This thesis explores two ways of developing a fracture diagnostics tool capable of estimating hydraulic fracture propped length and orientation. Both approaches make use of an electrically conductive proppant. The fabrication of an electrically conductive proppant is believed to be possible and an option currently on the market is calcined petroleum coke. The first approach for tool development was based on principles of antenna resonance whereas the second approach was based on low frequency magnetic induction. The former approach had limited success due to the lack of resonant features at the stipulated operating conditions. Low frequency induction is a more promising approach as electromagnetic fields showed measurable changes that were dependent on fracture length in simulations. The operation of a logging tool was simulated and the data showed differences in the magnetic field magnitude ranging from 2% to 107% between fracture sizes of 20m, 50m, 80m, and 100m. Continuing research of the topic should focus not only on simulating more diverse fracture scenarios but also on developing an inversion scheme necessary for interpreting field data. / text

Hydraulic fracturing is an important stimulation method for producing unconventional gas reserves. Natural fractures are present in many low-permeability gas environments and often provide important production pathways for natural gas. The production benefit from natural fractures can be immense, but it is difficult to quantify. The Mesaverde Group in the Piceance Basin in Colorado is a gas producing reservoir that has low matrix permeability but is also highly naturally fractured. Wells in the Piceance Basin are hydraulically fractured, so the production enhancements due to natural fracturing and hydraulic fracturing are difficult to decouple. In this thesis, dipole sonic logs were used to quantify geomechanical properties by combining stress equations with critically-stressed faulting theory. The properties derived from this log-based evaluation were used to numerically model hydraulic fracture treatments that had previously been pumped in the basin. The results from these hydraulic fracture models, in addition to the log-derived reservoir properties were used to develop reservoir models. Several methods for simulating the reservoir were compared and evaluated, including layer cake models, geostatistical models, and models simulating the fracture treatment using water injection. The results from the reservoir models were compared to actual production data to quantify the effect of both hydraulic fractures and natural fractures on production. This modeling also provided a framework upon which completion techniques were economically evaluated. / text

Although many fracture models are based on two-dimensional plane strain approximations, accurately predicting fracture propagation geometry requires accounting for the three-dimensional aspects of fractures. In this study, we implemented 3-D displacement discontinuity (DD) boundary element modeling to investigate the following intrinsically 3-D natural or hydraulic fracture propagation problems: the effect of fracture height on lateral propagation of vertical natural fractures, joint development in the vicinity of normal faults, and hydraulic fracture height growth and non-planar propagation paths. Fracture propagation is controlled by stress intensity factor (SIF) and its determination plays a central role in LEFM. The DD modeling is used to evaluate SIF in Mode I, II and III at the tip of an arbitrarily-shaped embedded crack by using crack-tip element displacement discontinuity. We examine the accuracy of SIF calculation is for rectangular, penny-shaped, and elliptical planar cracks. Using the aforementioned model for lateral propagation of overlapping fractures shows that the curving path of overlapping fractures is strongly influenced by the spacing-to-height ratio of fractures, as well as the differential stress magnitude. We show that the angle of intersection between two non-coincident but parallel en-echelon fractures depends strongly on the fracture height-to-spacing ratio, with intersection angles being asymptotic for "tall" fractures (large height-to-spacing ratios) and nearly orthogonal for "short" fractures. Stress perturbation around normal faults is three-dimensionally heterogeneous. That perturbation can result in joint development at the vicinity of normal faults. We examine the geometrical relationship between genetically related normal faults and joints in various geologic environments by considering a published case study of fault-related joints in the Arches National Park region, Utah. The results show that joint orientation is dependent on vertical position with respect to the normal fault, the spacing-to-height ratio of sub-parallel normal faults, and Poisson's ratio of the media. Our calculations represent a more physically reasonable match to measured field data than previously published, and we also identify a new mechanism to explain the driving stress for opening mode fracture propagation upon burial of quasi-elastic rocks. Hydraulic fractures may not necessarily start perpendicular to the minimum horizontal remote stress. We use the developed fracture propagation model to explain abnormality in the geometry of fracturing from misaligned horizontal wellbores. Results show that the misalignment causes non-planar lateral propagation and restriction in fracture height and fracture width in wellbore part. / text

