Rate Of Fluid Loss Research Articles

An investigation of the behaviour of polymer fluids in the American Petroleum Institute filter press

The American Petroleum Institute (API) filter press test has been used for decades in the construction industry as part of the quality control regime for bentonite-based excavation support fluids. The industry has carried over the use of this test to polymer fluids despite the lack of published evidence of its suitability for these fluids and the very different mechanisms by which polymer fluids and bentonite slurries achieve excavation support. This paper presents the first systematic investigation of this issue through a combination of laboratory testing and theoretical analysis. The investigation demonstrates the very different behaviours of bentonite slurries and polymer fluids. In contrast to the results for bentonite slurries, API filter press results for polymers are shown to be highly sensitive to the filter paper used. In particular, repeatability testing revealed a substantial variation in the polymer fluid loss rates attributable to three primary factors: (a) the filter paper pore size; (b) filter paper damage resulting from the applied test pressure; (c) apparent ‘clogging’ of the filter paper pore space. Furthermore, the study demonstrates the poor repeatability of the API filter press test for polymer fluids even when filter papers of the same type are used. Interestingly, analysis of polymer flow with respect to filter paper pore size and the applied pressure showed that the filter papers were behaving as porous media rather than a simple bundle of capillaries; their behaviour could not be modelled using a simple capillary bundle model. Importantly, this finding shows that the filter press may provide a rapid method of assessing the apparent viscosity of polymer fluids in porous media at high shear rates – data that cannot be obtained by rotational viscometry, and would otherwise require resort to permeameter testing of coarse soils. The investigation demonstrates that the filter press test is not useful for the on-site quality control of polymer fluids but, given the theory presented in the paper, it can be a useful laboratory tool that provides valuable insight into polymer fluid flow behaviour in soils of high hydraulic conductivity, the most challenging soils for polymer fluid support.

125 Could yeast derivatives change beef cattle water intake in different scenarios?

Abstract Adequate water intake is linked to greater dry matter intake, heat loss, and productivity. To measure the water intake of beef cattle reared in groups, two experiments were carried out in Brazil (South East/Middle East) using water throughs coupled with scales (Intergado, Betim, Brazil) and RFID individual identification systems, allowing the recording of individual water intake of animals. In experiment 1, young bulls (n = 96; 105 d on feed - feedlot) were randomly assigned to four treatments: 1) Control, no yeast derivative; 2) AY – 7 g·animal⁻¹·d⁻¹, Autolyzed Yeast grown on sugarcane molasses (RumenYeast, ICC, Brazil); 3) YM – 3 g·animal⁻¹·d⁻¹, yeast rich in soluble Yeast Metabolites; 4) YB – 5 g·animal⁻¹·d⁻¹, Yeast Blend (live Yeast plus autolyzed Yeast). Diets (adaptation, growing, and finishing) x treatments were treated as fixed effects on the complete randomized design. In experiment 2, backgrounding bull calves (n = 32) reared on grazing and 710 g/d of protein supplements (90 d) were randomly assigned to two treatments: 1) Control, no yeast derivative; 2) AY – 7 g·animal⁻¹·d⁻¹, Autolyzed Yeast (RumenYeast), the means were subjected to ANOVA analyses. In both experiments, additives were inserted into the diet (mineral premix or supplement), animals were the experimental unit, and differences were declared significant at P < 0.05. Yeast derivatives increased (P < 0.05) water intake in both experiments (Figure 1). The average increment in water intake (L·animal⁻¹·d⁻¹ was 13.9%. Interestingly, the increment in relation to control was noted for all yeast derivatives and scenarios covered by the experiments (feedlot adaptation diet, feedlot growing diet, feedlot finishing diet, and grazing system). Until now, there seems to be no literature explanation for our findings. However, these results could help to explain the positive effects of yeast derivatives on rumen pH, protein microbial flow, and thermal stress since greater water intake increases the passage rate of rumen fluid and body heat loss. Statistical correlations may not be understood as a cause-consequence link. However, when dealing with a new question, correlations may give us a path to go on and investigate. Malheiros et al. (2023) noted a negative correlation between water intake and rumen dimethylamine. Autolyzed yeast can strongly decrease the concentration of rumen methylamines in cows facing subacute acidosis (Humer et al., 2018). Niacin metabolism should also be investigated since its supplementation enhances cows’ blood niacin levels and water intake. Yeast derivatives are rich in niacin, and autolyzed yeast supplementation can increase blood niacin and body heat loss during summer (Dias et al., 2018), probably increasing water need. In conclusion, yeast derivatives increased the water intake of beef cattle, and this finding adds to the understanding of how yeast derivatives supplementation benefits ruminants.

