Workers involved in hydraulic fracking processes are exposed to various types of chemicals and dusts in their workplaces, such as proppants, which hold open the fissures created in the fracking process. Recently, ceramic proppants have been developed that may be less hazardous to workers than traditional proppants. Pulmonary function testing of workers producing ceramic proppant was used to assess the potential inhalation hazards of ceramic proppant. Male workers (n = 100) from a producer of ceramic proppant were evaluated with pulmonary function test data collected and evaluated using The American Thoracic Society (ATS) acceptability criteria. A comparison group was selected from the Third National Health and Nutrition Examination Survey (NHANES III) spirometry laboratory subset. No pulmonary function deficits were found in the worker group in comparison to the NHANES III population. Multiple linear regression analysis showed that the mean FEV1 and FVC values in workers were 0.11 and 0.08 liters respectively, and were greater as compared to the NHANES III population. Curiously, an FEV1/FVC ratio of less than 0.8, when compared to the NHANES III group, produced an odds ratio of 0.44 in worker group, indicating less risk of preclinical pulmonary dysfunction. Overall, exposure to ceramic proppant was not found to produce an adverse impact on pulmonary function in workers engaged in the manufacture of ceramic proppant.

The increase in unconventional shale gas extraction in Pennsylvania has resulted in an increased number of groundwater contamination claims. Well water quality was investigated in southern Butler County, PA where 387 unconventional gas wells have been drilled since 2006. A total of 121 households participated in a survey and 238 well water samples were tested. Specific conductivity, pH, and dissolved oxygen in these samples were measured in the field and seven anion concentrations and thirty metal concentrations were measured in the lab. A subset of 91 water wells was also tested for light hydrocarbons (methane, ethane, ethylene, propylene, propane, butane). Pennsylvania DEP file reviews were used to create GIS maps indicating legacy oil and gas, unconventional wells, and plot water testing results. Results indicate few wells had high quality groundwater, with 86% containing one or more contaminants above (secondary) Maximum Contaminant Levels, with manganese (56%), iron (47%), fluoride (18%), TDS (18%), pH (17%), aluminum (17%) the most common. / Bayer School of Natural and Environmental Sciences; / Environmental Science and Management (ESM) / MS; / Thesis;

Esta tese avaliou se o Brasil, sob a perspectiva regulatória, encontra-se preparado para iniciar localmente o desenvolvimento de gás de folhelho, principal fonte de gás não convencional. Para tal, adotou como metodologia uma análise comparativa entre a legislação do setor de gás natural dos EUA e do Brasil, com foco na regulamentação das operações de fraturamento hidráulico, buscando evidenciar e contextualizar os principais fatores de sucesso da experiência estadunidense. Na realização dessas investigações foram utilizados diversos conceitos da Política Ambiental que podem ser empregados na elaboração de normas e condutas voltadas para o gás não convencional. Pautada no resultado dessas análises, que apontou a necessidade de estudos ambientais, sociais e econômicos mais aprofundados, apresentou-se como principal recomendação uma proposta de Avaliação Ambiental Estratégica (AAE). Tal ferramenta pode orientar a decisão do governo em relação à exploração de hidrocarbonetos não convencionais no Brasil, bem como auxiliar o país na obtenção de uma licença social para operar e na criação das condições necessárias para explorar seus possíveis recursos de gás de folhelho de maneira segura e responsável. / This thesis assesses whether Brazil, from the regulatory point of view, is ready to start a local production of shale gas, the main source of unconventional gas. For this purpose, the study conducted a comparative analysis of the primary laws regulating of oil and gas exploration and production activities in the USA and Brazil, focusing on the hydraulic fracturing operations, in order to determine and contextualize the major factors of success for the American shale gas experience. Several approaches of Environmental Policy that can be used in the development of standards and rules for unconventional gas were used. The results indicated the need for additional environmental, social and economic studies. Therefore, a Strategic Environmental Assessment (SEA) proposal was the main recommendation. This tool may guide the government\'s decision about the unconventional resources production in Brazil, help the county to achieve a social license to operate and meet the conditions required to explore its potential shale gas resources.

