behavior of the fluid samples, followed by the model of Carreau, Herschel-Bulkley and Robertson-Stiff, in decreasing order of fidelity.

Nano-Enhanced Drilling Fluids: Pioneering Approach to Overcome Uncompromising Drilling Problems

2011 ◽  
Vol 134 (1) ◽  
Author(s):  
J. Abdo ◽  
M. Danish Haneef
Keyword(s):  
Rheological Properties ◽  
Size Distribution ◽  
Oil And Gas ◽  
Drilling Fluid ◽  
Drilling Fluids ◽  
Lost Circulation ◽  
Drilling Operations ◽  
Cost Efficient ◽  
A Chain ◽  
Size Distribution Of Particles

The idea of pushing the limits of drilling oil and gas wells by improving drilling fluids for undemanding and cost efficient drilling operations by extracting advantage from the wonders of nanotechnology forms the basis of the work presented here. Foremost, in order to highlight the significance of reducing the size distribution of particles, new clay ATR which has a chain like structure and offers enormous surface area and increased reactivity was tested in different sizes that were chemically and mechanically milled. Bentonite which is a commonly used drilling fluid additive was also tested in different particle size distribution (PSD) and rheological properties were tested. Significant reduction in viscosity with small sized particles was recorded. The tested material called ATR throughout this paper is shown to offer better functionality than bentonite without the requirement of other expensive additives. Experiments were performed with different size distributions and compositions and drastic changes in rheological properties are observed. A detailed investigation of the shear thinning behavior was also carried out with ATR samples in order to confirm its functionality for eliminating the problem of mechanical and differential pipe sticking, while retaining suitable viscosity and density for avoidance of problems like lost circulation, poor hole cleaning and inappropriate operating hydrostatic pressures.

scholarly journals Viscosity Models for Drilling Fluids—Herschel-Bulkley Parameters and Their Use

Energies ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 5271 ◽  
Author(s):  
Arild Saasen ◽  
Jan David Ytrehus
Keyword(s):  
Shear Rate ◽  
Yield Point ◽  
Drilling Fluid ◽  
Sufficient Accuracy ◽  
Drilling Fluids ◽  
Thermodynamic Quantities ◽  
Shear Rates ◽  
Viscosity Measurements ◽  
Viscosity Models ◽  
Mineralogical Compositions

An evaluation is presented of the practical usage of the Herschel-Bulkley viscosity model for drilling fluids. If data from automatic viscosity measurements exist, the parameters should be selected from relevant shear rate ranges to be applicable. To be able to be used properly, viscosity measurements must be measured with a sufficient accuracy. It is shown that a manual reading of standard viscometers may yield insufficient accuracy. It is also shown that the use of yield point/plastic viscosity (YP/PV) as measured using API or ISO standards normally provide inaccurate viscosity parameters. The use of the Herschel-Bulkley model using dimensionless shear rates is more suitable than the traditional way of writing this model when the scope is to compare different drilling fluids. This approach makes it also easier to make correlations with thermodynamic quantities like pressure and temperature or chemical or mineralogical compositions of the drilling fluid.

The Influence of Drilling Fluid Rheological Properties on Primary Solids Control

2015 ◽  
Author(s):  
Arild Saasen ◽  
Helge Hodne
Keyword(s):  
Rheological Properties ◽  
Drilling Fluid ◽  
Drilling Fluids ◽  
Gel Structure ◽  
Practical Applications ◽  
Drilling Operations ◽  
Exploration Drilling ◽  
Flow Through ◽  
And Performance ◽  
Elliptical Motion