Evaluating Filtration and Thermal Stability of Water-Based Mud Using Green Synthesized Zinc Oxide Nanoparticles

Nanoparticles (NPs) have unique capabilities that make them an eye-opener opportunity for the upstream oil industry. Their nano-size allows them to flow within reservoir rocks without the fear of retention between micro-sized pores. Incorporating NPs with drilling and completion fluids has proved to be an effective additive that improves various properties such as mud rheology, filtration, thermal conductivity, and wellbore stability. However, the biodegradability of drilling fluid chemicals is becoming a global issue as the discharged wetted cuttings raise toxicity concerns and environmental hazards. Therefore, it is urged to utilize chemicals that tend to break down and susceptible to biodegradation. This research presents the practical application of bio-based Zinc Oxide nanoparticles (ZnO NPs) prepared chemically from celery leaf plant extract as green additive in water-based mud drilling fluid (WBM). The study aimed to evaluate the filtration and thermal stability of WBM using green-synthesized ZnO NPs. The results showed that the ZnO NPs have minimal effect of mud density, but significant improvement in mud thermal stability and filtration properties were attained with concentrations lower than 1g. The fluid loss rate was reduced by 33% with 0.45g of ZnO nanoparticles, and the thinnest mud cake was obtained as well. In terms of thermal stability, the bio-based ZnO NPs greatly enhanced the rheological properties of WBM at elevated temperatures. The rate of increment in plastic viscosity (PV) or decrement in yield point (YP) and gel strength occurred in a controllable manner compared to the rheological properties of base mud at high temperatures reaching 90°C. This study provides insight into the effect of green-synthesized ZnO nanoparticles on the performance of water-based mud and highlights their potential as an effective and environmentally friendly additive for the oil and gas industry.

Research and performance optimization of carbon dioxide foam fracturing fluid suitable for shale reservoir

Compared to conventional fracturing techniques, foam fracturing has numerous advantages, including good shear resistance, strong sand carrying capacity, low fluid loss, low damage, and fast return rates. It is particularly suitable for stimulation in low pressure, low permeability, and water-sensitive formations. Specifically, CO2 foam fracturing is crucial in energy savings and emission reductions, controlling the expansion of reservoir clay minerals, reducing crude oil viscosity, and improving the production of water-locked reservoirs. In this paper, we investigate the foam fracturing fluid and evaluate its performance. We selected thickeners with good foaming stability and foaming agents with excellent performance at low dosage levels, based on experimental evaluation. We finally determined the formulation of the foam fracturing fluid by analyzing the experimental data, such as foam half-life, foam mass, and viscosity. We experimentally evaluated the viscosity, static sand settling properties, and rheological properties of the fluid. After being tested on the reservoir core, the foam fracturing fluid has a viscosity of 2 mPas. Moreover, the residue content is 1.1 mg/L, the surface tension is 24.5 mN/m, and the interfacial tension is 1.5 mN/m. The fluid-carrying sand experiment of 40–70 mesh ceramic particles, commonly used in shale gas fracking, was evaluated. The sand-to-liquid ratio was set at 40% for the static sand-carrying experiment. The flow of the fluid-carrying sand was good, and the settling property was satisfactory for 3 h. We used shale reservoir cores from well W-1 to assess the rate of foam fracture, which was less than 19%. Under the experimental conditions of a shear rate of 170 S−1 and a temperature of 90°C, the viscosity of fracturing fluid was measured to be greater than 50 mPas, 90 min after shear, demonstrating the excellent temperature and shear resistance of the foam fracturing fluid. Using CO2 foam fracturing fluid can significantly improve the reconstruction effect of low permeability hydrocarbon reservoirs (especially unconventional reservoirs) and solve problems related to water resources and environmental protection during the process of oil and gas reservoir development. It will be a major factor in improving construction impacts and addressing water and environmental concerns for low permeability hydrocarbon reservoirs, particularly unconventional ones that utilize CO2 foam fracturing fluids.

