The oil and gas industry, aerospace, and automotive industries are constantly pushing technology beyond their current operational boundaries, spurring the need for extreme environment electronics. The oil and gas industry, in particular, is the oldest and largest market for high-temperature electronics, where the operating environment can extend up to 260 degrees Celsius. The electronics currently employed in this field are only rated to 200 degrees Celsius, but with the rise of wideband gap technologies, this could be extended to 250 degrees Celsius or more without the needed for active or passive cooling. This reduces the complexity, weight, and cost of the system while improving reliability. In addition, current downhole telemetry data rates are insufficient for supporting more sophisticated and higher resolution well-logging sensors. Increasing the data rates can also save the industry significant amount of time by decreasing the amount of well-logging excersions and by increasing the logging speed. Previous work done by this research group saw the prototyping of a high bit rate transceiver operating at 230 MHz - 300 MHz and 230 degrees Celsius; however, at these frequencies, the system could not meet size requirements. Thus, a new high-temperature high data rate transceiver design using the 2.4 GHz - 2.5 GHz ISM band is proposed to miniaturize the design and to allow for IC implementation. The transceiver was designed to meet the minimum specifications necessary to give designers flexibility between power consumption and performance. The performance of the design is simulated using AWR design environment software, which shows the system can support a downlink data rate up to 68 Mbps and an uplink data rate up to 170 Mbps across 10 channels. The effects temperature has on the system performance is also evaluated in the simulation. / Master of Science / The oil and gas industry is currently the largest and oldest market for high-temperature electronics. One of the major applications within this industry for high-temperature electronics is known as well-logging, during which a suite of sensors and systems is lowered into a well to survey the health and geology of the well. Among these sensors and systems, the communication system is one of the most crucial components as it relays real-time data back to the surface during the well-logging operation. Current high-temperature communication systems are capable of operating up to 200 ℃, meeting the operating requirements of current wells. As these wells deplete, however, new wells must be explored, and higher operating temperatures are expected. In addition, the communication systems currently employed fail to meet increasing data rate demands due to the growing complexity of the sensors. Recent developments in semiconductor technologies have given rise to devices, which can increase the operating temperature of electronics up to 250 ℃ while meeting demands for high data rate communication systems. Previous work has leveraged these devices to prototype such a system; however, the proof-of-concept failed to meet size and weight restrictions of practical systems. Therefore, a new system design for a high-temperature high data rate communication system is proposed. The system operates at 2.4 – 2.5 GHz to miniaturize the circuits and make chip implementation possible. The impacts of temperature on the system are investigated and the system performance is simulated within its intended operating temperature range. Developments from this research can be extended to the automotive and aerospace industries, where demand for high-temperature electronics is growing.

Electronics are normally designed to operate at temperatures less than 125 oC. For high temperature applications, the use of those normal electronics becomes challenging and sometimes impractical. Conventionally, many industries tried to push the maximum operating temperature of electronics by either using passive/active cooling systems or tolerating degraded performance. Recently, there has been a demand for more robust electronics that can operate at higher temperature without sacrificing the performance or the use of any weighty, power hungry, complex cooling systems. One of the major industries that need electronics operating at high temperature is the oil and gas industry. Electronics have been used within the field in many areas, such as well logging downhole telemetry systems, power networks, sensors, and actuators. In the past, the industry has managed to use the existing electronics at temperatures up to 150 oC. However, declining reserves of easily accessible natural resources have motivated the oil and gas industry to drill deeper. The main challenge at deep wells for downhole electronics is the high temperatures as the pressures are handled mechanically. The temperature in deep basins can exceed 210 oC. In addition, existing well logging telemetry systems achieve low data transmission rates of less than 2.0 Mbps at depth of 7.0 Km which do not meet the growing demand for higher data rates due to higher resolution sensors, faster logging speeds, and additional tools available for a single wireline cable. The main issues limiting the speed of the systems are