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Hydrate Ridge is a peanut shape bathymetric high located about 80 km west of Newport, Oregon on the Pacific continental margin, within the Cascadia subduction zone’s accretionary wedge. The ridge's two topographic highs (S. and N. Hydrate Ridge) are characterized by gas vents and seeps that were observed with previous ODP initiatives. In 2008, we acquired a 3D seismic reflection data set using the P-Cable acquisition system to characterize the subsurface fluid migration pathways that feed the seafloor vent at S. Hydrate Ridge. The new high-resolution data reveal a complex 3D structure of localized faulting within the gas hydrate stability zone (GHSZ). We interpret two groups of fault-related migration pathways. The first group is defined by regularly- and widely-spaced (100-150 m) faults that extend greater than 300ms TWT (~ 250 m) below seafloor and coincide with the regional thrust fault orientations of the Oregon margin. The deep extent of these faults makes them potential conduits for deeply sourced methane and may include thermogenic methane, which was found with shallow drilling during ODP Leg 204. As a fluid pathway these faults may complement the previously identified sand-rich, gas-filled stratigraphic horizon, Horizon A, which is a major gas migration pathway to the summit of S. Hydrate Ridge. The second group of faults is characterized by irregularly but closely spaced (~ 50 m), shallow fractures (extending < 160ms TWT below seafloor, ~ 115 m) found almost exclusively in the GHSZ directly beneath the seafloor vent at the summit of S. Hydrate Ridge. These faults form a closely-spaced network of fractures that provide multiple migration pathways for free gas entering the GHSZ to migrate vertically to the seafloor. We speculate that the faults are the product of hydraulic fracturing due to near-lithostatic gas pressures at the base of the GHSZ. These fractures may fill with hydrate and develop a lower permeability, which will lead to a buildup of gas pressures below the GHSZ. This may lead to a vertical propagation of new fractures to release the overpressure, which results in the high concentration of shallow fractures within the GHSZ seen in the 2008 data. / text

The thesis research examined localized socio-environmental perceptions related to amplified fresh water requirements for hydraulic fracturing and subsequent flowback disposal activities. These requirements are associated with increasing shale gas development in the Duvernay formation, located within the Kaybob region of West-central Alberta, Canada. Fresh water refers to surface and groundwater with a total dissolved solids concentration of less than 4,000 ppm. Through recourse to a mixed methods approach, combined with triangulation as a method of further validation, the research demonstrates that there exists a public sensitivity related to fresh water use in the Kaybob region. This sensitivity arises from increasing development activities in the Duvernay shale gas formation. The thesis presents conclusions and recommendations whereby industry may address stakeholder concerns, and provides advice for future research.

The reliance upon and depletion of fossil fuels as an energy source puts pressure on individuals, communities, energy companies, and policy-makers. Hydraulic fracturing – known colloquially as fracking – as a method of drilling for oil and natural gas temporarily alleviates this pressure since it allows for the extraction previously inaccessible fossil fuels in shale rock deposits deep beneath the Earth’s surface. This has resulted in a nationwide “fracking boom,” which has come with its share of economic benefits. However, the process of fracking can be detrimental to human and environmental health. In reaction to the increasing development of this practice, many communities across the country are mobilizing against fracking. This thesis will focus on the grassroots activism against fracking in New York, where fracking was banned in December 2014, and in California, which is largely slated as the next frontier for the expansion of fracking and thus battleground for the fight against fracking. Using grassroots academic literature, media coverage of fracking and activism in each state, and interviews from organizers working in each state, this thesis will examine the motivations, frameworks, strategies, and tactics used in each grassroots campaign in order to offer lessons in successes and opportunities for improvement within these anti-fracking efforts and others across the country.

This work is about fracture conductivity; how to measure and model it based on experimental data. It is also about how to determine the relative importance of the factors that affect its magnitude and how to predict its magnitude based on these factors. We dynamically placed the slurry hereby simulating the slurry placement procedure in a field-scale fracture. We also used factorial and fractional factorial designs as the basis of our experimental investigation. The analysis and interpretation of experimental results take into account the stochastic nature of the process. We found that the relative importance of the investigated factors is dependent on the presence of outliers and how they are handled. Based on our investigation we concluded that the investigated factors arranged in order of decreasing impact on conductivity are: closure stress, polymer loading, flow back rate, presence of breaker, temperature and proppant concentration. In particular, we find that at high temperatures, fracture conductivity was severely reduced due to the formation of a dense proppant-polymer cake. Also, dehydration of the residual gel in the fracture at high flow back rates appears to cause severe damage to conductivity at higher temperatures. This represents a new way of thinking about the fracture cleanup process; not only as a displacement process, but also as a displacement and evaporative process. In engineering practice, this implies that aggressive flow back schemes are not necessarily beneficial for conductivity development. Also, we find that at low proppant concentrations, there is the increased likelihood of the formation of channels and high porosity fractures resulting in high fracture conductivities. The uniqueness of this work is a focus on the development of a conductivity model using regression analysis and also the illustration of a procedure that can be used to develop a conductivity model using dimensional analysis. We reviewed both methodologies and applied them to the challenge of modeling fracture conductivity from experimental studies.

