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Geological risk and reservoir quality in hydrocarbon explorationXia, Changyou January 2018 (has links)
In the next 20 years, the global demand for oil is forecast to grow by 0.7% every year, and the demand for natural gas will increase by 1.6% annually. But as we continue to produce oil and gas, the resources of our current oilfields are depleting. To meet the rising global energy demand, it is essential that we can keep discovering more petroleum resources in the future. The primary aim of this PhD project is to deepen our understanding of hydrocarbon reservoirs and enhance our ability to explore. The first project looked at the geological risks in hydrocarbon exploration. It reviewed and statistically analysed the data of 382 unsuccessful boreholes in the UK offshore area. The results suggest that the most significant risk for an exploration well is encountering a thin or absent target reservoir. This risk happened to 27 ± 4% of the past unsuccessful wells. The following most common risks are low-porosity reservoirs (22 ± 4% of all cases) and the lack of a closed trap (23 ± 4%). The probability of a target reservoir having a leaky caprock is 5 ± 2%. The study has calculated the probability of occurrence of all the geological risks in exploration, and this risk data can be applied to predict the potential geological risks in future exploration. One challenge in developing saline aquifers as CO2 storage reservoirs is the lack of subsurface data, unless a well has been drilled. Drawing on the experience of hydrocarbon exploration, a potential CO2 storage site identified on seismic profiles will be subject to many uncertainties, such as thin or low-porosity reservoirs, leaky seals, which are analogue to the geological risks of an undrilled hydrocarbon prospect. Since the workflow of locating CO2 storage reservoirs is similar to the exploration for hydrocarbon reservoirs, the risk data of hydrocarbon exploration wells can be applied to infer the geological risks of the exploration wells for CO2 storage reservoirs. Based on this assumption, the study of Chapter 3 estimated that the probability of a borehole encountering a reservoir suitable for CO2 storage is c. 41-57% (90% confidence interval). For reservoirs with stratigraphic traps within the UKCS, the probability of success is slightly lower, at 39 ± 10% (90% confidence). Chapter 4 studies the porosity and diagenetic process of the Middle Jurassic Pentland Formation in the North Sea. The analysis data come from 21 wells that drilled and cored the Pentland Formation. Petrographic data suggest the content of detrital illite is the most important factor affecting the porosity of the Pentland Sandstone - the porosities of the sandstones with more than 15% of illite (determined by point-count) are invariably low (< 10%). Quartz cement grows at an average rate of 2.3 %/km below the depth of 2km, and it is the main porosity occluding phase in the deep Pentland Sandstone. Petrographic data shows the clean, fine-grained sandstones contain the highest amount of quartz cement. Only 1-2 % of K-feldspar seems to have dissolved in the deep Pentland Sandstone (> 2 km), and petrographic data suggest that K-feldspar dissolution does not have any substantial influence on the sandstone porosity. There is no geochemical evidence for mass transfer between the sandstones and shales of the Pentland Formation. Chapter 5 investigates the high porosity of the Pentland Sandstone in the Kessog Field, Central North Sea. The upper part of the Kessog reservoir displays an anomalously high porosity (c. 25 %, helium porosity) that is 10 % higher than the porosity of other Pentland sandstones at the same depth (c. 15 %, 4.1 - 4.4 km). Petrographic data show these high porosities are predominantly primary porosity. The effects of sedimentary facies, grain coats, secondary porosity and overpressure on the formation of the high porosity are considered to be negligible in this case. Early hydrocarbon emplacement is the only explanation for the high porosity. In addition to less quartz cement, the high-porosity sandstones also contain more K-feldspar and less kaolin than the medium-porosity sandstones of the same field. This indicates that early hydrocarbon emplacement has also inhibited the replacement of K-feldspar. The last chapter studies the potential mass transfer of silica, aluminium, potassium, iron, magenesium and calcium at sandstone-shale contacts. The study samples include 18 groups of sandstones and shales that were collected from five oilfields in the North Sea. The interval space between the samples of each group varies from centimetres to meters. The research aim is to find evidence of mass transfer by studying the samples' variation of mineralogy and chemistry as a function of the distance to the nearest sandstone-shale contact. The sandstones are mostly turbidite sandstones, and the shales are Kimmeridge Clay shales. Petrographic, mineralogical and chemical data do not provide firm evidence for mass transfer within any group of the samples. The result indicates that the scale of mobility of silica, aluminium, potassium, iron, magenesium and calcium in the subsurface may be below the scale of detection of the study method, i.e. < 5 cm.
