This thesis addresses the factors which lead the Russian government to increase natural gas prices for Ukraine in 2006. Through the use of methodological individualism, an explanation which links system, state, and individual levels of analysis is constructed. The system level variables concerned include global energy prices and the increasing importance of Turkmen natural gas to Russia and other regional gas consumers. State level variables, include changes in Russia’s patrimonial society (changing source of rents, increased authoritarianism); and increasing state control over Russia’s natural gas industry. Changes in these conditioning factors influence individuals’ beliefs about their preferred source of rents, and the nature of their rent seeking and distributing. The resulting actions bring about variations in Russia’s natural gas price for Ukraine. This framework is tested over three time periods (1995-1999, 2000-2004, 2004-2008) selected based on the nature of the conditioning variables over those years. Evidence from these case studies suggests that the above mentioned factors played a large role in the Russian government’s decision. Further, it is concluded that methodological individualism offers a way to bring together system, state, and individual levels of analysis when explaining this event, and perhaps other events in international politics.

This thesis addresses the factors which lead the Russian government to increase natural gas prices for Ukraine in 2006. Through the use of methodological individualism, an explanation which links system, state, and individual levels of analysis is constructed. The system level variables concerned include global energy prices and the increasing importance of Turkmen natural gas to Russia and other regional gas consumers. State level variables, include changes in Russia’s patrimonial society (changing source of rents, increased authoritarianism); and increasing state control over Russia’s natural gas industry. Changes in these conditioning factors influence individuals’ beliefs about their preferred source of rents, and the nature of their rent seeking and distributing. The resulting actions bring about variations in Russia’s natural gas price for Ukraine. This framework is tested over three time periods (1995-1999, 2000-2004, 2004-2008) selected based on the nature of the conditioning variables over those years. Evidence from these case studies suggests that the above mentioned factors played a large role in the Russian government’s decision. Further, it is concluded that methodological individualism offers a way to bring together system, state, and individual levels of analysis when explaining this event, and perhaps other events in international politics.

Oil and natural gas are the most strategic raw materials to meet the expanding energy requirement in today&rsquo / s world. They have great impact on issues such as economy, national security, development, competition, and political consistency. Being a developing country, Turkey&rsquo / s natural gas requirement is increasing rapidly. However, the production is far from covering the demand. Recent assumptions point out that natural gas demand of Turkey will reach 44 billion cubic meters in 2010 with a financial burden of 10 billion $ to the national economy. Therefore Turkey requires meeting natural gas demand by using its own conventional natural gas resources. The geological researches and global data encourage Turkey to drill more exploration wells in offshore side of Western Black Sea .In early 2007, the production will be started in Western Black Sea Region with 1.42 million cubic meter gas per day. Moreover, further exploration and production activities in the region are still continuing in order to increase the production. In this thesis, issues such as importance of the natural gas for Turkey and the world, Turkey&rsquo / s present energy situation and natural gas supply and demand scenarios for Turkey have been investigated. The possible impact of natural gas exploration and production in Black Sea region on Turkey&rsquo / s economy in near future has been emphasized. An extensive literature survey using related printed and unprinted media has been performed in order to collect the necessary data and information.

