Letteratura scientifica selezionata sul tema "Permeability decline"
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Articoli di riviste sul tema "Permeability decline"
1
Yuan, Yingzhong, Zhilin Qi, Zhangxing Chen, Wende Yan e Zhiheng Zhao. "Production decline analysis of shale gas based on a probability density distribution function". Journal of Geophysics and Engineering 17, n. 2 (10 febbraio 2020): 365–76. http://dx.doi.org/10.1093/jge/gxz122.
Testo completoAbstract (sommario):
Abstract Production decline analysis is a simple and efficient method to forecast production dynamics of shale gas. The traditional Arps decline model is also widely used in the production decline analysis of shale gas, but an obvious error is often generated. Based on the Weibull and χ2 probability density distribution function, the monotonic decreasing production prediction equations of shale gas are established. It is deduced that recently, the widely used Duong model is essentially a Weibull probability density distribution model. Decline analysis results of production data from actual shale gas well and numerical simulations indicate that the fitting results of the Weibull (Duong) model and χ2 distribution model are better than the Arps model whose deviation of early data is large. For a shale gas reservoir with very low permeability, pressure conformance area is small and it is obviously influenced by fractures. Early shale gas production rate mainly contributed to by fractures declines quickly and the later production rate mainly contributed to by the matrix declines slowly over time. The production decline curve has obvious long-tail distribution characteristics and it is a better fit to the data with a χ2 distribution model. As for the increase of permeability, the fitting accuracy of the Weibull (Duong) model gradually becomes better than the χ2 distribution model. Research results provide theoretical guidance for choosing a reasonable production decline model of a shale gas reservoir with a different permeability.
2
Denney, Dennis. "Relationship of Decline Analysis to Relative Permeability". Journal of Petroleum Technology 51, n. 01 (1 gennaio 1999): 44–45. http://dx.doi.org/10.2118/0199-0044-jpt.
Testo completo
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Tan, Yunhui, Yan Li, Margaretha C. M. Rijken, Karim Zaki, Bin Wang, Ruiting Wu, Oya Karazincir e Wade Williams. "Modeling of Production Decline Caused by Fines Migration in Deepwater Reservoirs". SPE Journal 25, n. 01 (13 agosto 2019): 391–405. http://dx.doi.org/10.2118/187263-pa.
Testo completoAbstract (sommario):
Summary Many deepwater wells experience steep productivity declines. Some field observations indicate that this decline is partly attributable to fines-migration effects. In this paper, we present a numerical workflow to simulate the effect (over time) of flow-induced fines migration on production decline in deepwater reservoirs. A permeability-reduction function was extracted from long-term coreflood tests and implemented into a reservoir simulator. Using the permeability-reduction function, production degradation caused by fines migration was simulated in a detailed single-well model. From previous research, it was understood that fines migration does not start until the flow velocity is greater than the critical velocity. After many long-term coreflood tests, or extended fines-migration (EFM) tests, we concluded that the permeability damage induced by fines migration is a function of the pore-volume (PV) throughput (fluid volume flowing through the core divided by the PV of the core). To address these observations, the numerical model was updated such that the interstitial flow velocity was tracked in each individual cell. When the interstitial velocity is greater than the critical velocity, the cell's permeability follows the permeability-reduction trend obtained from laboratory data. Validation of the workflow is performed using a cylinder model to match the laboratory test core-plug data. A detailed 3D model was constructed to study the fines-migration effect in each part of the near-wellbore (e.g., perforation, fracture) region and the reservoir. As expected, fines migration started near the perforation where the flow velocity was the highest. Depending on the permeability-decline rate, the production asymptotes eventually reached a constant value after a certain period. Both the decline rate and the ultimate residual permeability had a strong effect on the final production. Sensitivities were run to study the effect of fines migration in different completions. To the authors’ understanding, this is the first time that laboratory-based fines-migration data were incorporated into a reservoir simulator to predict the production decline using experiment-based fines-migration functions. This workflow will help reservoir engineers predict the damage caused by fines migration, predict production decline, and plan for remediation.
4
Russell, Thomas, Larissa Chequer, Alexander Badalyan, Zhenjiang You e Pavel Bedrikovetsky. "Effect of kaolinite content on formation damage due to fines migration: systematic laboratory and modelling study". APPEA Journal 58, n. 2 (2018): 743. http://dx.doi.org/10.1071/aj17189.
Testo completoAbstract (sommario):
Laboratory tests have been done to investigate the effect of kaolinite content on the behaviour of unconsolidated sandstone rocks during the injection of low-salinity water. Artificial cores comprised of kaolinite and chemically washed sand were prepared and compacted for this study. Five cores with kaolinite weight percentages ranging from 1% to 10% were injected sequentially with sodium chloride solutions of stepwise decreasing salinity. The permeability of the cores declined to as little as 1/54 times the initial permeability. Negligible permeability decline was observed when the kaolinite content was only 1% of the total mass. Generally, the extent of permeability decline was greater in cores with a larger percentage of kaolinite. The results are explained by the effect of kaolinite not only on the abundance of detachable clays, but also on the pore size. The results from the laboratory test were fitted with an exact solution of a model for fines migration. The parameters from these tests were input into a model for radial injection of low-salinity water to predict the extent of injectivity decline. The results serve as a benchmark for correlating injectivity decline due to fines migration between wells using the rock mineralogy. The tests suggest that mineralogy alone is not sufficient to fully predict formation damage, and that pore geometry and the nature of particle detachment are still critical factors for this process.
