Well control in drilling operations is priority to personnel safety. Detection of kicks, or the unscheduled entry of formation fluids into the wellbore, is vital to well control. It has been determined that return flow rate is the parameter most sensitive to detecting kicks and lost circulation. One kick detection method associated with this parameter is delta flow early kick detection or simply the delta flow method. This method has limitations on floating vessels. Inaccurate readings can occur due to the heave motion of a vessel. This is a result of the sensor being downstream of the compensatory slip joint. Expansion and compression of this joint can result in return flow readings that are not representative of the actual value. Inaccurate readings could create situations in which a false kick or false lost circulation is detected. Other inaccurate readings could result in an actual kick or lost circulation situation not being detected. In the past, work has been done to address this by developing a sensor that adjusts for heave. This work supports a project aimed at removing the need for motion compensation by relocating the sensor to a location independent of this motion. A company is currently developing a delta flow early kick detection sensor to be placed at or near the seafloor. The stationary location of this sensor aims to remove the inaccuracy caused by slip joint compensation of vessel movement. This work will consist of a parametric study on the relationship of various drilling system and kick parameters at the seafloor using a well control simulator. The goal is to understand these relationships and determine the delta flow accuracy required based on a given kick size. As a result, this study found that a sensor capable of detecting a 10 barrel kick would require an accuracy of 2.4% and a 20 barrel kick would require a 4.6% accuracy for detection. This case was a shallow water, low kick intensity scenario. This accuracy and the others reported for the drilling and kick parameter ranges provide the boundaries for a well control sensor to be placed at the seafloor.

The limits of directional drilling continue to be pushed back as horizontal or near-horizontal reservoir sections are being drilled, cased, cemented and completed to tap reserves at extreme distances. Continuous development of new technology and adopting a technical-limit approach to performance delivery are key elements for the success and further development of extended-reach drilling projects. For this study a two-phase well control simulator was used to evaluate different kick scenarios that are likely to occur in extended-reach wells. An extensive simulation study covering a vide range of variables has been performed. Based on this investigation together with a literature review, well-control procedures have been developed for extended-reach wells. The most important procedures are as follows: Perform a "hard" shut-in when a kick is detected and confirmed. Record the pressures and pit gain, and start to circulate immediately using the Driller's Method. Start circulating with a high kill rate to remove the gas from the horizontal section. Slow down the kill circulation rate to 1/2 to 1/3 of normal drilling rate when the choke pressure starts to increase rapidly. The simulator has been used to validate the procedures.

The petroleum industry is in a constant state of change. Few industries have advanced as far technologically as the petroleum industry has in its relatively brief existence. The produced products in the oil and gas industry are finite. As such, the easier to find and produce hydrocarbons are exploited first. This forces the industry to enter new areas and environments to continue supplying the world's hydrocarbons. Many of these new frontiers are in what is considered ultradeep waters, 5000 feet or more of water. While all areas of the oil and gas industry have advanced their ultradeep water technology, one area has had to remain at the forefront: drilling. Unfortunately, while drilling as a whole may be advancing to keep up with these environments, some segments lag behind. Blowout control is one of these areas developed as an afterthought. This lax attitude towards blowouts does not mean they are not a major concern. A blowout can mean injury or loss of life for rig personnel, as well as large economic losses, environmental damage and damage to the oil or gas reservoir itself. Obviously, up-to-date technology and techniques for the prevention and control of ultradeep water blowouts would be an invaluable part of any oil and gas company's exploration planning and technology suite. To further the development of blowout prevention and control, COMASim Cherokee Offshore, MMS, Texas A&M Simulator) was developed. COMASim simulates the planning and execution of a dynamic kill delivered to a blowout. Through a series of over 800 simulation runs, we were able to find several key trends in both the initial conditions as well as the kill requirements. The final phase of this study included a brief review of current industry deepwater well control best practices and how the COMASim results fit in with them. Overall, this study resulted in a better understanding of ultradeep water blowouts and what takes to control them dynamically. In addition to this understanding of blowouts, COMASim's strengths and weaknesses have now been exposed in order to further develop this simulator for industry use.

