No description available.

No description available.

Fluid flow process in fractured reservoirs is controlled primarily by the connectivity of fractures. The presence of fractures in these reservoirs significantly affects the mechanism of fluid flow. They have led to problems in the reservoir which results in early water breakthroughs, reduced tertiary recovery efficiency due to channeling of injected gas or fluids, dynamic calculations of recoverable hydrocarbons that are much less than static mass balance ones due to reservoir compartmentalization, and dramatic production changes due to changes in reservoir pressure as fractures close down as conduits. These often lead to reduced ultimate recoveries or higher production costs. Generally, modeling flow behavior and mass transport in fractured porous media is done using the dual-continuum concept in which fracture and matrix are modeled as two separate kinds of continua occupying the same control volume (element) in space. This type of numerical model cannot reproduce many commonly observed types of fractured reservoir behavior since they do not explicitly model the geometry of discrete fractures, solution features, and bedding that control flow pathway geometry. This inaccurate model of discrete feature connectivity results in inaccurate flow predictions in areas of the reservoir where there is not good well control. Discrete Fracture Networks (DFN) model has been developed to aid is solving some of these problems experienced by using the dual continuum models. The Discrete Fracture Networks (DFN) approach involves analysis and modeling which explicitly incorporates the geometry and properties of discrete features as a central component controlling flow and transport. DFN are stochastic models of fracture architecture that incorporate statistical scaling rules derived from analysis of fracture length, height, spacing, orientation, and aperture. This study is focused on developing a methodology for application of DFN to a shale gas reservoir and the practical application of DFN simulator (FracGen and NFflow) for fracture modeling of a shale gas reservoir and also studies the interaction of the different fracture properties on reservoir response. The most important results of the study are that a uniform fracture network distribution and fracture aperture produces the highest cumulative gas production for the different fracture networks and fracture/well properties considered.

Similar to cancer cells, HIV-infected cells differ from HIV-uninfected cells in that they have altered interferon signaling pathways, the apparent reason for the selectivity of certain oncolytic viruses (OVs). Therefore, it was hypothesized that use of an OV, such as recombinant Maraba virus (MG1), may be a potential approach to eliminate latently-infected cells constituting the HIV reservoir while sparing HIV-uninfected cells. This was studied in U1, ACH-2, OM-10 and J1.1 cells and their respective HIV-uninfected parent cell lines in addition to CD4+CD25-HLADR- cells from HIV-infected individuals on effective antiretroviral therapy. Although MG1 infected and killed latently HIV-infected U1 cells to a greater degree than the HIV-uninfected parent U937 cells, this was not observed in the other HIV-infected cell lines and their respective parent cell lines. Furthermore, results from primary cells suggest that MG1 alone does not appear to eliminate cells which comprise the major HIV reservoir. Challenges of studying the HIV reservoir and priorities for future studies examining the use of OVs as a potential strategy to eliminate the HIV reservoir are discussed.