As gas production from conventional gas reservoirs in the United States decreases, industry is turning more attention to the exploration and development of unconventional gas resources (UGR). This trend is expanding quickly worldwide. Unlike North America where development of UGRs and technology is now mature and routine, many countries are just beginning to develop unconventional gas resources. Rogner (1996) estimated that the unconventional gas in place, including coalbed methane, shale gas and tight-sand gas, exceeds 30,000 Tcf worldwide. As part of a research team, I helped to develop a software package called Unconventional Gas Resource Advisory (UGRA) System which includes the Formation Analog Selection Tool (FAST) and Basin Analog Investigations (BASIN) to objectively and rapidly identify and rank mature North American formations and basins that may be analogous to nascent international target basins. Based on BASIN and FAST results, the relationship between mature and underexplored basins is easily accessed. To quantify the unconventional resource potential in typical gas basins, I revised and used a computer model called the Petroleum Resources Investigation Summary and Evaluation (PRISE) (Old, 2008). This research is based on the resource triangle concept, which implies that all natural resources, including oil and gas, are distributed log-normally. In this work, I describe a methodology to estimate values of technically recoverable resources (TRR) for unconventional gas reservoirs by combining estimates of production, reserves, reserves growth, and undiscovered resources from a variety of sources into a logical distribution. I have also investigated mature North American unconventional gas resources, and predict unconventional resources in underexplored basins worldwide for case study. Based on the results of testing BASIN and PRISE, we conclude that our evaluation of 24 North American basins supports the premise that basins analysis can be used to estimate UGRs.

Esta tese avaliou se o Brasil, sob a perspectiva regulatória, encontra-se preparado para iniciar localmente o desenvolvimento de gás de folhelho, principal fonte de gás não convencional. Para tal, adotou como metodologia uma análise comparativa entre a legislação do setor de gás natural dos EUA e do Brasil, com foco na regulamentação das operações de fraturamento hidráulico, buscando evidenciar e contextualizar os principais fatores de sucesso da experiência estadunidense. Na realização dessas investigações foram utilizados diversos conceitos da Política Ambiental que podem ser empregados na elaboração de normas e condutas voltadas para o gás não convencional. Pautada no resultado dessas análises, que apontou a necessidade de estudos ambientais, sociais e econômicos mais aprofundados, apresentou-se como principal recomendação uma proposta de Avaliação Ambiental Estratégica (AAE). Tal ferramenta pode orientar a decisão do governo em relação à exploração de hidrocarbonetos não convencionais no Brasil, bem como auxiliar o país na obtenção de uma licença social para operar e na criação das condições necessárias para explorar seus possíveis recursos de gás de folhelho de maneira segura e responsável. / This thesis assesses whether Brazil, from the regulatory point of view, is ready to start a local production of shale gas, the main source of unconventional gas. For this purpose, the study conducted a comparative analysis of the primary laws regulating of oil and gas exploration and production activities in the USA and Brazil, focusing on the hydraulic fracturing operations, in order to determine and contextualize the major factors of success for the American shale gas experience. Several approaches of Environmental Policy that can be used in the development of standards and rules for unconventional gas were used. The results indicated the need for additional environmental, social and economic studies. Therefore, a Strategic Environmental Assessment (SEA) proposal was the main recommendation. This tool may guide the government\'s decision about the unconventional resources production in Brazil, help the county to achieve a social license to operate and meet the conditions required to explore its potential shale gas resources.

Various models featuring horizontal wells with multiple induced fractures have been proposed to characterize flow behavior over time in tight gas and shale gas systems. Currently, there is little consensus regarding the effects of non-ideal fracture geometries and coupled primary-secondary fracture interactions on reservoir performance in these unconventional gas reservoirs. This thesis provides a grid construction tool to generate high-resolution unstructured meshes using Voronoi grids, which provides the flexibility required to accurately represent complex geologic domains and fractures in three dimensions. Using these Voronoi grids, the interaction between propped hydraulic fractures and secondary "stress-release" fractures were evaluated. Additionally, various primary fracture configurations were examined, where the fractures may be non-planar or non-orthogonal. For this study, a numerical model was developed to assess the potential performance of tight gas and shale gas reservoirs. These simulations utilized up to a half-million grid-blocks and consider a period of up to 3,000 years in some cases. The aim is to provide very high-definition reference numerical solutions that will exhibit virtually all flow regimes we can expect in these unconventional gas reservoirs. The simulation results are analyzed to identify production signatures and flow regimes using diagnostic plots, and these interpretations are confirmed using pressure maps where useful. The coupled primary-secondary fracture systems with the largest fracture surface areas are shown to give the highest production in the traditional "linear flow" regime (which occurs for very high conductivity vertical fracture cases). The non-ideal hydraulic fracture geometries are shown to yield progressively lower production as the angularity of these fractures increases. Hence, to design optimum fracture completions, we should endeavor to keep the fractures as orthogonal to the horizontal well as possible. This work expands the current understanding of flow behavior in fractured tight-gas and shale-gas systems and may be used to optimize fracture and completion design, to validate analytical models and to facilitate more accurate reserves estimation.

