Thesis (Ph. D.)--Rutgers University, 2009. / "Graduate Program in Geological Sciences." Includes bibliographical references.

Thesis (Ph. D.)--Rutgers University, 2009. / "Graduate Program in Geological Sciences." Includes bibliographical references (p. 278-287).

Thesis (M.S.)--Kent State University, 2009. / Title from PDF t.p. (viewed Mar. 8, 2010). Advisor: Peter S. Dahl. Keywords: Precambrian; Black Hills; geochronology; provenance; ion-microprobe; zircon; monazite; xenotime. Includes bibliographical references (p. 120-126).

Thesis (Ph. D.)--West Virginia University, 2003. / Title from document title page. Document formatted into pages; contains xi, 191 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 137-139).

<p>Petroleum is generated from finely grained source rocks rich in organic materials and accumulated and trapped in reservoir rocks with relatively higher permeability and porosity. Expulsion of petroleum through and out of source rocks is called primary migration. Primary migration, as a link between source rocks and carrier rocks, presents a vital challenge to the society of petroleum geosciences and exploration and attracts the research interests of many geologists and geochemists. Despite extensive research the effective mechanisms responsible for primary migration of hydrocarbons are still in intensive debate. </p><p> Conversion of kerogen to oil and/or gas results in appreciable volume increase due to the density difference between the precursor and the products. Overpressure is developed as a natural consequence in well-sealed dense source rocks at great depths. When the overpressure reaches some critical value, bedding-parallel microcracks are initiated owing to laminated structure and strength anisotropy of source rocks. As transformation proceeds, microcracks are driven to grow subcritically by the overpressure. Such microcracks serve as migration conduits for hydrocarbon flow and may connect to other preexisting conductive fractures to form fracture networks or systems, which may facilitate further migration of hydrocarbons. Convincing evidence from observations in nature and laboratory experiments is found to support the idea that microcracks caused mainly by overpressure buildup from hydrocarbon generation functions as effective primary migration pathways. Based on those published findings, the present dissertation adopted an integrated approach consisting of petroleum geochemistry, petrophysics and fracture mechanics to assess the role of self-propagating microfractures as an effective mechanism for primary migration of hydrocarbons. Four models were developed: migration though subcritical propagation and coalescence of collinear oil-filled cracks, migration through subcritical propagation of an oil-filled penny-shaped crack in isotropic source rocks, subcritical growth of a penny-shaped crack filled by hydrocarbon mix in anisotropic source rocks, and a penny-shaped crack driven by overpressure during conversion of oil to gas. To predict the migration time and quantities of oil and natural gas, we use the reaction kinetics taking into account of pressure and temperature histories during continuous burial of sediments. To account for the compressibility of gas at high temperatures and pressures, we adopt an equation of state for methane, the predominant component of natural gas. To address the excess pressure buildup through volume expansion associated with kerogen degradation and initiation of microfractures, we employ linear fracture mechanics. To simulate the propagation of microcracks, hence the migration of hydrocarbons, we use a finite difference approach. The time period for pressure build-up, the overpressure evolution over time, and crack propagation distance and duration are determined using the coupled model where the interaction of hydrocarbon generation and expulsion is included. A detailed systematic parametric study is carried out to investigate the sensitivity of hydrocarbon migration behavior to variations in the input parameters including elastic and fracture properties of source rocks, richness and type of organic matter and burial history. </p><p> Oil retained in the microfractures may be subjected to thermal cracking to form gas when the gas window is reached as the temperature and pressure continue to increase with the progressive burial. Numerical results are presented for the two cases: kerogen conversion to hydrocarbon mix and subsequently oil conversion to gas. The modeling results agree well with published geological observations which suggest that microfractures caused by overpressures mainly due to hydrocarbon generation serve as effective migration pathways for hydrocarbons within well-sealed source rocks under favorable burial conditions. The fully coupled multiphysics modeling allows us to gain some insight on the primary migration of hydrocarbons, which is essential for the exploration of source rocks. </p>

