Cake Thickness Research Articles

A Novel Technique in Determining Mud Cake Permeability in SiO2 Nanoparticles and KCl Salt Water Based Drilling Fluid using Deep Learning Algorithm

The permeability of the mud cake formed at the formation-wellbore interface is an important factor in the designing of water-based drilling fluids. This study presents a novel approach to utilizing experimental thixotropic and rheological parameters of polymeric water-based drilling fluids having varying concentrations of SiO2 nanoparticles and KCl salt. A fully connected feed-forward multi-layered neural network, more commonly known as a Multilayer Perceptron (MLP) was developed to predict the mud cake permeability using input parameters such as SiO2 & KCl concentration, differential pressure, temperature, mud cake thickness, API LPLT and HPHT filter loss volume and spurt loss volume. The results suggested that the developed Multilayer Perceptron model effectively determined the mud cake permeability based on the input parameters of the WBDF mentioned above. The model converged on the global minima, minimizing the loss function using the Gradient descent algorithm. A higher Coefficient of Determination (R2) value i.e., 0.8781, and a lesser Root Mean Square Error (RMSE) value i.e., 0.04378 indicates the higher accuracy of the model. Pearson’s Coefficient of Correlation obtained via the heatmap indicates that mud cake permeability is strongly influenced by the differential pressure followed by filter loss volume, spurt loss volume, mud cake thickness, and temperature. Previous similar studies have focused on using machine learning algorithms, this study utilized a robust deep learning algorithm i.e., Multilayer Perceptron (MLP) neural network to simultaneously model the combined effects of SiO2 nanoparticles and KCl salt concentrations on mud cake permeability, offering an unprecedented level of accuracy in predicting key WBDF performance parameters

Evaluation of filtration characteristics of bentonite-free water-based mud utilizing carboxymethylated tapioca starch

Optimizing filtercake thickness is crucial to prevent fluid losses during well drilling and avoid borehole instability and complex operations. This research develops a non-damaging water-based mud with chemically modified carboxymethylated tapioca starch and investigating its filtration control properties. Fluid loss volume and filtercake thickness were determined both at API, HPHT (500 psi and 212 °F), and hot roll temperatures (200, 230, and 260 °F) using filterpress. The mud’s properties were compared to the existing fluid loss control agent-PAC-LV. The results indicated that optimum samples exhibited 17.33% reduction before hot rolling and 46.76%, 31.67%, and 70.51% reductions at 200, 230, and 260 °F, respectively. At ambient and after hot rolling at 200 °F and 230 °F, 8 ppb CMTS concentration achieved the lowest cake thickness. At 260 °F, the 10-ppb concentration had the lowest thickness. Optimized values resulted in permeability reductions of 49.73%, 58.74%, 57.04%, and 60.10% for BHR and AHR at 200, 230, and 260 °F, respectively. Morphological study showed the fingerlike structure effectively bound free water and plugged channels, reducing permeability and fluid loss volume.

Evaluation of shell powders of bush mango and hamburger bean as eco-friendly fluid loss control additives in water-based drilling mud

The use of agro-based additives in drilling mud to reduce fluid loss and improve the rheological properties of mud has gained enormous attention owing to its biodegradability and low cost. This study evaluates the effects of shell powders of hamburger bean and bush mango as eco-friendly and cheap filtration control additives in water-based mud. Samples were formulated with different concentrations (5 g, 10 g, 15 g, and 20 g) of the shell powders to determine their effects on the filtration and rheological properties of the mud. From the results, both hamburger beans and bush mango shell powders improved the rheological properties of the fluid. Meanwhile, only 15 and 20 g of Bush mango shell powders reduce fluid loss by 10.5 and 13.2%, respectively. Similarly, the addition of 5 g, 10 g, 15 g, and 20 g of hamburger bean shell powders reduced fluid loss by 1.4, 8.82, 14.71, and 20.6%, respectively. Both Bush Mango and Hamburger Beans shell powders based mud produced cake thickness between 1.2 and 1.8 mm. The research demonstrates that Hamburger Beans shell powders provides a progressive decrease in filtration rate as the content increases, and it stand as a cheap and eco-friendly alternative additive for the enhancement of rheological and filtration properties in water-based drilling fluids.

