One of the most important, but often ignored, factors affecting the transport and the seismic properties of hydrocarbon reservoir is pore shape. Transport properties depend on the dimensions, geometry, and distribution of pores and cracks. Knowledge of pore shape distribution is needed to explain the often-encountered complex interrelationship between seismic parameters (e.g. seismic velocity) and the independent physical properties (e.g. porosity) of hydrocarbon reservoirs. However, our knowledge of reservoir pore shape distribution is very limited. This dissertation employs a pore structure parameter via a rock physics model to characterize mean reservoir pore shape. The parameter was used to develop a new physical concept of critical clay content in the context of pore compressibility as a function of pore aspect ratio for a better understanding of seismic velocity as a function of porosity. This study makes use of well log dataset from offshore Norway and from North Viking Graben in the North Sea. In the studied North Sea reservoir, porosity and measured horizontal permeability was found to increase with increasing pore aspect ratio (PAR). PAR is relatively constant at 0.23 for volumes of clay (V_cl) less than 32% with a significant decrease to 0.04 for V_cl above 32%. The point of inflexion at 32% in the PAR –V_cl plane is defined as the critical clay volume. Much of the scatters in the compressional velocity-porosity cross-plots are observed where V_cl is above this critical value. For clay content higher than the critical value, Hertz-Mindlin (HM) contact theory over-predicts compressional velocity (V_p) by about 69%. This was reduced to 4% when PAR distribution was accounted for in the original HM formulation. The pore structure parameter was also used to study a fractured carbonate reservoir in the Sichuan basin, China. Using the parameter, the reservoir interval can be distinguished from those with no fracture. The former has a pore structure parameter value that is ≥ 3.8 whereas it was < 3.8 for the latter. This finding was consistent with the result of fracture analysis, which was based on FMI image. The results from this dissertation will find application in reservoir characterization as the industry target more complex, deeper, and unconventional reservoirs.

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In this thesis, PN simulations of drying are compared with experimentally obtained data fromdrying of a representative 2D microfluidic network in SiO2 under varying thermal conditions withthe aim to identify governing physical pore scale effects. Gravity and viscous effects aredisregarded in this thesis. Instead drying with slight local temperature variation and drying withimposed thermal gradients are studied. Based on this investigation, a powerful non-isothermalPNM is developed. This model incorporates i) the phenomena associated with the temperaturedependency of pore scale invasion, namely thermally affected capillary invasion and vapor flow aswell as ii) the secondary effects induced by wetting liquid films of different morphology. This studyclearly evidences that the macroscopic drying behavior is fundamentally dictated by thetemperature gradient imposed on the PN and moreover by the secondary capillary invasion aswell. In agreement with literature, invasion patterns as in invasion percolation with progressiveevaporation of single clusters are observed in drying with negligible local temperature variation;gradients with temperature decreasing from the surface (negative temperature gradient) canstabilize the drying front, evolving between the invading gas phase and the receding liquid phase,whereas temperature increasing from the surface (positive temperature gradient) leads todestabilization of the liquid phase with early breakthrough of a gas branch and initiation of asecond invasion front migrating in opposite direction to the evaporation front receding from theopen surface of the PN. Special attention is paid on the distinct drying regimes found in thesituation of a positive gradient because they are associated with different pore scale invasionprocesses. More precisely, temperature dependency of surface tension dictates the order ofinvasion as long as the liquid phase is connected in a main liquid cluster (usually found during thefirst period of drying). In contrast to this, detailed study of the vapor transfer mechanismsemphasizes that vapor diffusion through the partially saturated region can control the pore leveldistributions of liquid and gas phase during the period of drying when the liquid phase isdisconnected into small clusters. This is also related to the cluster growth induced by partialcondensation of vapor. It is shown and discussed in detail in this thesis that this effect not onlydepends on direction and height of the temperature gradient for a given pore size distribution butthat moreover the overall evaporation rate influences the cluster growth mechanism. This indicatesthat liquid migration during drying of porous media might be controlled by the interplay of thermalgradients and drying rate. In summary, the study of thermally affected drying of the 2-dimensionalPN reveals complex pore scale mechanisms, usually also expected in drying of real porous media.This leads to the development of a strong mathematical pore scale model based on experimentalfindings. It is demonstrated how this model might be applied to understand and develop moderndrying processes based on the simulation of thermally affected pore scale mass transfer

