Papers by Keyword: Rheological Properties

Abstract: The rheological properties of drilling fluids, such as plastic viscosity, yield point, and gel strength, are critical for ensuring efficient and safe oil and gas well drilling. Traditional methods for rheological analysis, reliant on manual or semi-automated viscometers, suffer from delays and inability to provide continuous data, increasing operational risks. This study presents the development and validation of an automated software-hardware complex designed for real-time monitoring of drilling fluid rheology. The system integrates inline rheometers, pressure and temperature sensors, and advanced data processing algorithms to deliver accurate measurements with a response time of 0.8 seconds. Laboratory tests demonstrated errors of ±4.2% for viscosity and ±7.8% for yield point compared to the Fann 35 viscometer, while field tests under simulated drilling conditions (30–100°C, 5–20 MPa) confirmed reliability with errors below ±9.2%. Case studies showcased rapid detection of anomalies, enabling proactive fluid management. The complex offers a scalable, integrated solution, reducing non-productive time and enhancing well stability. Recommendations include machine learning integration for predictive analytics and cloud-based analytics for remote monitoring, with future work targeting extreme conditions and other fluid types. This advancement significantly improves drilling fluid management, contributing to safer and more efficient drilling operations.

Abstract: Maintaining the optimal properties of drilling fluids such as rheology, fluid loss, and mud cake thickness is crucial for wellbore stability, shale inhibition, and efficient drilling operations. However, the addition of shale swelling inhibitors can alter these properties either positively or negatively, necessitating a thorough investigation of their compatibility and effectiveness. In this study, polyethyleneimine (PEI) and potassium citrate (PC) were used as a shale swelling inhibitor, and their effect on water-based muds’ (WBM) compatibility and rheological properties were investigated and compared to the commercial inhibitor, potassium chloride (KCl). Compatibility tests were conducted to visually examine the water-based drilling fluid after the addition of the shale swelling inhibitors for over 24 hours. Mud density and pH were measured using a mud balance and a pH meter. The rheological properties were then determined using a rotational viscometer by taking readings at 600 rpm and 300 rpm. These are done to observe the flow behavior of the fluids and their abilities to maintain wellbore stability. Further, the fluid loss and mud cake thickness properties of the WBM formulations were determined using a dynamic fluid loss apparatus (HPHT API RP 13B-1) at a pressure of 1000 psi and 90°C. Based on this study, the PEI, PC, and KCl inhibitors were found to be compatible with the drilling fluid as their interactions affected the optical properties but not the physical state. Also, the rheological properties of the WBM were not highly compromised upon the addition of 1 v/v % KCl as a shale inhibitor. However, it was highly compromised upon the addition of 1 v/v % PEI and PC. It was found that cationic PEI interfered with the interactions and structures developed by the anionic components in the drilling fluid. This led to a 16% reduction in viscosity, a 21% reduction in yield point, and a 46% reduction in gel strength. The effects were also most adverse on the fluid loss characteristics of the fluids. In contrast, the use of 1 v/v % PC improved structural integrity and interactions and thus increased the viscosity and the yield point by 16 % and 68 %, respectively. The optimal balance was achieved with the formulation of 0.6 v/v % PEI: 0.4 v/v % PC, which effectively maintained and enhanced the desirable rheological properties of the WBM while maintaining favorable fluid loss control and mud cake formation. The PEI and PC interactions appear to have had a synergistic effect on the overall performance of the WBM.

Abstract: Acrylate-styrene-acrylonitrile (ASA) was filled with waste non-metallic printed circuit boards (WNMPCB). ASA/WNMPCB composites were successfully prepared using various filler concentrations at 0, 10, 20, 30, 40 and 50 phr. Styrene-maleic anhydride (SMA) was also used as a compatibilizer to enhance the properties of ASA/WNMPCB composites. All materials were prepared using a two-roll mill at 245 °C for 15 minutes and test specimens were shaped using a compression molding machine. The effects of different WNMPCB ratios on phase morphology, rheological behavior, density, water absorption, flammability and thermal properties of ASA/WNMPCB composites were analyzed. The incorporation of WNMPCB filler into ASA matrix led to improved composite properties. It was found that an increase in WNMPCB content of up to 50 phr enhanced the density of ASA/WNMPCB composites, consistent with SEM micrographs, which demonstrated that polymer composites with WNMPCB as a filler had a rougher surface compared with neat ASA. The compatibility between the matrix (ASA) and filler (WNMPCB) improved using 3 phr of SMA as a compatibilizer. From 0 to 50 phr, the SEM-EDX images showed that the amount of Si particles increased as the WNMPCB amount increased and compatibility between the matrix and filler was maintained. Results indicated that adding WNMPCB, containing glass fiber, thermoset resin and flame retardants enhanced the rheological properties and decomposition temperature of the composites while reducing flammability.