Improving methods of hydrocarbon production and developing new techniques for the creation of natural gas storage facilities are critically important for the petroleum industry. This dissertation focuses on two key topics: (1) mechanisms of sand production from petroleum reservoirs and (2) mechanical characterization of caverns created in carbonate rock formations for natural gas storage. Sand production is the migration of solid particles together with the hydrocarbons when extracted from petroleum reservoirs. It usually occurs from wells in sandstone formations that fail in response to stress changes caused by hydrocarbon withdrawal. Sand production is generally undesirable since it causes a variety of problems ranging from significant safety risks during high-rate gas production, to the erosion of downhole equipment and surface facilities. It is widely accepted that a better understanding of the mechanics of poorly-consolidated formations is required to manage sand production; which, in turn, enables the cost effective production of gas and oil resources. In this work, a series of large-scale laboratory experiments was conducted in fully saturated, cohesionless sand layers to model the behavior of a petroleum reservoir near a wellbore. We directly observed several key characteristics of the sand production phenomenon including the formations of a stable cavity around the wellbore and a sub-radial flow channel at the upper surface of the tested layer. The flow channel is a first-order feature that appears to be a major part of the sand production mechanism. The channel cross section is orders of magnitude larger than the particle size, and once formed, the channel becomes the dominant conduit for fluid flow and particle transport. The flow channel developed in all of our experiments, and in all experiments, sand production continued from the developing channel after the cavity around the borehole stabilized. Our laboratory results constitute a well constrained data set that can be used to test and calibrate numerical models employed by the petroleum industry for predicting the sand production phenomenon. Although important for practical applications, real field cases are typically much less constrained. We used scaling considerations to develop a simple analytical model, constrained by our experimental results. We also simulated the behavior of a sand layer around a wellbore using two- and three-dimensional discrete element methods. It appears that the main sand production features observed in the laboratory experiments, can indeed be reproduced by means of discrete element modeling. Numerical results indicate that the cavity surface of repose is a key factor in the sand production mechanism. In particular, the sand particles on this surface are not significantly constrained. This lack of confinement reduces the flow velocity required to remove a particle, by many orders of magnitude. Also, the mechanism of channel development in the upper fraction of the sample can be attributed to subsidence of the formation due to lateral extension when an unconstrained cavity slope appears near the wellbore. This is substantiated by the erosion process and continued production of particles from the flow channel. The notion of the existence of this surface channel has the potential to scale up to natural reservoirs and can give insights into real-world sand production issues. It indicates a mechanism explaining why the production of particles does not cease in many petroleum reservoirs. Although the radial character of the fluid flow eventually stops sand production from the cavity near the wellbore, the production of particles still may continue from the propagating surface (interface) flow channel. The second topic of the thesis addresses factors affecting the geometry and, hence, the mechanical stability of caverns excavated in carbonate rock formations for natural gas storage. Storage facilities are required to store gas when supply exceeds demand during the winter months. In many places (such as New England or the Great Lakes region) where no salt domes are available to create gas storage caverns, it is possible to create cavities in limestone employing the acid injection method. In this method, carbonate rock is dissolved, while CO₂ and calcium chloride brine appear as products of the carbonate dissolution reactions. Driven by the density difference, CO₂ rises towards the ceiling whereas the brine sinks to the bottom of the cavern. A zone of mixed CO₂ , acid, and brine forms near the source of acid injection, whereas the brine sinks to the bottom of the cavern. Characterization of the cavern shape is required to understand stress changes during the cavity excavation, which can destabilize the cavern. It is also important to determine the location of the mixture-brine interface to select the place of acid injection. In this work, we propose to characterize the geometry of the cavern and the location of the mixture-brine interface by generating pressure waves in a pipe extending into the cavern, and measuring the reflected waves at various locations in another adjacent pipe. Conventional governing equations describe fluid transients in pipes loaded only by internal pressure (such as in the water hammer effect). To model the pressure wave propagation for realistic geometries, we derived new governing equations for pressure transients in pipes subjected to changes in both internal and external (confining) pressures. This is important because the internal pressure (used in the measurement) is changing in response to the perturbation of the external pressure when the pipe is contained in the cavern filled with fluids. If the pressure in the cavern is perturbed, the perturbation creates an internal pressure wave in the submerged pipe that has a signature of the cavern geometry. We showed that the classic equations are included in our formulation as a particular case, but they have limited validity for some practically important combinations of the controlling parameters. We linearized the governing equations and formulated appropriate boundary and initial conditions. Using a finite element method, we solved the obtained boundary value problem for a system of pipes and a cavern filled with various characteristic fluids such as aqueous acid, calcium chloride brine, and supercritical CO₂ . We found that the pressure waves of moderate amplitudes would create measurable pressure pulses in the submerged pipe. Furthermore, we determined the wavelengths required for resolving the cavern diameter from the pressure history. Our results suggest that the pressure transients technique can indeed be used for characterizing the geometry of gas storage caverns and locations of fluid interfaces in the acid injection method.