The petroleum industry is in a constant state of change. Few industries have advanced as far technologically as the petroleum industry has in its relatively brief existence. The produced products in the oil and gas industry are finite. As such, the easier to find and produce hydrocarbons are exploited first. This forces the industry to enter new areas and environments to continue supplying the world's hydrocarbons. Many of these new frontiers are in what is considered ultradeep waters, 5000 feet or more of water. While all areas of the oil and gas industry have advanced their ultradeep water technology, one area has had to remain at the forefront: drilling. Unfortunately, while drilling as a whole may be advancing to keep up with these environments, some segments lag behind. Blowout control is one of these areas developed as an afterthought. This lax attitude towards blowouts does not mean they are not a major concern. A blowout can mean injury or loss of life for rig personnel, as well as large economic losses, environmental damage and damage to the oil or gas reservoir itself. Obviously, up-to-date technology and techniques for the prevention and control of ultradeep water blowouts would be an invaluable part of any oil and gas company's exploration planning and technology suite. To further the development of blowout prevention and control, COMASim Cherokee Offshore, MMS, Texas A&M Simulator) was developed. COMASim simulates the planning and execution of a dynamic kill delivered to a blowout. Through a series of over 800 simulation runs, we were able to find several key trends in both the initial conditions as well as the kill requirements. The final phase of this study included a brief review of current industry deepwater well control best practices and how the COMASim results fit in with them. Overall, this study resulted in a better understanding of ultradeep water blowouts and what takes to control them dynamically. In addition to this understanding of blowouts, COMASim's strengths and weaknesses have now been exposed in order to further develop this simulator for industry use.

DEA ?? 63, Floating Vessel Blowout Control is a blowout containment study which was completed in 1990, and it did not include discussions about operations in the water depths we currently operate in. As offshore drilling is continuously moving into deeper and deeper waters, a need to further investigate well control and blowout containment in ultradeep water has arisen. This project describes the development and assessment of an electronic cross-reference tool for well control and blowout containment, with added focus on ultradeep water operations. The approach of this manual is fully electronic, thus being able to serve the needs of the engineer/driller with greater ease in both pre-planning and in a stressful onthe- job setting. The cross-reference is a manual for the state of the art in well control and blowout containment methodology. It provides easy-to-use topical organization by categories and subcategories, and aims at providing clear links between symptoms, causes, and solutions. Clear explanations to complicated issues are provided, and confirmation of applicable blowout intervention procedures, be it conventional or unconventional, are discussed. Human error and equipment failure are the causes of blowouts, and they are bound to happen in an ultradeep water environment. Well control events are harder to detect andhandle in ultradeep water, and quick reaction time is essential. After detection and shutin, the Driller??s method is the preferred circulation method in ultradeep water, due to its responsiveness and simplicity. In case kick handling is unsuccessful, contingency plans should be in place to handle a potential blowout. If a blowout does occur, and the blowing well does not self-kill through bridging, a dynamic kill through relief well intervention is likely to be necessary, as underwater intervention is difficult in ultradeep water. With new ultradeep water drilling technologies providing potential for increased performance, alternative well control methods might be necessary. Along with these new technologies follow new unfamiliar procedures, and proper education and training is essential.

The worst scenario of drilling operation is blowout which is uncontrolled flow of formation fluid into the wellbore. Blowouts result in environmental damage with potential risk of injuries and fatalities. Although not all blowouts result in disaster, outcomes of blowouts are unknown and should be studied before starting an operation. Plans should be available to prevent blowouts or provide safe and secure ways of controlling the well before the drilling operation starts. The plan should include procedures in case of any blowout incident as a proactive measure. A few commercial softwares are available in the industry for dynamic kill and transient modeling. All models are proprietary and very complex which reduces the flexibility of the program for specific cases. The purpose of this study is to develop a pseudo transient hydraulic simulator for dynamic kill operations. The idea and concept is to consider the flow of each phase as a single phase flow. The summation of hydrostatic and frictional pressure of each phase determines the bottomhole pressure during the dynamic kill operation. The simulator should be versatile and capable of handling special cases that may encounter during blowouts. Some of the main features of the proposed dynamic kill simulator include; quick and robust simulation, fluid properties are corrected for pressure and temperature, sensitivity analysis can be performed through slide bars, and capable of handling variety of wellbore trajectories. The results from the proposed simulator were compared to the result of commercial software, OLGA ABC. The results were in agreement with each other. It is recommended to apply the simulator for operations with required kill fluid volumes of one to two wellbore volumes.

