In this work, two topics of reservoir simulations are discussed. The first topic is the two-phase compositional flow simulation in hydrocarbon reservoir. The major obstacle that impedes the applicability of the simulation code is the long run time of the simulation procedure, and thus speeding up the simulation code is necessary. Two means are demonstrated to address the problem: parallelism in physical space and the application of sparse grids in parameter space. The parallel code can gain satisfactory scalability, and the sparse grids can remove the bottleneck of flash calculations. Instead of carrying out the flash calculation in each time step of the simulation, a sparse grid approximation of all possible results of the flash calculation is generated before the simulation. Then the constructed surrogate model is evaluated to approximate the flash calculation results during the simulation. The second topic is the wormhole propagation simulation in carbonate reservoir. In this work, different from the traditional simulation technique relying on the Darcy framework, we propose a new framework called Darcy-Brinkman-Forchheimer framework to simulate wormhole propagation. Furthermore, to process the large quantity of cells in the simulation grid and shorten the long simulation time of the traditional serial code, standard domain-based parallelism is employed, using the Hypre multigrid library. In addition to that, a new technique called “experimenting field approach” to set coefficients in the model equations is introduced. In the 2D dissolution experiments, different configurations of wormholes and a series of properties simulated by both frameworks are compared. We conclude that the numerical results of the DBF framework are more like wormholes and more stable than the Darcy framework, which is a demonstration of the advantages of the DBF framework. The scalability of the parallel code is also evaluated, and good scalability can be achieved. Finally, a mixed finite element scheme is proposed for the wormhole simulation.

Flood-control reservoirs experience water level fluctuations that control survival of their biota. I explored diverse but related aspects of water-level management. Three frameworks were indentified for directing rule curve (i.e., daily targets for water levels) changes in flood-control reservoirs managed by the U.S. Army Corps of Engineers (USACE), with differing scopes and requirements. Framework choice depends on the reservoir’s primary authorization and magnitude of the contemplated change. Changes without congressional approval must be based on flood risk. Quantile regression was used to model a maximum water level with a user-specified level of risk. Because actions that request changes to water levels from natural resource professionals should have a sound ecological basis, I analyzed the relationships between water level fluctuations and vegetation in reservoirs. Remote sensing methods were used to calculate a greenness index from vegetation in the reservoir based on 14 years of satellite imagery and water levels.

Though the Cotton Valley Group is productive in Mississippi, Louisiana, and Texas, little is known about production potential of the Bossier Formation (Lower Cotton Valley Shale) in southwest Mississippi. The Bossier Formation in Jefferson County, Mississippi is an organic-poor, carbonate-rich mudrock with siliciclastic intervals. Examination of cuttings by petrographic and scanning electron microscopy revealed fractures that have been filled by calcite and poreilling pyrite. Porosity exists within and around pyrite framboids, in unfilled fractures, and within peloid grains. Organic matter is rare in Lower Cotton Valley samples suggesting it is not self-sourcing. Total Organic Carbon (TOC) values are low (0.86-1.1% TOC) compared to the productive Haynesville Shale Formation (2.8% TOC). Porosity of the Lower Cotton Valley Shale is low (2.5- 4.2%) compared to productive Haynesville Shale Formations (8-12%). With current technology and gas prices, the Lower Cotton Valley Shale in Jefferson County, Mississippi does not have production potential.

The United States Forest Service desires to build a 2,700 acre surface water reservoir by constructing a dam to impound water on Oakohay Creek in Smith County, Mississippi. A previous study from 2007 deemed the proposed location based on the hydrologic and geologic characteristics. The reinvestigation study objectives focused on the site’s hydrology and geology. The hydrologic study was accomplished by developing daily water storage models for the proposed reservoir. Archived data from the Southern Regional Climate Center were used in the models. The geologic study evaluated the Glendon Limestone through field surveying, ground penetrating radar, sonic rig drilling, surface water quantity measurements, and surface water quality analysis. A dedicated stream monitoring station was installed along the banks of Oakohay Creek. ArcGIS 9.3.1 and Microsoft Excel were used to support the objectives. Results from the study suggest that the proposed site location is suitable for reservoir development.

