Numerical reservoir simulation has been used to describe mechanism of methane gas desorption process, diffusion process, and fluid flow in a coalbed methane reservoir. The reservoir simulation model reflects the response of a reservoir system and the relationship among coalbed methane reservoir properties, operation procedures, and gas production. This work presents a procedure to select the optimum well spacing scenario by using a reservoir simulation. This work uses a two-phase compositional simulator with a dual porosity model to investigate well-spacing effects on coalbed methane production performance and methane recovery. Because of reservoir parameters uncertainty, a sensitivity and parametric study are required to investigate the effects of parameter variability on coalbed methane reservoir production performance and methane recovery. This thesis includes a reservoir parameter screening procedures based on a sensitivity and parametric study. Considering the tremendous amounts of simulation runs required, this work uses a regression analysis to replace the numerical simulation model for each wellspacing scenario. A Monte Carlo simulation has been applied to present the probability function. Incorporated with the Monte Carlo simulation approach, this thesis proposes a well-spacing study procedure to determine the optimum coalbed methane development scenario. The study workflow is applied in a North America basin resulting in distinct Net Present Value predictions between each well-spacing design and an optimum range of well-spacing for a particular basin area.

Seismic attributes are a descriptive and quantifiable characteristic of seismic data, and so they represent subsets of the total information contained in the original seismic data. Consequently, seismic attrjbutes can be important qualitative and quantitative predictors of physical reservoir properties. Seismic attribute analysis began with the search for bright spots in the late 1960s and early 1970s. Subsequent work in the last decades has established seismic attribute analysis as a valuable tool in reservoir characterization studies. I present in this thesis two seismic attribute analyses for the interpretation of the characteristics of the seismic trace to predict significant geological features (e.g., lithology, rock properties and/or fluid content). The first study is an example of the applicability of seismic attributes to predict geologic controls on production data in a coal bed methane reservoir. Based on the calibration of log data with seismic data procedure, I defined a window of analysis, from which I computed amplitude, frequency and phase related attributes. Then, I used a quantitative multiattribute analysis to derive a seismic attribute-based model that predicts coal thickness. Thereafter, I used with a curvature attribute analysis with the objective to map subtle structural features and predict areas with enhanced permeability. The integration of production data with results achieved from both attribute analyses indicates that best production is associated with thicker coal and the immediate vicinity to seismically defined structures. [...] / Les attributs sismiques ont comme caractéristique de pouvoir décrire et quantifier les données sismiques, de telle manière qu’ils représentent un sous-ensemble de l’information totale contenue dans les données originales. En conséquence, les attributs sismiques peuvent être d’importants paramètres qualitatifs et quantitatifs des propriétés physiques d’un réservoir. L’analyse d’attributs sismiques a commencé avec la prospection de tâches lumineuses (<< bright spots >>) vers la fin des années 1960 et début des années 1970. Des travaux subséquents pendant les dernières décennies ont permis d’établir l’analyse d’attributs sismiques comme un outil valable lors d’études de caractérisation d’un réservoir. Je présente dans cette thèse deux études d’attributs sismiques pour l’interprétation de la forme de la trace sismique afin de prédire des caractéristiques géologiques significatives tels que: la lithologie, les propriétés des roches et/ou le contenu liquide. La première étude est un exemple de l’application d’attributs sismiques pour prédire des contrôles géologiques sur la production d’un réservoir coalbed methane. D’après les résultats de la calibration des diagraphies au câble avec des données sismiques, j’ai défini une fenêtre d’investigation à partir de laquelle des attributs sismiques de type amplitude, fréquence et phase ont été calculés. J’ai utilisé une analyse muIti-attribut pour dériver un model statistique dans le but d’estimer l’épaisseur du réservoir. Par la suite, j’ai utilisé des attributs mesurant la courbature d’une surface pour mettre en relief de subtiles structures géologiques et prédire les régions dans le réservoir avec une perméabilité augmentée. L’intégration des données de production avec les résultats obtenus lors d’analyses d’attributs sismiques indique que la meilleure production est en association avec l’épaississement du réservoir et le voisinage immédiat de structures géologiques. [...]