The energy retrieval process in an Enhanced Geothermal System (EGS) depends on fracture networks to facilitate fluid movement, thereby enabling the extraction of heat from adjacent rocks matrix. Nonetheless, due to the inherent heterogeneity and intricate multi-physics characteristics of these systems, high-fidelity physics-based forward simulations ($f_h$) can be computationally demanding. This presents a considerable obstacle to the efficient management of these reservoirs. Therefore, creating an effective and robust optimization framework is essential, with the primary aim being to maximize the thermal extraction from Enhanced Geothermal Systems (EGS). A deep learning-assisted reservoir management framework incorporating a low-fidelity forward surrogate model ($f_l$) alongside gradient-based optimizers is developed to expedite reservoir management. A thermo-hydro-mechanical (THM) model for EGS is established by utilizing finite element-based reservoir simulation techniques. By parameterizing the fracture aperture and well controls, we carried out the THM simulation to produce 2500 datasets. Subsequently, we employed these datasets to train two distinct deep neural network (DNN) architectures to predict the variations in pressure and temperature distributions. Ultimately, these predictions from the forward model are used in calculating the total net energy. Instead of executing the optimization workflow with a large number of simulations from $f_h$, we directly optimize the well control parameters relative to the geological parameters using $f_l$. Since $f_l$ is efficient and fully differentiable, it could be combined with various gradient-based or gradient-free optimization algorithms to maximize the total net energy by determining the optimal decision parameters. Drawing from the simulation datasets, we analysed the effect of fracture aperture variation on temperature and pressure evolution. Our investigation revealed that the spatial distribution of the fracture aperture is a predominant factor in controlling the propagation of the thermal front. Variations of the fracture aperture exhibit a strong correlation with temperature fluctuations within the fracture, primarily due to thermal stress changes. When compared with a comprehensive physics simulator, our DNN-based forward surrogate model offers a significant computational acceleration, approximately 1500 times faster, without compromising predictive accuracy, achieving an $R^2$ value of 99%. The forward model $f_l$, when combined with gradient-based optimizers, enables optimization to proceed 10 to 68 times faster than when using derivative-free global optimizers. The proposed reservoir management framework exhibits both efficiency and scalability, facilitating the real-time execution of each optimization process.

Orientador: Paulo Roberto Ribeiro / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica, Instituto de Geociencias / Made available in DSpace on 2018-08-12T16:33:33Z (GMT). No. of bitstreams: 1 Avelar_CarolinaSilva_M.pdf: 15432162 bytes, checksum: cbaa0b149cf8200fccff3cea6905b066 (MD5) Previous issue date: 2008 / Resumo: As explorações de campos de petróleo têm abrangido diferentes cenários, incluindo perfuração de poços profundos com elevadas pressões e temperaturas em águas profundas e ultraprofundas. O estudo do controle de poços nestes cenários exige um simulador capaz de prever o comportamento das pressões do poço durante uma situação de kick de forma confiável e eficiente. Considerando estes aspectos, foi implementado um simulador de kicks baseado em um modelo matemático que resolve um conjunto de três equações diferenciais de conservação utilizando o método diferenças finitas. Os cálculos das perdas de carga por fricção, do deslizamento entre as fases e da expansão do gás foram incorporados ao modelo. O modelo é capaz de simular um kick em poços verticais ou horizontais, em poços terrestres ou marítimos, utilizando fluido de perfuração com base de água. Os resultados do simulador foram comparados com dados experimentais e um estudo sobre o efeito de algumas variáveis do controle de poços foi realizado. / Abstract: The oil field industry has been drilling in different scenarios, subjected to high pressures and high temperatures in deep wells located in deep and ultradeep waters. The well control study in these scenarios demands a kick simulator capable to do precise predictions of the pressure behavior inside the wellbore during a kick situation. Regarding this scenario, a kick simulator has been implemented. The simulator is based in a mathematical model that solves a set of three conservation equations using the finite difference approach. The effects of the frictional pressure losses, the gas slip and expansion have been incorporated to the model. The model is capable of simulating a single kick in a vertical or horizontal hole, onshore or offshore, with water-based drilling fluid. The simulator results have been compared with experimental data and the effect of some important parameters in well control has been studied. / Mestrado / Explotação / Mestre em Ciências e Engenharia de Petróleo