A new wormhole mechanistic model for radial acid flow geometry using novel 3D flow correlations

In carbonate reservoirs, matrix acidizing is used to improve well performance by creating conductive channels called wormholes. Predicting wormhole propagation rate in radial acid flow geometry up to the real wellbore scale is the main problem regarding designing field operations in previous studies which are still challenging. In this study, a new mechanistic approach is presented to predict the radial flow acidizing up to near wellbore scale by considering the vital effects of porous media size and geometrical parameters of wormhole patterns.Accordingly, wormhole tip velocity and wormhole wall fluid loss rate will be introduced as the scale transferring parameters between different porous media sizes which are correlated in terms of rock diameter and wellbore height, wormhole size and density. These novel correlations are extracted from the large databank of flux distribution between rock matrix and wormhole channel obtained in 60 different 3D FEM flow simulations for various patterns of wormhole propagating and different wellbore sizes. In addition, an HPHT radial acid flooding setup is designed and constructed to perform radial acid coreflood on ultra-low permeable rocks (k«1md) for model validation. During the experiments, the breakthrough pore volume, pressure behavior and CT scan of samples are closely monitored. The results showed that due to the tight window of pore size distribution, faster breakthroughs with 1.23 and 1.45 pore volumes occurred in these tight samples compared to those reported already which are confirmed by developed model prediction. Besides, the model results showed that increasing the rock height (open-hole interval) would increase wormhole tip velocity and decrease acid breakthrough time. In addition, the higher temperature shifted the acid response curve to the right, toward higher acid breakthrough volume and higher acid concentration shifted it toward lower breakthrough volumes. The model is validated using radial acid experiments and previous radial acid models for different rock sizes with good agreement (R2 = 0.9547, MSE = 0.02161 and RMSE = 0.14701). The new radial acidizing model is capable to quickly predict wormhole propagation rate up to wellbore scale without requiring excess up-scaling data due to considering wide ranges of porous rock sizes from (25.4–152.4 cm) diameter and (5–25.4 cm) pay zone height (sufficient size for considering repetitive wormhole patterns). This technique can be utilized for tuning parameters of various radial cases to predict the acid tests results leading to reduce the number of required experiments.

Permeability damage and hydrate dissociation barrier caused by invaded fracturing fluid during hydrate reservoir stimulation

Hydraulic fracturing is a promising stimulation technology for enhancing the gas productivity and energy efficiency of low-permeability hydrate reservoirs. Presently, most studies focus on the fracturing feasibility of hydrate-bearing sediments and recovery efficiency after fracturing. Although the fracturing fluid inevitably invades the hydrate reservoirs during fracturing, the effects of invaded fracturing fluid on sediment permeability and hydrate dissociation have not been investigated yet. In this study, the invasion of water-based fracturing fluid into hydrate-bearing sediments was experimentally studied to clarify the dynamic characteristics of the fracturing fluid invasion, including its effects on sediment permeability and hydrate dissociation. The results revealed that the fracturing fluid loss rate was initially high but abruptly became extremely small, potentially because of the filter cake deposition on the fracture surface and the secondary hydrate formation in the invaded zone. However, the invaded fracturing fluid increased the dissociated gas flow resistance and inhibited the hydrate dissociation and gas production that yielded a two-stage gas production process, including slow hydrate dissociation in the invaded zone followed by relatively fast hydrate dissociation in the uninvaded zone. Furthermore, the degree of permeability damage in the invaded zone gradually decreased with the increasing invasion distance that was caused by the variations in the microscopic filtrate–sediment reactions. Interestingly, the water saturation measured by NMR gradually decreased from about 90% to 60% (initial water saturation) along the invasion distance. This phenomenon indicates that water sensitivity and water lock acted as the primary sources of permeability damage to the clayey–silty sediments after fracturing fluid invasion, suggesting that inhibiting clay swelling and increasing the flowback rate of the invaded fluid were essential for reducing permeability damage. Noted that using the fracturing fluid with breaker and KCl exhibited the lowest degree (25%) and shortest distance (<15 cm) of sediment permeability damage. The present results are vital for applying hydraulic fracturing in the field tests of hydrate reservoirs to optimize the fracturing fluid and improve the fracturing stimulation effect.

