Water-based Drilling Mud Research Articles

Modified Corn Starch as an Environmentally Friendly Rheology Enhancer and Fluid Loss Reducer for Water-Based Drilling Mud

SummaryDrilling fluid rheology and fluid loss property are fundamental parameters that dictate the effectiveness and easiness of a drilling operation. Maintaining these parameters under high temperatures is technically challenging and has been an exciting research area for the drilling industry. Nonetheless, the use of drilling mud additives, particularly synthetic polymers, threaten ecological environments. Herein, modified corn starch (MCS) was synthesized, characterized, and investigated as an environmentally friendly rheology enhancer and filtration loss controlling agent for water-based mud (WBM) at high temperatures. The experimental results indicated that MCS exhibits better performance in improving rheological properties and fluid loss controlling ability for WBM than the commonly used mud additives. With the addition of an optimal concentration (0.3 wt%), MCS improved the rheology and fluid loss behavior of WBM formulation at harsh aging temperature (220°C) by practically 4 times and 1.7 times, respectively. The MCS was revealed to perform superbly over polyanionic cellulose (PAC) addition at all investigated temperatures. The better performance of the MCS was ascribed to the improved entanglements in the mud system owing to the additional hydroxyl (OH) groups. Besides, the Herschel-Bulkley model was found to be a constitutive model that described the rheological properties of the investigated muds satisfactorily. Moreover, the MCS was found to exhibit acceptable biodegradability properties.

Evaluation of using waste pinecones as an eco-friendly additive to water-based mud

This study is investigating the possibility of using pinecones as additive materials to develop a water-based drilling mud. Pinecones are environmentally friendly agricultural wastes and have no practical applications. Therefore, this study is of great importance in that it highlights the investment of these natural waste materials in practical fields. The study focused on the effectiveness of pinecone powder in a water-based drilling mud. To this end, an experimental study on five types of pinecones (Austrian pinecones, Black Hills Spruce, Sitka Spruce, Norway Spruce, and White pinecones) was performed and tested to determine their ability to reduce filter loss and also the effect of those eco-friendly materials on the rheological properties and density of the mud. In the study, 26 samples of water-based mud mixed with the different types of pinecones at different concentrations based on the weight of mud sample (1 wt%, 2 wt%, 3 wt%, 4 wt%, and 5 wt%) were used to perform the experiments. The results of the study showed that pinecones have a great ability to reduce filter loss, particularly Norway Spruce cones, which, based on this study, are considered the superior type with a concentration of 3 wt%.

Effect of Cassava Starch and Sodium Carbonate on the Properties of Local Drilling Mud: Beneficiation to Improve the Rheological and Flow Properties of Locally Formulated Mud

Drilling mud is a key component in drilling operations and in accessing oil and gas reservoirs. Bentonite is applied as a viscosifier, fluid loss control agent, and as a weighting material in water-based drilling mud. The type of bentonite used in drilling mud formulation is sodium bentonite due to its high dispersion properties and high swelling capacity. Nigeria has a huge bentonite clay deposit resources which can be evaluated and enhanced in order to be utilized as drilling mud. However, bentonite clay from different parts of Nigeria was investigated and found to be calcium bentonite which is not suitable for drilling mud, because it has low swelling capacity and poor rheological properties. In this study, local bentonite obtained from Afuze, Edo state was used to formulate different samples of drilling mud with each treated using thermo-chemical beneficiation process with sodium carbonate and cassava starch, and then undergo characterization to identify the changes in physical properties and finally, draw comparison with API values for standard drilling mud. The results obtained from this study indicates that, the flow and rheological properties of the beneficiated drilling mud developed through thermo-chemical treatment, showed significant improvement compared to the untreated mud. Therefore, pure calcium bentonite from natural deposits in Nigeria can be modified to sodium bentonite and sufficiently used in drilling mud formulation.

Experimental investigation of water based drilling mud by using graphene

In the oil and gas industry, the need for a particular composition-based drilling mud is characterized by its rheological and fluid loss properties. Enhancing these properties will increase the efficiency of drilling fluid and, hence, the wellbore damage will be controlled. Recent advancements show that the application of nanoparticles in drilling fluids will enhance their efficiency. This research investigates the influence of adding graphene nanoparticles on the performance of water-based drilling fluids. The main objective of this experiment was to investigate the effect of nanoparticles on water-based drilling mud with different concentrations of nanoparticles added to the mud.