The exploration for unconventional energy reserves has rapidly increased over the last five to ten years. Currently, there are a number of companies actively exploring for coalbed methane (CBM) in New Zealand. This study investigates one of these prospects, the subbituminous Huntly coalfield. Coal core was retrieved from the two major seams in the coalfield, the Renown and the Kupakupa. Three coals types were identified (1) bright lustre, non-banded, (2) bright lustre, moderately banded and (3) bright lustre, highly banded. As the degree of banding increases, the average thickness of the vitrain bands increase, the amount of structured vitrinite macerals also increase and the vitrodetrinite content decreases. The Renown seam is predominantly composed of bright non-banded coal while in the Kupakupa seam the more banded coal types are dominant. On average, the Renown seam has both the capacity to hold more gas and has higher gas contents than the stratigraphically lower Kupakupa seam. Additionally, gas content, on average, was found to be highest in intervals of the non-banded coal type and lowest in the highly banded coal type. Cluster analysis found that gas content is associated with hydrogen, volatile matter, calorific value and collodetrinite. As such, gas appears to be preferentially retained/produced in the matrix-dominated material. While not causally linked with gas content, gas holding capacity showed associations with the sporinite, inertodetrinite, funginite and vitrodetrinite; of note, these macerals are highest in the non-banded coal type. Gas holding capacity is thought to be a function of coal texture. Ash yield was found to inversely affect total gas content when ash yield is >10%. Below 10%, it is thought that inorganic elements are organically bound. The small angle scattering analysis indicated that inorganic matter was in the 12.5 Å < r < 125 Å pore size range. The influence of inorganic material was more noticeable in vitrain than matrix samples and is proposed to exist as thin inorganic coatings. Total porosity of the Huntly coal is primarily composed of micropores with macroporosity only contributing a small proportion. In addition, the specific surface area of the coals is also largely contributed by the micropores. Methane holding capacity on a dry, ash-free basis showed positive correlations with both micro- and macroporosity. When methane holding capacity was considered on an ‘as analysed’ basis, correlation was only identified with macroporosity. Possibly gas holding capacity is affected by the presence of moisture blocking access to gas adsorption sites in smaller pores. Considerable variation is present in both gas adsorption and gas desorption results between drill holes, between seams and also within individual seam intersections. Gas adsorption capacity and gas content are used to calculate % saturation for a reservoir, a key assessment parameter. It was found that multiple samples of both gas adsorption capacity and gas content are required to reduce the uncertainty around the calculated % saturation (at least three of each in the current study). Additionally, adsorption isotherm samples need to be collected as fresh as possible to minimize oxidation and moisture loss. Delaying sample analysis was found to result in an overestimation of gas adsorption capacity.

Thesis (Ph. D.)--University of Wyoming, 2006. / Title from PDF title page (viewed on April 11, 2008). Includes bibliographical references.

Thesis (M.S.) -- University of Montana, 2008. / Title from author supplied metadata. Description based on contents viewed on June 20, 2009. ETD number: etd-12192008-143539. Includes bibliographical references.

Thesis (M.S.)--West Virginia University, 2004. / Title from document title page. Document formatted into pages; contains xiii, 149 p. : ill. (some col.), maps. Includes abstract. Includes bibliographical references (p. 149).

Thesis (M.S.)--West Virginia University, 2009. / Title from document title page. Document formatted into pages; contains vi, 41 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 40-41).

Thesis (M.S.)--University of Wyoming, 2008. / Title from PDF title page (viewed on August 6, 2009). Includes bibliographical references (p. 50-54).

Thesis (Ph. D.)--University of Wyoming, 2007. / Title from PDF title page (viewed on Sept. 1, 2009). Includes bibliographical references.

Thesis (Ph.D.) - University of Queensland, 2003. / Includes bibliography.