Qualitative Analysis of Drilling Fluid Loss Through Naturally-Fractured Reservoirs

Summary Drilling becomes extremely challenging when dealing with naturally fractured reservoirs (NFR). A comprehensive solution is developed in this study to perform qualitative analysis on drilling fluid loss rate and volume to examine how they can be affected by NFR characteristics, drilling fluid rheology, leakoff phenomenon, and wellbore condition. In this regard, the solution is applied to generate type curves to facilitate the sensitivity analysis (refer to the provided Supplementary Materials). The presented solution accounts for not only drilling fluid pseudoplasticity in the total system but also matrix medium under wellbore constant pressure assumption (by including dimensionless matrix contribution parameter). It is also able to measure mud loss advancement not only through NFR but also through homogeneous reservoirs. The developed solution is validated by reducing it to the preexisting solution (designed for Newtonian fluid case) by incorporating assumptions into it. The result demonstrates the significance of NFR properties and drilling fluid pseudoplasticity on the leakoff phenomenon and total loss volume, especially when constant pressure is established inside the wellbore. The finding reveals that three periods can be identified through generated type curves depending on NFR characteristics, drilling fluid rheology, and leakoff coefficient. Therefore, different drilling fluids with specific pseudoplasticity should be used in each period to mitigate drilling fluid loss effectively. In this regard, the study is supposed to design drilling fluid in a way to maintain its pseudoplasticity at a higher level at early and late times, while being maintained at a lower level during the transient period, a critical aspect for managed pressure drilling techniques, particularly in the context of dual-gradient drilling applications. Additionally, a procedure should be implemented to lessen the transient period while attempting to keep drilling fluid advancement occurrence at a lower rate, which shows that drilling fluid pseudoplasticity can be used as an effective tool to manage this period. The obtained result also indicates that the importance of drilling fluid rheology to control total loss volume is greater for NFR with higher leakoff than with lower leakoff. Furthermore, the greater the differential pressure inside the wellbore, the greater the importance of mud rheology to reduce drilling fluid loss. The outcome of the study not only facilitated qualitative and quantitative analyses through NFR but also enabled decision-makers to instantaneously select optimal wellbore conditions and drilling fluid pseudoplasticity.

Assessment of the activity of secondary caries lesions with short-wavelength infrared, thermal, and optical coherence tomographic imaging.

Significance: Leakage in the interfaces between restorative materials and tooth structure allows for fluid and bacterial acid infiltration, causing restoration failure due to secondary caries. Dentists spend more time replacing composite restorations than placing new ones. Previous in vitro and in vivo studies on enamel and root surfaces using shortwave-infrared (SWIR) and thermal imaging during dehydration with forced air have been promising for assessing lesion activity. Aim: We hypothesized that SWIR reflectance and thermal imaging methods can be used to monitor the activity of secondary caries lesions around composite restorations. The objective of this study was to employ these methods to measure the rate of fluid loss from lesions during dehydration with forced air to assess lesion activity. Approach: Sixty-three extracted human teeth with total of 109 suspected secondary lesions were examined using SWIR and thermal imaging during dehydration. The thickness of the highly mineralized transparent surface layer (TSL) at lesion interfaces indicative of lesion activity was measured by optical coherence tomography (OCT). Micro-computed tomography (MicroCT) was used to further confirm lesion severity and structure. OCT and MicroCT measurements of lesion structure, depth, and severity were correlated with fluid loss rates measured with SWIR reflectance and thermal imaging. Results: TSL thickness measured with OCT correlated with both SWIR reflectance and thermal measurements of rates of fluid loss ( ). Increasing TSL thickness led to decreased permeability of lesions, potentially indicating full lesion arrest at . SWIR performed better than thermal imaging for secondary lesion activity assessment, although both methods performed best on smooth surface lesions. Conclusions: Nondestructive SWIR reflectance and OCT imaging methods are promising for clinically monitoring the activity of secondary caries lesions.