Wyznaczanie dynamicznego ciśnienia formacji w strefie odwiertu

The article shows that the pressure drop in the near-wellbore zone decreases with increasing time that the well is left uncased due to the filtration of the drilling fluid filtrate into the formation. Under certain conditions, this does not pose a risk of drill string sticking. From the perspective of establishing the nature of changes in dynamic reservoir pressure behind the mud cake, the experimental studies by Johnson and Klotz (Stepanov, 1999), which determine the amount of filtrate entering the reservoir under both static and dynamic conditions, are particularly interesting. It should be noted that establishing the amount of filtrate experimentally takes into account in advance the nonlinearity of fluid movement along the borehole wall and through formation rocks. Reservoir pressure will increase to the depth of penetration of the drilling fluid filtrate, so the value of Rk is taken equal to the radius of a certain contour with formation pressure. The article shows that the dynamic reservoir pressure behind the mud cake initially rises intensively over time, and then, after a certain point, remains almost constant; the filtrate from the drilling fluid entering the formation partially displaces the reservoir fluid and fills the resulting pore space. During dynamic filtration, an intensive increase in pressure behind the mud cake occurs within 20–30 hours and depends little on the absolute values of fluid loss from the washing liquid, the thickness of the mud cake, and the initial pressure drop. Experience in drilling deep wells shows that sticking of the lower part of the drill string primarily occurs when opening productive horizons with low permeability (0.06–2) · 10–15 m2. Consequently, the ratio of the permeability of the rock of deep-lying productive horizons to that of the mud cake is approximately more than 1,000. Therefore, when opening productive horizons, pressure equalization practically does not occur, and leaving the drill string against these rock formations without movement for 15–20 minutes leads to its sticking due to the pressure difference.

Assessing the Rheological and Filtration Loss Control Potential of Selected Plant-Based Additives in Oil-Based Mud

In drilling operations, chemical additives pose environmental concerns during mud disposal. This study evaluated three plant-based additives, namely rice husk (RH), <i>Detarium microcarpum</i> (DM), and <i>Brachystegia eurycoma</i> (BE), in oil-based mud at low-pressure, low-temperature conditions. The mud’s rheological profile followed Herschel Bulkley’s model. With 8 g additive content, RH increased the mud's apparent viscosity (AV), plastic viscosity (PV), and yield point (YP) by 62.5%, 51.25%, and 34.38%, respectively. DM showed higher increases of 200.0%, 195.0%, and 162.5%, while BE exhibited the most significant improvements of 287.5%, 272.5%, and 250.0%. The filtration tests indicated that RH reduced spurt loss and fluid loss volumes by 83.33% and 62.35%, while DM decreased by 82.41% and 47.94%, as BE had the highest reduction of 94.44% and 51.18%. Again, the filter cake thickness of RH, DM, and BE muds increased by 210.29%, 273.53%, and 79.41%, respectively, with permeabilities of 8.90×10<sup>-3</sup> mD, 11.87×10<sup>-3</sup> mD, and 7.35×10<sup>-3</sup> mD. Furthermore, the mud susceptibility to NaCl showed that AV decreased for RH, DM, and BE, while YP decreased significantly. The filter cake thickness and permeability increased by 62.38 and 359.55% for RH, as the DM decreased by 93.80% and 84.37% and the BE by 96.68% and 96.62%, which indicates that RH is more susceptible to NaCl than DM and BE in the mud. Also, these plant-based additives in mud exhibited fragile gel strength and commendable cake characteristics: firm, smooth, and soft/slippery, which make them potentially suitable for oil well drilling.