Abstract: The effect of magnesium hydrophosphate on rheokinetic, chemical-colloidal and flame retardant properties of flame retardant aluminosilicate paints for wood has been investigated. It is shown that the introduction of magnesium hydrophosphate in the paint composition in the amount of 1-1.5% allows to stabilize the change of dynamic viscosity from 164500 to 120000 cP in the range of speeds from 0.35 to 1 RPM, as well as to provide wettability (s=0. 659-0.6603) and stability of spread ability (k=-43.48 and k=- 43.65) of the paint on pine substrate, which corresponds to the criterion requirements. According to the data of fire tests it was found that modification of aluminosilicate bases of paints with magnesium hydrophosphate in the amount of 1-1.5% puts them in the category of difficult combustible and difficult to ignite, the temperature of flue gases did not exceed the critical value (<260С), mass loss did not exceed 5.4-7.2%, which corresponds to the I group of flammability G1 according to the standard. According to the shear force data (SS=24.95 to 176.45 dynes/cm² and SS=23.18 to 172.4 dynes/cm²) the investigated formulations can be applied on wooden surfaces by air spraying with a screw paint feed.

Abstract: In this study, the behavior of biocomposites reinforced with natural fibers from African palm and sugar cane in a recycled polyethylene matrix is investigated. The aim is to analyze the rheological and mechanical properties of these materials to optimize their processability by injection. Natural fibers treated through a steam explosion process and subsequent drying and grinding were used to obtain a size suitable for extrusion. Biocomposites with different percentages of fiber (30% and 40%) were prepared and evaluated by melt flow index (MFI) and capillary rheometry tests. The results indicated a significant reduction in material fluidity with increasing fiber content, which was mitigated by the addition of a lubricant additive, stearic acid. Simulation of the injection process made it possible to determine crucial parameters such as injection pressure and filling time. Subsequently, injection tests were carried out varying the temperature and fiber concentration, followed by tensile tests to evaluate the mechanical resistance of the injected specimens. The results showed that the addition of the additive significantly improved the fluidity of the material, facilitating its injection without damaging the machinery and maintaining good mechanical properties. This study provides a solid foundation for the development of biocomposites eco-friendly with potential applications in the plastics industry.

Abstract: The aim of this study was to improve the stability and rheological properties of water-in-oil-in-water (W/O/W) multiple emulsions containing 30 wt% paraffin oil, and 4 wt% polyglycerol-3-polycinoleate (PGPR) as a lipophilic surfactant. This was done by adding different concentrations of xanthan gum (GX) and the hydrophilic surfactants (Polyoxyethylene (80) sorbitan monooleate (Tween® 80), poloxamer 407(Lutrol® F127) using the emulsification in a two-steps process. The stability of the W/O/W multiple emulsions was analyzed over one-month storage period using physicochemical and rheological measurements. An excellent structure appeared with 0.175 wt% of xanthan gum in the outer aqueous phase and 1 wt% of Tween® 80. The modified Cross model was successfully applied to fit the flow curves of multiple W/O/W emulsions at different concentrations of xanthan gum. The incorporation of xanthan gum in a concentration range of 0.05-0.175 wt% induced an increase in the yield stress, in the zero-shear rate viscosity, and in the infinite shear rate viscosity of the multiple emulsions. The study also showed that adding xanthan gum in a concentration range of 0.05-0.175 wt% to W/O/W emulsions caused an increase in the viscosity of the system in the Newtonian regime and viscoelastic behavior.