Orientador: Paulo Roberto Ribeiro / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica e Instituto de Geociencias / Made available in DSpace on 2018-08-03T18:14:08Z (GMT). No. of bitstreams: 1 Nunes_JoaoOtavioLeite_M.pdf: 4170180 bytes, checksum: 7c2064f4ba67fccb4f1c209b60bf69c7 (MD5) Previous issue date: 2002 / Resumo: O controle de poço sempre foi um assunto muito importante na exploração e explotação de óleo e gás, pois envolve aspectos econômicos, de segurança de pessoas e questões ambientais. O avanço das explorações offshore, particularmente em águas profundas e ultra-profundas, tem aumentado cada vez mais a relevância do controle de kicks e prevenção de blowouts. Práticas de perfuração largamente utilizadas têm sido otimizadas e reavaliadas, então novas tecnologias têm sido desenvolvidas para tratar problemas relacionados a operações de perfuração em águas profundas, tal como uma prática de controle de poço confiável e eficiente. Este esforço é de grande importância em paises como o Brasil, que tem a maior parte da produção de óleo e gás em campos offshore, sendo que a maioria dos campos localiza-se em águas profundas e ultra-profundas. Considerando-se tal cenário, um modelo matemático foi desenvolvido para simular um kick de gás e prever a variação de pressão na linha do choke e no espaço anular de um poço, durante uma situação de controle de poço em águas profundas. Considerações sobre o efeito da geometria do poço, perdas de carga por fricção, expansão do influxo e modelagem bifásica foram implementadas. O efeito de algumas variáveis no controle de poço, tais como o pit gain, lâmina d'água, densidade e reologia do fluido de perfuração e vazão de bombeio foram estudadas / Abstract: Well control has always been a very important issue in the oi! and gas exploitation business, since it involves money savings, people safety and environment threatening. The advancement of the exploration frontiers from onshore to offshore fields, particularly, deep and ultra-deep waters, has increased even more the relevance of kick control and blowout prevention during drilling operations. Widely used drilling practices have been optimized and re-evaluated, so have new technologies been developed to handle specific issues related to deepwater drilling operations, such as reliable and efficient well control practices. This effort has great importance to some countries like Brazil, which have most part of their oil and gas production concentrated on offshore wells, about of those reserves are located in deepwaters. Regarding such scenario, a mathematical model has been developed to simulate a gas kick and predict the pressure variation in the choke line and the annular space of the well during well control situation in deepwater scenarios. Considerations regarding the effects of wellbore geometry, frictional pressure losses, influx expansion, and two-phase flow aspects have been implemented in the present model. The effects of some variables in well control, such as the pit gain, water depth, mud weight and rheology and pump flow rate have been studied. / Mestrado / Geociencias / Mestre em Ciências e Engenharia de Petróleo

Orientador: Paulo Roberto Ribeiro / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica e Intituto de Geociencias / Made available in DSpace on 2018-08-12T15:54:27Z (GMT). No. of bitstreams: 1 Monteiro_EduardoNascimento_M.pdf: 16240698 bytes, checksum: 5bca1c01db0a9ae851bdb07bd2770078 (MD5) Previous issue date: 2007 / Resumo: O estudo da interação entre o gás da formação produtora e o fluido de perfuração durante as operações é essencial para perfuração de cada fase do poço de forma segura e econômica. Aspectos ambientais e técnicos peculiares à perfuração em águas profundas e ultra profundas exigem o uso de fluidos de perfuração sintéticos, de baixa toxicidade. O principal objetivo, deste trabalho foi o estudo do comportamento PVT desses fluidos através da determinação experimental e modelagem de propriedades termodínâmicas, tais como solubilidade, densidade e fator volume de formação dos fluidos. Estas propriedades têm um impacto importante na detecção e circulação de um kick e devem ser consideradas no planejamento e execução do controle do poço. Os resultados experimentais foram obtidos em uma célula PVT pressurizada por injeção de mercúrio e com um limite operacional de 177°C e 70 MPa. O gás utilizado foi o metano e os líquidos foram emulsões e fluidos não adensados à base de n-parafina, testados a 70°C, 90 °C e 150°C. Os efeitos da temperatura e da composição do fluido foram analisados e os resultados experimentais para solubilidade e fator volume de formação foram comparados com predições baseadas na hipótese da aditividade e ajustes matemáticos nos resultados experimentais. Alguns exemplos de cálculo do volume ganho no tanque usando as expressões analíticas obtidas são discutidos. / Abstract: The study of the interaction between the formation gas and the drilling fluid during the operations is essential to safely and economically drill each phase of the well. The environmental regulatory issues and the peculiar technical aspects involved in deep and ultradeep waters require low toxicity' synthetic drilling fluids. The main objective ofthis study was to understand the PVT behavior of those fluids by the experimental determination and modeling of thermody'pamic properties such as: solubility, specific gravity and formation volume factor of the fluids. Those properties have a direct impact on kick detection and circulation out of the well, what sb.ould be addressed in wellcontrol planning and execution. The experimental data were obtained by means of a PVT cell pressurized by mercury injection with an operating capacity of 177 °C and 70 MPa. The gas used was methane and the liquids were n-paraffin based emulsions and unweighted drilling fluids, tested at 70 °C, 90 °C and 150 °c. The temperature and fluid composition influences had been analyzed and the experimental data for solubility and formation volume factor have been compared with predictions considering the additivity hypothesis and mathematical fittings based in the experimental data. Some pit gain calculation examples using the analytical expressions obtained are also discussed. / Mestrado / Explotação / Mestre em Ciências e Engenharia de Petróleo