5
Zhang, Zhang, Shun Li He, Hai Yong Zhang, Shao Yuan Mo e Shuai Li. "Decline Curves of a Vertical Well in Stress-Sensitive Reservoir". Advanced Materials Research 772 (settembre 2013): 781–88. http://dx.doi.org/10.4028/www.scientific.net/amr.772.781.
Testo completoAbstract (sommario):
Stress-sensitivity effects have been recognized to have impact on the pressure/rate transient behavior of wells in several reservoirs. Although the effects of stress-sensitivity have been considered in well testing theory in the past thirty years, little has been done to determine their influence on rate decline behavior. This paper presents a single phase flow model considering stress-sensitive formation permeability to investigate the characteristic of production rate decline of a vertical well. The stress-sensitive permeability is considered as an exponential form. The permeability changes with pressure drop are described by a permeability modulus. By introducing two pseudo functions, the equations of the mathematical model are linearized and approximate semi-analytical solutions are obtained. The analytical solutions are carefully verified through numerical simulation. Two sets of new decline type curves are diagramed on a log-log plot for constant rate case and constant bottomhole pressure case respectively. The influence of stress-sensitive permeability on decline curves are analyzed and compared. From this work, we recognized that the rate decline characteristics of stress-sensitive reservoir under constant rate and constant bottomhole producing condition are different. New analysis method should be developed to analyze field variable rate/variable pressure drop data.
6
Machenbach, I., T. Leiknes e H. Ødegaard. "Coagulation/submerged hollow-fibre ultrafiltration for natural organic matter removal". Water Supply 3, n. 5-6 (1 dicembre 2003): 401–7. http://dx.doi.org/10.2166/ws.2003.0195.
Testo completoAbstract (sommario):
Experiments were carried out to investigate the removal of humic substances from highly coloured raw water (50 mg Pt/L) by coagulation and outside-in hollow-fibre membrane filtration. Chitosan, a cationic biopolymer produced from crustacean shells, and polyaluminium chloride (PACl) were used as coagulants. The rate of permeability decline was determined for different backwash frequencies and different fluxes at a 95% water recovery of the membrane. Coagulation with PACl gave a good and consistent permeate quality with removals of 95.6%, 84.9%, and 66.1% for true colour, UV absorbers, and dissolved organic carbon, respectively. Longer filtration intervals with less frequent backwashing as well as lower specific aluminium dosages increased the rate of permeability decline. The particle size distribution in the retentate tank was not affected by the frequency of backwashing. Chitosan was less effective in coagulating humic substances and the removal efficiencies were notably lower. Preliminary results suggest that the permeability declines somewhat faster for chitosan compared to PACl-coagulated water.
7
Kimura, Katsuki, Naoko Ogawa e Yoshimasa Watanabe. "Permeability decline in nanofiltration/reverse osmosis membranes fed with municipal wastewater treated by a membrane bioreactor". Water Science and Technology 67, n. 9 (1 maggio 2013): 1994–99. http://dx.doi.org/10.2166/wst.2013.080.
Testo completoAbstract (sommario):
Decline in the permeability in nanofiltration (NF)/reverse osmosis (RO) membranes that filtered effluents from a membrane bioreactor (MBR) treating municipal wastewater was investigated in this study. Four different 2-inch spiral-wound NF/RO membrane elements were continuously operated for 40 days. The results showed that the amount of deposits on the membrane surface did not affect the degree of permeability decline. Laboratory-scale filtration tests with coupons obtained from the fouled membranes also revealed that the contribution of the gel/cake layer to total filtration resistance was minor. Rather, constituents that were strongly bound to the membranes were mainly responsible for permeability decline. Chemical cleaning of the fouled membranes carried out after removal of the cake showed that silica played an important role in the decline in permeability. A considerable amount of organic matter which was mainly composed of carbohydrates and proteins was also desorbed from the fouled membranes.
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Li, Chen, e Sheng Ling Xiao. "A Comparative Analysis of the Performance of PVC Film Aging by Ultraviolet and Thermal Methods". Advanced Materials Research 830 (ottobre 2013): 45–48. http://dx.doi.org/10.4028/www.scientific.net/amr.830.45.
Testo completoAbstract (sommario):
In this article, the changes of the polyvinyl chloride (PVC) film properties and its law are analyzed during the ultraviolet and thermal aging. Using accelerated aging methods in laboratory,it was found that the tensile strength by ultraviolet aging fell down, on the contrary, it raised by thermal aging. This result indicate that PVC film was not aged to reduce the tensile strength at 50°C for 120h.We found the air permeability curves rose firstly then to decline, and the moisture permeability of PVC film curves declined by the two aging methods. The effects of the ultraviolet aging on the air and moisture permeability were a marked decrease.