Les problématiques de l’énergie et de l’environnement sont un des principaux défis pour l’humanité au XXIème siècle. La croissance mondiale de la demande d’énergie est confrontée aux préoccupations environnementales (y compris la pollution, le réchauffement climatique et la réduction des émissions de CO2), en particulier dans les régions en croissance économique rapide comme l’Asie. Le transfert de l’utilisation des sources d’énergies traditionnelles comme le charbon, le pétrole, vers les sources d’énergie plus propres et des énergies renouvelables est une tendance inévitable à l’avenir. Dans le contexte actuel, le gaz naturel est considéré comme une source d’énergie propre qui jouera un rôle important dans le processus de transition énergétique vers une économie bas-carbone. Les conséquences pour les marchés de gaz naturel peuvent être considérables. La condition d’une telle évolution est de disposer d’une offre en gaz naturel importante. Le développement du gaz non conventionnel, en particulier le gaz de schiste, fournit une opportunité d’expansion de l’approvisionnement gazier mondial comme le montre la « révolution du gaz de schiste » aux États- Unis. Celle-ci a profondément modifié les marchés gaziers régionaux. Toutefois, cette « révolution » n’est guère reproductible à d’autres régions du monde. Cette thèse démontre en particulier qu’en dehors des facteurs géologiques, des conditions institutionnelles (fiscalité, droits de propriété), économiques (prix, technologies) et organisationnelles (libéralisation des marchés) sont nécessaires pour assurer un développement à grande échelle des ressources non conventionnelles. Cette thèse montre que ces conditions ne sont pour la plupart pas réunies ni en Europe ni en Asie (notamment en Chine). Dès lors, une transition par le gaz pour répondre aux enjeux climatiques en Asie se fera par la voie des importations et non par une production propre à la région. A partir de trois scénarios du modèle POLES basés sur des hypothèses de politique climatique, de développement du gaz de schiste et d’augmentation rapide de la demande de gaz dans le mix énergétique, en particulier en Asie, deux principales conclusions émergent. Tout d’abord, l’importance du développement des gaz de schistes aux USA, leur bas coût de production induisent au niveau mondial une offre de gaz abondante et compétitive par rapport à d’autres énergies notamment par rapport au charbon. Par conséquent, même sans politique climatique, les conditions sont réunies pour que la part du gaz naturel puisse croître dans le mix énergétique. Deuxièmement, une politique climatique affirmée a des effets contradictoires quant à l’importance du gaz naturel dans les mix énergétiques des pays asiatiques. D’un côté elle permet une pénétration plus importante du gaz naturel dans leur mix énergétique. Mais dans le même temps, limitant la demande d’énergie, les volumes de gaz naturel demandés ne sont que légèrement plus importants que dans des scénarios sans politique climatique. / Energy and environmental issues are one of the main challenges for humanity in the 21st century. Global growth in energy demand links to environmental concerns including pollution, global warming and reduction of CO2 emissions. In particular, it is an urgent request in rapidly growing developing regions such as Asian countries. Using cleaner energy sources, renewable energy instead of traditional energy sources like coal and oil is an inevitable option in the future. In the current context, natural gas is seen as a clean energy source which plays a major role in the energy transition process towards a low-carbon economy. The consequences for natural gas markets are significant and the condition of this change is an abundant supply of natural gas. The development of unconventional gas, particularly shale gas, provides an opportunity to expand the global gas supply. This is illustrated by the “shale gas revolution” in US which has profoundly changed the regional gas markets. However, this "revolution" is hardly reproducible in other regions of the world. This thesis demonstrates particularly that apart from geological, institutional conditions (taxation, property rights), economic (prices, technologies) and organizational (free markets) are necessary for a large scale development of unconventional resources. This research also shows that most of these conditions are not met in Europe or Asia (especially in China). Therefore, an energy transition by natural gas to meet climate challenges in Asia will be solved through imports, rather than through regional production. From three scenarios of the POLES model based on assumptions about climate policy, shale gas development and rapid increase of demand for gas in the energy mix (particularly in Asia), two main conclusions emerge. The developments of shale gas with low cost in the USA make the global gas supply abundant and more competitive than other energies, particularly coal. Therefore, even without climate policy, the conditions are ripe for the increaseof natural gas proportion in the energy mix. Secondly, a strong climate policy has contradictory effects on the relative share of natural gas in the Asian energy mix. On the one hand, it allows natural gas larger penetration into the energy mix of Asia. But at the same time, with limitation of energy demand, requested natural gas volumes are only slightly higher than in scenarios without climate policy.