Thesis (MA)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: Hydraulic fracturing is a geo-engineering procedure designed to extract shale gas from below the earth’s surface. Shale gas is often considered a natural, alternative source of energy that has the potential to increase global energy supplies but the scientific literature is not unanimous regarding the implications that hydraulic fracturing may have, and whether it should continue (Vermeulen 2012). Given the contentious nature of hydraulic fracturing, this study investigates the ways in which hydraulic fracturing is represented in South African media texts. The study draws on Gee’s (1996) model of critical discourse analysis (CDA), which views discourse as a means to represent and reproduce social practices. Thus, the study conceptualises hydraulic fracturing as a social practice with an affiliated discourse or discourses, which represent or construct the process of hydraulic fracturing, as well as the participants involved and context in which it takes place. Furthermore, these discourses are also presumed to have the power to legitimise, and thus perpetuate hydraulic fracturing, or to critique it. Subsequent to an examination of 32 South African news articles, and a close and critical analysis of four of them, this study reveals that hydraulic fracturing is presented in both positive and negative ways. Where positive constructions prevail, writers draw on the perspectives of those working in multinational corporations (MNCs) to construct shale gas as a way to increase energy supplies and achieve economic prosperity. Where negative constructions prevail, writers draw on the perspectives of environmentalists to construct hydraulic fracturing as an environmentally-harmful activity that depletes natural resources. In doing so, the study not only highlights the media’s role in perpetuating confusion about hydraulic fracturing, but highlights dominant ideologies that give rise to common representations of hydraulic fracturing in media texts. / AFRIKAANSE OPSOMMING: Hidrobreking is ’n geo-ingenieursprosedure waardeur ondergrondse skaliegas ontgin word. Skaliegas word dikwels beskou as ’n natuurlike, alternatiewe energiebron met die potensiaal om die wêreld-energievoorraad te verhoog, maar die wetenskaplike literatuur is verdeeld oor die effek van hidrobreking en die voortsetting van hierdie praktyk (Vermeulen 2012). Gegee die netelige aard van die onderwerp, word daar in hierdie studie ondersoek gedoen na die wyses waarop hidrobreking voorgestel word in Suid-Afrikaanse mediatekste. Die analise word gerig deur Gee (1996) se model van kritiese diskoersanalise waarvolgens diskoers dien as instrument in die voorstelling en voortsetting van sosiale praktyke. As sodanig word hidrobreking in hierdie studie gekonsepsualiseer as ’n sosiale praktyk met een of meer gepaardgaande diskoerse wat die proses van hidrobreking, die deelnmers in hierdie proses asook die konteks waarin hierdie proses plaasvind, voorstel of konstrueer. Verder word daar veronderstel dat hierdie diskoerse die krag het om hidrobreking te regverdig en sodoende voor te sit, of om dit te kritiseer. Op grond van die bestudering van 34 Suid-Afrikaanse nuusberigte en ’n kritiese ontleding van vier daarvan, word daar bevind dat hidrobreking op beide positiewe en negatiewe wyses voorgestel word. In die geval van positiewe konstruksies steun skrywers op die uitgangspunte van persone in multinasionale korporasies om skaliegas te konstrueer as ’n manier om energievoorrade te verhoog en ekonomiese vooruitgang te bevorder. In die geval van negatiewe konstruksies steun skrywers op die uitgangspunte van omgewingsdeskundiges om hidrobreking te konstrueer as ’n omgewingskadelike aktiwiteit wat natuurlike hulpbronne uitput. Hierdie bevindinge beklemtoon die rol van die media in die voortgesette verwarring aangaande hidrobreking, asook die dominante ideologieë wat aanleiding gee tot algemene voorstellings van hidrobreking in mediatekste.

Master of Landscape Architecture / Department of Landscape Architecture/Regional and Community Planning / Blake Belanger / In recent decades, traditional methods of oil and gas extraction in the United States have been fortified by hydraulic fracturing, or fracking. The process of fracking involves injecting water, aggregates, and chemicals into the earth to rupture rock that is trapping oil and gas. This process has unlocked access to once unobtainable reserves, and as a result, U.S. oil and gas production has continued to increase despite recurring forecasts that supplies would peak. While increased production has strengthened some sectors in the U.S. economy, it has also renewed a reliance on non-renewable energy, compromised the well-being of communities, and poses serious environmental threat. While research into the process of hydraulic fracturing and its effects are common, little discussion has been generated regarding the broader impacts of the systems required to construct, supply, and maintain fracking operations. The processes of hydraulic fracturing contain a dense array of components that effect both the present and future state of communities, environments, and economies. As energy demands grow and resources deplete, these millions of facilities will demarcate the wicked problems of a post-oil and gas future and reveal a dense system of derelict infrastructure and underutilized lands. This report presents the Fracklands. Fracklands are a comprehensive telling of the landscapes of hydraulic fracturing. They offer insight into what a dynamic and complex system of modern oil and gas extraction infrastructure looks like. After first defining fracking and discussing current practices and policies as grounds, I present a classification framework for defining the Fracklands. Organized by four approaches – Systems, Typologies, Trends and Futures – this Framework utilizes a set of descriptive methods conducted in three U.S. regions to present and discuss the Fracklands. Results reveal a more complete picture of fracking’s effects on the American landscape today, while giving hints of what the Fracklands will present in the future. The Fracklands are a little understood system of components and processes that profoundly affect land, people, place, and society. By presenting the Fracklands framework in this report, I aspire that planners, designers, and decision-makers will have a clear outline for better understanding the nature of this wicked problem. As a point of departure, I propose three unique design-based alternatives to address the future of the Fracklands and dilemmas yet materialized. With the Fracklands revealed, footholds are set for a methodology to be adapted and used in future study for understanding the ever-changing landscape of hydraulic fracturing.