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Shen, Yinghao, Xinyu Yang e Yuelei Zhang. "Production Analysis of Tight Sandstone Reservoir in Consideration of Stress-Sensitive Permeability". Open Petroleum Engineering Journal 10, n. 1 (28 aprile 2017): 82–93. http://dx.doi.org/10.2174/1874834101710010082.
Testo completoAbstract (sommario):
Background: Tight sandstone reservoirs play an important role in the oil industry. The permeability of tight sandstone reservoir generally has stronger stress sensitivity than that of conventional reservoir because of the latter’s poor physical properties. However, the production analysis of tight sandstone reservoir did not fully considered the stress-sensitive permeability yet. Objective: This paper proposed a production analysis method considering the stress- sensitive permeability. Method: This paper firtstly investigated the stress sensitivity characteristics and the effect of stress-sensitive permeability on a tight reservoir. Decline-type curves that consider stress-sensitive permeability are then established, and a systematic analysis method was built for the production analysis to obtain the single-well controlled dynamic reserves and reservoir physical properties. Results: A field analysis was performed in combination with Block Yuan-284 of Changqing Oilfield. Results show that with the reduction of reservoir pressure, stress sensitivity leads to the decline in reservoir permeability and the increase in seepage resistance, thus reducing the actual single-well controlled reserve and radius. Conclusion: By utilizing the analysis method based on the decline curves, we can effectively predict the single-well controlled dynamic reserves of such reservoirs and evaluate the characteristic parameters of reservoirs.
10
Yan, Qing Hui, Han Min Xiao, Ling Hui Sun, Wei Dong Liu e Jun Cheng Hu. "Study on the Features of Production Decline Law in Oil Manufacturing System in Wangyao Block". Applied Mechanics and Materials 252 (dicembre 2012): 388–93. http://dx.doi.org/10.4028/www.scientific.net/amm.252.388.
Testo completoAbstract (sommario):
Features of production decling determines the deployment of development project in oilfield, which has heavy influence on the oil manufacturing system. Eq.(17)and (18) have shown the final results. The characteristics of oil and water percolation, presented by Figure.1, are the primary factors for decline law. Oil-water relative permeability equations of WangYao Block, in AnSai oilfield, was deducted, and the oil-water relative permeability curves were drawn according to the equations. The oil phase curve presents a change from a linear relationship to an exponential relationship with the increase of the water saturation, which means an exponential decrease and a harmonic decrease of the single well production.
Tesi sul tema "Permeability decline"
1
Ilk, Dilhan. "Well Performance Analysis for Low to Ultra-low Permeability Reservoir Systems". 2010. http://hdl.handle.net/1969.1/ETD-TAMU-2010-08-8574.
Testo completoAbstract (sommario):
Unconventional reservoir systems can best be described as petroleum (oil and/or gas) accumulations
which are difficult to be characterized and produced by conventional technologies. In this work we
present the development of a systematic procedure to evaluate well performance in unconventional (i.e.,
low to ultra-low permeability) reservoir systems.
The specific tasks achieved in this work include the following:
● Integrated Diagnostics and Analysis of Production Data in Unconventional Reservoirs: We identify
the challenges and common pitfalls of production analysis and provide guidelines for the analysis of
production data. We provide a comprehensive workflow which consists of model-based production
analysis (i.e., rate-transient or model matching approaches) complemented by traditional decline
curve analysis to estimate reserves in unconventional reservoirs. In particular, we use analytical
solutions (e.g., elliptical flow, horizontal well with multiple fractures solution, etc.) which are
applicable to wells produced in unconventional reservoirs.
● Deconvolution: We propose to use deconvolution to identify the correlation between pressure and
rate data. For our purposes we modify the B-spline deconvolution algorithm to obtain the constantpressure
rate solution using cumulative production and bottomhole pressure data in real time
domain. It is shown that constant-pressure rate and constant-rate pressure solutions obtained by
deconvolution could identify the correlation between measured rate and pressure data when used in
conjunction.
● Series of Rate-Time Relations: We develop three new main rate-time relations and five
supplementary rate-time relations which utilize power-law, hyperbolic, stretched exponential, and
exponential components to properly model the behavior of a given set of rate-time data. These
relations are well-suited for the estimation of ultimate recovery as well as for extrapolating
production into the future. While our proposed models can be used for any system, we provide application almost exclusively for wells completed in unconventional reservoirs as a means of
providing estimates of time-dependent reserves. We attempt to correlate the rate-time relation
model parameters versus model-based production analysis results. As example applications, we
present a variety of field examples using production data acquired from tight gas, shale gas
reservoir systems.
2
McMillan, Marcia Donna. "Determining Reserves in Low Permeability and Layered Reservoirs Using the Minimum Terminal Decline Rate Method: How Good are the Predictions?" Thesis, 2011. http://hdl.handle.net/1969.1/ETD-TAMU-2011-05-9525.
Testo completoAbstract (sommario):
This thesis evaluates the applicability of forecasting production from low permeability and layered tight gas wells using the Arps hyperbolic equation at earlier times and then switching to the exponential form of the equation at a predetermined minimum decline rate. This methodology is called the minimum terminal decline rate method.
