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Hydrologic Tests at Characterization Well R-14

Description: Well R-14 is located in Ten Site Canyon and was completed at a depth of 1316 ft below ground surface (bgs) in August 2002 within unassigned pumiceous deposits located below the Puye Formation (fanglomerate). The well was constructed with two screens positioned below the regional water table. Individual static depths measured for each isolated screen after the Westbay{trademark} transducer monitoring system was installed in mid-December 2002 were nearly identical at 1177 ft bgs, suggesting only horizontal subsurface flow at this time, location, and depth. Screen 1 straddles the geologic contact between the Puye fanglomerate and unassigned pumiceous deposits. Screen 2 is located about 50 ft deeper than screen 1 and is only within the unassigned pumiceous deposits. Constant-rate, straddle-packer, injection tests were conducted at screen 2, including two short tests and one long test. The short tests were 1 minute each but at different injection rates. These short tests were used to select an appropriate injection rate for the long test. We analyzed both injection and recovery data from the long test using the Theis, Theis recovery, Theis residual-recovery, and specific capacity techniques. The Theis injection, Theis recovery, and specific capacity methods correct for partial screen penetration; however, the Theis residual-recovery method does not. The long test at screen 2 involved injection at a rate of 10.1 gallons per minute (gpm) for 68 minutes and recovery for the next 85 minutes. The Theis analysis for screen 2 gave the best fit to residual recovery data. These results suggest that the 158-ft thick deposits opposite screen 2 have a transmissivity (T) equal to or greater than 143 ft{sup 2}/day, and correspond to a horizontal hydraulic conductivity (K) of at least 0.9 ft/day. The specific capacity method yielded a T value equal to or greater than 177 ft{sup 2}/day, and a horizontal …
Date: August 1, 2004
Creator: McLin, S. & Stone, W.
Partner: UNT Libraries Government Documents Department

Annual Hanford Seismic Report for Fiscal Year 1998

Description: Seismic monitoring at the Hanford Site was established in 1969 by the United States Geological Survey (USGS) under a contract with theJ.J.S. Atomic Energy Commission. In 1975, the University of Washington (UW) assumed responsibility for the network and subsequently expanded it. In 1979, the Basalt Waste o Isolation Program (13WIP) became responsible for collecting seismic data for the Hdord Site as part of site " characterization activities. Rockwell Htiord Operations, followed by Westinghouse Ha&ord Company . (WHC), operated the local network and were the contract technical advisors for the Eastern Washington Regional Network @wRN) operated and maintained by the UW. Funding for BWIP ended in December 1988. Seismic Monitoring and responsibility for the University of Washington contract were then trans- ferred to WHC'S Environmental Division. Maintenance responsibilities for the EWRN were also Assigned to WHC, who made major upgrades to EWRN sites. Effective October 1,1996, Seismic Monitoring was transfemed to the Pacific Northwest National Laboratory (PI@lL*). Seismic Monitoring is part of PNNL's Applied Geology and Geochemistry Group, Energy Technology Division. The Hanford Strong Motion Accelerometer network was constructed during 1997 and came online in May 1997. It operated continuously until September 30, 1997, when it was mothballed due to can- . cellation of fimding. Funding was restored on October 1, 1998, by joint agreement between the U.S. Department of Energy (DOE) and PNNL. Operation of the free-field sites resumed on November 20, 1998.
Date: December 22, 1998
Creator: Hartshorn, D. C.; Reidel, S. P. & Rohay, A. C.
Partner: UNT Libraries Government Documents Department

Fractional Calculus in Hydrologic Modeling: A Numerical Perspective

Description: Fractional derivatives can be viewed either as a handy extension of classical calculus or, more deeply, as mathematical operators defined by natural phenomena. This follows the view that the diffusion equation is defined as the governing equation of a Brownian motion. In this paper, we emphasize that fractional derivatives come from the governing equations of stable Levy motion, and that fractional integration is the corresponding inverse operator. Fractional integration, and its multi-dimensional extensions derived in this way, are intimately tied to fractional Brownian (and Levy) motions and noises. By following these general principles, we discuss the Eulerian and Lagrangian numerical solutions to fractional partial differential equations, and Eulerian methods for stochastic integrals. These numerical approximations illuminate the essential nature of the fractional calculus.
Date: January 1, 2012
Creator: Benson, David A.; Meerschaert, Mark M. & Revielle, Jordan
Partner: UNT Libraries Government Documents Department