Natural gas is one of the fastest growing primary energy sources in the world today. The increasing world demand for energy requires increased production of high quality natural gas. For the natural gas to be fed into the mainline gas transportation system, it must meet the pipe-line quality standards. Natural gas produced at the wellhead is usually "sub-quality" and contains various impurities such as CO2, H2S, and higher hydrocarbons, which must be removed to meet specifications. Carbon dioxide is usually the most abundant impurity in natural gas feeds and high CO2 partial pressures in the feed can lead to plasticization, which causes loss of some methane product and may ultimately render the membrane ineffective. Moreover, the presence of highly sorbing higher hydrocarbons in the feed can further reduce membrane performance. Covalent crosslinking has been shown to increase plasticization resistance in dense films by suppressing the degree of swelling and segmental chain mobility in the polymer, thereby preserving the selectivity of the membrane. This research focuses on extending the dense film success to asymmetric hollow fibers. In this work, the effect of high pressure CO2 (up to 400 psia CO2 partial pressure) on CO2/CH4 mixed gas separation performance was investigated on defect-free the hollow fiber membrane at different degrees of crosslinking. All the crosslinked fibers were shown to exhibit good resistance to selectivity losses from CO2 induced plasticization, significantly more than the uncrosslinked fibers. Robust resistance of the hollow fiber membranes in the presence of toluene (a highly sorbing contaminant) was also demonstrated as the membranes showed no plasticization. Antiplasticization was found to occur in the presence of toluene feeds with the crosslinkable fibers used in this work.

The global growth in demand for transportation has been phenomenal, owing to an exponential increase in population, industrialization and urbanization. This has led to a corresponding increase in the number of motor vehicles on the roads globally which has made the transport industry one of the main contributors to environmental pollution and energy insecurity. The profile of alternative fuels has been rising as an important component of the solutions to the challenge of energy sustainability. Compressed natural gas is one of the most successful alternative fuels for motor vehicle applications because of its compatibility with the internal combustion engine, reduced engine maintenance costs, reduced criteria air pollutants, low cost, abundance and the existence of renewable sourced natural gas from biomass. The infrastructure for the delivery of compressed natural gas forms part of the primary energy supply network, which has a significant interdependence with the electricity supply network. The compressed natural gas fuelling station is one of the vital nodes of the gas delivery network, that is also reliant on the electricity supply due to the energy intensive compressors that are required to achieve the right pressure conditions for gas transfer to vehicle tanks. At the same time, the increase in human population, industrialization, urbanization and market volatility have threatened the reliability and stability of electricity supply networks. Traditional reliance on supply upgrading to meet rising demand has proven to be unsustainable due to prohibitively high costs and associated environmental impact. As a result, demand side management solutions, where better use of the existing capacity is emphasized have received increasing attention. Demand side management requires that electricity consumers also play a role in the efficient operation of the electricity grid by minimizing their electricity usage as well as shifting their flexible loads away from peak electricity demand periods, so that grid stability is sustained. In order to participate in demand side management initiatives, operators of compressed natural gas stations need technically and economically sound strategies for the operation of station compressors and system components so that energy costs are minimized and gas transfer performance is enhanced. The compressed natural gas fast-fill station, being the most used configuration for commercial fuelling service is the focus of the work carried out in this thesis, with a description of solutions to minimize energy consumption, minimize energy costs and improve gas transfer performance through reduction of filling time. For this purpose, firstly, an optimal control strategy that minimizes energy cost by shifting the compressor load optimally away from the peak electricity pricing period under a time-of-use electricity tariff, while meeting the gas demand is