Two separate completion types have been analyzed. The first is horizontal completions with multi-stage hydraulic fractures while the second is vertical fractured wells in layered formations, completed with hydraulic fractures. For both completion types both simulated data and real world well performance histories have been evaluated using differing minimum terminal decline rates and the benefit of increasing portions of production history to make predictions.
The application of the minimum terminal decline rate method to the simulated data in this study (3 percent minimum decline applied to multiple fractured horizontal wells MFHW- and 7 percent applied to vertical fractured layered wells) gave high errors for some simulations within the first two years. Once additional production data is considered in making predictions, the errors in estimated ultimate recovery and in remaining reserves is significantly reduced. This result provides a note of caution, when using the minimum decline rate method for forecasting using small quantities of production history.
The evaluation of real world data using the minimum terminal decline rate method introduces other inaccuracies such as poor data quality, low data frequency, operational changes which affect the production profile and workovers / re-stimulations which require a restart of production forecasting process.
Real well data for MFHW comes from the Barnett Shale completions of the type which have been widely utilized since 2004. There is insufficient production history from real wells to determine an appropriate minimum terminal decline rate. In the absence of suitable analogs for the determination of the minimum terminal decline rate it would be impossible to correctly apply this methodology.
Real well data for vertical fractured layered wells from the Carthage Cotton Valley field indicate that for wells similar to Conoco operated Panola County wells a feasible decline rate is between 5 percent and 10 percent. Further if a consistent production trend and with more than 2 years of production history are used to forecast, the EUR can be predicted to within plus/minus 10 percent and remaining reserves to within plus/minus 15 percent.
3
Lacayo, Ortiz Juan Manuel. "Pressure Normalization of Production Rates Improves Forecasting Results". Thesis, 2013. http://hdl.handle.net/1969.1/151370.
Testo completoAbstract (sommario):
New decline curve models have been developed to overcome the boundary-dominated flow assumption of the basic Arps’ models, which restricts their application in ultra-low permeability reservoirs exhibiting long-duration transient flow regimes. However, these new decline curve analysis (DCA) methods are still based only on production rate data, relying on the assumption of stable flowing pressure. Since this stabilized state is not reached rapidly in most cases, the applicability of these methods and the reliability of their solutions may be compromised. In addition, production performance predictions cannot be disassociated from the existing operation constraints under which production history was developed. On the other hand, DCA is often carried out without a proper identification of flow regimes. The arbitrary application of DCA models regardless of existing flow regimes may produce unrealistic production forecasts, because these models have been designed assuming specific flow regimes.
The main purpose of this study was to evaluate the possible benefits provided by including flowing pressures in production decline analysis. As a result, it have been demonstrated that decline curve analysis based on pressure-normalized rates can be used as a reliable production forecasting technique suited to interpret unconventional wells in specific situations such as unstable operating conditions, limited availability of production data (short production history) and high-pressure, rate-restricted wells. In addition, pressure-normalized DCA techniques proved to have the special ability of dissociating the estimation of future production performance from the existing operation constraints under which production history was developed. On the other hand, it was also observed than more consistent and representative flow regime interpretations may be obtained as diagnostic plots are improved by including MBT, pseudovariables (for gas wells) and pressure-normalized rates. This means that misinterpretations may occur if diagnostic plots are not applied correctly.
In general, an improved forecasting ability implies greater accuracy in the production performance forecasts and more reliable reserve estimations. The petroleum industry may become more confident in reserves estimates, which are the basis for the design of development plans, investment decisions, and valuation of companies’ assets.
4
Boechat, Chequer Larissa. "Particle Detachment in Single-Phase and Two-Phase Flows in Porous Media". Thesis, 2019. http://hdl.handle.net/2440/124362.