Use of ARM Products in Reanalysis Applications and IPCC Model Assessment

Description: Year-3 of the project was spent developing an observed cloud climatology for Barrow, AK and relating the observed cloud fractions to the surface circulation patterns and locally observed winds. Armed with this information, we identified errors and sources of errors of cloud fraction simulations by numerical models in the Arctic. Specifically, we compared the cloud simulations output by the North American Regional Reanalysis (NARR) to corresponding observed cloud fractions obtained by the Department of Energy’s Atmospheric Radiation Measurement (ARM) program for four mid-season months: (January, April, July, and October). Reanalyses are obtained from numerical weather prediction models that are not run in real-time. Instead, a reanalysis model ingests a wide variety of historical observations for the purpose of producing a gridded dataset of many model-derived quantities that are as temporally homogeneous as possible. Therefore, reanalysis output can be used as a proxy for observations, although some biases and other errors are inevitable because of model parameterizations and observational gaps. In the observational analysis we documented the seasonality of cloudiness at the north slope including cloud base height and dependence on synoptic regime. We followed this with an evaluation of the associations of wind-speed and direction and cloud amounts in both the observational record and the reanalysis model. The Barrow cloud fraction data show that clear conditions are most often associated with anomalous high pressure to the north of Barrow, especially in spring and early summer. Overcast skies are most commonly associated with anomalous low pressure to the south. The observational analysis shows that low, boundary layer clouds are the most common type of cloud observed North Slope ARM observing site. However, these near-surface clouds are a major source of errors in the NARR simulations. When compared to observations, the NARR over-simulates the fraction of low clouds during the winter months, …
Date: September 30, 2011
Creator: Walsh, John E. & Chapman, William L.
Partner: UNT Libraries Government Documents Department

Mechanisms Leading to Co-Existence of Gas Hydrate in Ocean Sediments

Description: In this project we have sought to explain the co-existence of gas and hydrate phases in sediments within the gas hydrate stability zone. We have focused on the gas/brine interface at the scale of individual grains in the sediment. The capillary forces associated with a gas/brine interface play a dominant role in many processes that occur in the pores of sediments and sedimentary rocks. The mechanical forces associated with the same interface can lead to fracture initiation and propagation in hydrate-bearing sediments. Thus the unifying theme of the research reported here is that pore scale phenomena are key to understanding large scale phenomena in hydrate-bearing sediments whenever a free gas phase is present. Our analysis of pore-scale phenomena in this project has delineated three regimes that govern processes in which the gas phase pressure is increasing: fracturing, capillary fingering and viscous fingering. These regimes are characterized by different morphology of the region invaded by the gas. On the other hand when the gas phase pressure is decreasing, the corresponding regimes are capillary fingering and compaction. In this project, we studied all these regimes except compaction. Many processes of interest in hydrate-bearing sediments can be better understood when placed in the context of the appropriate regime. For example, hydrate formation in sub-permafrost sediments falls in the capillary fingering regime, whereas gas invasion into ocean sediments is likely to fall into the fracturing regime. Our research provides insight into the mechanisms by which gas reservoirs are converted to hydrate as the base of the gas hydrate stability zone descends through the reservoir. If the reservoir was no longer being charged, then variation in grain size distribution within the reservoir explain hydrate saturation profiles such as that at Mt. Elbert, where sand-rich intervals containing little hydrate are interspersed between intervals containing large hydrate …
Date: December 31, 2011
Creator: Bryant, Steven & Juanes, Ruben
Partner: UNT Libraries Government Documents Department

Hedberg Research Conference on Fundamental Controls on Flow in Carbonates: Request for Travel Support for Post-Doctoral Fellows

Description: Carbonate reservoirs pose a scientific and engineering challenge to geophysical prediction and monitoring of fluid flow in the subsurface. Difficulties in interpreting hydrological, reservoir and other exploration data arise because carbonates are composed of a hierarchy of geological structures, constituents and processes that span a wide spectrum of length and time scales. What makes this problem particularly challenging is that length scales associated with physical structure and processes are often not discrete, but overlap, preventing the definition of discrete elements at one scale to become the building blocks of the next scale. This is particularly true for carbonates where complicated depositional environments, subsequent post-deposition diagenesis and geochemical interactions result in pores that vary in scale from submicron to centimeters to fractures, variation in fabric composition with fossils, minerals and cement, as well as variations in structural features (e.g., oriented inter- and intra layered - interlaced bedding and/or discontinuous rock units). In addition, this complexity is altered by natural and anthropogenic processes such as changes in stress, fluid content, reactive fluid flow, etc. Thus an accurate geophysical assessment of the flow behavior of carbonate reservoirs requires a fundamental understanding of the interplay of textural and structural features subjected to physical processes that affect and occur on various length and time scales. To address this complexity related to carbonates, a Hedberg conference on “Fundamental Controls on Flow in Carbonates” was held July 8 to 13, 2012, to bring together industry and academic scientists to stimulate innovative ideas that can accelerate research advances related to flow prediction and recovery in carbonate reservoirs. Participants included scientist and engineers from multiple disciplines (such as hydrology, structural geology, geochemistry, reservoir engineering, geophysics, geomechanics, numerical modeling, physical experiments, sedimentology, well-testing, statistics, mathematics, visualization, etc.) who encompass experience as well as the latest advances in these multi-faceted fields. …
Date: April 28, 2013
Creator: Pyrak-Nolte, Laura J.
Partner: UNT Libraries Government Documents Department