modelled and evaluated. The controller further minimizes the switching frequency of the compressor thereby avoiding an increase in wear and tear which would lead to higher maintenance costs. The results show the effectiveness of the optimal operation model to achieve a huge reduction in electricity cost for the compressed natural gas station, when compressor-on time is shifted to offpeak and standard electricity pricing times. Further strategies for the minimization of switching frequency are compared and the superior approach identified. Secondly, a hierarchical operation optimization model is designed and evaluated. The strategy achieves minimized electricity cost and optimal vehicle filling time by optimally controlling the gas dispenser and priority panel valve function under an optimised schedule of compressor operation. The results show that the proposed approach is effective in achieving a minimum electricity costs in the upper layer optimisation while meeting vehicle gas demand over the control horizon. Further, a reduction in filling time is achieved through a lower layer model predictive control of the pressure-ratio-dependent fuelling process. Thirdly, an evaluation of compressor optimal sizing is carried out to minimize energy consumption and cascade the benefits of optimal operation of the compressed natural gas compressor under the time-of-use tariff. A comparison of the implication of using a variable speed drive or a fixed speed drive which are optimally sized is carried out. Results show that indeed further reduction in electricity costs for the compressed natural gas station is realized when optimally sized compressor drives are used in combination with optimal operation strategies. Additionally, the four line priority panel is evaluated for gas transfer performance and found to further increase the efficiency of vehicle fuelling which is a performance indicator for consumer convenience. The outcomes of this work demonstrate the effectiveness of the approaches proposed as necessary to integrate compressed natural gas stations, which are vital nodes of the gas delivery network, with the demand side management of the electricity grid while at the same time enhancing the gas transfer performance. This increases the economic efficiency of the compressed natural gas as an alternative fuel and also advances the goals of demand side management in electricity grid reliability and stability. / Thesis (PhD)--University of Pretoria, 2019. / Electrical, Electronic and Computer Engineering / PhD / Unrestricted

Global climate change concerns help shape current environmental regulations, which increasingly seek to reduce or capture CO2 emissions. Methods for capturing CO2 emissions from energy processes have been the focus of numerous studies to provide support for those seeking to reduce the environmental impact of their processes. This research has (1) simulated a baseline case of energy-storing cryogenic carbon capture for implementation on a 550 MWe coal fired power plant, (2) presented a novel cryogenic carbon capture process for removing CO2 from natural gas down to arbitrary levels, (3) presented a natural gas liquefaction process that has the ability to be highly CO2 tolerant, and (4) developed theoretical models and their experimental validation of CO2 capture predictions for all aforementioned processes.

Thesis (MBA)--Stellenbosch University, 2004. / ENGLISH ABSTRACT: Although natural gas is utilised as a major source of energy in the world, in the past it has made a negligible contribution to the primary energy needs of Mozambique, Namibia and South Africa. This deviation from the rest of the world is in spite of known natural gas reserves in Mozambique, as well as off the coast of Namibia and South Africa. The reasons why natural gas is not a primary energy source of note in Southern Africa relate to the fact that cheap coal has always been available in abundance in South Africa, past exploration activities were focused on finding crude oil and regional conflicts prevented the development of the available natural reserves. The current interest in natural gas as a source of energy relates to the environmental advantages of natural gas over coal and crude oil, as well as the stated objective of the governments of Namibia and South Africa to diversify the energy supply to these countries The purpose of this study was to determine the economic impact of establishing a natural gasbased industry in Mozambique, Namibia and South Africa. To this end it was necessary to estimate the potential size of the natural gas reserves available in Southern Africa. It was also necessary to calculate the economic value to be added by utilising the few technologies applicable to