Testo completoAbstract (sommario):
Hereby I present a PhD thesis by publications. This thesis includes seven journal papers, of which six have already been published in peer-reviewed journals and one has been submitted for publication and is presently under review. This thesis shows that the commonly used single particle-single surface Derjaguin-Landau-Verwey-Overbeek (DLVO) calculations do not always effectively predict particle detachment. Therefore, the mobilisation of clustered structures under particle-particle attraction is investigated. The critical detachment velocity of clusters is higher than for single colloids and provides better agreement with the laboratory results. The behaviour of particles and clusters was also investigated during drainage and imbibition in visualisation experiments. Particles remain on the air-water interfaces of residual liquid patches left behind the drainage front. Later, these particles join the imbibition front away from the substrate. In a previously dried channel, the vapour condensation ahead of the imbibition front detaches particles from the surface by a rising air-water interface. This thesis presents an extension of the traditional mathematical model for colloid transport by including equations for the particle re-attachment rate and the attached-concentration-dependency of permeability. The new model captures the effect of permeability increase due to colloid mobilisation and further re-attachment in stagnant zones of the porous space. This effect was observed during high-salinity water injection in cores with low kaolinite concentrations. This model is also extended to account for the presence of a residual phase. Compared with fines migration under single-phase flow, having a residual phase significantly reduces the permeability variation. Analytical solutions for over and undersaturated state of fines were also derived in this thesis. Oversaturation means that particles begin to detach as soon as the flow starts. In the undersaturated case, particle detachment occurs only with further increase in detaching torque or decrease in attaching torque. The derived models allow formulating the fingerprints for the flow of over and undersaturated fines in porous media. Novel analytical models for one-dimensional linear and axisymmetric suspension-colloidal transport accounting for fines detachment and capture were also derived. Laboratory experiments with low-salinity water injection were performed. The model coefficients obtained from laboratory data treatment were used for reliable laboratory-based prediction of well injectivity decline. The results show that fines migration during low-salinity water injection results in significant well injectivity impairment. The thesis also investigates low-salinity water slug injection followed by a high-salinity chase drive in a two layer-cake reservoir. The formation damage caused by fines mobilisation during low-salinity water injection diverts the injected water flux into low-permeability zones and enhances sweep efficiency. An optimal low-salinity slug size existed for all simulated cases. The optimal slug size is similar to the pore volume of the high-permeability layer. The analytical models derived in this thesis are applicable in numerous environmental and engineering processes, including the injection of low-salinity or hot water in a reservoir, ocean water invasion into aquifers, freshwater storage, and contamination of subterranean waters by viruses and bacteria. It also has many applications in hydrology and ecology, such as ground cleaning from non-aqueous phase liquids, remediation of contaminated soil and groundwater, and natural filtration of pathogenic microorganisms.Thesis (Ph.D.) -- University of Adelaide, Australian School of Petroleum and Energy Resources, 2020
Libri sul tema "Permeability decline"
1
Badimon, Lina, e Gemma Vilahur. Atherosclerosis and thrombosis. Oxford University Press, 2015. http://dx.doi.org/10.1093/med/9780199687039.003.0040.
Testo completoAbstract (sommario):
Atherosclerosis is the main underlying cause of heart disease. The continuous exposure to cardiovascular risk factors induces endothelial activation/dysfunction which enhances the permeability of the endothelial layer and the expression of cytokines/chemokines and adhesion molecules. This results in the accumulation of lipids (low-density lipoprotein particles) in the extracellular matrix and the triggering of an inflammatory response. Accumulated low-density lipoprotein particles suffer modifications and become pro-atherogenic, enhancing leucocyte recruitment and further transmigration across the endothelium into the intima. Infiltrated monocytes differentiate into macrophages which acquire a specialized phenotypic polarization (protective or harmful), depending on the stage of the atherosclerosis progression. Once differentiated, macrophages upregulate pattern recognition receptors capable of engulfing modified low-density lipoprotein, leading to foam cell formation. Foam cells release growth factors and cytokines that promote vascular smooth muscle cell migration into the intima, which then internalize low-density lipoprotein via low-density lipoprotein receptor-related protein-1 receptors. As the plaque evolves, the number of vascular smooth muscle cells decline, whereas the presence of fragile/haemorrhagic neovessels increases, promoting plaque destabilization. Disruption of this atherosclerotic lesion exposes thrombogenic surfaces that initiate platelet adhesion, activation, and aggregation, as well as thrombin generation. Both lipid-laden vascular smooth muscle cells and macrophages release the procoagulant tissue factor, contributing to thrombus propagation. Platelets also participate in progenitor cell recruitment and drive the inflammatory response mediating the atherosclerosis progression. Recent data attribute to microparticles a potential modulatory effect in the overall atherothrombotic process. This chapter reviews our current understanding of the pathophysiological mechanisms involved in atherogenesis, highlights platelet contribution to thrombosis and atherosclerosis progression, and provides new insights into how atherothrombosis may be modulated.
2
Badimon, Lina, e Gemma Vilahur. Atherosclerosis and thrombosis. Oxford University Press, 2017. http://dx.doi.org/10.1093/med/9780199687039.003.0040_update_001.
Testo completoAbstract (sommario):
Atherosclerosis is the main underlying cause of heart disease. The continuous exposure to cardiovascular risk factors induces endothelial activation/dysfunction which enhances the permeability of the endothelial layer and the expression of cytokines/chemokines and adhesion molecules. This results in the accumulation of lipids (low-density lipoprotein particles) in the intimal layer and the triggering of an inflammatory response. Accumulated low-density lipoprotein particles attached to the extracellular matrix suffer modifications and become pro-atherogenic, enhancing leucocyte recruitment and further transmigration across the endothelium into the intima. Infiltrated pro-atherogenic monocytes (mainly Mon2) differentiate into macrophages which acquire a specialized phenotypic polarization (protective/M1 or harmful/M2), depending on the stage of the atherosclerosis progression. Once differentiated, macrophages upregulate pattern recognition receptors capable of engulfing modified low-density lipoprotein, leading to foam cell formation. Foam cells release growth factors and cytokines that promote vascular smooth muscle cell migration into the intima, which then internalize low-density lipoproteins via low-density lipoprotein receptor-related protein-1 receptors becoming foam cells. As the plaque evolves, the number of vascular smooth muscle cells decline, whereas the presence of fragile/haemorrhagic neovessels and calcium deposits increases, promoting plaque destabilization. Disruption of this atherosclerotic lesion exposes thrombogenic surfaces rich in tissue factor that initiate platelet adhesion, activation, and aggregation, as well as thrombin generation. Platelets also participate in leucocyte and progenitor cell recruitment are likely to mediate atherosclerosis progression. Recent data attribute to microparticles a modulatory effect in the overall atherothrombotic process and evidence their potential use as systemic biomarkers of thrombus growth. This chapter reviews our current understanding of the pathophysiological mechanisms involved in atherogenesis, highlights platelet contribution to thrombosis and atherosclerosis progression, and provides new insights into how atherothrombosis may be prevented and modulated.