Rheological properties of clay-polymer systems: application on water-based drilling mud

Rheological properties of clay-polymer systems: application on water-based drilling mud

Multiscale Approaches Including ANN and M5P-Tree with SI and OBJ Assessment Tools to Predict the Shear Thinning of Bentonite Drilling Muds Modified with Clay Nanosize at Various Elevated Temperatures

Improving the flowability behavior of the water-based drilling mud (WBM) using bentonite under high-temperature conditions is significant in the drilling borehole operations. In this study, the influence of bentonite and clay nanoparticle (CNP) contents on the non-Newtonian fluid (rheology) properties such as initial shear stress and fluid’s resistance to flow (viscosity) under high-temperature conditions were tested and quantified. The shear stress and shear strain rate relationships of WBM were simulated using two new rheological models of the vapor pressure and modified Hoerl models, and the modeling outcomes were validated with the Herschel–Bulkley (HB) model. This study also analyzed and formulated more than 268 data sets, including observational data and data obtained from previously published studies ranging with bentonite in the drilling muds from 2% to 8% (%wt. of water), 0% to 1% of CNP (%wt. of bentonite), and heating temperatures were ranging from 25°C to 100°C. The HB rheological model predicted initial shear stress better than the other two rheological models depending on several statistical assessments. The initial shear stress of drilling muds can be predicted well based on bentonite, CNP contents, and temperature using various simulation techniques. According to several statistical tests, the nonlinear regression and artificial neural network (ANN) performed stronger than other model techniques to predict the yield stress of WBM as a function of bentonite, CNP contents, and temperature.

Characterization of magnesium oxide nanoparticle for water-based drilling mud formulation

This research is based on the synthesis and analysis to determine the efficiency and cost effectiveness of nanoparticle materials used in drilling fluid during oilfield exploration process. The study was carried out in the formulation of a waterbased drilling fluid, in which the prepared additives were treated with magnesium oxide (MgO) nanoparticles. The rheological properties of nanoparticle materials, such as flow time, viscosity, shear rate, shear stress, torque difference, and separation of solids and liquids, have been determined. The study also analyzed the fluid loss with respect to time in a manual filter press for low temperature and low pressure versus high pressure and high temperature using filter press hydraulic dead weight assembly in high temperature and high pressure. The nanoparticle used for the study was characterized using Fourier transform infrared spectroscopy (FTIR), X-ray diffractometer and particle size analyzer. Viscosity parameters were optimized using a multi-speed viscometer, lubricity tester and pH meter at effective concentration, as well as contact time, temperature and pressure changes as a function of concentration. The study suggests the use of MgO nanoparticle as an additive for water-based mud exploration in oilfields.

Investigation of rheological and filtration properties of water-based drilling mud using commercially available additives

Drilling fluids are an essential component of the drilling system. Conventional copolymers have shown degradation at high temperature. To significantly improve the drilling fluid, the use of nanoparticles (NPs) for advancement of their rheological properties and fluid loss control is introduced. In this study commercially available additives, barite and nano-silica, are taken and in varying concentrations to identify the most optimized fluid that can be used for drilling operations. With this we hope to reiterate the significant difference between the ability of nanomaterials and other additives and verify those claims by performing experimentation. The observation in the past researches and the experimentation concur that nanoparticle enhanced mud has better rheological and improved filtration properties compared to the barite mud.

Characterization based machine learning modeling for the prediction of the rheological properties of water-based drilling mud: an experimental study on grass as an environmental friendly additive

