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Using the Schur Complement to Reduce Runtime in KULL's Magnetic Diffusion Package (open access)

Using the Schur Complement to Reduce Runtime in KULL's Magnetic Diffusion Package

Recently a Resistive Magnetohydrodynamics (MHD) package has been added to the KULL code. In order to be compatible with the underlying hydrodynamics algorithm, a new sub-zonal magnetics discretization was developed that supports arbitrary polygonal and polyhedral zones. This flexibility comes at the cost of many more unknowns per zone - approximately ten times more for a hexahedral mesh. We can eliminate some (or all, depending on the dimensionality) of the extra unknowns from the global matrix during assembly by using a Schur complement approach. This trades expensive global work for cache-friendly local work, while still allowing solution for the full system. Significant improvements in the solution time are observed for several test problems.
Date: December 15, 2010
Creator: Brunner, T A & Kolev, T V
System: The UNT Digital Library
Development and Implementation of a Program Management Maturity Model (open access)

Development and Implementation of a Program Management Maturity Model

In 2006, Honeywell Federal Manufacturing & Technologies (FM&T) announced an updatedvision statement for the organization. The vision is “To be the most admired team within the NNSA [National Nuclear Security Administration] for our relentless drive to convert ideas into the highest quality products and services for National Security by applying the right technology, outstanding program management and best commercial practices.” The challenge to provide outstanding program management was taken up by the Program Management division and the Program Integration Office (PIO) of the company. This article describes how Honeywell developed and deployed a program management maturity model to drive toward excellence.
Date: December 15, 2008
Creator: Hartwig, Laura & Smith, Matt
System: The UNT Digital Library
Final Report of the Simulation Optimization Task Force (open access)

Final Report of the Simulation Optimization Task Force

This is the final report of the ATLAS Simulation Optimization Task Force, establishedin June of 2007. This note justifies the selected Geant4 version, physics list, and range cuts to be used by the default ATLAS simulation for initial data taking and beyond. The current status of several projects, including detector description, simulation validation, studies of additional Geant4 parameters, and cavern background, are reported.
Date: December 15, 2008
Creator: Collaboration, ATLAS; Rimoldi, A.; Carli, T.; Dell'Acqua, A.; Froidevaux, D.; Gianotti, F. et al.
System: The UNT Digital Library
Control Banding and Nanotechnology Synergist (open access)

Control Banding and Nanotechnology Synergist

The average Industrial Hygienist (IH) loves a challenge, right? Okay, well here is one with more than a few twists. We start by going through the basics of a risk assessment. You have some chemical agents, a few workers, and the makings of your basic exposure characterization. However, you have no occupational exposure limit (OEL), essentially no toxicological basis, and no epidemiology. Now the real handicap is that you cannot use sampling pumps, cassettes, tubes, or any of the media in your toolbox, and the whole concept of mass-to-dose is out the window, even at high exposure levels. Of course, by the title, you knew we were talking about nanomaterials (NM). However, we wonder how many IHs know that this topic takes everything you know about your profession and turns it upside down. It takes the very foundations that you worked so hard in college and in the field to master and pulls it out from underneath you. It even takes the gold standard of our profession, the quantitative science of exposure assessment, and makes it look pretty darn rusty. Now with NM there is the potential to get some aspect of quantitative measurements, but the instruments are generally very …
Date: December 15, 2009
Creator: Zalk, D & Paik, S
System: The UNT Digital Library
Analysis of Flow Cytometry DNA Damage Response Protein Activation Kinetics Following X-rays and High Energy Iron Nuclei Exposure (open access)

Analysis of Flow Cytometry DNA Damage Response Protein Activation Kinetics Following X-rays and High Energy Iron Nuclei Exposure