3
Badimon, Lina, e Gemma Vilahur. Atherosclerosis and thrombosis. Oxford University Press, 2018. http://dx.doi.org/10.1093/med/9780199687039.003.0040_update_002.
Testo completoAbstract (sommario):
Atherosclerosis is the main underlying cause of heart disease. The continuous exposure to cardiovascular risk factors induces endothelial activation/dysfunction which enhances the permeability of the endothelial layer and the expression of cytokines/chemokines and adhesion molecules. This results in the accumulation of lipids (low-density lipoprotein particles) in the intimal layer and the triggering of an inflammatory response. Accumulated low-density lipoprotein particles attached to the extracellular matrix suffer modifications and become pro-atherogenic, enhancing leucocyte recruitment and further transmigration across the endothelium into the intima. Infiltrated pro-atherogenic monocytes (mainly Mon2) differentiate into macrophages which acquire a specialized phenotypic polarization (protective/M1 or harmful/M2), depending on the stage of the atherosclerosis progression. Once differentiated, macrophages upregulate pattern recognition receptors capable of engulfing modified low-density lipoprotein, leading to foam cell formation. Foam cells release growth factors and cytokines that promote vascular smooth muscle cell migration into the intima, which then internalize low-density lipoproteins via low-density lipoprotein receptor-related protein-1 receptors becoming foam cells. As the plaque evolves, the number of vascular smooth muscle cells decline, whereas the presence of fragile/haemorrhagic neovessels and calcium deposits increases, promoting plaque destabilization. Disruption of this atherosclerotic lesion exposes thrombogenic surfaces rich in tissue factor that initiate platelet adhesion, activation, and aggregation, as well as thrombin generation. Platelets also participate in leucocyte and progenitor cell recruitment are likely to mediate atherosclerosis progression. Recent data attribute to microparticles a modulatory effect in the overall atherothrombotic process and evidence their potential use as systemic biomarkers of thrombus growth. This chapter reviews our current understanding of the pathophysiological mechanisms involved in atherogenesis, highlights platelet contribution to thrombosis and atherosclerosis progression, and provides new insights into how atherothrombosis may be prevented and modulated.
Capitoli di libri sul tema "Permeability decline"
1
Nasr-El-Din, H. A. "Permeability Decline Due to Flow of Dilute Suspensions Through Porous Media". In Suspensions: Fundamentals and Applications in the Petroleum Industry, 289–319. Washington, DC: American Chemical Society, 1996. http://dx.doi.org/10.1021/ba-1996-0251.ch006.
Testo completo
2
Nation, Daniel A., e Elissa McIntosh. "The Blood–Brain Barrier in Cognitive Decline and Alzheimer’s Disease". In Vascular Disease, Alzheimer's Disease, and Mild Cognitive Impairment, 261–73. Oxford University Press, 2020. http://dx.doi.org/10.1093/oso/9780190634230.003.0012.
Testo completoAbstract (sommario):
The neurovascular unit is a multicellular organ that has attracted recent attention as a key microvascular regulator of cerebral blood flow and blood–brain barrier permeability that is implicated in homeostatic and pathological processes impacting cognitive function. Breakdown of the blood–brain barrier invariably causes brain tissue damage and dysfunction due to influx of toxic blood proteins, cells, ions and metals. Clinical studies employing markers of blood–brain barrier permeability suggest an important role in vascular and neurodegenerative dementias. The chapter discusses how the introduction of new neuroimaging and biomarker technologies has opened new pathways of investigation into the blood–brain function in Alzheimer’s disease.
3
Zhang, Yongzhong, Hualin Liu, Weigang Huang, Zhaolong Liu e Baohua Chang. "Identification and Characterization of High Permeability Zones Using Conventional Logging and Production Logging Data: A Case Study of Kela 2 Gas Field". In Advances in Transdisciplinary Engineering. IOS Press, 2021. http://dx.doi.org/10.3233/atde210260.
Testo completoAbstract (sommario):
High permeability zones in the water-drive gas reservoir tend to act as dominant channels for formation water to invade into gas reservoir from the aquifer. The presence of high permeability zones results in uneven water flow front in reservoir and early water breakthrough in gas well, which seriously affects the gas field development. In this paper, conventional logging and production logging data are used to identify and characterize high permeability zones, so as to guide the optimization of development plan of Kela 2 gas field. A method to determine the lower limit of high permeability zones by using cumulative frequency curve of permeability distribution is proposed, and high permeability zones of 21 wells are identified. These high permeability zones account for 10–15% of the effective reservoir thickness in single wells, and they are mainly distributed in the middle of the Bashijiqike (K1bs) Formation (i.e., K1bs12, K1bs21 and K1bs22). The analysis of production logging data shows that the effective gas producing intervals only account for 29.2% of the total number of test intervals, most of which are related to high permeability zones. Further study shows that the high gas flow from the high permeability zones dominates the wellbore production profile, and the gas in low permeability zones flows vertically to the high permeability zones and horizontally to wellbore through these zones. Through the analysis of production profiles over the years and computer modelling, it is confirmed that water channelling occurred in some gas wells at the depth where the high permeability zones are located, which leads to a significant decline in production of these wells. Based on the study of distribution and behaviour characteristics of the high permeability zones, two suggestions on controlling inhomogeneous water invasion are put forward to realize the sustainable and stable production of the gas field.