The ecological implications of altering the hydrologic regime, or hydroperiod, of a wetland system include major changes to both ecosystem structure and function. Wetland systems are generally sinks of nutrients such as phosphorus, nitrogen and carbon, which are important to water quality. Changes in the hydroperiod such as the inundation or drainage of a wetland system alter wetland function and may switch the system from functioning as a nutrient sink to a source. In this study, I explored the effects from the introduction of a seasonal inundation regime to the Begbie Lake wetland system. Begbie Lake is hydrologically connected to the Sooke Lake reservoir, the main drinking water supply for Greater Victoria, British Columbia. In 2002, the dam on the Sooke Lake reservoir was raised by 6 m, which led to the seasonal inundation of the Begbie Lake wetland system in 2005 and 2006. In 2005, the Begbie Lake wetland system was inundated for 57 days, from April through May. In 2006, the wetland was inundated for 123 days, from January through May. The seasonal inundation resulted in the release of phosphorus, nitrogen and carbon from the wetland system into Begbie Lake and the Sooke Lake reservoir. Nutrients such as phosphorus and nitrogen are especially important in drinking water reservoirs, where increases in concentrations often lead to increased algal biomass and possibly a shift toward cyanobacteria-dominated phytoplankton communities. Organic carbon in source water is correlated with disinfection by-product production during treatment, increases in bacterial biomass within distribution systems, and decreases in the efficacy of water treatment. The response to inundation of the wetland system, in terms of the release of key water quality nutrients into Begbie Lake was assessed. Water chemistry data collected from 2005 and 2006 were compared to pre-inundation baseline data (2003 and 2004) over the growing season. Phosphorus, nitrogen and organic carbon concentrations above the flooded wetland soils increased significantly during the inundation periods. Following drawdown, the total phosphorus concentration in Begbie Lake increased signi cantly. Total nitrogen and total organic carbon concentrations in Begbie Lake did not increase over this same period; the microbial mineralization and reduction of nitrogen and organic carbon, as well as the export of these nutrients into the Sooke Lake reservoir, are proposed as in uencing the observations. The inundation of the Begbie Lake wetland system also resulted in the export of large amounts of nitrogen and organic carbon to the Sooke Lake reservoir. The increase in the duration and extent of inundation in 2006 resulted in higher contributions from the Begbie Lake wetland system. The export of nitrogen increased from 3.8 kg in 2005 to 4.4 kg in 2006. Carbon export increased from 77.7 kg in 2005 to 171.1 kg in 2006. The export of high amounts of phosphorus were not observed during the study. While phosphorus concentrations increased above wetland soils, the data suggest that much of the phosphorus remained cycling within Begbie Lake.

Increasing hydrocarbon reserves by finding new resources in frontier areas and improving recovery in the mature fields, to meet the high energy demands, is very challenging for the oil industry. Reservoir characterization and heterogeneity studies play an important role in better understanding reservoir performance to meet this industry goal. This study was conducted on the Boonsville Bend Conglomerate reservoir system located in the Fort Worth Basin in central-north Texas. The primary reservoir is characterized as highly heterogeneous conglomeratic sandstone. To find more potential and optimize the field exploitation, it’s critical to better understand the reservoir connectivity and heterogeneity. The goal of this multidisciplinary study was to quantify the permeability heterogeneity of the target reservoir by integrating core, well log and 3D seismic data. A set of permeability coefficients, variation coefficient, dart coefficient, and contrast coefficient, was defined in this study to quantitatively identify the reservoir heterogeneity levels, which can be used to characterize the intra-bed and inter-bed heterogeneity. Post-stack seismic inversion was conducted to produce the key attribute, acoustic impedance, for the calibration of log properties with seismic. The inverted acoustic impedance was then used to derive the porosity volume in Emerge (the module from Hampson Russell) by means of single and multiple attributes transforms and neural network. Establishment of the correlation between permeability and porosity is critical for the permeability conversion, which was achieved by using the porosity and permeability pairs measured from four cores. Permeability volume was then converted by applying this correlation. Finally, the three heterogeneity coefficients were applied to the permeability volume to quantitatively identify the target reservoir heterogeneity. It proves that the target interval is highly heterogeneous both vertically and laterally. The heterogeneity distribution was obtained, which can help optimize the field exploitation or infill drilling designs.

The Alberta Basin has been the subject of various diagenetic studies but the precise understanding of the processes behind deep burial cementation remains unclear. This study investigates late-diagenetic calcites from the Devonian Southesk-Cairn Carbonate Complex with the purpose of constraining temperature, relative timing and chemistry of the paleo-fluids involved during calcite precipitation. Two types of late-diagenetic calcites were petrographically andgeochemicallycharacterized.Whereascalcite-Iresultedfrom thermochemical sulfate reduction, calcite-II precipitated with no or little oxidized organic carbon present. As shown by the Sr isotopic signatures, some reservoirs were exposed to radiogenic Sr-bearing fluids. A slight trend of increasing fluid inclusion homogenization temperatures with depth is only seen in calcite-I, and bitumen reflectance also increases with depth following a normal burial gradient. These results, however, are not conclusive to interpret the influence of tectonically-driven fluids during deep burial.

Thesis (MAppSc)--University of South Australia, 1996

Thesis (Ph. D.)--University of Texas at Austin, 2007. / Vita. Includes bibliographical references.

Thesis (M.S. - Hydrology and Water Resources)--University of Arizona. / Includes bibliographical references (leaves 88-90).