the bandwidth of multi-conductor copper cable and the low speed communication system connecting the tools with the telemetry modem. The next generation of the well logging telemetry system replaces the multi-conductor wireline between the surface and the downhole with an optical fiber cable and uses a coaxial cable to connect tools with the optical node in downhole to meet the growing needs for higher data rates. However, the downhole communication system between the tools and the optical modulator remains the bottleneck for the system. The downhole system is required to provide full duplex and simultaneous communications between multiple downhole tools and the surface with high data rates and able to operate reliably at temperatures up to 230 oC. In this dissertation, a downhole communication system based on radio frequency (RF) transmission is investigated. The major contributions of our research lie in five areas. First, we proposed and designed a downhole communication system that employs RF systems to provide high speed communications between the downhole tools and the surface. The system supports up to six tools and utilizes frequency division multiple access to provide full duplex and simultaneous communications between downhole tools and the surface data acquisition system. The system achieves 20 Mbps per tool for uplink and 6 Mbps per tool for downlink with bit error rate (BER) less than 10-6. Second, a RF front-end of transceiver operating at ambient temperatures up to 230 oC is designed and prototyped using Gallium Nitride (GaN) high electron mobility transistor (HEMT) devices. Measurement results of the transceiver's front end are reported in this dissertation. To our knowledge, this is the first RF transceiver that operates at this high temperature. Third, current-voltage and S-parameters characterizations of the GaN HEMT at ambient temperatures of 250 oC are conducted. An analytic model that accurately predicts the behavior of the drain-source resistor (RDS) of the GaN transistor at temperature up to 250 oC is developed based on these characterizations. The model is verified by the analysis and the performance of the resistive mixer. Fourth, a passive upconversion mixer operating at temperatures of 250 oC is designed and prototyped. The designed mixer has conversion loss (CL) of 6.5 dB at 25 oC under local oscillator (LO) power of 2.5 dBm and less than 0.75 dB CL variation at 250 oC under the optimum biasing condition. Fifth, an active downconversion mixer operating at temperatures up to 250 oC is designed and prototyped. The proposed mixer adopts a common source topology for a reliable thermal connection to the transistor source plate. The designed active mixer has conversion gain (CG) of 12 dB at 25 oC under LO power of 2.5 dBm and less than 3.0 dB CG variation at 250 oC. Finally, a novel high temperature negative adaptive bias voltage circuit for a GaN based RF block is proposed. The proposed design comprises an oscillator, voltage doubler, and temperature dependent bias controller. The voltage offset and temperature coefficient of the generated bias voltage can be adjusted by the bias controller to match the optimum biasing voltage required by a RF building block. The bias controller is designed using a Silicon Carbide (SiC) bipolar junction transistor. / PHD / A downhole communication system provides two-way communications for multiple tools located in a deep oil well. The main challenge for the downhole communication system as the oil wells get deeper is the high ambient temperatures as the pressures can be handled mechanically. The temperature in deep basins can exceed 210 °C. Cooling and heat extraction techniques with fans are impractical for downhole systems due to increased weight, power, and system complexity. In addition, the current downhole communication systems have low transmission speed, which do not meet the growing demand for higher data rates due to higher resolution sensors, faster logging speeds, and additional tools available for a single wireline cable. In this work, a downhole communication system based on radio frequency (RF) transmission is designed. The system supports up to six tools and provides high speed simultaneous communications which enable more sensors to be integrated in each tool. A high temperature RF front-end of the transceiver which will be connected to each tool is designed and prototyped using Gallium Nitride (GaN) semiconductor technology. GaN technology is selected due its ability to operate at harsh environment. The measurement results show a reliable performance for the RF front-end at temperatures up to 230 °C. To our knowledge, this is the first RF front-end that operates at 230 °C reported in the open literature. The proposed downhole communication system will enhance the speed and reliability of the oil and gas operations. This also will enable the industry to observe the wells and act in real time which in turns save operation time and bring a significant cost reduction in oil and gas operations. Most importantly, the proposed system will enable the industry to explore deeper untapped wells and add more features to the tools which were not possible before due to speed and high temperature limitations.