4
Sun, Miao, Kai Ma, Jie Wen, Guangxian Wang, Changliang Zhang, Qi Li, Xiaofeng Bao e Hui Wang. "A Review of the Brain-Gut-Microbiome Axis and the Potential Role of Microbiota in Alzheimer’s Disease". In Advances in Alzheimer’s Disease. IOS Press, 2022. http://dx.doi.org/10.3233/aiad220005.
Testo completoAbstract (sommario):
Alzheimer’s disease (AD) is a neurodegenerative process characterized by loss of neurons in the hippocampus and cerebral cortex, leading to progressive cognitive decline. Pathologically, the hallmark of AD is accumulation of “senile” plaques composed of amyloid-β (Aβ) protein surrounding neurons in affected regions. Despite extensive research into AD pathogenesis and therapeutic targets, there remains no breakthroughs in its management. In recent years, there has been a spark of interest in the connection between the brain and gastrointestinal tract, referred to as the brain-gut axis, and its potential implications for both metabolic and neurologic disease. Moreover, the gastrointestinal flora, referred to as the microbiome, appears to exert significant influence over the brain-gut axis. With the need for expanded horizons in understanding and treating AD, many have turned to the brain-gut-microbiome axis for answers. Here we provide a review of the brain-gut-microbiome axis and discuss the evidence supporting alterations of the axis in the pathogenesis of AD. Specifically, we highlight the role for the microbiome in disruption of Aβ metabolism/clearance, increased permeability of the blood-brain barrier and modulation of the neuroinflammatory response, and inhibition of hippocampal neurogenesis. The majority of the above described findings are the result of excellent, albeit basic and pre-clinical studies. Therefore, we conclude with a brief description of documented clinical support for brain-gut-microbiome axis alteration in AD, including potential microbiome-based therapeutics for AD. Collectively, these findings suggest that the brain-gut-microbiome axis may be a “lost link” in understanding and treating AD and call for future work.
5
Badimon, Lina, e Gemma Vilahur. "Atherosclerosis and thrombosis". In The ESC Textbook of Intensive and Acute Cardiovascular Care, a cura di Marco Tubaro, Pascal Vranckx, Eric Bonnefoy-Cudraz, Susanna Price e Christiaan Vrints, 447–62. Oxford University Press, 2021. http://dx.doi.org/10.1093/med/9780198849346.003.0037.
Testo completoAbstract (sommario):
Atherosclerosis is the main underlying cause of heart disease. The continuous exposure to cardiovascular risk factors induces endothelial activation/dysfunction which enhances the permeability of the endothelial layer and the expression of cytokines/chemokines and adhesion molecules. This results in the accumulation of lipids (low-density lipoprotein particles) in the intimal layer and the triggering of an inflammatory response. Accumulated low-density lipoprotein particles attached to the extracellular matrix suffer modifications and become pro-atherogenic, enhancing leucocyte recruitment and further transmigration across the endothelium into the intima. Infiltrated pro-atherogenic monocytes (mainly Mon2) differentiate into macrophages which acquire a specialized phenotypic polarization (protective/M1 or harmful/M2), depending on the stage of the atherosclerosis progression. Once differentiated, macrophages upregulate pattern recognition receptors capable of engulfing modified low-density lipoprotein, leading to foam cell formation. Foam cells release growth factors and cytokines that promote vascular smooth muscle cell migration into the intima, which then internalize low-density lipoproteins via low-density lipoprotein receptor-related protein-1 receptors becoming foam cells. As the plaque evolves, the number of vascular smooth muscle cells decline, whereas the presence of fragile/haemorrhagic neovessels and calcium deposits increases, promoting plaque destabilization. Disruption of this atherosclerotic lesion exposes thrombogenic surfaces rich in tissue factor that initiate platelet adhesion, activation, and aggregation, as well as thrombin generation. Platelets also participate in leucocyte and progenitor cell recruitment are likely to mediate atherosclerosis progression. Recent data attribute to extracellular vesicles (mainly microvesicles) a role in all stages of atherosclerosis development and evidence their potential use as systemic biomarkers of thrombus growth. This chapter reviews our current understanding of the pathophysiological mechanisms involved in atherogenesis, highlights platelet contribution to thrombosis and atherosclerosis progression, and provides new insights into how atherothrombosis may be prevented and modulated.
6
Abriola, Linda M., e Kurt D. Pennell. "Persistence and Interphase Mass Transfer of Liquid Organic Contaminants in the Unsaturated Zone : Experimental Observations and Mathematical Modeling". In Vadose Zone Hydrology. Oxford University Press, 1999. http://dx.doi.org/10.1093/oso/9780195109900.003.0012.