<p> Geothermal energy has the potential to become a substantially greater contributor to the U.S. energy market. An adequate investment in Enhanced Geothermal Systems (EGS) technology will be necessary in order to realize the potential of geothermal energy. This study presents an optimization of a waterbased Enhanced Geothermal System (EGS) modeled for AltaRock Energy&rsquo;s Newberry EGS Demonstration location. The optimization successfully integrates all three components of the geothermal system: (1) the present wellbore design, (2) the reservoir design, and (3) the surface plant design. </p><p> Since the Newberry EGS Demonstration will use an existing well (NWG 55-29), there is no optimization of the wellbore design, and the aim of the study for this component is to replicate the present wellbore conditions and design. An in-house wellbore model is used to accurately reflect the temperature and pressure changes that occur in the wellbore fluid and the surrounding casing, cement, and earth during injection and production. For the reservoir design, the existing conditions, such as temperature and pressure at depth and rock density, are incorporated into the model, and several design variables are investigated. The engineered reservoir is modeled using the reservoir simulator TOUGH2 while using the graphical interface PetraSim for visualization. Several fracture networks are investigated with the goal of determining which fracture network yields the greatest electrical output when optimized jointly with the surface plant. A topological optimization of the surface is completed to determine what type of power plant is best suited for this location, and a parametric optimization of the surface plant is completed to determine the optimal operating conditions. </p><p> The conditions present at the Newberry, Oregon EGS project site are the basis for this optimization. The subsurface conditions are favorable for the production of electricity from geothermal energy with rock temperatures exceeding 300&deg;C at a well depth of 3 km. This research was completed in collaboration with AltaRock Energy, which has provided our research group with data from the Newberry well. The purpose of this thesis is to determine the optimal conditions for operating an Enhanced Geothermal System for the production of electricity at Newberry. </p><p> It was determined that a fracture network consisting of five fractured zones carrying 15 kg/s of fluid is the best reservoir design out of those investigated in this study. Also, it was found that 100 m spacing between the fractured zones should be implemented as opposed to only 50 m of spacing. A double-flash steam power plant provides the best method of utilization of the geothermal fluid. For the maximum amount of electricity generation over the 30-year operating lifetime, the cyclone separator should operate at 205&deg;C and the flash vessel should operate at 125&deg;C.</p>

<p> Modified imbibition tests were performed on 69 subsurface samples from Monterey Formation reservoirs in the San Joaquin Valley to measure wettability variation as a result of composition and silica phase change. Contact angle tests were also performed on 6 chert samples from outcrop and 3 nearly pure mineral samples. Understanding wettability is important because it is a key factor in reservoir fluid distribution and movement, and its significance rises as porosity and permeability decrease and fluid interactions with reservoir grain surface area increase. Although the low permeability siliceous reservoirs of the Monterey Formation are economically important and prolific, a greater understanding of factors that alter their wettability will help better develop them. Imbibition results revealed a strong trend of decreased wettability to oil with increased detrital content in opal-CT phase samples. Opal-A phase samples exhibited less wettability to oil than both opal-CT and quartz phase samples of similar detrital content. </p><p> Subsurface reservoir samples from 3 oil fields were crushed to eliminate the effect of capillary pressure and cleansed of hydrocarbons to eliminate wettability alterations by asphaltene, then pressed into discs of controlled density. Powder discs were tested for wettability by dispensing a controlled volume of water and motor oil onto the surface and measuring the time required for each fluid to imbibe into the sample. The syringe and software of a CAM101 tensiometer were used to control the amount of fluid dispensed onto each sample, and imbibition completion times were determined by high-speed photography for water drops; oil drop imbibition was significantly slower and imbibition was timed and determined visually. Contact angle of water and oil drops on polished chert and mineral sample surfaces was determined by image analysis and the Young-Laplace equation. Oil imbibition was significantly slower with increased detrital composition and faster with increased silica content in opal-CT and quartz phase samples, implying decreased wettability to oil with increased detrital (clay) content. However, contact angle tests showed that opal-CT is more wetting to oil with increased detritus and results for oil on quartz-phase samples were inconsistent between different proxies for detritus over their very small compositional range. Water contact angle trends also showed inconsistent wetting trends compared to imbibition tests. We believe this is because the small range in bulk detrital composition between the "pure" samples used in contact angle tests was close to analytical error and because small-scale spatial compositional variability may be significant enough to effect wettability. These experiments show that compositional variables significantly affect wettability, outweighing the effect of silica phase.</p>

Little is known about Julius Haast's life prior to his arrival in New Zealand in 1858 at the age of 36. Without knowing something about his background, it is difficult to explain his life in New Zealand. This work pursues a historical context that can more fully explain Haast's remarkably active career in New Zealand. The geological survey of the Canterbury Province, the Philosophical Institute of Canterbury and the Canterbury Museum represent Haast's major contributions to science and culture in New Zealand. Julius Haast carefully engineered his own transition from geologist to museum director within the social and political climate of Canterbury in order to remain in Christchurch where he raised his family. Heinrich von Haast's book about his father has been the accepted source of information about his father since its publication in 1948. Until recently, scholars have failed to explore beyond the scope of von Haast's biography. There is now a trend toward recognising Julius Haast as having made significant contributions to many aspects of science and society.

Thesis (M.S.)--Ohio University, August, 2006. / Title from PDF t.p. Includes bibliographical references.

Thesis (Ph.D.) -- University of Adelaide, National Centre for Petroleum Geology and Geophysics, 2000. / Four folded maps in pocket on back cover. Copy of author's previously published work inserted. Includes bibliographical references (9 leaves).