An Inventory of Geothermal Resources in Nebraska

The goal of the State Coupled Resource Assessment Program is to identify and evaluate geothermal resources in the state, particularly low-temperature potential. Eight tasks were identified and documented in this report as follows: TASK ONE: Bottom-hole Temperature Survey TASK TWO: Heat Flow and Temperature Gradient Survey TASK THREE: Data Translation studies TASK FOUR: Gravity Data TASK FIVE: Substate Regions TASK SIX: Information Dissemination Heat Flow and Temperature Gradient Survey TASK SEVEN: State Geothermal Map TASK EIGHT: Reports The project had three major products; (1) a map Geothermal Resources of Nebraska,” (2) a significant amount of thermal data collected and documented within the state, and (3) a series of publications, presentations and meetings (documented as an Appendix)

Performance Improvements for a Large-scale Geological Simulation

AbstractGeological models have been successfully used to identify and study geothermal energy resources. Many computer simulations based on these models are data-intensive applications. Large-scale geological simulations require high performance computing (HPC) techniques to run within reasonable time constraints and performance levels. One research area that can benefit greatly from HPC techniques is the modeling of heat flow beneath the Earth's surface. This paper describes the application of HPC techniques to increase the scale of research with a well-established geological model. Recently, a serial C++ application based on this geological model was ported to a parallel HPC applications using MPI. An area of focus was to increase the performance of the MPI version to enable state or regional scale simulations using large numbers of processors. First, synchronous communications among MPI processes was replaced by overlapping communication and computation (asynchronous communication). Asynchronous communication improved performance over synchronous communications by averages of 28% using 56 cores in one environment and 46% using 56 cores in another. Second, an approach for load balancing involving repartitioning the data at the start of the program resulted in runtime performance improvements of 32% using 48 cores in the first environment and 14% using 24 cores in the second when compared to the asynchronous version. An additional feature, modeling of erosion, was also added to the MPI code base. The performance improvement techniques under erosion were less effective

Deep Direct Use Geothermal Energy in the North Dakota Clean Energy Transition Strategy

The geothermal heat in the Williston Basin is an energy giant that can provide sustainable, renewable, and ecologically sound heat and power for the state of North Dakota (ND). We have known of this resource for decades, but development has been delayed for reasons which can be summed as economic competition from existing fossil fuel energy sources. With the “seismic” shock of the Covid-19 pandemic reverberating through the state’s carbon-centric economy, the timing is ideal for acting quickly to develop this energy resource. Coincidentally, the State Energy Research Center (SERC) within the Energy & Environmental Research Center (EERC), has recently embarked on an analysis of ND’s energy future, and the availability and sustainability of resources for the state and the citizens of ND. Thus, the opportunity to examine the case for including geothermal energy in the strategy is at hand. The option we examine here is Deep Direct Use (DDU) geothermal energy, in multiple applications and in conjunction with Advanced Energy Storage technology. DDU can reduce and replace demand on energy supplies in two applications: direct use heat and electrical power. While in grid energy terms each DDU unit is relatively small, hundreds of these units would have a significant impact and merit consideration in the energy strategy. Realizing that DDU development is not currently market-driven, we are framing the analysis for potential early adopters and energy policy advisors based on a reference design and using that design to examine the project economics. The purpose of this paper is to get an early indication of whether the early stage project economics indicate “stop now”, or “proceed with caution”

Differences between repeated borehole temperature logs in the southern Canadian Prairies-validating borehole climatology

International audienceTemperature-depth (T-z) profiles from twenty-four shallow boreholes of less than 250 m in depth located in flat, semi-arid areas of the southern Canadian Prairie Provinces initially measured in the late 1980's and early 1990's and repeated between 2004 and 2006 show strong ground surface temperature (GST) warming signatures. GST changes of 0.1?0.2°C, and 0.4°C, are observed between the measurements for the shorter (decade) and longer (two decades) time spans, respectively. Borehole sites with repeated temperature logs are selected to demonstrate that multiple T-z profiles provide general agreement between GST warming and observed surface air temperature (SAT) warming measured at nearby historical climate stations. A comparison of measured changes from repeated temperature logs with those simulated from SAT forcing demonstrates the influence of SAT on the observed deviation of temperature with depth despite variations in snow cover. Repeated borehole measurements from the northern Great Plains of the USA also identify a similar positive temperature change but of lower magnitude. Temperature changes since 1900 in the southern Canadian Prairies and the adjoining northern Great Plains of the USA, as derived from the functional state inversion (FSI) of deeper borehole logs, average 2.5°C but show a strong latitudinal gradient