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Planejamento estocástico de lavra: metodologias de simulação, otimização e gestão de risco para a mina do futuro. / Stochastic mine planning: simulation, optimization and risk management methods for the mine of the future.Freitas, Sandro Bernard Moreira de 23 September 2015 (has links)
O desempenho operacional e econômico de empreendimentos de mineração é de suma importância para a sustentação dos níveis de produção demandados, sendo imprescindível um nível de governança capaz de prever e gerenciar eficazmente as incertezas e riscos inerentes ao processo de lavra, sejam eles geológicos, operacionais ou financeiros. O recente desenvolvimento de tecnologias e do conceito de \"mina do futuro\" ou \"mina autônoma\" indica a possibilidade de captura de dados através de sensores variados e do uso destes dados para geração de simulações estocásticas, para otimização tanto do ativo físico quanto do aproveitamento do recurso ou ativo mineral, minimizando riscos e custos. O planejamento estocástico de lavra vem nos últimos anos apresentando potenciais ferramentas para esse nível de gerenciamento de riscos na mineração, contudo sua resposta em diversos tipos de depósito é ainda pouco conhecida e carece de esforços de pesquisa e desenvolvimento. A presente pesquisa tem o objetivo de descrever essas abordagens probabilísticas de planejamento comparando com as tradicionais (determinísticas), definir procedimentos de aplicação desses conceitos na indústria, integrados em um sistema de gestão, quantificar seus impactos no desempenho de uma operação mineira e gerar informações para a comunidade acadêmica e técnica da indústria mineral preocupados com o futuro da mineração, quanto à aplicabilidade efetiva de técnicas como planejamento estocástico de lavra e simulação de lavra, englobando incertezas relativas ao ativo mineral e ativo físico da operação mineira. Para tanto, foi realizada inicialmente uma extensa pesquisa bibliográfica em relação ao tema proposto, destacando os pontos de maior relevância, permitindo então o desenvolvimento de uma metodologia de gestão que auxilie, de forma eficaz, o processo de tomada de decisões referentes à otimização de ativos em minas a céu aberto. Visando-se atingir tais objetivos, serão realizados testes piloto em uma mina na Província Mineral de Carajás-PA. A Mina do Sossego, em operação desde 2004, é a primeira mina de cobre da VALE, está entre as maiores minas brasileiras e será o foco do estudo da presente pesquisa. / Both operational and economic performance of mining projects are critical for sustaining the demanded production levels, being indispensable a level of governance able to predict and effectively manage the uncertainties and risks inherent to mining process such as geological, operational or financial risks. Recent developments of technologies and concepts of \"mine of the future\" or \"Autonomous mine\" indicates a possibility of on-line data acquisition by a number of sensors and the use of such data to generate stochastic simulations for optimization of equipments assets and mineral resource, minimizing risks and costs. Stochastic mining planning recently have been presenting potential tools for this level of risk management in mining, but the response of such approach in various types of deposit is still poorly understood and requires research and development efforts. This research aims to describe these probabilistic mine planning approaches comparing to traditional approaches (deterministic), to define procedures for implementation of these concepts in the industry in an integrated management system, to quantify their performance impacts of a mining operation and to generate information for the academic community and mineral industry technical staff concerned about the future of mining, as the applicability of planning techniques such as stochastic mining planning and discrete event simulation, covering uncertainties related to mineral assets and physical assets (equipments) of the mining operation. Thus, initially will be performed an extensive literature review regarding the proposed theme, highlighting the points of major relevance, thus allowing the development of a management methodology that effectively assists the decision making process regarding asset optimization in open pit mines. Aiming to achieve these goals, pilot tests will be performed at an operating mine in the Carajás Mineral Province-PA. The Sossego Mine, in operation since 2004, is the first VALE copper mine, is among the largest Brazilian mines and will be the focus of the case study of this research.
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Planejamento estocástico de lavra: metodologias de simulação, otimização e gestão de risco para a mina do futuro. / Stochastic mine planning: simulation, optimization and risk management methods for the mine of the future.Sandro Bernard Moreira de Freitas 23 September 2015 (has links)
O desempenho operacional e econômico de empreendimentos de mineração é de suma importância para a sustentação dos níveis de produção demandados, sendo imprescindível um nível de governança capaz de prever e gerenciar eficazmente as incertezas e riscos inerentes ao processo de lavra, sejam eles geológicos, operacionais ou financeiros. O recente desenvolvimento de tecnologias e do conceito de \"mina do futuro\" ou \"mina autônoma\" indica a possibilidade de captura de dados através de sensores variados e do uso destes dados para geração de simulações estocásticas, para otimização tanto do ativo físico quanto do aproveitamento do recurso ou ativo mineral, minimizando riscos e custos. O planejamento estocástico de lavra vem nos últimos anos apresentando potenciais ferramentas para esse nível de gerenciamento de riscos na mineração, contudo sua resposta em diversos tipos de depósito é ainda pouco conhecida e carece de esforços de pesquisa e desenvolvimento. A presente pesquisa tem o objetivo de descrever essas abordagens probabilísticas de planejamento comparando com as tradicionais (determinísticas), definir procedimentos de aplicação desses conceitos na indústria, integrados em um sistema de gestão, quantificar seus impactos no desempenho de uma operação mineira e gerar informações para a comunidade acadêmica e técnica da indústria mineral preocupados com o futuro da mineração, quanto à aplicabilidade efetiva de técnicas como planejamento estocástico de