ON""GENERAL CONSERVATION EQUATIONS FOR MULTIPHASE SYSTEMS: 1. AVERAGING PROCEDURE"" BY M. HASSANIZADEH AND W.G. GRAY.

Description: The author comments upon a point made in the referenced paper on general conservation equations. The author directs attention to the fact that the referenced paper's authors correctly point out that when an averaging operation involves integration, the integrand multiplied by the infinitesimal volume must be an additive quantity. The importance of this requirement is emphasized.
Date: December 1, 1979
Creator: Narasimhan, T.N.
Partner: UNT Libraries Government Documents Department

Derivation of site-specific relationships between hydraulic parameters and p-wave velocities based on hydraulic and seismic tomography

Description: In this study, hydraulic and seismic tomographic measurements were used to derive a site-specific relationship between the geophysical parameter p-wave velocity and the hydraulic parameters, diffusivity and specific storage. Our field study includes diffusivity tomograms derived from hydraulic travel time tomography, specific storage tomograms, derived from hydraulic attenuation tomography, and p-wave velocity tomograms, derived from seismic tomography. The tomographic inversion was performed in all three cases with the SIRT (Simultaneous Iterative Reconstruction Technique) algorithm, using a ray tracing technique with curved trajectories. The experimental set-up was designed such that the p-wave velocity tomogram overlaps the hydraulic tomograms by half. The experiments were performed at a wellcharacterized sand and gravel aquifer, located in the Leine River valley near Göttingen, Germany. Access to the shallow subsurface was provided by direct-push technology. The high spatial resolution of hydraulic and seismic tomography was exploited to derive representative site-specific relationships between the hydraulic and geophysical parameters, based on the area where geophysical and hydraulic tests were performed. The transformation of the p-wave velocities into hydraulic properties was undertaken using a k-means cluster analysis. Results demonstrate that the combination of hydraulic and geophysical tomographic data is a promising approach to improve hydrogeophysical site characterization.
Date: January 10, 2012
Creator: Brauchler, R.; Doetsch, J.; Dietrich, P. & Sauter, M.
Partner: UNT Libraries Government Documents Department

Mechanisms Leading to Co-Existence of Gas Hydrate in Ocean Sediments

Description: In this project we have sought to explain the co-existence of gas and hydrate phases in sediments within the gas hydrate stability zone. We have focused on the gas/brine interface at the scale of individual grains in the sediment. The capillary forces associated with a gas/brine interface play a dominant role in many processes that occur in the pores of sediments and sedimentary rocks. The mechanical forces associated with the same interface can lead to fracture initiation and propagation in hydrate-bearing sediments. Thus the unifying theme of the research reported here is that pore scale phenomena are key to understanding large scale phenomena in hydrate-bearing sediments whenever a free gas phase is present. Our analysis of pore-scale phenomena in this project has delineated three regimes that govern processes in which the gas phase pressure is increasing: fracturing, capillary fingering and viscous fingering. These regimes are characterized by different morphology of the region invaded by the gas. On the other hand when the gas phase pressure is decreasing, the corresponding regimes are capillary fingering and compaction. In this project, we studied all these regimes except compaction. Many processes of interest in hydrate-bearing sediments can be better understood when placed in the context of the appropriate regime. For example, hydrate formation in sub-permafrost sediments falls in the capillary fingering regime, whereas gas invasion into ocean sediments is likely to fall into the fracturing regime. Our research provides insight into the mechanisms by which gas reservoirs are converted to hydrate as the base of the gas hydrate stability zone descends through the reservoir. If the reservoir was no longer being charged, then variation in grain size distribution within the reservoir explain hydrate saturation profiles such as that at Mt. Elbert, where sand-rich intervals containing little hydrate are interspersed between intervals containing large hydrate …
Date: December 31, 2011
Creator: Bryant, Steven & Juanes, Ruben
Partner: UNT Libraries Government Documents Department
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