Influence of perlite on the stability of filter cake in low-density drilling fluids system

Enhancing drilling fluid performance in the oil and gas industry involves addressing various criteria across technical, environmental, and economic aspects. Consequently, this study encompassed several factors such as rheology, filtration, formation damage, and additives to design appropriate and cost-effective drilling fluid. The potential of perlite as an additive for low-density drilling was assessed in this work. A comprehensive laboratory experimental approach was applied to gain an in-depth understating of perlite's performance. The investigation included evaluating the rheological properties, filter cake quality, and characterizing filtration medium pore distribution. Additionally, sensitivity tests were also conducted to judge the effectiveness of perlite as a primary viscosifier and filtration agent. Through these tests, a holistic assessment of perlite's capabilities was achieved. The findings indicated that while perlite was not suitable for use as the primary viscosifier or as the main filtration agent, its use as a secondary agent exhibited a positive impact, particularly in reducing solid invasion by approximately 93%. The optimum perlite concentration was 3 lb./bbl., with good enhancements in filtration volume, filter cake thickness and porosity by 50%, 40%, and 14%, respectively. Additionally, employing a combined particle distribution approach for the calcite, rather than a singular grade, resulted in substantial improvements in the examined properties. The most notable improvement was observed in filter cake permeability, which decreased by nearly 93%. The other parameters were improved by 80% for filtration volume, 74% for filter cake thickness, and 24% for solid invasion. This work highlighted the usability of perlite in low-density mud and how it can improve the drilling fluid properties.

Exploring the Performance of Dry Bamboo Leaves Powder from Bambusa Heterostachya as Additive in Water-Based Mud

In the evolving landscape of petroleum drilling, the quest for eco-friendly alternatives to traditional mud additives is paramount. This study explored the performance of Dry Bamboo Leaves Powder (DBLP) from Bambusa heterostachya as an additive in water-based mud. Dry Bamboo Leaves were obtained, crushed, and then sieved to 106-micron size. Mud properties, including mud weight, plastic viscosity, yield point, gel strength, mud cake thickness and filtrate volume were examined under fresh conditions by integrating different concentrations of DBLP (3.5 g, 7.0 g, 10.5 g, and 14 g). The laboratory experiments adhered to the standards set by the American Petroleum Institute (API). The introduction of DBLP concentrations resulted in a reduction in the alkalinity and mud weight of the drilling mud. Additionally, the drilling mud's yield point and plastic viscosity were altered at different DBLP concentrations. The inclusion of DBLP enhanced the gel strength and decreased filtrate volume while maintaining the same mud cake thickness.

Experimental Study on Infiltration of Seawater Bentonite Slurry

A bentonite slurry mixed with seawater is prone to sedimentation, which will reduce the quality of the filter cake and lower the stability of the excavation surface in undersea tunnels. It is necessary to study the performance and influencing factors of the bentonite slurry mixed with seawater. This article simulates the process of undersea slurry shield tunnel construction, where the pressurized slurry penetrates into the sand layer and forms a filter cake when the shield stops pressurizing. We investigated the effects of bentonite, additives (CMC), fine sand, pressure, and formation permeability on the performance of the seawater slurry and filter cake. The sedimentation of mud caused by seawater interfered with the experiment, which manifested as the increase in bentonite, and delayed the formation of the filter cake. Fine sand with a particle size close to the average value of the formation can improve the speed and quality of filter cake formation. By conducting a sensitivity analysis on experimental data, the degree of influence of various factors on the formation rate, thickness, and porosity of the filter cake was determined. Fine sand and bentonite are the factors that have the greatest impact on the formation rate, thickness, and porosity of the filter cake.