The successful drilling operation depends upon the achievement of target drilling attributes within the environmental and economic constraints but this is not possible only on the basis of laboratory testing due to the limitation of time and resources. The chemistry of the mud decides its rheological potential and selection of the techniques required for recycling operations. Conductivity, pH, and photometer testing were performed for the physio-chemical characterization of the grass to be used as an environmental friendly drilling mud additive. In this study, different particle sizes (75, 150, and 300 µm) of grass powder were mixed in mud density of 8.5, 8.6, and 8.7 ppg in the measurement of gel strength and viscosity of drilling mud. The grass additive was added in different weight conditions considering no additive, 0.25, 0.5, and 1 g to assess the contribution of grass on the gel strength and viscosity of the drilling mud. The machine learning techniques (Multivariate Linear Regression Analysis, Artificial Neural Network, Support Vector Machine Regression, k-Nearest Neighbor, Decision Stump, Random Forest, and Random Tree approaches) were applied to the generated rheological data. The results of the study show that grass can be used for the improvement of the gel strength and viscosity of the drilling mud. The highest improvement of the viscosity was seen when grass powder of 150 µm was added in the 8.7 ppg drilling mud in 0.25, 0.5, and 1 g weights. The gel strength of the drilling mud was improved when the grass additive was added to the drilling mud 8.7 ppg. Random forest and Artificial Neural Network had the same results of 0.72 regression coefficient (R2) for the estimation of viscosity of the drilling mud. The random tree was found as the most effective technique for the modeling of gel strength at 10 min (GS_10min) of the drilling mud. The predictions of Artificial Neural Network had 0.92 R2 against the measured gel strength at 10 s (GS_10sec) of the drilling mud. On average, Artificial Neural Network predicted the rheological properties of the mud with the highest accuracy as compared to other machine learning approaches. The work may serve as a key source to estimate the net effect of grass additives for the improvement of the gel strength and viscosity of the drilling mud without the performance of any large number of laboratory tests.

Synthesis of Hematite Nano Material and Its Effect on Properties of Water Based Drilling Mud

The worldwide use of nanotechnology in most industries, such as in oil and gas industries, the world now has been directed towards introducing this modern technology in drilling fluids for the purpose of reaching and extracting hydrocarbons that exist at high depth where high temperatures and high pressure present using this technology to achieve the required mud properties with lowest cost.
 In this research, the particles of Nano hematite were prepared in laboratory using two methods, the first method by chemical reaction between iron nitrate (Fe (NO3)3• 9H2O) and ammonium hydroxide (NH4OH), after that, prepared Nano-materials were subjected to AFM, XRD testing in order to investigate the size and type of particles, the investigations showed that the formed particles were Fe2O3 (<100nm). The second method is similar to the first method except adding (CTAB) material in order to reduce the interfacial tension leading to 4.5nm Nano-material. Three samples of drilling mud were prepared, the first sample was prepared from water and bentonite only, the second sample was prepared from water, bentonite and nano (prepared from first method), the third samples was prepared from water, bentonite and nano (prepared from second method), rheological properties, filtration, density, lubricity, sagging and magnetism properties were measured by analyzing and comparing the results. The results were obtained showed that the small effect of nano material filtration, density, lubricity, and sagging properties, except the viscosity increase when the second sample of Nano hematite was added to the mud prepared from water and bentonite. Also, the magnetism increase when the second sample of nano hematite was added to the mud prepared from water and bentonite, due to the difference in the molecular arrangement caused by the presence of CTAB.

Effect of Two Types of Fly Ash on Rheological and Filtration Properties of Water-Based Drilling Mud

In this study, the usage of class F fly ash (brown coal) and class C fly ash (lignite) with increasing concentration in water based mud mainly composed of bentonite dispersion was investigated at ambient conditions. Experimental results indicate that efficiency of the mud is significantly controlled by type of the fly ash tested and its concentrations. The results show that Class F fly ash enhanced filtration properties (filtrate loss and mud cake) of the mud and have no effect on the rheology including, yield point, viscosity whereas the class C fly ash increased the rheology parameters and degraded water loss into the formation and filer cake thickness dramatically. This study showed that class F fly ash displays superior performance than class C fly ash. Through this study, it was reveal that class F fly ash is a promising additive to improve the filtration characteristics of bentonite based drilling fluids, thereby contributing to reducing formation damage caused by drilling mud.

Production of water-based mud for drilling operation application

A successful drilling operation is heavily dependent on the effectiveness of the drilling fluid's design in use. This study attempts to evaluate the rheological and filtration properties of water-based drilling mud (WBDM) upon the addition of Stearyl Acrylate-Behenyl Acrylate (SABA) copolymer, silicon dioxide (SiO2), and nickel (III) oxide (Ni2O3) nanoparticles. This SABA copolymer-nanofluid was prepared by dissolving the nanofluid in a SABA polymer solution and homogenizing it using ultrasonication. The properties were studied using mud balance, viscometer, and low-pressure low-temperature (LPLT) filter press. The rheological and filtration properties of SABA copolymer were found to imply that it could improve drilling fluid performance. However, the addition of nanoparticles gave a better performance of rheological and filtration properties on WBDM. SABA copolymer with 5000 ppm concentration shows the best performance due to showing the highest viscosity compared to basic drilling fluid. Also, the addition of 800 ppm of Ni2O3 concentration into 5000 ppm of SABA shows the lowest fluid losses. The experimental results indicate that SABA copolymer shows a great potential application and the addition of nanoparticles shows that nanotechnology has a lot of potentials to improve WBM performance