Southern Africa to consume the natural gas. Based on the economic value added, it was recommended that initiatives to develop the available natural gas resources in Southern Africa should continue. When developing a natural gas-based industry, care must be taken to ensure that a balanced supply chain is established. The principle of a supply chain holds that there must be balanced growth through all the links of the supply chain. The principle of a supply chain highlights the balance to be played in developing the upstream segment as well as the downstream segment of a natural gas industry. Excessive rewards for risks taken by developers in the upstream segment of a natural gas supply chain will be to detriment of encouraging new consumers for natural gas. Significant efforts have been made to establish a regulatory framework in Mozambique, Namibia and South Africa to facilitate a balanced development of the available natural gas resources. There are however areas where the established regulatory framework does not adhere to these requirements and must therefore be reviewed. Several initiatives must also be launched to establish large volume anchor consumers for natural gas. These initiative include increased access to foreign capital as well as a pricing mechanism promoting the long-term development of natural gas resources Once large volume anchor consumers have been established, is will be a simple matter to grow the natural gas industry by adding smaller consumers to the established distribution infrastructure. / AFRIKAANSE OPSOMMING: Alhoewel natuurlike gas 'n belangrike bron van energie is vir die res van die wêreld, het natuurlike gas in die verlede 'n weglaatbare breukdeel van die primêre energiebehoeftes van Mosambiek, Namibië en Suid-Afrika voorsien. Hierdie verskil teenoor die res van die wêreld is ten spyte daarvan dat daar ontdekte natuurlike gasreserwes in Mosambiek sowel as in Namibiese en Suid-Afrikaanse gebiedswaters was. Die redes hoekom natuurlike gas nie 'n belangrike bron van primêre energie in Suidelike Afrika is nie, is te wyte aan die feit dat goedkoop steenkool nog altyd in oorvloed beskikbaar was in Suid-Afrika; dat eksplorasie aktiwiteite gefokus het op ruolie eerder as natuurlike gas en dat streekskonflikte verhoed het dat die beskikbare natuurlike gasbronne ontwikkel kon word. Die huidige belangstelling in natuurlike gas as 'n bron van energie is te wyte aan die omgewingsvoordele wat natuurlike gas inhou bo steenkool en ru-olie, sowel as die verklaarde beleid van die Namibiese en Suid-Afrikaanse regerings om die energieverskaffing aan hierdie lande te versprei tussen verskillende bronne. Die doel van hierdie studie was om die ekonomiese effek te bereken wat die onwikkeling van 'n natuurlike gasgebaseerde industrie in Mosambiek, Namibië en Suid-Afrika teweeg kan bring. Om die ekonomiese effek te bereken moes 'n skatting gemaak word van die verwagte grootte van beskibare natuurlike gasvelde in Suidelike Afrika. Dit was ook nodig om die ekonomiese toegevoegde waarde te bereken deur gebruik te maak van die beskikbare tegnologie, van toepassing op Suidelike Afrika, wat natuurlike gas kan verbruik. Gebaseer op die ekonomiese toegevoegde waarde is dit aanbeveel dat die pogings om die beskikbare natuurlike gasbronne in Suidelike Afrika te ontwikkel, moet voortgaan. Wanneer 'n natuurlike gas-gebaseerde industrie ontwikkel word, is dit belangrik dat 'n gebalanseerde verskaffingslyn geskep moet word. Die beginsel van 'n verskaffinglyn is dat daar eweredige groei in al die onderskeie komponente van die verskaffingslyn moet wees. Die beginsel van'n verskaffingslyn beklemtoon die balans wat gehandhaaf moet word tussen die stroom-op en stroom-af segmente van 'n natuurlike gas industrie. Oormatige beloning vir risiko's deur ontwikkelaars in the stroom-op segment van die natuurlike gasverskaffingslyn sal tot nadeel wees van nuwe verbruikers in die stroom-af segment. Daadwerlike pogings is aangewend om 'n regulatoriese raamwerk te skep binne Mosambiek, Namibië en Suid-Afrika sodat 'n gebalanseerde ontwikkeling van die beskikbare natuurlike gasbronne kan geskied. Daar is egter areas waar die regulatoriese raamwerk nie aan die vereistes voldoen nie en daarom sal dit hersien moet word. Verskeie aksies sal ook geloods moet word om hoë volume ankerkliënte van natuurlike gas te vestig. Hierdie aksies sluit verhoogde toegang tot buitelandse kapitaal, sowel as die ontwikkeling van 'n prysmeganisme wat die langtermynontwikkeling van die natuurlike gasbronne ten doel het. Sodra 'n hoë volume ankerkliënt gevestig is, is dit 'n eenvoudige aksie om groei in die natuurlike gas industrie te bewerkstellig deur kleiner kliënte by die bestaande verspreidingsinfrastruktuur te voeg.