Effect and consequence of the rheological properties of nano Fe2O3-modified drilling muds in the Dibella oil field

The development of supportable, cost-effective, and high-performance nanoparticles (NPs) is one of the new examination points within penetrating applications. The consideration of tailorable nanoparticles offers the chance to figure out water-based drilling fluids (WBDFs) with upgraded properties, providing exceptional opportunities in the energy, oil, gas, water, or framework enterprises. In WBDFs, nano and micron materials are investigated to control their rheological properties and their influence. This paper aims to analyze the influence of nano Fe2O3 on the rheological behavior of drilling fluid muds under high temperatures and pressure. Additionally, we seek to identify the optimal concentration of iron oxide nanoparticles that maintain consistent rheology; we examined the interfering effects of shear rates and iron oxide nanoparticle temperature on the shear type of the changed depleting liquid in the Dibella oil field to make the penetrating activity efficient, realistic, and skilled. We observe that as the temperature increases, the water-based mud (WBM), plastic viscosity (PV), yield point (YP), and gel strength (Gs) decrease until the reject structure is disrupted. Therefore, we must proceed with our assessment using nano Fe2O3 to resolve the shortcomings of the slope framework. Six water-based mud cakes containing 0.5, 1, 1.5, 2, 2.5, and 3 g weight percent of iron oxide (Fe2O3) nanoparticles were prepared for this evaluation. The experimental outcomes revealed an optimal nanoparticle mixing of 2.5 g weight percent, which resulted in a 13.8% reduction in the API filtrate volume and a 40% reduction in filter cake thickness. At 300°F temperature and type 10.00 pressure, the results of our experiments consistently demonstrate a decrease of 14.77% in the rheological properties of PV and YP and 10 s and 10 min in the gel strength of carbon oxide nanoparticles. The YP–PV span is 2.7, and the yield strength is 11 lb/100 ft2. On the other hand, mud cake A, which contains 0.5 wt% NPs, loses 6 mL of fluid after 30 min. In contrast, drilling mud cake E, which is composed of 3 wt% NPs, shows a fluid loss of 5.1 mL in the API filter press test. Based on the Bingham plastic model, the maximum shear stress versus shear rate was observed for bentonite drilling muds E and F, with 2.5 wt% and 3 wt% NPs, respectively, and this result indicates that the use of nano Fe2O3 can effectively adjust the properties of drilling fluids.

Performance evaluation of the nano-biodegradable drilling fluid using the greenly synthesized zinc nanorods and gundelia seed waste

Addressing the increasing demand for green additives in drilling fluids is essential for the sustainable development of the oil and gas industry. Fluid loss into porous and permeable formations during drilling presents significant challenges. This study introduced an innovative, environmentally sustainable drilling fluid known as nano-biodegradable drilling fluid (NBDF). The NBDF formulation incorporates greenly synthesized zinc nanorods (ZNRs) and gundelia seed shell powder, with ZNRs derived from Cydonia oblonga plant extracts using an eco-friendly method. The research developed multiple drilling fluid variants for experimentation: a reference drilling fluid (BM); biodegradable drilling fluid (BDF) with particle sizes of 75, 150, 300, and 600 µm at concentrations ranging from 0.5 to 1 wt% (GSMs); a drilling nanofluid (DNF) with ZNRs at a 0.1 wt% concentration (ZNR); and NBDF combining both nano and gundelia waste (GS-ZNR). Experimental tests were conducted under various temperature and pressure conditions, including low temperature and low pressure (LTLP) and high temperature and high pressure (HTHP). Rheological and filtration measurements were performed to assess the impact of the nano-biodegradable additives on flow behavior and fluid loss. Results indicated that incorporating 1 wt% of gundelia seed shell powder with a particle size of 75 µm led to a 19.61% reduction in fluid loss compared to BM at 75 °C and 200 psi. The performance of the same GSM improved by 31% under identical conditions when 1 wt% of zinc ZNRs was added. Notably, the GS-ZNR formulation demonstrated the most effective performance in reducing fluid loss into the formation, decreasing mud cake thickness, and enhancing the flow behavior of the non-Newtonian reference drilling fluid. This study highlights the relevance of particle size in the effectiveness of biodegradable additives and underscores the potential of NBDF to address environmental concerns in the oil and gas drilling industry.