Using Geothermal Energy to Reduce Oil Production Costs

The economic impact of the Covid-19 pandemic on the oil industry has been devastating. The decline in demand and price collapse have been particularly disruptive for shale oil extraction which is inherently more expensive than conventional operations. Survival and continuing operations will depend partly on reducing operating costs, and a ubiquitous and substantial cost in oil production is electrical power used primarily for pumping the wells. The Bakken in North Dakota play is particularly vulnerable because there is not an adequate electrical grid in the region. Many Bakken fields rely on generators burning propane, gasoline or diesel fuel at costs about $0.28 per kWh - four times grid costs. Shale plays have the unique characteristic of multiple wells per pad so that the total fluid available can be enough for coproduction of 10s to 100s of kW with an ORC on site. Bakken temperatures range from 100 °C where heat flow is low (≈50 mW m-2) and the Bakken is shallower on the eastern margin of the shale play to 140 °C where heat flow is higher (≈70 mW m-2) and the Bakken is deeper in the center of the basin. Previous analyses of the potential for coproduction were based on total field and large multi-well pad production volumes and did not address fluid flow per individual well. Analysis of heat loss with 2-D and 3-D models indicates coproduction is not feasible because fluids in Bakken wells lose too much heat during the slow 3-km transit to the surface. Water-rich carbonate rocks underlying the Bakken have higher temperatures and could generate several MW of power at local sites. Three scenarios for the higher power operations include: 1) Recompleting marginally economic existing oil wells in the overlying Lodgepole Formation and converting to water production; 2) Installing ORCs on the many water flood projects in the basin; 3) Drilling dedicated well fields for geothermal power production. After use in the ORCs, the hot waters could be used for low-cost space heating and further reduction of energy costs. An average submersible pump requires 16 kW, so, for example, if an ORC generated 160kW it could supply enough electricity to pump 10 wells

Geothermal resource assessment for North Dakota. Final Report

Temperatures in four geothermal aquifers, inyan Kara (Cretaceous), Mission Canyon (Mississippian), Duperow (Devonian), and Red River (Ordovician) are in the range for low and moderate temperature geothermal resources within an area of about 130,000 km{sup 2} in North Dakota. The accessible resource base is 13,500 x 10{sup 18} J., which, assuming a recovery factor of 0.001, may represent a greater quantity of recoverable energy than is present in the basin in the form of petroleum. A synthesis of heat flow, thermal conductivity, and stratigraphic data was found to be significantly more accurate in determining formation temperatures than the use of linear temperature gradients derived from bottom hole temperature data. The thermal structure of the Williston Basin is determined by the thermal conductivities of four principal lithologies: Tertiary silts and sands (1.6 W/m/K), Mesozoic shales (1.2 W/m/K), Paleozoic limestones (3.2 W/m/K), and Paleozoic dolomites (3.5 W/m/K). The stratigraphic placement of these lithologies leads to a complex, multi-component geothermal gradient which precludes use of any single component gradient for accurate determination of subsurface temperatures

A Relook at Canada’s Western Canada Sedimentary Basin for Power Generation and Direct-Use Energy Production

The Alberta No. 1 Project, under the terms of Canada’s Federal government’s Emerging Renewable Power Program (ERPP), must produce 5MWe net. The goal of this study was to identify areas where three essential constraining conditions overlap; (1) the temperature gradient is sufficiently high that 120°C brines at depths of 4,500m or less are potentially available, (2) there are formations at the depths targeted with known high fluid flows, and (3) there is adequate existing infrastructure that supports low-cost power grid connection as well as a direct use application. A fluid temperature of at least 120oC is needed to profitably operate the plant. Temperatures below this require increasingly greater amount of fluids to be pumped and injected making them uneconomic. Three hundred liters per second (l/sec) of 120oC water is required to generate 5 MW net of electrical power with an Organic Rankin Cycle (ORC) binary plant. A depth cut off from a project economics perspective is about 4,500m for large diameter geothermal wells. Fortunately, these formations don’t need to be thick to supply these volumes of water to the well bore and thin permeable formations are expected to be laterally extensive in the regional layer cake (Western Canada Sedimentary Basin, WCSB) geology of Alberta. Thus, targeting known high fluid producing geologic units, rather than narrow faults is an important aspect of developing a geothermal project in the WCSB. Alberta No. 1 identified nine study areas to assess for geothermal potential. Of these, the Tri-Municipal Industrial Park (south of Grande Prairie) was determined to be the most suitable for both power production and development, followed by Edson (west-central Alberta). Other areas were identified as being most suitable for basement EGS to produce power, as well as direct use from shallower formations