Throughout the last decades, the design and performance of the primary solid control devices have changed significantly. Some five decades ago, the circular motion shakers dominated the marked. These shakers operated by sending the drilling fluid downhill a vibrating screen. Thereafter appeared the elliptical motion or linear motion shakers where the cuttings particles were vibrated upwards a tilted screen. Onto these shakers, the use of double screen decks and finally triple screen decks became common. Within the last years also the vacuum devices appeared. Throughout the last two decades, there has been an effort to increase the g-forces on these shakers and the industry seems to have preferred the high g-force devices recently. Laboratory studies, however, has indicated that the very high g-forces are not necessary to perform proper solids control. Instead, different vibration modes interacts with the gel structure of the drilling fluid and remove yield stresses. Hence, the fluid becomes mobile for flow through the screen. Flow through screens is strongly dependent on the extensional properties within the drilling fluid rheology. Drilling fluids with high extensional viscosity seldom has a very strong gel structure, and are generally not affected equally much by vibrations. This explains why solids control is more difficult using a KCl/polymer water based drilling fluid than if using an oil based drilling fluid. This article focuses on describing how the drilling fluid rheological properties alter during primary solids control. It is based on theoretical analysis, rheological studies in the laboratory and finally on practical applications in two recent exploration drilling operations. The solids control efficiency resulting from using different screen configurations is outside the scope of this article, as this topic requires a higher focus on separation technology.

scholarly journals Influence of Degree of Dispersion of Noncovalent Functionalized Graphene Nanoplatelets on Rheological Behaviour of Aqueous Drilling Fluids

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Arif Ibrahim ◽  
Syahrir Ridha ◽  
Asna Amer ◽  
Radzi Shahari ◽  
Tarek Ganat
Keyword(s):  
Aqueous Solution ◽  
Rheological Properties ◽  
Carbon Nanomaterials ◽  
Drilling Fluid ◽  
Research Work ◽  
Rheological Behaviour ◽  
Graphene Nanoplatelets ◽  
Drilling Fluids ◽  
Shear Rates ◽  
Degree Of Dispersion

Application of carbon nanomaterials in oil well drilling fluid has been previously studied and was found to enhance its filtration properties. There is a general consensus that addition of colloids in suspension will alter its rheology, i.e., carbon nanomaterials, in this research work; graphene nanoplatelets are hydrophobic materials, which require functionalisation to improve its dispersion in aqueous solution. However, different degrees of dispersion may vary the rheological properties behaviour of drilling fluid. The objective of this study was to characterize the colloidal dispersion of graphene nanoplatelets (GNP) in aqueous solution and its impact on the rheological properties behaviour of water-based drilling fluid. Dispersion of graphene nanoplatelets was achieved through noncovalent functionalisation by means of surfactant attachment. UV-visible spectroscopy was employed to analyze the dispersion of GNP in aqueous solution. The rheological test was carried out using a simple direct-indicating viscometer at six different speeds. Results revealed that the degree of dispersion of GNP using Triton X-100 was generally higher than both SDS and DTAB. Comparison between the rheological properties behaviour of drilling fluid with GNP dispersed using different surfactants shows little to no difference at low shear rates. At high shear rates, however, greater dispersion of GNP shows higher thinning properties while fluid with a low dispersion of GNP exhibited linear behaviour to thickening properties.

scholarly journals Rheological behavior of a bentonite mud

2020 ◽  
Vol 30 (1) ◽  
pp. 107-118
Author(s):  
Daniela Martins Marum ◽  
Maria Diná Afonso ◽  
Brian Bernardo Ochoa
Keyword(s):  
Shear Stress ◽  
Shear Rate ◽  
Temperature Effects ◽  
Drilling Fluids ◽  
Drilling Process ◽  
Gas Extraction ◽  
Pseudoplastic Fluid ◽  
Shear Rates ◽  
Couette Viscometer ◽  
Mud Flow

Abstract Predicting drilling fluids rheology is crucial to control/optimize the drilling process and the gas extraction from drilling fluids in logging systems. A Couette viscometer measured the apparent viscosity of a bentonite mud at various shear rates and temperatures. The bentonite mud behaved as a yield-pseudoplastic fluid, and a modified Herschel-Bulkley model predicted the shear rate and temperature effects upon the shear stress. A pipe viscometer was built to seek a correlation between the mud flow rate and the pressure drop and thereby determine refined Herschel-Bulkley parameters. Coupling a rheological model to a pipe viscometer enables the continuous acquisition of apparent viscosities of Newtonian or non-Newtonian fluids at a rig-site surface.