The impact of particle size distribution of haematite‐based drilling fluid on perlite functionality

AbstractDrilling fluid additives are essential in formulating an optimal mud composition for the desired geological formation. They provide different functions that enable the drilling process to reach a target zone. However, the effectiveness of these additives may be limited under certain conditions. The physical attributes of the weighting material additives such as solid particle size (particle size distribution [PSD]). The PSD can influence multiple drilling fluid properties, including the rheology, filtration, and filter cake properties. This work examined the performance of perlite when incorporated into water‐based mud with three different grades of haematite particle sizes. The investigation focused on the rheological properties, filtration, and filter cake characteristics utilizing two distinct filtration mediums: the ceramic disk and core sample. The results indicated that the PSD minimally impacts the filtration and the filter cake properties when the pore distribution of the filtration medium is uniform at low drilling mud density. However, a more pronounced effect was observed when core samples were utilized during the filtration test, reflecting the variation in pore distribution. Remarkably, perlite exhibited exceptional effectiveness in improving the drilling fluid properties. Its influence became particularly evident when core samples were employed as the filtration medium, demonstrating resilience against changes in both filtration medium pore distribution and haematite‐varied particle size grades. In this case, maximum improvements of 69%, 84%, and 86% were achieved in filtration volume, filter cake thickness, and filter cake permeability, respectively. Perlite showed an excellent performance at varied conditions represented by filtration medium and weighting material PSD.

Evaluation of using micronized saudi calcite in ilmenite-weighted water-based drilling fluid

A high-density water-based drilling fluid (WBDF) is crucial for maintaining wellbore stability, controlling formation pressures, and optimizing drilling performance in challenging subsurface conditions. In the present research, the effect of micronized calcium carbonate (calcite), extracted from the Aruma formation outcrop, is evaluated as one of the additives that could be added to the ilmenite-weighted WBDF to enhance and optimize its properties. Various concentrations of Calcite microparticles were introduced into identical fluid formulations to assess their impact. The concentrations ranged from 0, 10, 20, to 30 lb/bbl, providing a comprehensive examination of the effects of calcite microparticles across a spectrum of concentrations within the fluid. The results highlighted that adding Barite microparticles to the WBDF revealed a notable enhancement in rheological properties. Specifically, the yield point demonstrated an increase of 37%, 37%, and 11% for concentrations of 10, 20, and 30 lb/bbl of calcite, respectively. Equally significant, high-pressure-high-temperature (HPHT) filtration analysis indicated a considerable enhancement for the fluids containing calcite microparticles. A reduction of 14.5%, 24.6%, and 13% were observed in HPHT filtrate for concentrations of 10 lb/bbl, 20 lb/bbl, and 30 lb/bbl respectively. Simultaneously, there is a reduction in filter cake thickness by 20%, 40%, and 20%, respectively. No ilmenite settling was observed in the sample containing 20 lb/bbl of calcite, unlike the other concentrations. These diverse results strongly suggest that the optimal concentration for calcite microparticles is 20 lb/bbl. The combined utilization of the optimal concentration of calcite microparticles alongside the established additives proves to be an effective strategy for optimizing the ilmenite-weighted WBDF performance in terms of both thermal stability and rheological behavior.

Empirical Assessment of African Oil Bean Husk as a Fluid-Loss Control Agent in Oil-Based Drilling Mud