A produção brasileira de gás natural (GN) cresceu 7,7% ao ano, entre 2006 e 2016, acompanhada do crescimento das descobertas de reservas de GN associado ao petróleo, oriundas dos campos contidos no polígono do pré-sal. Observa-se que a demanda por GN apresenta taxa de crescimento anual de 3,4% no período compreendido entre 2006 e 2018. No âmbito da oferta de GN, a reinjeção em poços demonstra um crescimento de 200% no período compreendido entre 2013 e 2018. Destaca-se na fonte de suprimento importada, através do gasoduto Bolívia-Brasil, o término da vigência do contrato de suprimento, previsto para 2019, que permitirá a renegociação das condições de fornecimento em termos de quantidade, preço e prazo. Tal importação também deverá se adequar às realidades de consumo e expectativas de crescimento da oferta doméstica no longo prazo. Este desequilíbrio, entre oferta e demanda, se apresenta como uma oportunidade no plano do aprimoramento da segurança energética do país, bem como nas diferentes dimensões de atrações de investimentos para expansão da indústria gasífera, através de métodos alternativos de movimentação de GN. Estes métodos são caracterizados neste trabalho como gás natural comprimido (GNC) e gás natural liquefeito em pequena escala (GNL). Identifica-se a competividade destes métodos de movimentação bem como são apresentados os principais elementos que compõem a formação de custos destes sistemas de movimentação de GN. Em seguida, é proposto um modelo de estimação de custos por unidade energética (USD/MMBTU), cuja competitividade, obtida através de simulações e comparadas com custos de gasodutos (utilizando-se o método abordado no PEMAT), é avaliada. Demonstra-se que, para volumes movimentados de 0.1MTPA, o a movimentação de GN por gasoduto apresenta menor custo por unidade energética até distâncias de 380 quilômetros (km). A partir desta distância, a movimentação através de sistemas de GNL apresenta-se mais competitiva. Observa-se que o GNC é mais competitivo que o GNL para distâncias de até 18 km, para o mesmo volume movimentado. Analisa-se as mesmas curvas para volumes movimentados de 0.5 MTPA e 1 MTPA, cuja competitividade do GNL, frente ao gasoduto, é observado em 650 km de distância no primeiro caso e não pode ser verificada no segundo caso. Em adição, o GNC apresentou resultados competitivos para volumes movimentados inferiores, cerca de 100 vezes, aos avaliados neste trabalho. Após a modelagem de estimação custos, aplica-se o modelo de GNL em pequena escala para abastecimento dos municípios situados no estado de São Paulo e em conjunto com o plano de metas do setor de gás natural (PMGN) para o estado. Observa-se que, dos 139 municípios avaliados, 103 municípios apresentaram competitividade ponderada para substituição de eletricidade e óleo combustível para fins térmicos industriais por GN. Do universo estudado, 85 municípios estavam contidos no PMGN com expectativa de instalação de infraestrutura de distribuição de GN entre 2022 e 2029 e cujo suprimento de NG poderia ser antecipado pelo sistema de GNL em pequena escala. / The Brazilian natural gas (NG) production has been growing 7,7% per year during 2006 and 2016, this growth has been followed by the increase of the reserves of oil associated natural gas from the fields within the pre-salt polygon. From the demand side, one can observe a growth of 3,4% per annum for the period starting in 2006 to 2018. It Worth to mention that the imported NG supply contract from Bolivia has its termination due to 2019, which will enable the negotiation of conditions of supply such as quantities, term and price. This import contract is expected to reflect the current conditions of demand and future supply from indigenous production in the long term. Based on that, on can observe an imbalance between supply and demand, which can be explored as an opportunity for improvements in the energy security of the country and also as an opportunity for investments in alternative methods for transportation of NG, in order to foster the industry. These alternative methods are described in this research as compressed natural gas (CNG) and small-scale LNG (SSLNG). It is explored not only the competitiveness of those methods but also the cost indicatives and the state of the art technologies are presented. Followed the characterising of CNG and SSLNG, a cost per-unit-of-energy estimation model is proposed for CNG and SSLNG and compared with the pipelines cost estimation adopted