We developed a mathematical method to analyze flow cytometry data to describe the kinetics of {gamma}H2AX and pATF2 phosphorylations ensuing various qualities of low dose radiation in normal human fibroblast cells. Previously reported flow cytometry kinetic results for these DSB repair phospho-proteins revealed that distributions of intensity were highly skewed, severely limiting the detection of differences in the very low dose range. Distributional analysis reveals significant differences between control and low dose samples when distributions are compared using the Kolmogorov-Smirnov test. Radiation quality differences are found in the distribution shapes and when a nonlinear model is used to relate dose and time to the decay of the mean ratio of phosphoprotein intensities of irradiated samples to controls. We analyzed cell cycle phase and radiation quality dependent characteristic repair times and residual phospho-protein levels with these methods. Characteristic repair times for {gamma}H2AX were higher following Fe nuclei as compared to X-rays in G1 cells (4.5 {+-} 0.46 h vs 3.26 {+-} 0.76 h, respectively), and in S/G2 cells (5.51 {+-} 2.94 h vs 2.87 {+-} 0.45 h, respectively). The RBE in G1 cells for Fe nuclei relative to X-rays for {gamma}H2AX was 2.05 {+-} 0.61 and 5.02 {+-} 3.47, at 2 …
Date: December 15, 2010
Creator: Association, Universities Space Research; Chappell, Lori J.; Whalen, Mary K.; Gurai, Sheena; Ponomarev, Artem; Cucinotta, Francis A. et al.
System: The UNT Digital Library
Phased array compaction cell for measurement of the transversely isotropic elastic properties of compacting sediments (open access)

Phased array compaction cell for measurement of the transversely isotropic elastic properties of compacting sediments

Sediments undergoing compaction typically exhibit transversely isotropic (TI) elastic properties. We present a new experimental apparatus, the phased array compaction cell, for measuring the TI elastic properties of clay-rich sediments during compaction. This apparatus uses matched sets of P- and S-wave ultrasonic transducers located along the sides of the sample and an ultrasonic P-wave phased array source, together with a miniature P-wave receiver on the top and bottom ends of the sample. The phased array measurements are used to form plane P-waves that provide estimates of the phase velocities over a range of angles. From these measurements, the five TI elastic constants can be recovered as the sediment is compacted, without the need for sample unloading, recoring, or reorienting. This paper provides descriptions of the apparatus, the data processing, and an application demonstrating recovery of the evolving TI properties of a compacting marine sediment sample.
Date: December 15, 2010
Creator: Nihei, K.T.; Nakagawa, S.; Reverdy, F.; Meyer, L.R.; Duranti, L. & Ball, G.
System: The UNT Digital Library
Isotopic evidence for the infiltration of mantle and metamorphic CO2-H2O fluids from below in faulted rocks from the San Andreas Fault System (open access)

Isotopic evidence for the infiltration of mantle and metamorphic CO2-H2O fluids from below in faulted rocks from the San Andreas Fault System

To characterize the origin of the fluids involved in the San Andreas Fault (SAF) system, we carried out an isotope study of exhumed faulted rocks from deformation zones, vein fillings and their hosts and the fluid inclusions associated with these materials. Samples were collected from segments along the SAF system selected to provide a depth profile from upper to lower crust. In all, 75 samples from various structures and lithologies from 13 localities were analyzed for noble gas, carbon, and oxygen isotope compositions. Fluid inclusions exhibit helium isotope ratios ({sup 3}He/{sup 4}He) of 0.1-2.5 times the ratio in air, indicating that past fluids percolating through the SAF system contained mantle helium contributions of at least 35%, similar to what has been measured in present-day ground waters associated with the fault (Kennedy et al., 1997). Calcite is the predominant vein mineral and is a common accessory mineral in deformation zones. A systematic variation of C- and O-isotope compositions of carbonates from veins, deformation zones and their hosts suggests percolation by external fluids of similar compositions and origin with the amount of fluid infiltration increasing from host rocks to vein to deformation zones. The isotopic trend observed for carbonates in veins and …
Date: December 15, 2010
Creator: Pili, E.; Kennedy, B.M.; Conrad, M.E. & Gratier, J.-P.
System: The UNT Digital Library
Prompt Energy Distribution of 235U(n,f)gamma at Bombarding Energies of 1 to 20 MeV (open access)