Efficiency of drilling mud is partly determined by filtrate loss. In this article, research on suitability of African oil bean husk (AOBH), as a fluid loss control additive for oil-based drilling mud (OBM) is presented. Dry AOBH of particle sizes 63µm, 125µm and 250µm were used. Fourier Transform Infrared Spectrophotometer (FTIR) and Phenom Prox model of the Scanning Electron Microscope energy dispersive X-ray spectroscopy (SEM-EDS) were used to determine morphology and chemical properties of AOBH. OBM samples were prepared using the various sizes of AOBH as fluid-loss control additives and Grel Alphatex as industrial grade additives. Power Law Model and Herschel-Bulkley Models were used to model rheology of samples. Results show that AOBH contains mainly asphaltic compounds, is eco-friendly and biodegradable. Results from mud tests show close values in performances of AOBH and industrial grade. Filter cake thickness was 2.1mm – 2.8mm for AOBH-additives mud, but 2.3mm for industrial-additives mud. Filtrate loss was 2.0ml – 3.4ml for AOBH-additives mud, but 2.3ml for industrial-additives mud. Apparent viscosity for AOBH-additives mud was 77.5 -92.0cp, but 99.0cp for industrial–additives mud. Plastic viscosity for AOBH-additives mud was 73.0 - 81.0cp, but 87.0cp for industrial-additives mud. Yield point for AOBH-additives mud was 9.0 – 22.0, but 24.0 for industrial-additives mud. Both models show that efficiency of the mud containing AOBH in cleaning hole increased as grain size of AOBH reduced.

Fine-Tuning Filter Cake Sealing Performance: The Role of Particle Size in Hematite Weighted Water-Based Drilling Fluid.

Three hematite grades with different particle sizes (i.e., large, medium, and small) were evaluated, and the selection criterion was median particle size. The investigation involves the following stages: rheology, filtration, and filter cake formation. Different rheological models including Bingham, Power law, Herschel-Bulkley, and Robertson-Stiff were implemented to find the optimum model for characterizing fluid behavior. The results showed that medium-sized hematite particles produced the highest filtration volume, filter cake thickness, and filter cake permeability. These results were confirmed when a varied pore distribution filtration medium was used. The NMR results showed the same trend where the highest reduction in core porosity was found when a medium-size particle distribution was used. There is a minimum alteration in the rheological behavior of the drilling fluid as the particle size was varied, and the drilling fluids showed a shear-thinning behavior and were best described by the Herschel-Bulkley model. Particle size ratio emerges as a key factor for controlling and enhancing the filtration properties and filter cake characteristics.

Application of black tea waste as eco-friendly deflocculant and rheology stabilizer for water-based mud

Maintaining and regulating the rheological properties of the drilling mud at the desired level is essential for successful drilling operations. Bentonite is the key additive used in most water-based drilling mud for enhanced rheological properties. However, the flocculation tendency of bentonite particles poses a significant challenge for the industry due to the undesirable and unpredictable changes in rheological properties of the fluid with downhole increasing temperature. This study aims to develop a low-cost and eco-friendly deflocculant from black tea waste (BTW) that can prevent the aggregation and flocculation of the bentonite and stabilize the rheology of bentonite-polymer muds. Rheological properties were evaluated with different concentrations (0.25%, 0.5%, 0.75%, and 1%) of BTW at 95 °F and 140 °F. The Bingham Plastic (BP) and Power Law (PL) models were studied to characterize the flow behavior and identify the best-fit model through statistical analysis. Along with rheological properties, thinning efficiency, mud stability, thermal aging effect, thixotropic behavior, and shear thinning behavior were investigated through different shear-temperature-time dependent tests. In addition, the lubricating properties and filtration loss characteristics were assessed at ambient conditions. Finally, the findings were compared with the industrially used deflocculant, lignosulphonate (LS). The results revealed that BTW can effectively prevent bentonite flocculation and stabilize the mud rheology even at a very low concentration of 0.25%. Significant improvements were observed in the lubricating and filtration characteristics. With the addition of 1% BTW, the filtrate loss, mud cake thickness, and friction coefficient were reduced by 22.2%, 50%, and 13.29%, respectively. The multifunctional activities of black tea waste (BTW) are attributed to its polyphenolic compounds, the presence of which was confirmed through UV–visible spectroscopy testing. The TG analysis confirmed that BTW remains thermally stable up to 200 °C. Considering the synergistic performance compared with lignosulphonate, availability, and environmental and economic acceptance, BTW may be effectively utilized as a multifunctional deflocculant and rheology stabilizer for water-based bentonite-polymer muds.

