Measuring transport properties of rock samples under stress is essential to understanding and predicting the migration of fluids within the Earth's crust. Mudrocks play an essential role in petroleum systems as they are often the source rock and may act as a seal due to their low permeability. With increasing production from unconventional reservoirs where the mudrock is source, reservoir and seal, there is now even greater demand to understand the permeability and storativity of mudstones and tight sandstones. When hydraulic fracture treatment is used to enhance production, flow of hydrocarbons into the fractures will be ultimately controlled by the matrix permeability. Knowledge of the fluid transport properties of mudstones is currently hindered by a scarcity of published experimental data. In this thesis, a combination of permeability and ultrasonic velocity measurements allied with image analysis is used to distinguish the primary microstructural controls on effective stress dependent permeability. Permeabilities of cylindrical samples of Whitby Mudstone and Eagle Ford Shale have been measured using the oscillating pore pressure method at confining pressures ranging between 30-95 MPa and pore pressures ranging between 1-80 MPa. The results show that samples must be pressure cycled in order to obtain a reproducible behaviour, after which the relationship between permeability and effective stress can be described by an exponential law. The permeability of the Whitby Mudstone samples ranges between 7 ×10-21 m2 and 2 ×10-19 m2 (7 nd to 188 nd) and decreases by ~1 order of magnitude across the applied effective stress range. The permeability of the Eagle Ford Shale samples is slightly higher ranging between 2 ×10-18 m2 and 42 ×10-18 m2 (2 μd to 42 μd) and decreases by half an order of magnitude across the applied effective stress range. Permeability is shown to be more sensitive to changes in pore pressure than changes in confining pressure yielding values of alpha between 1.1-2.1 for Whitby Mudstone and 1.6-4.6 for Eagle Ford Shale. Gas slippage (Klinkenberg) effects are restricted to pore pressures below 10 MPa in the Whitby Mudstone and therefore do not affect the results presented. The permeability-effective stress relationship is thus empirically described using a modified effective stress law in terms of confining pressure, pore pressure and a Klinkenberg effect. Use of a simple reservoir model demonstrates that if pressure dependent permeability is not taken into account, substantial overestimation of gas flow rate and original gas in place will be made from well tests. Changes in ultrasonic velocity and pore volume were related to the observed loss of permeability with increasing effective stress, providing further insight into the nature of the permeability-controlling pore network. Combining the petrophysical data with pore conductivity modelling and microstructural analysis shows that at low effective stresses, permeability is controlled by a network of long, thin crack-like pores associated with grain boundaries. At high effective stresses, these cracks are closed and fluid is restricted to flowing through a less permeable network of higher aspect ratio, stiffer, nm-scale pores in the clay matrix. Applying the methods developed in the present work to different mudstones with a range of compositions and textures will help to refine understanding of the variability in fluid-conducting pore networks, thereby advancing the interpretation of data from well logs and well tests used for reservoir evaluation.

The cleat permeability of coal, a key to the success of any coalbed methane (CBM) recovery operation, is a dynamic parameter impacted by changes in effective stress and desorption-induced "matrix shrinkage". Most commonly-used theoretical models developed to predict CBM production as a result of permeability changes are based on the assumption that the deformation of a depleting coalbed is limited to the vertical direction; that is, the coal is under uniaxial strain conditions. However, most laboratory studies completed to estimate the changes in coal permeability have used triaxial state of stress, thus violating the underlying principles of the models. An experimental study was, therefore, undertaken to estimate the permeability variation of coal with a decrease in pore pressure under replicated in situ conditions where flow through coal, held under uniaxial strain conditions, was measured. Three samples were tested, one from the San Juan basin and the other two from the Illinois basin. The experimental results showed that, under uniaxial strain conditions, decreasing pore pressure resulted in a significant decrease in horizontal stress and increased permeability. The permeability increased non-linearly with decreasing pore pressure, with a small increase in the high pressure range, which increased progressively as the pressure dropped below a certain value. The experimental results were used to validate two theoretical models, namely the Palmer and Mansoori and Shi and Durucan, commonly used to project permeability variation with continued production. The models failed to provide good agreement with the experimental results below 300 psi, suggesting a shortcoming in the modeling philosophy. Although the measured permeability and stress changes were in qualitative agreement with the modeling results, both models predicted negative horizontal stresses at low pore pressures for one coal type, which was not supported by experimental results. The sorption-induced strain was also found to be significantly higher in the low pore pressure range, clearly suggesting a direct relationship between the sorption-induced strain and permeability. Moreover, the increase in permeability was different for the three coal types tested, with the largest increase for the core taken from maximum depth. Finally, a gradual increase in the logarithm of permeability was measured with reduction in horizontal stress. These results suggest a distinct advantage for deeper coals, which have generated limited interest to date, primarily due to the low initial permeability. Extending the deformation of a cylindrical rock sample loaded axially, a hypothesis was developed where coal undergoes maximum deformation at the middle of its length. Using this hypothesis, permeability variation with decreasing pore pressure was estimated and the established trend was used to modify one of the existing models. The agreement between laboratory results and the modified model showed definite promise for improving permeability projection capability.