Keith County, Nebraska, Map Series

KEITH COUNTY--LIST OF MAPS AND THEIR AUTHORS Topography--U. S. Geological Survey Index of 7.5\u27 Topographic Quadrangles and Township Boundaries--R. F. Diffendal, Jr. Generalized Soils Map--M. Kuzila and J. Culver Approximate Loess Thickness--R. F. Diffendal, Jr. Bedrock Geologic Map--R. F. Diffendal, Jr. Volcanic Ash Localities--R. F. Diffendal, Jr. Ogallala Vertebrate Faunal Sites--R. F. Diffendal, Jr. Ogallala Group Outcrops--R. F. Diffendal, Jr. White River Group Outcrops--R. F. Diffendal, Jr. Conservation and Survey Division Test Hole Locations--R. F. Diffendal, Jr. Oil and/or Gas Test Hole Locations--R. F. Diffendal, Jr. Mineral Resources Localities--R. F. Diffendal, Jr. Locations of Registered Irrigation Wells--R. F. Diffendal, Jr. Configuration of Top of Bedrock--R. F. Diffendal, Jr. Configuration of Top of White River Group (= Brule Fm.)--R. F. Diffendal, Jr. Configuration of Top of Cretaceous--H. M. DeGraw Configuration of Top of Niobrara Fm.--H. M. DeGraw Configuration of Base of Greenhorn Limestone--H. M. DeGraw Configuration of Top of Permian System--R. R. Burchett Structural Contours on Top of Stone Corral--R. R. Burchett Structural Contours on Top of Pennsylvanian System--R. R. Burchett Depth to Precambrian Surface--M. P. Carlson Configuration of Top of Precambrian--R. R. Burchett and M. P. Carlson Geothermal Projected Temperatures on Top of Dakota Group--D. Eversoll and W. Gosnold Bouguer Gravity Anomaly Map--R. R. Burchett and T. Eversol

Conduction‐dominated heat transport of the annual temperature signal in soil

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/95182/1/jgrb13727.pd

Keith County, Nebraska, Map Series

KEITH COUNTY--LIST OF MAPS AND THEIR AUTHORS Topography--U. S. Geological Survey Index of 7.5\u27 Topographic Quadrangles and Township Boundaries--R. F. Diffendal, Jr. Generalized Soils Map--M. Kuzila and J. Culver Approximate Loess Thickness--R. F. Diffendal, Jr. Bedrock Geologic Map--R. F. Diffendal, Jr. Volcanic Ash Localities--R. F. Diffendal, Jr. Ogallala Vertebrate Faunal Sites--R. F. Diffendal, Jr. Ogallala Group Outcrops--R. F. Diffendal, Jr. White River Group Outcrops--R. F. Diffendal, Jr. Conservation and Survey Division Test Hole Locations--R. F. Diffendal, Jr. Oil and/or Gas Test Hole Locations--R. F. Diffendal, Jr. Mineral Resources Localities--R. F. Diffendal, Jr. Locations of Registered Irrigation Wells--R. F. Diffendal, Jr. Configuration of Top of Bedrock--R. F. Diffendal, Jr. Configuration of Top of White River Group (= Brule Fm.)--R. F. Diffendal, Jr. Configuration of Top of Cretaceous--H. M. DeGraw Configuration of Top of Niobrara Fm.--H. M. DeGraw Configuration of Base of Greenhorn Limestone--H. M. DeGraw Configuration of Top of Permian System--R. R. Burchett Structural Contours on Top of Stone Corral--R. R. Burchett Structural Contours on Top of Pennsylvanian System--R. R. Burchett Depth to Precambrian Surface--M. P. Carlson Configuration of Top of Precambrian--R. R. Burchett and M. P. Carlson Geothermal Projected Temperatures on Top of Dakota Group--D. Eversoll and W. Gosnold Bouguer Gravity Anomaly Map--R. R. Burchett and T. Eversol