An Investigation of the Impact of Precipitation Temperature and Filter Cake Thickness on the Physical Stability of Amorphous Solids: A Case Study.

The purpose of this study was to resolve the issue of physical instability in amorphous solid drugs, which can result in unwanted crystallization, affecting solubility and dissolution rates. The focus was on precipitating physically stable amorphous forms of the nilotinib free base, an anticancer drug, by monitoring preparation conditions such as precipitation temperature and filter cake thickness. A comprehensive set of characterization techniques, including powder X-ray diffraction (PXRD), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and focused beam reflectance measurement (FBRM), were used. These were supplemented by advanced data analysis methods that incorporated pair distribution function (PDF), reduced crystallization temperature (Rc), and principal component analysis (PCA) to evaluate the physical stability of the amorphous samples. Results emphasized that optimal physical stability was achieved when amorphous solids were prepared at a precipitation temperature of 10 °C and a filter cake thickness of 4 cm. Moreover, the integration of PDF analysis with Rc values was confirmed as an innovative approach for assessing physical stability, thus offering enhanced efficiency and accuracy over conventional accelerated stability testing methods.

Theoretical model and parameter sensitivity analysis of the filter cake formation during slurry shield tunnelling

The filter cake formation during slurry shield tunneling in high permeability soil layers is complex and difficult to monitor. There is no reliable method to evaluate the mechanical characteristics during the filter cake formation. A theoretical model is proposed to describe the filter cake formation and development in this study. The finite difference method is used to simulate the whole filter cake formation process. In addition, the influence of the key bentonite slurry parameters and of the deep infiltration on the filter cake formation is investigated based on the proposed model. The results show that the excess pore water pressure within the filter cake is not uniformly distributed. The slurry support effect is manifested by a pressure drop generated on both sides of the filter cake. The development process of the filter cake can be summarized into three stages: prior infiltration filling of the filter cake, accumulation and thickening of the new filter cake, and compression and consolidation of the prior filter cake. The slurry deep infiltration results reflected by the membrane specific resistance have the most significant effect on the filter cake development. Compared with the slurry concentration, the viscosity has a greater influence on the formation and final thickness of the filter cake.

Rheological properties of magnesium bentonite and sepiolite suspensions after dynamic ageing at high temperatures

Abstract The rheological properties of three Na-activated, trioctahedral Mg-bentonites (hectorite clay from the CMS Source Clay Project repository, saponite clay from Spain and stevensite clay from Rhassoul, Morocco) and a sepiolite clay from Greece were examined after dynamic ageing at temperatures up to 230°C. The 5% w/v suspensions were prepared by dispersing the clay mineral samples in distilled water. The suspensions underwent dynamic, thermal ageing for 16 h before determination of the viscosity, filtration loss, filter cake thickness and pH and the concentration of dissolved Na+ and Mg2+. Thermal ageing contributed to the dispersion of clay particles, with a direct effect on plastic and apparent viscosity, introducing pseudoplastic behaviour. With the exception of the stevensite clay at 230°C that displayed limited dissolution at 230°C and partial conversion to kerolite, the clays were stable at high temperatures. The Na-activation of all clays except for stevensite was not adversely affected by thermal ageing. Thermal ageing of stevensite at 230°C facilitated Na exchange and yielded suspension with high viscosity and low filtrate loss. Only the suspensions of hectorite and those of stevensite aged at 230°C met with American Petroleum Institute specifications. The thermal behaviour and rheological properties of the clays might be interpreted according to the intrinsic properties of the clay minerals, such as layer charge and charge distribution.