No description available.

Technologies such as horizontal wells and multi-stage hydraulic fracturing have made ultra-low permeability shale and tight gas reservoirs productive but the industry is still on the learning curve when it comes to addressing various production issues. Some of the problems encountered while hydraulically fracturing these reservoirs are the absence of frac barriers, thinner shales and the increased presence of geological hazards. Induced vertical fractures sometimes extend to an underlying aquifer and become a conduit to the well. We have developed a low-concentration, low-viscosity and delayed-crosslink polymeric gel system as a water shutoff agent for hydraulically-fractured tight gas and shale reservoirs, where some fractures might connect to water rich zones. The system also is a significant improvement over traditional flowing gels for fracture water shutoff in conventional reservoirs because of these features. The gel uses high molecular weight hydrolyzed polyacrylamide (HPAM) at low polymer concentrations with a delayed organic crosslinker. This crosslinker is more environmentally benign and provides much longer gelation time and stronger final gels than comparable polymer loadings with chromium carboxylate crosslinkers at higher temperatures. The low viscosity system allows low-pressure extrusion of gelant into the narrow-aperture fractures present in unconventional gas reservoirs. The gelant can be pumped at low pressures due to lower polymer concentrations and delayed gelation point. This allows the potential to seal problem zones that are producing excess water even when the fractures conducting water have very narrow apertures. By impeding water production, the gel system developed here can effectively delay water loading thereby avoiding abandonment or installation of expensive equipment with increased operational costs, thus extending life and reserves of unconventional gas wells.

Submitted by ARTHUR VALLE (arthurvalle.f@gmail.com) on 2014-02-25T15:54:39Z No. of bitstreams: 1 ARTIGO SHALE FINAL (atual FGV-OS).pdf: 455344 bytes, checksum: 3be4fa41a18545524133c57cfb9e5de6 (MD5) / Rejected by ÁUREA CORRÊA DA FONSECA CORRÊA DA FONSECA (aurea.fonseca@fgv.br), reason: Prezado aluno, Substituir a folha de alterações nº 2 pela folha de aprovação com assinatura dos membros da banca e submeter novamente. ÁUREA SRA on 2014-02-26T13:41:40Z (GMT) / Submitted by ARTHUR VALLE (arthurvalle.f@gmail.com) on 2014-03-08T14:26:34Z No. of bitstreams: 1 ARTIGO SHALE FINAL (ENTREGUE - FGV).pdf: 600365 bytes, checksum: 3a72197ea83d5df9f9e396366e535e1e (MD5) / Approved for entry into archive by ÁUREA CORRÊA DA FONSECA CORRÊA DA FONSECA (aurea.fonseca@fgv.br) on 2014-04-04T17:04:35Z (GMT) No. of bitstreams: 1 ARTIGO SHALE FINAL (ENTREGUE - FGV).pdf: 600365 bytes, checksum: 3a72197ea83d5df9f9e396366e535e1e (MD5) / Approved for entry into archive by Marcia Bacha (marcia.bacha@fgv.br) on 2014-04-09T13:43:33Z (GMT) No. of bitstreams: 1 ARTIGO SHALE FINAL (ENTREGUE - FGV).pdf: 600365 bytes, checksum: 3a72197ea83d5df9f9e396366e535e1e (MD5) / Made available in DSpace on 2014-04-09T14:52:02Z (GMT). No. of bitstreams: 1 ARTIGO SHALE FINAL (ENTREGUE - FGV).pdf: 600365 bytes, checksum: 3a72197ea83d5df9f9e396366e535e1e (MD5) Previous issue date: 2014-01-13 / O presente estudo versa sobre os fatores tecnológicos e ambientais que vêm resultando no crescimento da produção de gás natural não convencional nos EUA. Os objetos de analise principais serão as políticas públicas, assim como a dinâmica entre os atores sociais e o ambiente propício que fora criado para que houvesse o adensamento do fomento e do estímulo às inovações tecnológicas sucedidas no setor. / The present study deals with the technological and environmental factors that have resulted in increased of production of unconventional natural gas in the U.S.. The objects of analysis will be the public policies, as well as the dynamics between social actors and enabling environment which was created to promote and the encourage the successful technological innovations in the industry.