Cleat permeability of coal is the most critical parameter affecting the amount of production from a coalbed methane (CBM) reservoir. As a result, there have been many studies about how cleat permeability changes over the life of a reservoir, leading to the development over time of several different permeability models. Most permeability models used today consider volumetric strain as an input parameter; however, permeability is impacted primarily by the increase in cleat aperture, resulting from matrix shrinkage in the horizontal direction. Recent work has shown that coal exhibits transverse isotropy, with total strain in the vertical direction being significantly higher than either horizontal direction. Hence, the inclusion of vertical strain through use of the volumetric strain parameter could be predicting inaccurate permeability variation results. The objective of this study was to determine the difference in permeability modeling with volumetric strain compared to permeability modeling with only horizontal strain, and assess the degree to which different parameters affect results from modeling using only horizontal strain. Experimental results showed that matrix strain remained consistent with transversely isotropic results of previous works. When included into the Palmer and Mansoori (P&M) permeability model, modeling results showed that permeability with horizontal strain is significantly lower than that with volumetric strain. The three unmeasured parameters in the Palmer and Mansoori permeability model have a major effect on the final results and need to be history matched in order to improve the level of accuracy in their estimation.

abstract: The main objective of this study is to numerically investigate: (i) the ionic transport, especially chloride ion penetration into cementitious materials under imposed electric fields, and (ii) moisture transport through cracked concretes as a function of the crack geometry. Numerical methods were implemented to simulate the ionic transport process, based on coupling the Nernst-Planck equation and Poisson's equation to account for transport dominated by electromigration. This mathematical model was also modified to account for the chloride binding mechanism (physical and chemical trapping of chlorides by the cement hydrates) and the concentration dependence of the diffusion coefficient of each ion in the transport process. To validate the numerical model, experimental data from a companion work was used in this study. The non-steady state migration test, which is one of the common accelerated chloride ion transport test, is numerically simulated. The simulation provides a linear relationship between ionic concentration and ionic flux, which indicates that the diffusion part is negligible under a strong external voltage environment. The numerical models along with adjustments for the concentration-dependent diffusion coefficients, a pore structure factor (from electrical measurements) and chloride binding considerations are found to be successful in predicting the chloride penetration depth into plain and modified concretes under imposed electrical potentials. Moisture transport through cracked concrete was examined in the second part of this thesis. To better understand the crack's influence on the permeability, modified Louis' equation was chosen to relate the permeability with crack characteristics. 3D concrete crack models were developed using a MATLAB program with distinct crack tortuosities, roughnesses and sizes. As a comparison, Navier-Stokes equation and the Lattice Boltzmann method were also applied on the 3D model of the cracked concrete to evaluate their permeability. The methodology developed here is expected to be useful in understanding the influence of cracking on moisture transport, and when properly coupled with an ionic transport model that will be further developed, helps comprehensively understand the coupling effects of moisture and ionic transport on deterioration in concrete structures. / Dissertation/Thesis / M.S. Civil and Environmental Engineering 2014