A new method for formulating finite difference equations for reservoir simulation has been developed. It can be applied throughout the entire simulated reservoir or to local segments. When applied to cells containing vertical, fully penetrating, straight-line wells in a homogeneous reservoir, the resulting equations are equivalent to Peaceman's classical well equations used in most reservoir simulators today. However, when the new finite difference equations are applied to both the well-containing cells, and their neighbors, the accuracy of the simulation improves substantially. The method produces still better accuracy results when applied throughout the reservoir. Unlike the Peaceman correction, the new method also applies to reservoirs containing wells of complex geometry. This includes wells that are closely spaced and wells near reservoir faults and external boundaries. The method results from the incorporation of approximate analytical expressions for the pressure into the reservoir simulator's finite difference equations. By incorporating the “physics” of the flow into the solution, rather than relying on polynomial-based finite difference equations based on Taylor's series, as is usually done, solution accuracy improves. Accuracy is particularly improved around the wells where near-singularities in the pressure occur. Polynomials are incapable of accurately representing singularities.

Limnological study of Moss Reservoir from May, 1975 through August, 1976 was conducted to evaluate the use of ATP assay in describing planktonic changes within the water column.

Advanced three-dimensional reservoir modeling was used to determine the optimum strategy for coalbed methane production in China's Qinshui Basin. Multiple completion strategies were analyzed for pre-mining methane drainage on the bases of economic, environmental, and mining-safety-based factors. Effective degasification in the Qinshui Basin is crucial to enhance the health and safety of the underground mining workforce and to decrease carbon dioxide equivalent greenhouse gas emissions. Active, large-scale degasification wells in the region include hydraulically stimulated vertical fracture wells and multilaterally drilled horizontal patterns, with the latter much less common. Reservoir modeling concludes that despite their limited implementation, horizontal coalbed methane drainage wells offer the benefits of faster reservoir depressurization, high gas production rates, and faster recovery times than traditional vertical fracture wells. Coupled with reservoir modeling results, discounted cash flow analyses show that high drilling density multilateral horizontal patterns are the most financially feasible degasification strategy in the Qinshui Basin, albeit a higher initial capital investment compared to traditional vertical fracture wells and lower drilling density horizontal patterns. Additionally, horizontal wellbore designs can be altered to account for varying permeability, enhancing the productivity of methane from reservoirs exhibiting permeability values less than 1 millidarcy. Furthermore, modeling suggests that proper orientation of select horizontal wellbore patterns is crucial to optimize recoverable reserves. Finally, a function was derived to represent the production rates of horizontal coalbed methane wells as a function of time. Analysis of the function's validity to actual production data and simulated production data suggest that it is most applicable in gassy coal seams up to 10 feet in thickness. The production rate curve was transformed to an analytical model, representing a function of well geometry and coal permeability as applied to other geological conditions of the Qinshui Basin. Scientific contributions associated with this research include: An in depth study of degasification associated with the Qinshui Basin's low permeability coals; The methodology for assessing environmental, safety and economic benefits of coal degasification; The relationship between lateral spacing and permeability to maintain substantial gas production rates; An improved production model to describe the entire producing period of coalbed methane wells. / Ph. D.

The Thrace Basin, NW Turkey, is one of the most important basins in Turkey in terms of hydrocarbon potential. Previous studies, starting in the 1930s, focused on tectonics, basin evolution, sedimentation and stratigraphy, depositional systems, and hydrocarbon potential. Eocene turbiditic sandstones and reefal limestones, and Oligocene deltaic sandstones are the major reservoir targets in the basin today. The focus of this research is the Upper Oligocene deltaic sandstones, namely the Danismen and Osmancik formations, which contain potential hydrocarbon reservoirs. The aims of research were to develop a better understanding of the geometric configuration of the Oligocene strata and to identify potential reservoirs within the study area. Accordingly, the geometric configurations of the strata were delineated using 3D seismic reflection data whereas petro-physical properties of the target formations were determined using wireline logs from three wells. A right-lateral strike slip or reverse fault system and associated NW-SE trending asymmetric fold extend across the study area. Both the fault system and the fold are truncated beneath the Miocene unconformity and are thus dated as late Oligocene to early Miocene in age. The Miocene unconformity forms a stratigraphic trap whereas the fault system and associated fold construct a NW-SE trending structural trap. Hydrocarbon-bearing, five main clean sandstone (shale volume less than %10) intervals were identified using wireline logs and evaluated as potential targets. Hydrocarbon concentrations increase through the fold structure. Thus, the fault system and the associated asymmetric fold were the main factors that affected the zonal distribution of hydrocarbons in the study area. / Master of Science

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