Enveloped viruses, such as influenza, infect cells by fusing their viral envelope with the cell membrane. The fusion pore is a macromolecular structure that links two membranes that are fusing. This paper will focus on the fusion pore initiated by the hemagglutinin (HA) protein of influenza virus upon infection of a host cell. Mutations in the HA protein can alter the time-course and structure of the developing fusion pore. While there is a clear relationship between HA's structure and the dynamic opening of the pore, the initial 3D structure of the fusion pore as it first begins to form remains unknown. We have attempted to address this unanswered question by measuring fusion pore conductance - a one dimensional electrophysiological measurement - at millisecond time resolution for both wild type and mutant HA proteins, using an automated patch clamp apparatus. Correlating the entire life history of the fusion pore with the snapshots we get from 3D imaging (cryo-electron tomography) would allow us to capture the initial pore opening, as well as better understand the effect that mutating the structure of HA has on influenza viral infection. At this time, we have not yet been able to observe the fusion event; however, we do believe that future experimentation using fusion pore conductance to investigate the effects of HA's structure on influenza viral infection are both promising and necessary.

CAMP factor is an extracellular pore-forming toxin secreted by the group B streptococci Streptococcus agalactiae. In conjunction with the action of sphingomyelinase secreted by Staphylococcus aureus, which converts membrane sphingomyline to ceramide, CAMP factor kills susceptible cells by creating holes in them. Since the monomeric or oligomeric structure of CAMP factor is not yet known, no studies on the membrane-penetrating domain of this toxin have been done. In the present study, the interaction of a putative hydrophobic domain between residues T90 and V115 with the target membrane was examined by cysteine-scanning mutagenesis and site-selective fluorescent labeling. The combination of steady state and lifetime fluorescence measurements and collisional quenching experiments with nitroxide labeled fatty acids indicate that residues from T90 to V115 contact the membrane upon binding and oligomerization of CAMP factor on cell membranes. More importantly, all these individual assays indicate that the residues from N104C to F109C insert superficially into the membrane with a β-sheet conformation.

CAMP factor is an extracellular pore-forming toxin secreted by the group B streptococci Streptococcus agalactiae. In conjunction with the action of sphingomyelinase secreted by Staphylococcus aureus, which converts membrane sphingomyline to ceramide, CAMP factor kills susceptible cells by creating holes in them. Since the monomeric or oligomeric structure of CAMP factor is not yet known, no studies on the membrane-penetrating domain of this toxin have been done. In the present study, the interaction of a putative hydrophobic domain between residues T90 and V115 with the target membrane was examined by cysteine-scanning mutagenesis and site-selective fluorescent labeling. The combination of steady state and lifetime fluorescence measurements and collisional quenching experiments with nitroxide labeled fatty acids indicate that residues from T90 to V115 contact the membrane upon binding and oligomerization of CAMP factor on cell membranes. More importantly, all these individual assays indicate that the residues from N104C to F109C insert superficially into the membrane with a β-sheet conformation.

The sizes of a bubble trapped in solid after nucleation on the solidification front during an upward freezing of water containing a dissolved oxygen or carbon dioxide gas are experimentally measured and quantitatively predicted in this work. From an in situ measurements of bubble shapes in solid at cold temperatures of -25 and -15 C, it quantitatively shows that pore formation can be divided into five regimes: (1) nucleation on the solidification front, (2) spherical growth, (3) solidification rate-controlled elongation, (4) disappearance of the bubbles, and (5) formation of the pores in solid. To interpret experimental results, equations incorporated with the growth rate of a spherical bubble and solidification rate to predict bubble shapes in the solid during the spherical growth and solidification rate-controlled elongation are successfully proposed. Experimental data show the effects of initial gas concentration and solidification rate on geometries of the bubble in solid.

This study examined the stratigraphic architecture, depositional and diagenetic histories, and resulting reservoir characteristics that have influenced the occurrence, distribution, and quality of flow units in the Diamond M field, Scurry County, Texas. The study area is located in the Midland Basin. The field has production from the Canyon (Pennsylvanian) Horseshoe Atoll carbonate buildup. Recent drilling in the Diamond M field was done to evaluate ways to improve recovery by water flooding. Classification of depositional texture based on detailed petrologic and petrographic studies on three cores was done. Subsequent genetic classification of pore types by thin section petrography revealed three dominant pore types: intramatrix, moldic, and vuggy. The reservoir was zoned according to dominant pore type and log signatures to evaluate correlations at field scale by using neutron logs. Equations determined from core analyses provided equations used for estimating porosity and permeability, which were used to develop a ranking scheme for reservoir quality based on good, intermediate, and poor flow units at field scale. Ultimately slice maps of reservoir quality at a 10 ft interval for a 150 ft section of the Canyon Reef reservoir were developed. These reservoir quality maps will provide a useful tool for the design and implementation of accurate and profitable development programs.

Thesis (Ph. D.)--Ohio State University, 2009. / Title from first page of PDF file. Includes bibliographical references (p. 100-111).