Abstract: The transporting of sediments across watershed systems and their placement in reservoirs causes expensive issues for the operators of dams in many different nations throughout the world. In addition to the reservoir's functional capacity steadily decreasing as sediment settles in it, silt removal is a sensitive and challenging process that frequently necessitates taking the reservoir out of service, which is practically unachievable in dry and semi-arid regions. De-silting by hydraulic dredging has recently become a necessity to increase their longevity. But during this operation there are load loss exists so it is necessary to find solutions to reduce it. The present paper revealed that use the Sodium Tripolyphosphate as a reducing agent of the friction factor during the hydraulic dredging of dams. To carry out this study, a rheumatic characterization of dams sediments and dams sediments -sodium tripolyphosphate mixtures was carried out using a torque controlled rheometer (Discovery Hybrid Rheometer DHR2 from TA instrument). The flow curves as a function of dose of sodium tripolyphosphate added to dam sediments were analysed by the modified Cross model. It is clearly shown, in this work, when the quantity of sodium tripolyphosphate is less than of 0.4 % causes a decrease in the yield stress, the zero shear rate viscosity (lower Newtonian plateau) and the infinite shear rate viscosity (upper Newtonian plateau). However, when dose of sodium tripolyphosphate is greater than the critical dose, the the yield stress, the zero shear rate viscosity (lower Newtonian plateau) and the infinite shear rate viscosity (upper Newtonian plateau) are increased. As a result, this study find that the increase on thixotropic behavior of dams sediments is occurred by the addition of sodium tripolyphosphate in a concentration ranging between 0.2 wt% and 0.8 wt% to 40 wt% and 45 wt% of dams sediments. The study also demonstrated that adding of 0.4 wt% of sodium tripolyphosphate to 40 wt% and 45 wt% dam sediments decreased the friction factor by 96% and 25% respectively.

Abstract: The rheological properties of drilling muds are critical for achieving optimal performances during drilling operations. In this study, bentonite, tannin, and xanthan gum were utilised as water-based drilling mud additives to enhance the rheological properties. The Response Surface Methodology (RSM) with Box-Behnken Design (BBD) was used to investigate the additive's effect on the rheological properties of the drilling muds. The concentration of bentonite, tannin and xanthan gum were considered as the independent variables, while plastic viscosity (PV), apparent viscosity (AV), and yield point (YP) as the responses in the design of experiment (DOE). The YP, AV and PV were determined using 9.0 ppg of drilling mud according to the API standard procedures. Response surface plots (3D) were used to analyse the effect of the independent factors on the rheological properties and resulting in R2 values of 0.9753 for PV, 0.9582 for AV and 0.9513 for YP, which indicates that the interaction between elements in the system were statistically significant as these R2 values were close to 1.0. Bentonite was observed to significantly increased the PV, AV, and YP, whereas it decreased as tannin concentration increased. The optimal rheological properties required for low PV and AV with a high YP could be achieved using WBM formulation of bentonite at 4.02 g, 7.29 g of tannin, and 0.53 g of xanthan gum. Meanwhile, xanthan gum had an insignificant effect on the PV, AV, and YP. This finding demonstrates that the RSM model is accurate and relevant tool; hence it may be utilised to optimise the experimental conditions of mud formulation and accurately predict the rheology parameters of drilling muds.

Abstract: Metal injection molding (MIM) is a proven technology for fabricating complex geometry and low-cost components. The binder system formulation and powder loading are the key parameters affecting the final properties of the manufactured parts in this process. This study investigates the influence of palm stearin (PS) content in a PS/High-Density Polyethylene (HDPE) binder system for three powder loadings of 60, 65, and 70 Vol.%. The manufactured feedstocks are characterized using scanning electron micrograph (SEM), thermo gravimetric analysis (TGA), and differential scanning calorimeter (DSC), rheological and mechanical tests. The results show that PS enhances mechanical properties at increased powder loading. In addition, residual carbon following changing the PS percentages has a significant role in determining the final characteristics of parts. Findings demonstrated that PS could drastically alter the rheological behavior, a crucial criterion for optimizing the feedstock formulation in the MIM process.

Abstract: High altitude and strong ultraviolet radiation in Qinghai Tibet Plateau induces the brittleness and hardening of asphalt, which leads to temperature cracks, pits and other diseases of asphalt pavement. In this paper, the accelerated UV aging test of rubber asphalt was carried out by simulating the UV radiation intensity in Xining, Qinghai Province, and the rheological properties and microstructure changes of rubber asphalt were analyzed. The results show that the complex modulus of rubber asphalt increases exponentially with the extension of UV aging time. The phase angle of rubber asphalt decreases linearly with UV aging, and the deformation recovery performance of rubber asphalt increases; UV radiation has the most significant effect on the micro morphology of rubber asphalt. With the further extension of UV aging time, micro cracks are formed in rubber asphalt, and the low-temperature crack resistance and fatigue failure resistance of rubber asphalt are gradually reduced.