lavra e simulação de lavra, englobando incertezas relativas ao ativo mineral e ativo físico da operação mineira. Para tanto, foi realizada inicialmente uma extensa pesquisa bibliográfica em relação ao tema proposto, destacando os pontos de maior relevância, permitindo então o desenvolvimento de uma metodologia de gestão que auxilie, de forma eficaz, o processo de tomada de decisões referentes à otimização de ativos em minas a céu aberto. Visando-se atingir tais objetivos, serão realizados testes piloto em uma mina na Província Mineral de Carajás-PA. A Mina do Sossego, em operação desde 2004, é a primeira mina de cobre da VALE, está entre as maiores minas brasileiras e será o foco do estudo da presente pesquisa. / Both operational and economic performance of mining projects are critical for sustaining the demanded production levels, being indispensable a level of governance able to predict and effectively manage the uncertainties and risks inherent to mining process such as geological, operational or financial risks. Recent developments of technologies and concepts of \"mine of the future\" or \"Autonomous mine\" indicates a possibility of on-line data acquisition by a number of sensors and the use of such data to generate stochastic simulations for optimization of equipments assets and mineral resource, minimizing risks and costs. Stochastic mining planning recently have been presenting potential tools for this level of risk management in mining, but the response of such approach in various types of deposit is still poorly understood and requires research and development efforts. This research aims to describe these probabilistic mine planning approaches comparing to traditional approaches (deterministic), to define procedures for implementation of these concepts in the industry in an integrated management system, to quantify their performance impacts of a mining operation and to generate information for the academic community and mineral industry technical staff concerned about the future of mining, as the applicability of planning techniques such as stochastic mining planning and discrete event simulation, covering uncertainties related to mineral assets and physical assets (equipments) of the mining operation. Thus, initially will be performed an extensive literature review regarding the proposed theme, highlighting the points of major relevance, thus allowing the development of a management methodology that effectively assists the decision making process regarding asset optimization in open pit mines. Aiming to achieve these goals, pilot tests will be performed at an operating mine in the Carajás Mineral Province-PA. The Sossego Mine, in operation since 2004, is the first VALE copper mine, is among the largest Brazilian mines and will be the focus of the case study of this research.
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Evaluación de la susceptibilidad de remoción en masa en la localidad de El Ingenio, comuna de San José de Maipo, ChileDíaz Valdivieso, Gabriela January 2018 (has links)
Memoria para optar al título de Geógrafa / Se evalúa la susceptibilidad de remoción en masa en la localidad de El Ingenio, comuna de San José de Maipo, lugar en donde se contempla una extensión urbana por parte de los instrumentos de planificación, lo que podría significar un aumento del riesgo en la zona, ya que dicho asentamiento se emplaza a los pies de laderas con evidentes procesos de remoción en masa que dan cuenta de la inestabilidad en la que se encuentran éstas. La metodología consistió en identificar y analizar la geomorfología de la zona, levantar un inventario a detalle de las remociones en masa, para luego, realizar una modelización de la susceptibilidad de ocurrencia de remoción a través de análisis estadísticos en el que se relacionan los factores condicionantes con los registros de remociones. Los resultados obtenidos dan cuenta de la geodinámica moderna de la zona, en donde las características estructurales de la Cordillera de los Andes determinan un ambiente morfoclimático de montaña que condiciona la estabilidad de las laderas. Se elaboró un Mapa de Susceptibilidad que muestra que casi el 40% de la zona presenta una alta susceptibilidad, lo mismo que ocurre con la mediana susceptibilidad, mientras que la baja susceptibilidad no alcanza el 20%. Se concluye que el área de estudio presenta un alto grado de inestabilidad, en donde los procesos de denudación favorecen la disponibilidad de material que es movilizado a través de diversos tipos de remociones en masa, traduciéndose en potenciales escenarios de desastres si es que no se considera la evaluación geodinámica del relieve en la planificación urbana. / The landslide susceptibility is assessmented for the locality of El Ingenio in the San José de Maipo commune, where an urban extension is contemplated by the planning instruments, which could mean an increase in the risk in the area, since this settlement is located at the foot of slopes with evident processes of landslides that account for the instability in which they are located. The methodology consisted of identifying and analyzing the geomorphology of the area, taking an inventory in detail of the landslides found, and then modeling the susceptibility of landslides in a statistical analysis of the determining factors of landslides, work processed by GIS. The methodology consisted of identifying and analyzing the geomorphology of the area, taking an inventory in detail of the landslides found, then making a modeling of the landslides susceptibility through statistical analysis where the conditioning factors are related to the records of landslides. The results obtained account for the current geodynamics of the area, where the structural characteristics of the Andes mountain range determine a morphoclimatic mountain environment that conditions the stability of the slopes. A Susceptibility Map was drawn up showing that almost 40% of the area presents a high susceptibility, as occurs with the medium susceptibility, while the low susceptibility doesn’t reach 20%. It is concluded that the study area presents a high degree of instability, where denudation processes favor the availability of material that is mobilized through various types of landslides, translating into potential disaster scene if it isn’t considered the geodynamic assessment of concerns in urban planning.
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