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When the paper web and press felt enter a nip in the press section of a paper machine, both the paper web and felt are compressed. Water is forced from the paper sheet into the press felt due to a hydrodynamic pressure gradient between the sheet and felt. Water not only flows through the felt in the transversal z-direction, but also flows through the felt in the machine and cross-machine directions. On the exit side of the nip, the pressure imposed on the sheet-felt system by the rolls begins to decrease. Both the paper web and press felt begin to expand, and a vacuum is created in the web and felt. The vacuum in the web is stronger than that in the felt, and thus water and air tend to flow from the felt back into the sheet, causing rewet. Three mechanisms that contribute to rewet have been proposed: 1) film splitting between the paper web and press felt, 2) capillary forces in the web drawing water from the felt into the web, and 3) the pressure differential between the web and felt during expansion. The objective of this project was to design and test under flow conditions similar to those in a press nip a smart water receiver to be used in the press section of a paper machine. In this manner, the feasibility of such a water receiver was to be determined. The purpose of this water receiver is to accept water that is pressed from the paper web in a nip and prevent the return of this water to the paper web upon exit from the nip. Thus, the smart water receiver allows flow through the felt in the positive z-direction of the felt (away from the paper web) and not in the negative z-direction (towards the paper web). The smart water receiver concept utilizes a layer of micro-check valves incorporated into the press felt to perform in the desired manner. A mathematical model and lab-scale prototype were created in order to predict the behavior of such a design in the press nip.

Saturated permeability is likely a good method for characterizing the susceptibility of portland cement concrete to various forms of degradation; although no widely accepted test exists to measure this property. The hollow cylinder dynamic pressurization test is a potential solution for measuring concrete permeability. The hollow cylinder dynamic pressurization (HDP) test is compared with the radial flow through (RFT) test and the solid cylinder dynamic pressurization (SDP) test to assess the accuracy and reliability of the HDP test. The three test methods, mentioned above, were used to measure the permeability of Vycor glass and portland cement paste and the results of the HDP test were compared with the results from the SDP and RFT tests. When the HDP and RFT test results were compared, the measured difference between the mean values of the two tests was 40% for Vycor glass and 47% for cement paste. When the HDP and SDP tests results were compared, the measured difference with Vycor glass was 53%. The cement paste permeability values could not be compared in the same manner since they were tested at various ages to show the time dependency of permeability in cement paste. The results suggest good correlation between the HDP test and both the SDP and RFT tests. Furthermore, good repeatability was shown with low coefficients of variation in all test permutations. Both of these factors suggest that the new HDP test is a valid tool for measuring the permeability of concrete materials.

Although pervious concrete was first used in the nineteenth century, it has only recently begun to increase in popularity. As urban areas expand, the problems associated with runoff management have become more challenging. The focus on the negative environmental effects associated with pavement runoff has also increased. These two issues have spurred the recent interest in pervious concrete pavements.Pervious concrete, however, has deficiencies which limit its application as pavements. These limitations include low compressive strength, flexural strength, clogging, and other durability issues. The overall purpose of this project was to provide tools to evaluate and improve the durability and strength of pervious concrete such that it may be more confidently employed in urban roadways. The specific objectives of this project were to (a) investigate the effect of mixture design on strength of pervious concrete (including the effect of fibers), (b) evaluate effect of clogging materials on coefficient of permeability, (c) and investigate the use of the dynamic pressurization test to evaluate the durability of pervious concrete, (d) develop a simple model for predicting removal of clogging particles from pervious concrete pavement surface pores. This thesis documents the results of the laboratory testing, and presents recommendations for mixture proportioning. In addition, recommendations are provided for optimizing the balance between compressive strength and permeability.