Invasion of CaCO3 particles and polymers into porous formations in presence of fibres

Formation damage can occur through migration of drilling fluid particles and polymers into porous formations. A methodology for assessing formation damage was applied to measure invasion of CaCO3 and polymers into porous formations, where the CaCO3 particles size had been selected using established particle size selection methods. Tests were conducted with and without the presence of a cellulose-based additive, to study if the fibres could reduce the fluid loss and limit the formation damage.Input factors such as applied differential pressures, ranging from 6.9 to 34.9 MPa (1000-5000psi), and median pore-throat openings of discs were also varied to investigate which parameters affected the significance of the formation damage.The results showed invasion of CaCO3/ground marble into the formation and that particle size selection methods used to reduce fluid loss also led to formation damage. Further it was discovered that the presence of fibres limited the invasion of both CaCO3 and polymers into the porous formations when the D90 of the fibres were ≥3/2 times the pore-throat size, and that higher applied pressures led to larger formation damage. The fluid loss tests also showed both lower total fluid losses and lower fluid loss rates over time with the fibres added to the fluids, indicating that the filter-cake permeability was reduced with the addition of the fibre particles.

Effect of fracture roughness on transport of suspended particles in fracture during drilling

Fractures with different roughness are important permeable channels in oil and gas reservoirs. However, the drilling fluid is prone to leakage through fractures, resulting in formation damage. Study on the migration behavior of suspended particles with drilling fluid loss is the basis for finding the damage mechanism of solid invasion and drilling fluid loss control measures. From a comprehensive review of the previous studies, the transport behavior of suspended particles considering particle-fluid-fracture interaction hasn't been fully understood and quantified. In this study, we examined flow behavior of the particle-fluid mixture by the unresolved CFD-DEM approach. The effects of particle concentration, particle size, fracture width, drilling fluid loss rate, drilling fluid viscosity and cohesive force on particle transport in different rough fractures were studied. The research suggests that: (1) Increase of particle concentration will not only result in significant increase in fluid-particle velocity, but will also increase the wall mechanical retardation. (2) Particle aggregation near the fracture walls is more serious than in the fracture center. The shape of the agglomeration particle clusters is mainly elongated, with the long axis direction consistent with the flow direction. (3) Rough fracture walls will not only lead to more energy loss due to frequent particle-particle and particle-fracture contact, but also cause more particles to migrate in the fracture center.

The modes and competing rates of cartilage fluid loss and recovery

Cartilage loses, recovers, and maintains its thickness, hydration, and biomechanical functions based on competing rates of fluid loss and recovery under varying joint-use conditions. While the mechanics and implications of load-induced fluid loss have been studied extensively, those of fluid recovery have not. This study isolates, quantifies, and compares rates of cartilage recovery from three known modes: (1) passive swelling – fluid recovery within a static unloaded contact area; (2) free swelling – unrestricted fluid recovery by an exposed surface; (3) tribological rehydration – fluid recovery within a loaded contact area during sliding. Following static loading of adult bovine articular cartilage to between 100 and 500 μm of compression, passive swelling, free swelling, and tribological rehydration exhibited average rates of 0.11 ± 0.04, 0.71 ± 0.15, and 0.63 ± 0.22 μm/s, respectively, over the first 100 s of recovery; for comparison, the mean exudation rate just prior to sliding was 0.06 ± 0.04 μm/s. For this range of compressions, we detected no significant difference between free swelling and tribological rehydration rates. However, free swelling and tribological rehydration rates, those associated with joint articulation, were ∼7-fold faster than passive swelling rates. While previous studies show how joint articulation prevents fluid loss indefinitely, this study shows that joint articulation reverses fluid loss following static loading at >10-fold the preceding exudation rate. These competitive recovery rates suggest that joint space and function may be best maintained throughout an otherwise sedentary day using brief but regular physical activity. Statement of SignificanceCartilage loses, recovers, and maintains its thickness, hydration, and biomechanical functions based on competing rates of fluid loss and recovery under varying joint-use conditions. While load-induced fluid loss is extremely well studied, this is the first to define the competing modes of fluid recovery and to quantify their rates. The results show that the fluid recovery modes associated with joint articulation are 10-fold faster than exudation during static loading and passive swelling during static unloading. The results suggest that joint space and function are best maintained throughout an otherwise sedentary day using brief but regular physical activities.

