The Experts below are selected from a list of 261 Experts worldwide ranked by ideXlab platform
Michael A. Smith - One of the best experts on this subject based on the ideXlab platform.
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Deep Sedimentary Thermal Gradient in the Continental Shelf off Alabama through Louisiana
2020Co-Authors: S. Nagihara, Michael A. SmithAbstract:Abstract Sedimentary thermal gradient down to ~7 km below the seafloor has been determined at 12 localities in the section of the Gulf of Mexico continental shelf off Alabama through Louisiana. In obtaining the geothermal gradient at each locality, we compiled bottom-Hole Temperature data reported from wells in the vicinity and corrected the data for disturbance caused by drill fluid circulation. The so-called Horner plot method was used for the bottom-Hole Temperature correction. This method requires that bottom-Hole Temperature be measured twice or more at a fixed depth while the well is shut in for wire-line logging operations. Thermal gradient values in the northeast (i.e., landward) of the Lower Cretaceous shelf margin off Alabama are quite uniform at about 0.028 K/m or 0.015°F/ft. Areas along the outer perimeter of the shelf margin also show similar thermal gradients. Further seaward (southwestward) of the shelf margin off Mississippi and Louisiana, in areas of deep marine deposition and salt diapirs, thermal gradient values tend to be lower and more variable. Lowest gradients (0.018 to 0.021 K/m) are observed in sediments flanking salt domes. At some other localities in the southwestern province, the thermal gradient seems to increase in deep (> ~3 km) sediments. At ~5 km sub-bottom depth, sedimentary Temperature fluctuates between 110°C and 160°C in the continental shelf. The Temperature variation may have impacted the hydrocarbon maturation history of the region and the bacterial and thermochemical sulfate reduction processes that yield hydrogen sulfide gas.
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Deep Sedimentary Thermal Gradient in the Continental Shelf off Alabama, Mississippi and Eastern Louisiana
2020Co-Authors: S. Nagihara, Michael A. SmithAbstract:Abstract Geothermal gradient within deep sediments down to ~7 km below the seafloor has been determined at 7 localities in the section of continental shelf off Alabama, Mississippi, and eastern Louisiana. In obtaining the geothermal gradient at each locality, we compiled bottom-Hole Temperature data reported from wells in the vicinity and corrected the data for disturbance due to drill fluid circulation. The so-called Horner plot method was used for the bottom-Hole Temperature correction. This method requires that bottom-Hole Temperature be measured twice or more at a fixed depth while the well is shut in for wire-line logging operations. Thermal gradient values in the northeast (i.e., landward) of the Lower Cretaceous shelf margin off Alabama are quite uniform at about 0.028° C per meter (°C/m) or 0.015° F/ft. Areas along the outer perimeter of the shelf margin also show similar thermal gradients. Further seaward of the shelf margin off Mississippi and eastern Louisiana, in areas of deep marine deposition and salt diapirs, thermal gradient values are generally lower. Especially within sediments flanking salt domes, gradient values are 0.018 to 0.025° C/m, or 0.010 to 0.014° F/ft. The difference in Temperature at 5 km below the seafloor is ~50° C (~90° F) between the diapiric province and the interior of the Lower Cretaceous carbonate platform. This Temperature difference may be large enough to significantly influence the hydrocarbon maturation history and the bacterial and thermochemical sulfate reduction processes that yield hydrogen sulfide gas within deep sediments.
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Geothermal gradient and Temperature of hydrogen sulfide-bearing reservoirs, Alabama continental shelf
AAPG Bulletin, 2005Co-Authors: Seiichi Nagihara, Michael A. SmithAbstract:Present-day formation Temperatures of the hydrogen sulfide (H2S)-bearing reservoirs in the James Limestone and the Norphlet Sandstone in the continental shelf off Alabama have been determined to be 138-149 and 191-217degreesC, respectively. Hydrogen sulfide gas in those reservoirs is generated by thermochemical sulfate reduction, a process sensitive to the ambient Temperature. Bottom-Hole Temperature data from 135 wells in the offshore lease areas of Mobile, Main Pass East Addition, and the northern section of Viosca Knoll were examined in the estimation of formation Temperatures. The bottom-Hole Temperatures were corrected for the thermal effect of drill-fluid circulation. Estimation of formation Temperatures permitted the determination of the geothermal gradient representative for the study area, leading to a Temperature range estimation for the H2S-bearing James and Norphlet reservoirs. Temperatures of offshore Norphlet reservoirs are higher than those reported previously for Norphlet reservoirs onshore. Temperatures of the James Limestone are close to the low-Temperature limit for thermochemical sulfate reduction previously suggested.