Experimental measurement and modeling of water-based drilling mud density using adaptive boosting decision tree, support vector machine, and K-nearest neighbors: A case study from the South Pars gas field

Exact determination of drilling mud weight in order to prevent fracture pressure and at the same time overcoming pore pressure is a key parameter in the drilling of oil and gas wells. Accurate design of drilling mud weight increases drilling safety, reduces mud loss, and also the duration of drilling operations. In this study, five efficient artificial intelligent models including Bayesian ridge regression (BRR), K-nearest neighbors (KNN), support vector machine (SVM), decision tree (DT), and Adaptive Boosting Regressor with Decision Tree (ABR-DT) were proposed for estimating mud weight based on a databank of 817 data points from five wells in the South Pars gas field. Variables influencing mud weight include true vertical depth (TVD), hole size, inclination, funnel viscosity, yield point (YP), plastic viscosity (PV), gel strength (measured at 10th second, 10th minute, and 30th minute), API fluid loss (FL), mud type (seawater, KCl-polymer, and salt-polymer), and formation lithology. According to the statistical analysis, the proposed ABR-DT and DT were the most accurate approaches that could predict mud weight with average absolute percent relative errors (AARE) of 0.5159% and 0.7560%, respectively. The accuracy of the models was ranked as: ABR-DT > DT > SVM > KNN > BRR. The sensitivity analysis showed that the predicted mud density is highly influenced by the values of plastic viscosity and true vertical depth. Lastly, the Leverage approach confirmed the validity of the employed data and the applicability area of the proposed ABR-DT model. • BRR, KNN, SVM, DT, and ABR-DT intelligent models were proposed for estimating water-base mud density. • A databank of 817 data points from five wells in the South Pars gas field was used. • Actual field data were used for the first time as inputs of the models. • The accuracy of the models was ranked as: ABR-DT > DT > SVM > KNN > BRR. • The predicted mud density is highly influenced by the values of plastic viscosity and true vertical depth.

Investigation into the Application of Cissus Populnea as Drilling Fluid Additive (Viscosifier) for Water Based Mud

Progress in drilling engineering demands more sophistication from the drilling mud in order to enhance the usage of drilling fluids, hence numerous additives were introduced, and a simple fluid became a complicated mixture of liquid, solid and chemicals. Some of the challenges with the existing drilling fluid additives has to do with compatibility, degradability, safety, cost, and environmental friendliness. Studies have been carried out on the economic benefits of Cissus Populnea which includes in areas of food, medicine, shelter, and transport but much attention has been paid to its applications in the Oil and Gas industry. This study investigates the rheological properties of Cissus Populnea for application as drilling fluid additive (viscosifier) in Water Based Drilling Mud. Fresh roots, stems and leaves of cissus populnea were sourced from Bayara, Bauchi State. Some liquid exudates of cissus populnea were collected and stored for analysis while some of the samples were dried and grinded in to powdered form. Exudate of the samples were characterized by FTIR, XRD and XRF. Drilling mud was formulated with the samples cisssus populnea and bentonite at different temperatures. The rheology of the formulated drilling mud was investigated and compared with that formulated using bentonite and carboxymethyl cellulose (CMC). Results from X-ray Fluorescence analysis show that the chemical composition of Cissus populnea stem and root are similar when comparing their major components (In2O3 and CaO), while that of leaf has its major components to be In2O3 and Cl. Therefore, in this research work, experiments were conducted with only stem and leaf since stem and roots have common features. From the results of FTIR spectra, the stem of cissus populnea has an OH peak wavelength of 3487.42 cm-1 while that of leave is 3340.82 cm-1. The diffractogram of the stem of cissus populnea was observed at 2q = 22.67o which is very close to that of CMC (2? = 20.31o) while the intense peaks of leaf were observed at around 28.65o. Viscosity of cissus populnea was investigated and found to be decreasing with the increase in temperature for stem exudate. While for leaf exudate, the viscosity was rather increasing with the increase in temperature at temperatures below 35 oC and then continue to decrease with the increase in temperature. The outcome of this research has confirmed the applicability of cissus populnea for drilling fluid additives, viscosifier.

