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Les interactions entre les eaux souterraines et les eaux de surface sont complexes et jouent un rôle prépondérant dans le fonctionnement des hydrosystèmes, tant en termes quantitatifs que qualitatifs. Ces deux compartiments interagissent à travers différentes interfaces emboitées depuis l’échelle locale, notamment la zone d’interface rivière-nappe, appelée zone hyporhéique (ZH) jusqu’à l’échelle régionale. La ZH se définit comme un buffer entre les eaux souterraines et les eaux de surface. Les variations des flux d’eau et de chaleur au niveau de cette zone modulent les processus biogéochimiques. Le but de cette thèse est d’améliorer la compréhension du régime thermique et hydrologique de la ZH et de sa variation spatiale. Cette problématique est abordée par l’utilisation de stations de mesures haute fréquence des échanges nappe-rivière (MOLONARI) sur le bassin des Avenelles (sous bassin de la Seine (46 km2)) et de la modélisation. Le suivi haute fréquence a permis de réaliser une analyse des données expérimentales présentant le régime hydro-climatique du bassin ainsi que l’évolution spatiale et temporelle du fonctionnement des différents compartiments de l’hydrosystème. Un cas synthétique a été réalisé afin de caractériser les différents facteurs contrôlant le régime thermique de l’interface nappe rivière et la variation de stocks d’énergie au sein de la ZH. La démarche de modélisation suivie pour le cas synthétique fournit un cadre d’analyse des données des cinq stations MOLONARI. Les données acquises sur ces stations ont été utilisées afin de déterminer les propriétés hydrodynamiques et thermiques de la ZH ainsi que des couches géologiques sous-jacentes par inversion à l’aide du modèle METIS couplé à un script de balayage de l’espace des paramètres afin de quantifier les flux d’eau et de chaleur à l’interface nappe-rivière le long d'un corridor hydraulique. Les résultats du modèle mettent en lumière la variabilité spatio-temporelle des échanges de chaleur au niveau des cinq stations MOLONARI. La quantification des flux de chaleur a fourni un nouvel éclairage des interactions entre les eaux de surface et les eaux souterraines à l’interface nappe-rivière du bassin des Avenelles. / The river-aquifer interactions are complex and play a preponderant role in hydrosystems functioning, in both qualitative and quantitative terms. These two compartments interact through various nested interfaces from the local scale in particular the river aquifer interface called the Hyporheic Zone (HZ) to the regional scale. The HZ acts as a buffer between the stream and the groundwater. The water and heat fluxes variation at this zone modulates the biogeochemical processes.The aim of this thesis, is to improve the understanding of the thermal and hydrological regime of the HZ and its spatial variation. This problem is approached by the use of high frequency measurement stations of river-aquifer exchanges (LOMOS) in the Avenelles basin (sub-basin of the Seine basin (46 km2)) and by modeling. The high frequency monitoring allowed to realize an analysis of the experimental data characterizing the hydroclimatic regime of the Avenelles basin as well as the spatial and temporal evolution of the hydrosystem various compartments functioning.A synthetic case was realized to characterize the main factors controlling the thermal regime at the river aquifer interface and the energy storage variation within the ZH. The modeling approach followed by the synthetic case provides an analysis framework of the five LOMOS data.The acquired LOMOS data were used to determine the hydrogeological and thermal properties of the HZ and of the underlying aquifers by inversion by means of a 2D finite element thermo-hydrogeological model (METIS) coupled with a parameters screening script to quantify water and heat fluxes through the stream – aquifer interface over along the stream network.The model results highlight the spatiotemporal variability of the heat exchanges at the five LOMOS. The quantification of heat fluxes provided a new lighting of the stream-aquifer interactions of the Avenelles basin.

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.

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.