Hossein Yousefi - One of the best experts on this subject based on the ideXlab platform.
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Numerical simulation of power production from abandoned oil wells in Ahwaz oil field in southern Iran
Geothermics, 2015Co-Authors: Younes Noorollahi, Meysam Pourarshad, Saeid Jalilinasrabady, Hossein YousefiAbstract:Abandoned oil and gas wells can be used as low Temperature geothermal resources for heat extraction from geological formations. They can provide valuable potential sources of heat without the extra cost of deep drilling required in traditional geothermal projects. In this study, two oil wells (AZ and DQ) in southern Iran were numerically simulated using a 3D technique for heat extraction. The bottom-Hole Temperature of wells AZ and DQ were 138.7. °C and 159.8. °C, respectively. Heat transfer between the fluid injected into the well and the surrounding hot rock was simulated. Well casing geometry and an exact thermal gradient for two abandoned oil wells were considered. The simulation results were optimized for parameters such as input and output fluid flow rates and Temperatures. The results revealed that, in addition to thermal gradient and input mass flow rate, well casing geometry and the size of injection and extraction pipes were essential to the output heat extraction rate. The small internal diameter of the wells and design of the injection and extraction pipes were limited, resulting in lower mass flow rate and higher power consumption by the injection pump. Total extractable rate of heat from wells AZ-II and DQ-II was 967. kW and 1842. kW, respectively, and net electricity generation using a geothermal binary cycle was 138. kW and 364. kW, respectively.
Cyril Chellemichou - One of the best experts on this subject based on the ideXlab platform.
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geothermal state of the deep western alpine molasse basin france switzerland
Geothermics, 2017Co-Authors: Cyril Chellemichou, Damien Do Couto, Andrea Moscariello, Philippe Renard, Elme RusillonAbstract:Abstract Over the last few years the Western Alpine Molasse Basin (WAMB) has been attracting large institutional, industrial and scientific interest to evaluate the feasibility of geothermal energy production. However, the thermal state of the basin, which is instrumental to the development of such geothermal projects, has remained to date poorly known. Here, we compile and correct Temperature measurements (mostly bottom Hole Temperature) from 26 existing well data mostly acquired during former hydrocarbon exploration in the basin. These data suggest that the average geothermal gradient of the WAMB is around 25–30 °C/km. We further use these data to build the first well data-driven 3D geostatistical Temperature model of the wHole basin and generate probabilistic maps of isotherms at 70 and 140 °C. This model highlights a number of positive and negative thermal anomalies that are interpreted in the context of heat advection caused by fluid circulation along faults and/or karst systems. This study confirms that the WAMB has a great potential for low-enthalpy geothermal resources and presents a typology of advection-dominated potential targets.
Wen-long Cheng - One of the best experts on this subject based on the ideXlab platform.
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Insights into geothermal utilization of abandoned oil and gas wells
Renewable and Sustainable Energy Reviews, 2018Co-Authors: Yong-le Nian, Wen-long ChengAbstract:Abandoned oil and gas wells (AOGW) with high bottom-Hole Temperature contain abundant geothermal energy, which can be retrofitted to a novel geothermal system for different utilizations without high-cost drilling. Thus, at recently, some researchers concentrate on evaluation of the performance of thermal energy extraction from AOGW and geothermal power generation using AOGW with Organic Rankine cycle (ORC) systems. The aim of this paper is not only to review advanced geothermal utilizations for AOGW, but also make insights into the thermal simulation methods and power generation as well as working fluids selection for AOGW geothermal system. Due to heat extraction from AOGW dominating the geothermal utilizations; firstly, this paper performed to summarize and discuss the heat transfer models of AOGW geothermal system, which involve wellbore heat transfer and transient heat conduction in surrounding formation. Then, for evaluating the performance of power generation systems using AOGW, three different power plants were compared and the influence factors were examined. In addition, the optimum selection criteria of working fluids were also summarized, and the optimal fluids for different wells were determined. At last, the summary of key problems of the AOGW geothermal utilizations were proposed, and the future development and applications of AOGW were suggested for improving the geothermal utilizations.