A semi-analytical approach to model drilling fluid leakage into fractured formation

Loss of circulation while drilling is a challenging problem that may interrupt operations and contaminate the subsurface formation. Analytical modeling of fluid flow in fractures is a tool that can be quickly deployed to assess drilling mud leakage into fractures. A new semi-analytical solution is developed to model the flow of non-Newtonian drilling fluid in fractured formation. The model is applicable for various fluid types exhibiting yield-power law (Herschel-Bulkley). We use finite-element simulations to verify our solutions. We also generate type curves and compare them to others in the literature. We then demonstrate the applicability of the proposed model for two field cases encountering lost circulations. To address the subsurface uncertainty, we combine the semi-analytical solutions with Monte Carlo and generate probabilistic predictions. The solution method can estimate the range of fracture conductivity, parametrized by the fracture hydraulic aperture, and time-dependent fluid loss rate that can predict the cumulative volume of lost fluid.

The Modes and Competing Rates of Cartilage Fluid Loss and Recovery

Cartilage loses, recovers, and maintains its thickness, hydration, and biomechanical functions by adjusting relative rates of load-induced fluid loss and competitive fluid recovery under varying joint-use conditions. While the mechanics and implications of fluid loss have been studied extensively, those of fluid recovery have not. This study isolates, quantifies, and compares rates of cartilage recovery from three known modes: (1) passive swelling – fluid recovery within a nominally unloaded contact; (2) free swelling – fluid recovery at an exposed surface; (3) tribological rehydration – fluid recovery within a loaded contact area during sliding. Following static loading of adult bovine articular cartilage to between 100 and 250 μm of compression, passive swelling, free swelling, and tribological rehydration rates were 0.18 ± 0.08 μm/s, 1.7 ± 0.3, and 1.8 ± 0.6 μm/s, respectively; the corresponding exudation rate was 0.06 ± 0.04 μm/s. For this range of compressions, we detected no significant difference between passive swelling and exudation rates. However, free swelling and tribological rehydration rates, those associated with joint articulation, were 10-fold faster than passive swelling and exudation rates. While previous studies show how joint articulation prevents fluid loss indefinitely, this study shows how quickly joint articulation reverses fluid loss following static loading (at 30:1 the exudation rate). These competitive recovery rates suggest that joint space and function may be best maintained throughout an otherwise sedentary day using brief but regular physical activities (e.g. a 5-minute walk).

Improving the rheological and fluid loss properties of the water-based mud using wheat flour

This study aims to evaluate the effect of wheat flour as a natural and environmentally friendly material on the properties of water-based mud. Recently, many experiments have been conducted with various additives to improve the properties of drilling fluids. The effect of using wheat flour as a new additive to drilling fluid was studied to improve rheological and filtration properties. In the laboratory several samples of water-based mud were prepared, different concentrations of wheat flour from 1 wt% to 7 wt% were added to the mud and tested by using a Fann 35 viscometer, 140 Fann Mud balance, and an API LT-LP filter press. The results showed that adding 7 wt% of wheat flour was the optimal concentration. It was found that the apparent viscosity and yield point increased by 50% and 35%, respectively, when 7 wt% of wheat flour was added to the water-based drilling fluid. Likewise, the fluid loss rate was reduced by 25% when using the same concentration of wheat flour.

Effect of Nanoparticle Shape on Viscoelastic Surfactant Performance at High Temperatures

Summary Viscoelastic surfactants (VESs) have been used for acid diversion and fracturing fluids. VESs were introduced because they are less damaging than polymers. VESs' high cost, low thermal stability, and incompatibility with several additives (e.g., corrosion inhibitors) limit their use. The goal of this study is to investigate the interaction of VES micelles with different nanoparticle shapes to reduce VES loadings and enhance their thermal stability. This work examined spherical and rod-shaped nanoparticles of silica and iron oxides. The effects of particle size, shape, and surface charge on a zwitterionic VES micellization were conducted. The physical properties were measured using ζ-potential, dynamic light scattering (DLS), and transmission electron microscopy (TEM). The rheological performances of VES solutions were evaluated at 280 and 350°F using a high-pressure/high-temperature rotational rheometer. The proppant-carrying capacity of the fracturing fluids was evaluated using a high-pressure/high-temperature see-through cell and dynamic oscillatory viscometer. The fluid loss and formation damage were determined using corefloods and computed-tomography scans. The interaction between nanoparticles and VES is strongly dependent on the VES concentration, temperature, nanoparticle characteristics, and concentration. The spherical particles at 7-lbm/1,000 gal loading extended the VES-based-fluid thermal stability at VES loading of 4 wt% up to 350°F. The nanorods effectively enhanced and extended the thermal-stability range of the VES system at VES concentration of only 2 wt%. Both particle shapes performed similarly at 4 wt% VES and 280°F. The addition of silica nanorods extended the thermal stability of the 4 wt% VES aqueous fluid, which resulted in an apparent viscosity of 200 cp for 2 hours. The addition of rod-shaped particles enhanced the micelle to micelle entanglement, especially at VES loading of 2 wt%. The use of nanoparticles enhanced the micelle/micelle networking, boosting the fluid-storage modulus and enhancing the proppant-carrying capacity. The addition of nanoparticles to the VES lowered its fluid-loss rate and minimized formation damage caused by VES-fluid invasion. This research gives guidelines to synthesize nanoparticles to accommodate the chemistry of surfactants for higher-temperature applications. It highlights the importance of the selected nanoparticles on the rheological performance of VES.