Application of the Quemada Viscosity Model for Drilling Fluids

2021 ◽  
Author(s):  
Sandra Knutsen ◽  
Eric Cayeux ◽  
Arild Saasen ◽  
Mahmoud Khalifeh
Keyword(s):  
Shear Rate ◽  
Yield Stress ◽  
Drilling Fluid ◽  
Model Fit ◽  
Drilling Fluids ◽  
Shear Rates ◽  
Rate Dependent ◽  
Dependent Viscosity ◽  
Very High

Abstract A number of different models are used to describe the shear rate dependent viscosity of drilling fluids. Most, such as the Herschel-Bulkley model, have a purely empirical basis. The Quemada model, while still empirical, is based on physical principles. It is based on the notion that structural units develop in the fluid at low shear rates which are then partially broken down as the applied shear rate increases. In the current work, drilling fluid rheological data are fitted to the Herschel-Bulkley and the Quemada model. The development of the Quemada model and the calculation of each model parameter are presented. We show that the Quemada model better fits measurements over a wider range of shear rates than the Herschel-Bulkley model. We describe how to select the parameters of the Quemada model. Knowing the difficulty of obtaining a known shear rate for fluids with yield stresses, we discuss how this can affect the quality of the Quemada model fit. Furthermore, in principle, the Quemada model is not applicable in presence a non-zero yield stress. Therefore, we show how to handle the yield stress using a (very high) zero shear rate viscosity.

Rheological Properties of Methane Hydrate Slurry in the Presence of Xanthan Gum

SPE Journal ◽  
2020 ◽  
Vol 25 (05) ◽  
pp. 2341-2352 ◽  
Author(s):  
Weiqi Fu ◽  
Zhiyuan Wang ◽  
Baojiang Sun ◽  
Jianchun Xu ◽  
Litao Chen ◽  
...  
Keyword(s):  
Shear Rate ◽  
Rheological Properties ◽  
Newtonian Fluid ◽  
Methane Hydrate ◽  
Xanthan Gum ◽  
Drilling Fluid ◽  
Hydrate Formation ◽  
Shear Thinning ◽  
Shear Rates ◽  
Blowout Preventer

Summary Methane hydrate formation in a xanthan-gum (XG) solution is an important problem for drilling in a deepwater environment. It not only alters the rheology of the drilling fluid in the wellbore but increases the risks of a hydrate blockage in the blowout preventer. The current work is performing groups of experiments to investigate the rheology of the hydrate slurry under XG concentrations of 0.15, 0.2, 0.25, and 0.3%, shear rates from 10 to 480 s−1, and hydrate concentrations from 1.01 to 9.12%. The experimental results show that the hydrate slurry with XG additives exhibits an obvious shear-thinning behavior, which is because the XG solution has strong pseudoplastic characteristics, and the inner structures of the flocculated hydrate particles suspended in the hydrate slurry are broken up during the hydrate-slurry flow. The increase of hydrate concentrations in the hydrate slurry can reduce the non-Newtonian fluid index and make the rheology of the hydrate slurry become more shear-thinning. However, as the XG concentration increases in the hydrate slurry, the influence of the hydrate concentration on the rheology of the hydrate slurry gradually weakens. Empirical Herschel–Bulkley-type equations are developed to describe the rheology of the hydrate slurry with XG for the current experimental condition, considering the shear rate, hydrate concentration, and XG concentration. In the proposed equations, the non-Newtonian factor and the consistency factor are expressed as functions of XG concentration empirically. Correction Notice:The preprint version of this paper was modified from its original version to correct Figs. 8 and 9 and Eqs. 6 through 9 on page 7. Errata explaining the corrections are included below as Supporting Information.

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