Local soil conditions influence the characteristics of earthquake ground shaking and these effects must be taken into account when specifying ground shaking levels for seismic design. These effects are quantified via site response analysis, which involves the propagation of earthquake motions from the base rock through the overlying soil layers to the ground surface. Site response analysis provides surface acceleration-time series, surface acceleration response spectra, and/or spectral amplification factors based on the dynamic response of the local soil conditions. This dissertation investigates and compares the results from different site response methods. Specifically, equivalent-linear time series analysis, equivalent-linear random vibration theory analysis, and nonlinear time series analysis are considered. In the first portion of this study, hypothetical sites and events are used to compare the various site response methods. The use of hypothetical events at hypothetical sites allowed for the seismic evaluation process used in engineering practice to be mimicked. The hypothetical sites were modeled after sites with characteristics that are representative of sites in the Eastern and Western United States. The input motions selected to represent the hypothetical events were developed using the following methods: stochastically-simulated time series, linearly-scaled recorded time series, and spectrally-matched time series. The random vibration theory input motions were defined using: seismological source theory, averaging of the Fourier amplitude spectra computed from scaled time series, and a response spectrum compatible motion. All of the different input motions were then scaled to varying intensity levels and propagated through the sites to evaluate the relative differences between the methods and explain the differences. Data recorded from borehole arrays, which consist of instrumentation at surface and at depth within the soil deposit, are used to evaluate the absolute bias of the site response methods in the second portion of this study. Borehole array data is extremely useful as it captures both the input motion and the surface motion, and can be used to study solely the wave propagation process within the soil deposit. However, comparisons using the borehole data are complicated by the assumed wavefield at the base of the array. In this study, sites are selected based on site conditions and the availability of high intensity input motions. The site characteristics are then developed based on site specific information and data from laboratory soil testing. Comparisons between the observed and computed response are used to first assess the wavefield at the base of the array, and then to evaluate the accuracy of the site response methods. / text

The Electrical Submersible Pump (ESP) manufactured by Baker Hughes, model no. WJE-1000 is designed for wells that are expected to have a high content of abrasive solids. It is a mixed flow, tandem compression type pump. Although the erosion of the pump diffuser and impeller stages are significant, the ESP study shows that the most sever failure is due to components that affect the pump’s rotor dynamics such as radial bearings and impeller seals when eroded with 100 mesh sand. Erosion of these seals will result in an internal leakage that can significantly affect stage pressure rise, efficiency, power consumption, vibration, pump life and running cost. The erosion study utilizing 100 mesh fracture sand at 0.2% concentration, with the pump operating at 3600 RPM, 40 PSI intake pressure, 1150 GPM for over 117 hours comparisons are made to the pump’s baseline performance. Measurements of the rotor bearings, impeller seals and their corresponding stators showed that the wear patterns generally increase with time and differ by location. Stage 1 bearings and seals suffered the least amount of erosion and stage 3 rotor components suffered the most erosion. The maximum change in stage 3 bearing clearances was 223% and the maximum change in stage 3 impeller seal clearances was 300%. Performance wise the total pump efficiency dropped by 6.77%, the total pressure rise dropped by 6.3%, the pump’s best efficiency point decreased by 0.78%, and the power consumption increased by 0.49%. Pump vibration patterns also changed with time and by location. The maximum shaft orbit diameter was at stage 3 and it grew 643% in diameter after 117 hours of erosion. The waterfall plots of the pump’s ramp up changed significantly with time. After 117 hours at 3600 RPM, sub-synchronous oscillations at 67% of the synchronous speed dominated the amplitude peaks showing that the rotor vibration locked with the rotor’s first natural frequency at around 2500 RPM. After 117 hours, another sub-synchronous started showing a peak at the rotor’s second natural frequency at 1500 RPM.

Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2017-07-28T17:55:36Z No. of bitstreams: 1 2016 - Frederico Martins Costa.pdf: 7875693 bytes, checksum: 1f9e0aaff0875ac10e2311a35da16d31 (MD5) / Made available in DSpace on 2017-07-28T17:55:36Z (GMT). No. of bitstreams: 1 2016 - Frederico Martins Costa.pdf: 7875693 bytes, checksum: 1f9e0aaff0875ac10e2311a35da16d31 (MD5) Previous issue date: 2016-12-27 / CAPES / The process of well cementing is very complex, beyond the fact that cement paste presents high density, different rheology fluids are injected into the annulus, altering downhole pressure due to changes on hydrostatic pressure and frictional losses. Knowing the operational window and assuring downhole pressure inside this constraint is primordial for security and well life cycle purposes. Due to downhole variations caused by the disturbances, the superior (fracture) and inferior window limits can be exceeded. As a result, loss circulation problems (mud penetration into a fracture) or kick (reservoir fluid inflow into the annulus) can disturb the cementing process, leading to serious accidents, financial losses, environmental damage and human losses. In order to represent the most important phenomena of cementing process, an experimental unit was built using on line flow, density and pressure measurements. Downhole pressure control through pumping 8, 11 and 14 ppg (lb/gal) fluids was analyzed under loss circulation and kick phenomena. The tracking of the downhole pressure at the set point, by employing a feedback control loop (PI), was implemented through using the opening index of the choke valve as the manipulated variable. / O processo de cimenta??o de po?os ? bastante complexo, al?m da pasta de cimento apresentar elevada densidade e ocorrer o bombeio de fluidos de diferentes reologias, a press?o no fundo do po?o sofre grandes varia??es, devido ? mudan?a na press?o hidrost?tica do po?o e ?s perdas por atrito. Conhecer a janela operacional do po?o e manter a press?o anular de fundo dentro desta ? primordial para a seguran?a e a vida ?til do po?o. Devido ?s varia??es na press?o ocasionadas pelos dist?rbios, a press?o anular de fundo pode extrapolar o limite superior (press?o de fratura) e o inferior (press?o de poros), da janela operacional. Ao extrapolar tais limites, os fluidos da regi?o anular podem migrar para a fratura (perda de circula??o) ou os fluidos nativos do reservat?rio podem migrar para a regi?o anular (kick), essas situa??es s?o indesejadas durante a cimenta??o, podendo causar s?rios acidentes, perdas humanas, preju?zos financeiros e danos ambientais irrevers?veis. Para representar os fen?menos mais importantes do processo de cimenta??o, foi constru?da uma unidade experimental com instrumenta??o capaz de quantificar vaz?o, densidade e press?o em tempo real. Foram analisados o comportamento da press?o anular de fundo no bombeio de fluidos com diferentes densidades (8, 11 e 14 ppg), al?m dos fen?menos de perda de circula??o com kick de g?s, controlando a press?o em um valor desejado (set point), utilizando uma estrat?gia de controle por realimenta??o (controlador PI), atrav?s do ?ndice da abertura da v?lvula choke.

[pt] A busca por maior eficiência, sistemas confiáveis e redução da pegada de carbono é uma tendência na indústria de Petróleo e Gás (OeG). A Completação Inteligente de Poços (IWC) tornou-se amplamente adotada, e a Válvula de Controlede Influxo/Intervalo (ICV) desempenha um papel significativo no controle da vazão de produção e injeção. A eletrificação dos ativos de OeG, incluindo as ferramentas de IWC, oferece um benefício duplo de aumento dos fatores de recuperação e alinhamento com os esforços globais de descarbonização. Para desenvolver uma ICV Elétrica, é necessário projetar um atuador eletromecânico capaz de operar sob condições desafiadoras e limitações de energia elétrica. Esta dissertação apresenta o projeto e os testes de um atuador eletromecânico em um protótipo de ICV Elétrica em escala real. O desempenho do atuador foi avaliado por meio de uma combinação de modelagem matemática e testes empíricos sob várias condições operacionais, incluindo alta e baixa temperaturas e pressões diferenciais. Os principais resultados desta pesquisa demonstraram que o modelo matemático apoiou efetivamente o design do atuador, com os resultados calculados alinhando-se com os testes funcionais em temperatura ambiente e pressão diferencial zero. / [en] The seek for higher efficiency, reliable systems, and carbon footprint reduction is a trend in the Oil and Gas (OandG) industry. Intelligent Well Completion (IWC) has become a widely adopted and the Inflow/Interval Control Valve (ICV) plays a significant role in controlling production and injection flow rates. Electrification of OandG assets, including the IWC tools, offers a dual benefit of increased recovery factors and alignment with global decarbonization efforts. To develop an Electric ICV, the design of an electromechanical actuator capable of operating under challenging conditions and electrical power limitations is required. This dissertation presents the design and testing of an electromechanical actuator in a full-scale prototype Electric ICV. The actuator s performance was assessed through a combination of mathematical modeling and empirical testing under various operational conditions, including high and low temperatures and differential pressures. Key findings from this research demonstrated that the mathematical model effectively supported the actuator s design, with calculated results aligning closely with functional tests at room temperature and zero differential pressure.