Orientador: Jose Luiz Donato / Dissertação (mestrado] - Universidade Estadual de Campinas, Facu.dade de Ciencias Medicas / Made available in DSpace on 2018-08-15T19:17:22Z (GMT). No. of bitstreams: 1 Reque_MariaLucia_M.pdf: 10714154 bytes, checksum: ae7569765a8246a32a670f4b5f2dc205 (MD5) Previous issue date: 2006 / Resumo: A barreira dérmica é representada por uma estrutura lipoprotéica e constitui um ambiente bioquímico altamente complexo. Trata-se de uma barreira muito eficiente ao ingresso de agentes químicos. Não há na literatura nenhum relato do uso de enzimas proteolíticas como agente potencializador da permeação de fármacos presentes em formulações para uso tópico. Neste trabalho desenvolvemos uma formulação de pomada contendo a enzima para potencializar a penetração de diclofenaco dietilamônio na pele, sendo realizado também o estudo da sua estabilidade na formulação através do acompanhamento da sua atividade catalítica, bem como a avaliação in vivo do seu potencial de alergenicidade cutânea. A atividade da papaína como potencializadora da penetração cutânea de diclofenaco dietilamônio em pomada foi avaliada in vitro através de células de difusão de Franz utilizando pele de porco, e in vivo, por meio de testes clínicos com voluntários humanos. O estudo de estabilidade, revelou que a atividade catalítica da papaina permaneceu estável na formulação quando a mesma foi armazenada a temperatura ambiente por pelo menos 24 meses, porém, sob condição acelerada (45°C e 70% U.R.), a enzima perdeu a sua atividade catalítica após seis meses de armazenamento. Não foi observada nos voluntários humanos, nenhuma reação adversa como eritema, pápulas ou vesículas durante o período de avaliação da alergenicidade cutânea da papaína, sendo a enzima aprovada para uso tópico. No teste de permeabilidade in vitro, foi observado um aumento de 50% no acúmulo de diclofenaco após quatro horas de permeação, quando a papaína esteve presente na formulação de diclofenaco dietilamônio em pomada. O teste de permeabilidade in vivo mostrou que a papaína aumentou a penetração de diclofenaco na pele quando a mesma foi tratada anteriormente com pomada contendo papaína e não quando a enzima foi administrada juntamente com o diclofenaco. Foi demonstrado o potencial da papaína como potencializadora da penetração de antiinflamatórios não-esteroidais (AINEs) em formulações de uso tópico, melhorando consideravelmente a eficiência das mesmas / Abstract: The skin barrier is represented by a lipoprotein structure and is a very complex biochemical environmental. It is considered a very efficient barrier to the absorption of many chemical compounds. There is no report about the use of proteolytic enzymes as a penetration enhancer of therapeutic drugs in topic formulations. In this study, an ointment formulation containing papain was developed to increase the diclofenac diethylammonium skin penetration. Stability studies were performed to verify the enzymatic activity after incorporation in the formulation. It was also evaluated the in vivo allergenecity potential of the papain. The penetration enhancing activity of this enzyme was investigated in vitro through Franz-type diffusion cell using porcine skin, and in vivo, through clinical tests with human volunteers. The stability study showed that papain remained stable in the formulation when it was stored at room temperature during 24 months, however, at accelerated condition ( 45°C and 70% of humidity) the enzyme lost its catalytic activity after 6 month of storage. Regarding in vivo allergenicity studies, the human volunteers no observed adverse reactions as eritema, papulas or vesicle during the period of evaluation, being the papain approved to topical use. On in vitro skin permeation study, an increase of about 50% in the diclofenac accumulation was observed after four hours of permeation when the papain was present in the formulation. The in vivo skin permeation study showed that papain increased diclofenac skin penetration when it was treated previously with ointment containing papain and no when the enzyme was administrated together diclofenac. It was demonstrated the papain potential as penetration enhancer in NSAIDs (non steroidal anti-inflammatory drugs) formulation for topical use improving its efficiency / Mestrado / Mestre em Farmacologia

No description available.