Investigation into the Application of Cissus Populnea as Drilling Fluid Additive (Viscosifier) for Water Based Mud

Progress in drilling engineering demands more sophistication from the drilling mud in order to enhance the usage of drilling fluids, hence numerous additives were introduced, and a simple fluid became a complicated mixture of liquid, solid and chemicals. Some of the challenges with the existing drilling fluid additives has to do with compatibility, degradability, safety, cost, and environmental friendliness. Studies have been carried out on the economic benefits of Cissus Populnea which includes in areas of food, medicine, shelter, and transport but much attention has been paid to its applications in the Oil and Gas industry. This study investigates the rheological properties of Cissus Populnea for application as drilling fluid additive (viscosifier) in Water Based Drilling Mud. Fresh roots, stems and leaves of cissus populnea were sourced from Bayara, Bauchi State. Some liquid exudates of cissus populnea were collected and stored for analysis while some of the samples were dried and grinded in to powdered form. Exudate of the samples were characterized by FTIR, XRD and XRF. Drilling mud was formulated with the samples cisssus populnea and bentonite at different temperatures. The rheology of the formulated drilling mud was investigated and compared with that formulated using bentonite and carboxymethyl cellulose (CMC). Results from X-ray Fluorescence analysis show that the chemical composition of Cissus populnea stem and root are similar when comparing their major components (In2O3 and CaO), while that of leaf has its major components to be In2O3 and Cl. Therefore, in this research work, experiments were conducted with only stem and leaf since stem and roots have common features. From the results of FTIR spectra, the stem of cissus populnea has an OH peak wavelength of 3487.42 cm-1 while that of leave is 3340.82 cm-1. The diffractogram of the stem of cissus populnea was observed at 2q = 22.67o which is very close to that of CMC (2θ = 20.31o) while the intense peaks of leaf were observed at around 28.65o. Viscosity of cissus populnea was investigated and found to be decreasing with the increase in temperature for stem exudate. While for leaf exudate, the viscosity was rather increasing with the increase in temperature at temperatures below 35 oC and then continue to decrease with the increase in temperature. The outcome of this research has confirmed the applicability of cissus populnea for drilling fluid additives, viscosifier.

Analysis of Effects of Foreign Clay and Local Clay Additives on Viscosity of Water Based Drilling Mud

This research compared the viscosity and other allied rheological properties of formulated water based drilling mud using local clay (that is modified with cheap and available additives) and foreign clay. These additives (such as xanthum gum, high viscosity polyanionic cellulose (PAC-R), modified natural polyanionic cellulose (PAC-L), potassium hydroxide (KOH), sodium carbonate (Na2CO3), and barite) are added to enhance/control the rheological properties (such as density, viscosity, yield point and gel strength) of the drilling mud. In this work, the viscosity and other allied rheological properties of water based mud were improved by the use of locally sourced clay from Awgu in Enugu State. The local clay was beneficiated/treated with hydrochloric acid (HCl) and characterized using x-ray fluorescence (XRF) spectrometer. The results of the characterization revealed that the local clay is more of silica which is typical of a kaolinitic clay. Local clay was examined as a possible replacement for foreign bentonite by comparing the rheological properties of water based mud (WBM) with bentonite and WBM with clay. Plastic viscosities (PV) of WBM with bentonite and WBM with clay were found to be 11.7 and 12.3 cP respectively. Other allied properties such as yield point, gel strength, pH and mud weight of WBM with bentonite and WBM with clay adequately compared closely. Laboratory analyses on the effects of three process variables (such as temperature, aging time and dosage of clay/bentonite) on the viscosity of the formulated muds were investigated. The laboratory results show that the readily available additives added to the local clay improved its viscosity and other allied rheological properties for effective drilling of oil and gas well when compared with foreign bentonite.

Chemical, morphological characterizations of Ririwai biotite and determination of yield point of its weighting agent application in drilling mud


 
 