Application of ultra-fine particles of potato as eco-friendly green additives for drilling a borehole: A filtration, rheological and morphological evaluation

Drilling fluid is crucial for oil and gas well drilling operations, serving key functions such as facilitating the removal of drill cuttings, maintaining borehole stability and controlling formation pressures. When the drilling fluid is lost into formations, it can alter the formation's integrity, contaminate groundwater and cause permeability damage. In addition, environmental concerns arise from the waste produced during drilling activities, particularly when discarded drilling fluids contain hazardous substances like heavy metals. This study explores the potential of integrating ultrafine potato powder (PP) into water-based drilling fluids (WBDFs) as environmentally friendly additives. Several analytical techniques including X-ray fluorescence (XRF), Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), scanning electronic microscope (SEM) and differential scanning calorimetry (DSC) were used to comprehensively characterize the prepared PPs. The study included API and HPHT filtration test, permeability plugging test and rheological evaluations of drilling fluids, assessing parameters such as filter loss, filter cake, apparent viscosity, plastic viscosity, yield point and gel strength under varied conditions of different particle sizes of PP, concentrations of PP, and temperature and pressure measurements. The obtaining results emphasize PP's potential to enhance the wellbore stability and reduce the fluid loss, the filtration of water or oil into the permeable formation, achieving 43% reduction in the filtration rate and 70% reduction in the filter cake thickness. Adding 0.5 wt% ultrafine PP improved the maximum gel strength to 32.2 lb/100 ft2, while the same concentration and particle size raised the plastic viscosity from 3 to 6.8 cP, which subsequently dropped to 6 cP in high temperature conditions. PP performed better compared with the reference fluid in improving the thinning behavior of the drilling fluids. Moreover, permeability plugging tests confirm that adding PP effectively lowered the filtration rate, with higher concentrations achieving greater reductions over time. These findings suggest that PP holds promise as an effective additive for drilling fluids, contributing to enhanced drilling efficiency, improved wellbore stability and a reduced likelihood of instability and lost circulation. The characterization and rheological analysis of PP biodegradable drilling fluids provide valuable insights for optimizing fluid formulations, tailoring them to specific operational conditions, and achieving a balance between fluidity, wellbore stability, and cuttings transport. This research highlights the potential of PP as a sustainable and efficient solution in the realm of drilling fluid additives.

Properties experimental investigation of water-based drilling mud contained tragacanth gum and synthesized zinc oxide nanoparticles

Drilling fluids play crucial role in the oil and gas production industry, consequently the optimization of flow behavior of these fluids has received remarkable attention from the beginning of this process. The objective of this study is to improve the rheological and filtration characteristics of water-based mud (WBM) by incorporating zinc oxide (ZnO) nanoparticles (NPs) and affordable tragacanth gum (TG) polymer. Initially, ZnO NPs were synthesized through a facile and straightforward sol–gel method and subjected to comprehensive characterization. Subsequently, these NPs were incorporated into TG polymer solutions to formulate drilling mud samples. The selection of optimal samples involved meticulously determining of ZnO NPs and TG polymer concentrations as influential parameters facilitated by the Design Expert software. The responses taken into consideration in this methodology included flow behavior index (n), consistency index (K), plastic viscosity (PV), and yield point (YP). The investigating rheological parameters entailed utilizing both the Power-law and Bingham-plastic models, underscoring the scholarly refinement of the study’s analytical approach. Subsequently, an analysis of variance (ANOVA) was conducted to assess the significance of the model and its parameters. Three optimal samples were carefully selected based on the results obtained from the modeling and analysis of the rheological parameters. The next phase involved utilizing these optimal samples to investigate their filtration properties in detail. The final step led to selecting the optimal sample composition, which was determined to be 0.25 wt% ZnO NPs and 750 ppm TG polymer based on the optimization results provided by the Design Expert software. Remarkably, this specific combination yielded significant improvements in PV (22.2 %), YP (109.5 %), mud cake thickness (20 %), and fluid loss (2.87 %). Moreover, the resulting mud exhibited desirable rheological properties, including a K of 31.20 (cp) and an n of 0.21. This specific combination was identified as the most favorable composition for achieving the desired rheological and filtration properties.