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Evaluation of geothermal heating from abandoned oil wells
Energy, 2018Co-Authors: Yong-le Nian, Wen-long ChengAbstract:With continuous petroleum exploitation, more and more oil wells have been abandoned, which contain abundant geothermal energy. For utilizing the geothermal energy, this paper presents a new geothermal heating system using abandoned oil wells (AOW), and a comprehensive model combing wellbore heat transfer, formation and building energy transport is built, parameters including geothermal production, room Temperature and fluid production Temperature are examined by the built model. Simultaneously, a formation Temperature return model was developed to investigate the formation rewarming after heating period. Furthermore, the economic and energy analysis were performed to assessment the thermo-economic performance of the presented system. Particularly, an existing AOW with depth of 3000 m was concerned to heat a virtual building with heating area of 10000 m2. The results showed that the AOW could keep the building at around 26°C with water flow rate 20 m3/h, and the maximum heating area could reach 11000 m2. Also, the bottom-Hole Temperature could return to a steady point after the 2nd year. The total geothermal energy production was 5.5 × 1012J during heating period, which could reducing CO2emission about 457 ton each year. Specially, the largest total annualized cost of the new heating system was about half of that of conventional heating system.
David D. Blackwell - One of the best experts on this subject based on the ideXlab platform.
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Effect of an 860-m thick, cold, freshwater aquifer on geothermal potential along the axis of the eastern Snake River Plain, Idaho
Geothermal Energy, 2017Co-Authors: Thomas E. Lachmar, Thomas G. Freeman, Joseph F. Batir, Christopher J. Sant, Dennis L. Nielson, John W. Shervais, Jeffrey R. Walker, James P. Evans, David D. BlackwellAbstract:A 1912-m exploration coreHole was drilled along the axis of the eastern Snake River Plain, Idaho. Two Temperature logs run on the coreHole display an obvious inflection point at about 960 m. Such behavior is indicative of downward fluid flow in the wellbore. The geothermal gradient above 935 m is 4.5 °C/km, while the gradient is 72–75 °C/km from 980 to 1440 m. Projecting the higher gradients upward to where they intersect the lower gradient on the Temperature logs places the bottom of the cold, freshwater Snake River Plain aquifer, which suppresses the geothermal gradient at this location, at least 860 m below the surface. The average heat flow for the coreHole between 983 and 1550 m is 132 mW/m^2. Although the maximum bottom-Hole Temperature extrapolated from a measured time–Temperature curve was only 59.3 °C, geothermometers suggest an equilibrium Temperature on the order of 125–140 °C based on a single fluid sample from 1070 m. Furthermore, below 960 m the basalt core shows obvious signs of alteration, including a distinct color change, the formation of smectite clay, and the presence of secondary minerals filling vesicles and fracture zones. This alteration boundary could act as an effective cap or seal for a hot-water geothermal system.
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a well by well method for estimating surface heat flow for regional geothermal resource assessment
PROCEEDINGS Thirty-Seventh Workshop on Geothermal Reservoir Engineering, 2012Co-Authors: George Stutz, Maria Richards, Mitchell Williams, Zachary Frone, Tim Reber, Teresa E Jordan, David D. Blackwell, Jeff TesterAbstract:To accurately map local Temperature variations, resource assessments have relied largely on bottom Hole Temperature (BHT) measurements, primarily from oil and gas wells because of the high density of well sites in explored areas. As the volume of BHT data grows due to increased drilling activity, the ability to quickly analyze and incorporate additional data is critical. Currently, in the Appalachian basin of West Virginia and Pennsylvania, more than 1,000 wells are being drilled every year. Incorporating this number of BHT points using current techniques may take weeks to months. This paper presents an approach to quickly and efficiently incorporate additional well data into existing geothermal resource maps.
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Temperature at depth maps for the conterminous u s and geothermal resource estimates
GRC Transactions, 2011Co-Authors: David D. Blackwell, Maria Richards, Mitchell Williams, Zachary Frone, Joseph Batir, A Ruzo, Ryan Dingwall, Smu HuffingtonAbstract:A third generation geothermal resource assessment has recently been completed for the conterminous US based on a revised heat flow map using over 35,000 data sites. Improvements include: nearly doubling the number of data points used in the analysis, more detailed thermal conductivity models for Temperature-at-depth and heat flow calculations, and addition of a significant number of calibration wells as checks on the bottom Hole Temperature (BHT) correction. The results increase the accuracy of Temperature-at-depth models for the conterminous US. These Temperature models are the key input required for evaluating the nonconventional geothermal resources on a regional to sub-regional basis. The new resource assessment was prepared according to a proposed global protocol for estimating Enhanced/ Engineered Geothermal Systems (EGS) resource potential. A comparison of the new assessment approach with previous studies is provided, along with a discussion of the differences associated with the revised approach.