Carbon dioxide sequestration is one of many mitigation tools available to help reduce carbon dioxide emissions while other disposal/repurposing methods are being investigated. Geologic sequestration is the most stable option for long-term storage of carbon dioxide (CO2), with significant CO2 trapping occurring through mineralization within the first 20-50 years. A fiber optic based monitoring system has been proposed to provide real time concentrations of CO2 at various points throughout the geologic formation. The proposed sensor is sensitive to the refractive index (RI) of substances in direct contact with the sensing component. As RI is a measurement of light propagating through a bulk medium relative to light propagating through a vacuum, the extraction of the effects of any specific component of that medium to the RI remains very difficult. Therefore, a requirement for a selective barrier to be able to prevent confounding substances from being in contact with the sensor and specifically isolate CO2 is necessary. As such a method to evaluate the performance of the selective element of the sensor was investigated. Polybenzimidazole (PBI) and VTEC polyimide (PI) 1388 are high performance polymers with good selectivity for CO2 used in high temperature gas separations. These polymers were spin coated onto a glass substrate and cured to form ultra-thin (>10 μm) membranes for gas separation. At a range of pressures (0.14 –0.41 MPa) and a set temperature of 24.2±0.8 °C, intrinsic permeabilities to CO2 and nitrogen (N2) were investigated as they are the gases of highest prevalence in underground aquifers. Preliminary RI testing for proof of concept has yielded promising results when the sensor is exposed exclusively to CO2 or N2. However, the use of both PBI and VTEC PI in these trials resulted in CO2 selectivities of 0.72 to 0.87 and 0.33 to 0.63 respectively, for corresponding feed pressures of 0.14 to 0.41 MPa. This indicates that both of the polymers are more selective for N2 and should not be used in CO2 sensing applications as confounding gas permeants, specifically N2, will interfere with the sensing element. / Graduate / 0428 / 0495 / 0542 / ben.t.davies@gmail.com

Made available in DSpace on 2014-12-17T14:08:50Z (GMT). No. of bitstreams: 1 PauloRMP_capa_ate_pag32.pdf: 5057325 bytes, checksum: bf8da0b02ad06ee116c93344fb67e976 (MD5) Previous issue date: 2012-02-06 / Originally aimed at operational objectives, the continuous measurement of well bottomhole pressure and temperature, recorded by permanent downhole gauges (PDG), finds vast applicability in reservoir management. It contributes for the monitoring of well performance and makes it possible to estimate reservoir parameters on the long term. However, notwithstanding its unquestionable value, data from PDG is characterized by a large noise content. Moreover, the presence of outliers within valid signal measurements seems to be a major problem as well. In this work, the initial treatment of PDG signals is addressed, based on curve smoothing, self-organizing maps and the discrete wavelet transform. Additionally, a system based on the coupling of fuzzy clustering with feed-forward neural networks is proposed for transient detection. The obtained results were considered quite satisfactory for offshore wells and matched real requisites for utilization / Originalmente voltadas ao monitoramento da opera??o, as medi??es cont?nuas de press?o e temperatura no fundo de po?o, realizadas atrav?s de PDGs (do ingl?s, Permanent Downhole Gauges), encontram vasta aplicabilidade no gerenciamento de reservat?rios. Para tanto, permitem o monitoramento do desempenho de po?os e a estimativa de par?metros de reservat?rios no longo prazo. Contudo, a despeito de sua inquestion?vel utilidade, os dados adquiridos de PDG apresentam grande conte?do de ru?do. Outro aspecto igualmente desfavor?vel reside na ocorr?ncia de valores esp?rios (outliers) imersos entre as medidas registradas pelo PDG. O presente trabalho aborda o tratamento inicial de sinais de press?o e temperatura, mediante t?cnicas de suaviza??o, mapas auto-organiz?veis e transformada wavelet discreta. Ademais, prop?e-se um sistema de detec??o de transientes relevantes para an?lise no longo hist?rico de registros, baseado no acoplamento entre clusteriza??o fuzzy e redes neurais feed-forward. Os resultados alcan?ados mostraram-se de todo satisfat?rios para po?os marinhos, atendendo a requisitos reais de utiliza??o dos sinais registrados por PDGs

A major concern for geotechnical engineers is the ability to predict how a soil will react to large ground motions produced by earthquakes. Of all the different types of soil, liquefiable soils present some of the greatest challenges. The ability to quantify the degradation of a soil's shear modulus as it undergoes liquefaction would help engineers design more reliably and economically. This thesis uses ground motions recorded by an array of downhole accelerometers on Port Island, Japan, during the 1995 Kobe Earthquake, to quantify the shear modulus of sand as it liquefies. It has been shown that the shear modulus of sand decreases significantly as it liquefies, apparently decreasing in proportion to the increasing excess pore water pressure ratio (Ru). When completely liquefied, the shear modulus of sand (Ru = 1.0) for a relative density of 40 to 50% is approximately 15% of the high-strain modulus of the sand in its non-liquefied state, or 1% of its initial low-strain value. Presented in this thesis is an approach to modeling the shear modulus degradation of sand as it liquefies. This approach, called the "degrading shear modulus backbone curve method" reasonably predicts the hysteretic shear stress behavior of the liquefied sand. The shear stresses and ground accelerations computed using this method reasonably matches those recorded at the Port Island Downhole Array (PIDA) site. The degrading shear modulus backbone method is recommended as a possible method for conducting ground response analyses at sites with potentially liquefiable soils.