Borehole temperature distribution when drilling fluid loss occurs in the two-dimensional area at the bottom-hole during drilling

During the drilling process, the temperature distributions of the borehole and the formation under the condition of drilling fluid loss have a very significant effect on the borehole pressure prediction, the rheological design of drilling fluid and the borehole stability. Aiming at the complex downhole situations as drilling fluid loss occurs during drilling, a new two-dimensional model is proposed to study the temperature distributions of the borehole and the surrounding formation in the presence of the lost circulation. The law of the borehole temperature distribution when drilling fluid loss took place in the two-dimensional area at the bottom of the well was obtained. Comparing with the scenario of no drilling fluid loss, the borehole temperature is reduced at the same well depth in the case of drilling fluid loss. The occurrence of drilling fluid loss greatly disturbs the temperature distribution of drilling fluid in the annulus in the drilling fluid loss area. The location of drilling fluid loss has a conspicuous effect on the borehole temperature distributions. The occurrence of drilling fluid loss renders a more prominent effect of casings on the temperature profile of the medium around the borehole. As the drilling fluid loss rate increases, the borehole temperature at the same well depth decreases.

MP40-12 USE OF ISOTONIC CONTRAST SOLUTION IN PRESSURE REGULATING BALLOON DOES NOT IMPACT ARTIFICIAL URINARY SPHINCTER LONGEVITY

You have accessJournal of UrologyUrodynamics/Lower Urinary Tract Dysfunction/Female Pelvic Medicine: Male Incontinence: Therapy I (MP40)1 Apr 2020MP40-12 USE OF ISOTONIC CONTRAST SOLUTION IN PRESSURE REGULATING BALLOON DOES NOT IMPACT ARTIFICIAL URINARY SPHINCTER LONGEVITY Brian Inouye*, William Boysen, and Andrew Peterson Brian Inouye*Brian Inouye* More articles by this author , William BoysenWilliam Boysen More articles by this author , and Andrew PetersonAndrew Peterson More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000000889.012AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Artificial urinary sphincter (AUS) is the gold standard for treatment of male stress urinary incontinence. The device can be filled with normal saline (NS) or isotonic contrast solution. Contrast can be useful for trouble shooting an AUS failure, to assess for fluid leak or sub-cuff atrophy. Many surgeons are hesitant to use contrast in the device due to concerns about the impact on device malfunction and longevity, but no studies have addressed this issue. We used industry data to identify differences in outcomes between NS and contrast-filled AUS. METHODS: Each AUS placement requires the submission of a patient information form that is sent to the manufacturer in order to track outcomes. This includes details of device preparation and the filling fluid. All patients in the industry database (Boston Scientific) from 2001 to 2016 were included. Groups were divided into AUS filled with NS and AUS filled with contrast. Patient demographics were recorded. Longevity of the device was defined as time to the need for reoperation (device removal, revision, or replacement). The groups were compared using t-test and chi-square test. A Kaplan Meier curve was created to compare device survival between AUS with filled NS versus contrast. RESULTS: A total of 39,591 patients were included in the cohort, of which 39,363 (99.5%) were male. 34,920 (88.2%) devices were filled with NS while 4,671 (11.8%) were filled with contrast. The reoperation rate overall was 16.1%, with no difference between groups (15.8% NS versus 18.1% contrast). The rate of fluid loss and device malfunction precipitating device removal did not differ between the groups (3.3% NS vs 4.1% contrast; 0.8% NS vs 0.9% contrast). The infection rate was similar between groups (1.9% NS vs 2.7% contrast). The mean time to reoperation overall was 3.9 years (± 3.4), and was significantly longer in the contrast filled cohort (3.8 ± 3.3 years NS vs 5.1 ± 3.9 years contrast, p<0.01). On Kaplan Meier analysis, the time to reoperation was longer in the contrast filled cohort (Figure 1). CONCLUSIONS: The use of contrast in the AUS did not change rates of device malfunction or fluid loss, and devices filled with contrast lasted longer than those filled with NS. We find that contrast in the device is useful for troubleshooting when a patient returns with recurrent incontinence, and should be considered by AUS implanters since this practice does not impact outcomes. Source of Funding: None © 2020 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 203Issue Supplement 4April 2020Page: e590-e590 Advertisement Copyright & Permissions© 2020 by American Urological Association Education and Research, Inc.MetricsAuthor Information Brian Inouye* More articles by this author William Boysen More articles by this author Andrew Peterson More articles by this author Expand All Advertisement PDF downloadLoading ...