Permeability changes in membranes of Protea neriifloia leaves during senescence were investigated. A complete preservative consisting of a-hydroxyquinoline sulphate (8-HQS), silver nitrate (AgN03), citric acid and sucrose was formulated by using different concentrations of the components. The % browning of the leaves, change in mass of the inflorescence and their water uptake over a period of 20 days was used as a measurement to determine the most effective concentrations. The results lead to the formulating of an effective preservative which can be used commercially. The preservative consists of 100 mg 8-HQS, 5 mg AgNo3, 100 mg citric acid. and 10 g sucrose, made up to 1 litre with distilled water. Scanning electron microscopy was used to investigate the effects of a complete preservative on protea leaves. The respiratory rate and water content of leaves from inflorescence in preservative and distilled water was determined and compared. The respiratory rate of leaves of inflorescence in preservative was considerably higher than that of the control. The preservative also resulted in the leaves having a better retention of their water...

>Magister Scientiae - MSc / The Bredasdorp Basin was formed consequent to extensional episodes during the initial stages of rifting in the Jurassic age. The basin acted as a local depocentre and was primarily infilled with late Jurassic and early Cretaceous shallow-marine and continental sediments. Two wells namely; D-D1 and E-AP1 were studied in order to evaluate the petrophysics and characterize sandstone reservoirs of the western Bredasdorp basin. This could be achieved by generating and comparing results from core analysis and wireline in order to determine if the two wells are comprised of good quality sandstone reservoirs and if the identified reservoirs produce hydrocarbons. A number of methods were employed in order to characterise and evaluate sandstone reservoir, these included; editing and normalization of raw wireline log data ,classification of lithofacies on the basis of lithology, sedimentary structures, facies distribution, grain size variation, sorting of grains, fossils and bioturbation; calibration of log and core data to determine parameters for petrophysical interpretation; volume of clay; determination of porosity, permeability and fluid saturation, cut-off determination to distinguish between pay and non-pay sands. Borehole D-D1 is located in the western part of the Bredasdorp Basin. Only two reservoirs in well D-D1 indicated to have pay parameters with an average porosity ranging from 11.3% to 16%, average saturation from 0.6% to 21.5% and an volume of clay from 26.5% to 31.5%. This well was abandoned due to poor oil shows according to the geological well completion report. On the contrary well E-AP1 situated in the northwestern section of the basin showed good quality reservoir sandstones occurring in the 19082m to 26963m intervals though predominantly water saturated. Pay parameters for all five reservoirs in this well showed zero or no average porosity, saturation and volume of clay.

No description available.

The persistence and severity of water repellency in soils as affected by slashburning was examined in the municipal watersheds of Vancouver by the water drop penetration time (WDPT) and contact angle method, respectively. Also, hydrophobic materials were extracted from soil, separated by column adsorption chromatography, and analysed for functional groups by infrared absorption. Slashburning increased soil water repellency, as indicated by the WDPT method. Precise responses of soil repellency to slashburning were not consistent, as many site specific factors are involved, but increased repellency was evident in soil up to six years following burning. The severity of increased soil repellency caused by slashburning could not be assessed because contact angle determinations using the capillary rise equation and Darcy's Law were not reliable. The WDPT method was more consistent, reliable and simpler than the contact angle method, hence the WDPT method was considered best to indicate the presence of soil water repellency. A combination of polar and non-polar organic solvents, methanol and benzene respectively, extracted hydrophobic compounds from soil. The extractant separated into three fractions, using benzene and increasing proportions of acetone as eluting agents. Virtually all of the extract (90%) was recovered in Fraction I, indicating that the extraction was predominantly non-polar. Fraction II and III accounted for 4 and 6 per cent, respectively, of the applied extractables. Material in all Fractions induced repellency in wettable sand when 1 mg or more was applied to 5 gm of sand. Repellency was increased by heating the extracted materials in sand to 250°C for 10 minutes and was eliminated after heating to 300°C in inverse proportion to the mass applied. At 350°C, hydrophobic materials volatilized and the sand regained wettability. Analysis of an extraction by infrared absorption revealed that hydrophobic substances have hydrophilic and hydrophobic components. Adsorption of hydrophobic materials to soil particles is therefore likely initially by the hydrophilic end leaving the hydrophobic end of the organic molecule to form the outer surface thus preventing water from infiltrating. During slashburns, adsorption of hydrophobic materials is probably enhanced by optimization of close range van der Waals and London forces. / Forestry, Faculty of / Graduate