Reservoir compartments, typical targets for new infill locations, are commonly created by faults that may reduce or enhanced permeabilities. Faults often contain narrow zones of intense shear comprised of geometrically complex elements that reduce permeability and compartmentalize blocks as a function of time and pressure. This thesis characterizes the permeability structure of shear zones and the relationship between fault permeability, host rock properties and the relative degree of deformation. The main objectives of this work are to (1) characterize the geometry and permeability of deformation elements within shear zones; (2) determine permeability anisotropy in shear zones according to fault characteristics and host lithology; and (3) develop a process to predict permeability anisotropy of faults in reservoirs using probabilistic approaches. The study results give a better understanding of fluid flow behavior of shear zones and their potential to create reservoir heterogeneity and compartmentalization. Fluid flow in a reservoir with faults is controlled by variables such as fault throw, shear-zone thickness, undeformed and deformed rock permeability and the geometry of all deformation elements. Methodology to predict permeability structure was developed using analytical and numerical simulation of selected core samples and laboratory measurements. We found useful relationships between permeability of the host rock and highly deformed elements according to the amount of throw of the fault. The high lateral continuity of the highly deformed elements and their predictable low permeability make these elements most important in controlling permeability in shale-free and low-shale shear zones created by low displacement (subseismic) faulting. Probe permeameter data is a precise, inexpensive and non-destructive source of permeability information that can be effectively incorporated in detailed models to investigate the effect of individual deformation elements in the whole shear zone permeability and their effect at the field scale.

The problem of evaluating permeability anisotropy in the Tilje Formation, Heidrum field, offshore mid-Norway, has been investigated by the Statoil Research Centre by a detailed combination of the geological and petrophysical data. The large diversity and contrasting levels of heterogeneity within depositional facies observed in the Tilje Formation reflect complicated patterns of deposition along deltaic shorelines and the adjunct shelf of a tidally influenced, narrow seaway. Permeability anisotropy can alter the directionality of the fluid flow in the reservoir, and thereby affect the most important exploration procedures: perforation, water and gas injection, production, and estimation of the field resource. This thesis presents a simplified method of modeling permeability anisotropy in the Tilje Formation.

The objective of this research is to develop and test a new concept for predicting permeability from routine rock properties. First, we develop a model predicting permeability as a function of capillary pressure. Our model, which is based on the work by Purcell, Burdine and Wyllie and Gardner models, is given by: (Equation 1 - See PDF) Combining the previous equation and the Brooks and Corey model for capillary pressure, we obtain: (Equation 2 - See PDF) The correlation given by this equation could yield permeability from capillary pressure (and vice-versa). This model also has potential extensions to relative permeability (i.e., the Brooks and Corey relative permeability functions) - which should make correlations based on porosity, permeability, and irreducible saturation general tools for reservoir engineering problems where relative permeability data are not available. Our study is validated with a large range/variety of core samples in order to provide a representative data sample over several orders of magnitude in permeability. Rock permeabilities in our data set range from 0.04 to 8700 md, while porosities range from 0.3 to 34 percent. Our correlation appears to be valid for both sandstone and carbonate lithologies.

This work presents the validation and enhancement of existing correlations for estimating and predicting the permeability in low permeability gas sands. The "original" problem of predicting the corrected or "liquid equivalent" permeability has been under investigation since the early 1940s — in particular, using the application of "gas slippage" theory to petrophysics by Klinkenberg. In the first part of this work, the viability of the Jones-Owens and Sampath-Keighin correlations for estimating the Klinkenberg-corrected (absolute) permeability from single-point, steady-state measurements were investigated. We also provide an update to these correlations using modern petrophysical data. In the second part of this work we proposed and validated a new "microflow" model for the evaluation of an equivalent liquid permeability from gas flow measurements. This work was based on a more detailed application of similar concepts employed by Klinkenberg. In fact, we obtained the Klinkenberg result as an approximate form of this result. A theoretical "microflow" result was given as a rational polynomial (i.e., a polynomial divided by a polynomial) in terms of the Knudsen number (ratio of the mean free path of the gas molecules to the characteristic flow length (typically the radius of the capillary)), and this result can be applied as an explicit correlation device, or as an implicit prediction model (presuming the model is tuned to a particular data set). The following contributions are derived from this work: ● Validation and extension of the correlations proposed by Jones-Owens and Sampath-Keighin for low permeability samples. ● Development and validation of a new "microflow" model which correctly represents the flow of gases in low permeability core samples. This model is also applied as a correlation for prediction of the equivalent liquid permeability in much the same fashion as the Klinkenberg model, although the new model is substantially more theoretical (and robust) as compared to the Klinkenberg correction model.