Testo completoAbstract (sommario):
Surface and subsurface releases of organic chemicals have resulted in widespread contamination of groundwaters and soils. Frequently, such chemicals are introduced into the subsurface as nonaqueous-phase liquids (NAPLs), which are only slightly miscible with water. These organic liquids tend to migrate downward through the unsaturated soil zone, displacing the pore gases under the action of gravitational forces. During its migration, a portion of the NAPL will become entrapped in the soil pores due to capillary forces, creating zones of persistent contamination in the soil matrix. Organic liquid saturation in such zones may range from approximately 4% to 10% of the pore space (Wilkins et al., 1995). This entrapped NAPL may serve as a long-term source of contamination to the aqueous and gaseous pore fluids through subsequent dissolution and volatilization. Soil vapor extraction (SVE) has evolved over the past decade as an attractive in situ remediation technology for unsaturated soils contaminated by entrapped volatile organic compounds (VOCs). This technology involves the induction of gas flow within the porous medium to enhance volatilization of entrapped contaminants (Hutzler et al., 1989). Based upon the success of a number of feasibility studies and the ease of implementation, SVE remediation technologies are currently employed at approximately 18% of Superfund sites (Travis and Macinnis, 1992). An extensive review of the literature pertaining to SVE and related technologies is given in Rathfelder et al. (1995). Although widely implemented, SVE systems are typically designed and installed with limited understanding of the processes that control their effectiveness. Clearly, the performance of SVE will be strongly influenced by contaminant volatility and effective gas-phase permeability (Pedersen and Curtis, 1991). Relatively little is known, however, about the physical and chemical processes that control contaminant vapor-phase mass transfer. The SVE systems characteristically exhibit large initial VOC recovery rates, followed by a rapid decline in effluent gas concentrations to a persistent low level (e.g., Crow et al., 1987; DiGiulio, 1992). Furthermore, a temporary increase in the produced gas organic concentration has often been observed following SVE shutdown periods (McClellan and Gilham, 1992). Such behavior suggests the presence of mass transfer limitations.
Atti di convegni sul tema "Permeability decline"
1
Mukherjee, H., S. Larkin e W. Kordziel. "Extension of Fracture Pressure Decline Curve Analysis to Fissured Formations". In Low Permeability Reservoirs Symposium. Society of Petroleum Engineers, 1991. http://dx.doi.org/10.2118/21872-ms.
Testo completo
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Nolte, K. G., M. G. Mack e W. L. Lie. "A Systematic Method for Applying Fracturing Pressure Decline: Part I". In Low Permeability Reservoirs Symposium. Society of Petroleum Engineers, 1993. http://dx.doi.org/10.2118/25845-ms.
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Palacio, J. C., e T. A. Blasingame. "UNAVAILABLE - Decline-Curve Analysis With Type Curves - Analysis of Gas Well Production Data". In Low Permeability Reservoirs Symposium. Society of Petroleum Engineers, 1993. http://dx.doi.org/10.2118/25909-ms.
Testo completo
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Castillo, J. L. "Modified Fracture Pressure Decline Analysis Including Pressure-Dependent Leakoff". In SPE/DOE Joint Symposium on Low Permeability Reservoirs. Society of Petroleum Engineers, 1987. http://dx.doi.org/10.2118/16417-ms.
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Egberts, P. "Modelling of permeability decline due to fluid injection". In 58th EAEG Meeting. Netherlands: EAGE Publications BV, 1996. http://dx.doi.org/10.3997/2214-4609.201409044.
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Li, James, Li Fan e Xu Zhang. "Unconventional Oil - Decline Permeability Multipliers for Model Calibration". In Abu Dhabi International Petroleum Exhibition & Conference. Society of Petroleum Engineers, 2019. http://dx.doi.org/10.2118/197256-ms.
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Maley, S. "The Use of Conventional Decline Curve Analysis in Tight Gas Well Applications". In SPE/DOE Low Permeability Gas Reservoirs Symposium. Society of Petroleum Engineers, 1985. http://dx.doi.org/10.2118/13898-ms.
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Masoner, L. O. "Decline Analysis' Relationship to Relative Permeability in Secondary and Tertiary recover". In SPE Rocky Mountain Regional/Low-Permeability Reservoirs Symposium. Society of Petroleum Engineers, 1998. http://dx.doi.org/10.2118/39928-ms.
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Lee, W. S. "Pressure Decline Analysis With the Christianovich and Zheltov and Penny-Shaped Geometry Model of Fracturing". In SPE/DOE Low Permeability Gas Reservoirs Symposium. Society of Petroleum Engineers, 1985. http://dx.doi.org/10.2118/13872-ms.
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Martins, J. P., e T. R. Harper. "Mini-Frac Pressure Decline Analysis for Fractures Evolving From Long Perforated Intervals and Unaffected by Confining Strata". In SPE/DOE Low Permeability Gas Reservoirs Symposium. Society of Petroleum Engineers, 1985. http://dx.doi.org/10.2118/13869-ms.
Testo completo