EXERGY ANALYSIS OF DOUBLE-CIRCUIT FLAT SOLAR COLLECTOR WITH THERMOSYPHON CIRCULATION

In the present work, an exergy analysis was done of two-circuit flat solar collector with thermosiphon circulation. The article presents a mathematical model of energy and exergic analysis of flat solar collectors, as well as calculations of solar radiation efficiency, temperature, flow rate of the fluid, exergy rates and exergy loss rates are done. The significance of the results achieved is high, since experimental studies can detect inefficient components of the solar heating system. The exergetic efficiency of a dual-circuit flat solar collector with a thermosiphon circulation describes irreversibility of the process according to thermodynamic parameters. This is caused by a large the degree of overheating achieved at the end of the processes of compression and evaporation, which leads to large differences in heat exchange temperature based on the heat pump cycle. The exergy efficiency value for the entire system is 70. Maximum values energy efficiency and exergy at noon, 32.5% and 2.23%, respectively. The efficiency of exergy is 4%, and the highest the loss of exergy is the difference between the absorber plates and the sun, accounting for 52.86% of the total exergy rate.

Coupled CFD-DEM simulation of granular LCM bridging in a fracture

Developed fractures are important storage space and permeable channel in hydrocarbon reservoirs. However, they will lead to drill-in fluid loss and induce severe formation damage. Fracture plugging with granular lost circulation material (LCM) is most commonly used to control drill-in fluid loss. To our best knowledge, traditional research about LCM bridging mainly performed by the trial-and-error method. However, the behavior of granular LCM migration and bridging in a fracture on mesoscale is still unclear. In this paper, the coupled CFD-DEM approach is used to simulate the flow of granular LCM in a vertical fracture. The effects of particle size distribution (PSD) and concentration on the fracture plugging process are studied by a series of controlled numerical experiments. The research suggests that: (1) When Wf/D50<1.5, the critical particle concentration softly increases with particle size distribution (PSD), but the area with Wf/D50>1.5 the critical particle concentration sharply increases with PSD. (2) The plugging process can be divided into two distinct stages from pressure drop rate: particle bridging and particle accumulation. (3) The drill-in fluid loss rate is affected by the plugging process, the structure of plugging zone and PSD.

Evaluation on Water Block in Low Permeability Formations and the Research of Water Block Control

Oleic permeability is severely impacted by the invasion of aqueous working fluids, especially in low porosity and low permeability reservoirs. This study mainly targeted at low permeability reservoir of Dongying Formation, Chengdao Offshore Oilfield. Water influx and its influence on oil threshold pressure were evaluated with constant-pressure injection, in which way the injuring extent of water block could be quantitatively expressed. Results indicated that, oil threshold pressure could be increased by 1.3 times merely with a water influx of 0.3 pore volumes. In addition, researches related to the system of fluid loss control had been conducted on the basis of the functional mechanism of water block. An emulsion working over fluid system had been developed by biodiesel with excellent emulsification characteristic. It can be inferred from water invasion tests that the emulsion system performed well in fluid loss control both in water phase and oil phase. The fluid loss rate could be decreased to 55.6%∼86.4%. Meanwhile, mutual solvent ethylene glycol monobutyl ether (EGMBE) had been efficiently adopted in water block remediation. The threshold pressure can be reduced by 79.7% according to evaluation tests.