in the PEMAT. It is demonstrated that, for the transportation volumes of 0.1MTPA, pipelines option is more competitive than SSLNG up to 380 kilometres (km) transportation distance. SSLNG option was observed more competitive for transportation distances higher than 380 km. On the other hand, CNG option has demonstrated competitiveness only against SSLNG option and for transportation distances up to 18 km. For the transportation volumes of 0.5 MTPA and 1 MTPA, the SSLNG option was observed more competitive than the pipeline option, for transport distances higher than 650 km for the former volumes transported and no competitiveness was observed for the latter volumes transported. Additionally, for the sake of illustration, CNG has demonstrated competitiveness against SSLNG and pipeline for lower transported volumes, around 100 times lower than 0.1MTPA. After the cost estimation modelling, the SSLNG model was applied in the municipalities of the state of São Paulo and together with the plan of targets for the NG sector (PMGN) for the state. One can observe 103 municipalities out of 139 have shown competitive costs of SSLNG in the displacement of electricity and oil fuel for the thermic energy uses in the industrial and agricultural sector. 85 municipalities out of the 103 were considered in the PMGN as municipalities that would have NG distribution pipelines infrastructure from 2022 to 2029 and could anticipate the use on NG by adopting the SSLNG.

Adotando os conceitos da Nova Economia Institucional (NEI) e de sua vertente, a teoria da Economia dos Custos de Transação (ECT), apresenta-se, neste trabalho, uma discussão sobre o ambiente institucional brasileiro para o setor de exploração e produção (E&P) de petróleo e gás natural, sua regulação e caracterização. Discute-se as especificidades relativas às condições de desenvolvimento das atividades em campos de petróleo considerados maduros e/ou marginais, que constituem a maior parte das bacias brasileiras conhecidas em terra. O trabalho defende que este segmento de atividades de E&P requer um tratamento diferenciado em termos de regulação e outras políticas públicas, visando privilegiar a entrada de novos agentes e aumentar seu dinamismo no longo prazo. Contrapondo ao ambiente institucional nacional, optou-se por estudar o desenvolvimento das atividades onshore no Texas. Assim, estabelece-se comparações entre as duas realidades com relação à sua regulamentação, programas de incentivos, estrutura industrial, histórico de atividades e, principalmente, em relação à ação dos respectivos órgãos reguladores, a Agência Nacional de Petróleo, Gás Natural e Biocombustíveis (ANP), pelo Brasil, e a Texas Railroad Commission (TRC), pelo Texas. A experiência da TRC no setor petroleiro texano, cujas características presentes, por se tratar de campos produtores de petróleo maduros, possuem certa similaridade com os campos em terra no Brasil, revela uma série de direções para o aprimoramento da regulação petroleira brasileira no sentido de promover suas atividades onshore. / By Adopting the New Institutional Economics (NIE), and the theory of Transaction Cost Economics (TCE), this work discuss about the Brazilian institutional environment for oil and natural gas exploration and production (E&P), the regulation and main features. This study discusses the specificities related to the development of onshore activities on mature and/or marginal oil and gas fields. These areas are the majority on the Brazilian developed onshore segment. The Thesis sustains that such a segment of E&P activities needs a special treatment in terms of regulation and other public policies, aiming at to improving the entrance of new players in the sector and its long-term growing. For a comparative analysis, the study of the onshore activities development in Texas provides important insights to understand and criticize de Brazilian situation. The Thesis compares both realities in terms of the regulation and incentives programs, industrial structure, history of activities as well as the main role players by the respective Oil and Gas Regulator, the National Petroleum Agency (ANP) in Brazil, and the Texas Railroad Commission (TRC) in Texas. TRC’s long experience in regulating Texas’ onshore oil and gas activities, whose present situation has similarities regarding to the Brazilian onshore areas (by their maturity), reveals a series of paths to improve Brazil’s oil and gas regulation and boost its onshore activities.