 Chemical, morphological characterizations and drilling mud yield point impact of Ririwai biotite have been investigated and reported in this work. Local Ririwai biotite mined in Doguwa Local Government Area of Kano State was used as a weighting agent in drilling mud formulation. Scanning Electron Microscopy (SEM) characterization, X-ray Diffraction (XRD) and Electron Dispersion X-ray (EDX) analysis of the Ririwai biotite were carried out. Water-based drilling mud was prepared using commercial bentonite according to the API 13A Standard. Effect of gradual addition of Ririwai weighting agent; 0 – 100 wt%, on the yield point of the formulated drilling mud was studied. XRD analysis showed that the dominant mineral phase in the material was biotite. Morphological analysis carried out showed that the Ririwai biotite had a sheet-like morphology while the commercial bentonite had clumpy morphology. The estimated average particle sizes were 60 and 25 μm for the Ririwai biotite and commercial bentonite, respectively. EDX analysis showed that silica-alumina ratio of the Ririwai biotite was 9.3 while that of the commercial bentonite was 1.58. The optimum yield point of the formulated drilling mud was 2.0 lb/100 ft2 corresponding to formulation having 0 – 30 wt% weighting agent composition. The specific gravity of Ririwai biotite was determined as 2.4.
 
 

Evaluation of rheological and filtration properties of a polymeric water-based drilling mud in presence of nano additives at various temperatures

Over the past decades, utilizing water-based muds (WBM) in drilling operations has been significantly increased due to their environmental-friendly characteristics. However, the performance of WBM in drilling operations compared to oil-based muds and synthetic-based muds is lower. Hence, some additives (i.e., polymers, nanoparticles (NPs)) have been added to improve WBM’s rheological properties. The objective of this research is to evaluate the impacts of silica (SiO2) and titanium dioxide (TiO2) NPs on rheological and filtration properties of a polymeric-WBM at 25, 50, and 75 °C. The NPs at concentrations from 0.01 to 0.5 wt% were dispersed in the polymeric WBM. The results revealed that by increasing the concentration of SiO2 NPs, the yield point (YP) and gel strength (GS) values of the base mud were increased by approximately 20% at all temperatures, while TiO2 NPs could only increase YP and GS values at 50 and 75 °C, and to a lesser extent than SiO2 NPs. Both NPs also resulted in decreasing of PV values by more than 20% at all temperatures. The lowest amount of PV was achieved at 0.1 wt% for both NPs. Besides that, both SiO2 and TiO2 NPs reduced fluid loss from the polymeric WBM at all applied temperatures. The lowest amount of fluid loss was obtained at 0.1 wt% SiO2 NPs, by roughly 35% reduction. Furthermore, both NPs also resulted in a higher quality mud cake as compared to the base mud. Overall, it can be concluded that SiO2 NPs followed by TiO2 NPs have great potential to improve the rheological and filtration properties of polymeric WBMs at operational conditions.

Experimental Investigation of MWCNTs Decorated with ZnO Nanoparticles as a Novel Additive in Conventional Water-based Drilling Mud

The effect of multi-walled carbon nanotubes (MWCNTs) decorated with ZnONPs on the rheological and filtration properties of conventional water-based drilling muds (WBDM) was investigated. ZnONPs and MWCNTs were synthesized separately, then MWCNTs were decorated with ZnONPs by chemical vapor deposition method and characterized by scanning electron microscopy and X-ray photoelectron spectroscopy. Synthesized and characterized ZnONPs/MWCNTs were added to conventional WBDM at a rate of 0.001% to 0.01%, and then rheological and filtration loss analyses were performed according to American Petroleum Institute standards. With the addition of ZnONPs/MWCNTs to the conventional WBDM, the values of plastic viscosity, apparent viscosity, yield point, cake thickness, 10 s and 10 min values increased by 42.8%, 31.6%, 28%, 22%, 25%, and 38.9%, respectively, while the value of filtration loss decreased by 13.8%. When all results were examined, the best addition rate was 0.01%. The results obtained show that ZnONPs/MWCNTs improved the rheological and the filtration loss properties of the drilling mud, proving that ZnONPs/MWCNTs can be used as additives in conventional WBDM.

Introducing a Rheology Model for Non-Newtonian Drilling Fluids

An API standard drilling fluid was investigated from laminar to turbulent flow conditions using an in-house-built viscometer at speeds from 200 to 1600 RPM. A power-based method was applied to obtain the apparent viscosity and the shear stress of the water-based drilling mud (WBM) in the annulus of the viscometer. Then, a MATLAB optimization program was developed to obtain model parameters for five rheology models integrated in a generalized Herschel-Bulkley-Extended (HBE) model and two widely used 4-parameter models in drilling industry. It is found that the Bingham, Cross, and HBE rheology models have precisely matched the WBM measurements in the viscometer. A generalized Reynolds number was applied to determine the Darcy friction factor although the PL (power law model) and the HB (Herschel-Bulkley model) exhibited a nonrealistic negative shift from the laminar friction factor.