Prompt Energy Distribution of 235U(n,f)gamma at Bombarding Energies of 1 to 20 MeV

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Date: December 15, 2011
Creator: Kwan, E.; Wu, C. Y.; Haight, R. C.; Lee, H. Y.; Bredeweg, T. A.; Chyzh, A. et al.
System: The UNT Digital Library
Krakatau's long goodbye in the Ocean (open access)

Krakatau's long goodbye in the Ocean

State-of-the-art climate models suggest that 20th Century ocean warming and sea-level rise were substantially reduced by the 1883 eruption of Krakatau. Volcanically induced cooling of the ocean surface penetrated into deeper layers where it persisted for decades. We find that volcanic eruptions have longer lasting effects than previously suspected, sufficient to offset a large fraction of ocean warming and sea-level rise caused by anthropogenic influences over the 20th Century. We examine the latest suite of coupled ocean-atmosphere model experiments that include time-varying external forcings (e.g., changes in greenhouse gases, solar irradiance, sulfate aerosols and volcanic aerosols) for the period 1880-2000 (see Methods). These models have differences in physics, resolution, initial conditions, 'spin-up' and ocean-atmosphere coupling procedures, as well as different combinations of external forcings. Uncertainties in both the applied forcings and in the model responses to them are therefore inherent in our investigation.
Date: December 15, 2005
Creator: Gleckler, P.; Wigley, T.; Santer, B.; Gregory, J.; AchutaRao, K. & Taylor, K.
System: The UNT Digital Library
Laboratory Physical Model for Pattern Injection in Geothermal Systems (open access)

Laboratory Physical Model for Pattern Injection in Geothermal Systems

In the development of geothermal sources for power generation, production of geothermal fluids as well as reinjection becomes an important aspect for significant heat extraction from the reservoir rock. The purpose of this work was to understand how cold water injection in five spot pattern affected the temperature distributions and production pressures in a physical model with a constant temperature heat source. The production and injection rates were varied as well as their respective depths. The model is a hot water dominated system with crushed limestone of 0.6-0.9 cm particle size as the reservoir rock, which had 40% porosity, 58 darcy permeability. The analysis revealed that injection rate should be at least 2/3 of production rate (measured as condensed water) so that the pressure decline at the producing end was stopped. Heat extraction from the system was high when injection was done towards the top of the model while production horizon was deeper.
Date: December 15, 1983
Creator: Parlaktuna, M. & Okandan, E.
System: The UNT Digital Library
One Component Two Phase Flow in Horizontal and Vertical Ducts: Some Basic Considerations (open access)

One Component Two Phase Flow in Horizontal and Vertical Ducts: Some Basic Considerations

For a description and analysis of the flow they consider the conservation equations of the two phases separately, but in thermal and mechanical equilibrium, coupled by the itnerface shear forces (two fluid model, drift flux model). Coupling may be weak or strong, depending on Froude and Mach numbers of the flow. The fluid is highly compressible, not because the individual phases move at such speeds that their individual density changes are significant but because evapiration (phase change) results in large density changes of the system at moderate pressure or temperature changes once flashing occurs. The slip between the phases is caused by unequal wall shear stress, acceleration of the fluid or gravitational forces and is hindered by the interface interaction. if they denote by {gamma} the ratio of the liquid density to the vapor density and by {sigma} the ratio of the vapor speed to the liquid speed they find that in horizontal flows {sigma} = {gamma}{sup 1/2} yields the maximum slip (neglecting acceleration effects) that can be reached with no interface force acting (assuming equal friction coefficients for both phases at the wall). If one investigates the conditions of thermodynamic flow similarity between different substances in two phase flow, …
Date: December 15, 1983
Creator: Maeder, Paul F.; Dickinson, David A. & Nikitopoulos, Dimitris E.
System: The UNT Digital Library
Design and Development of a Test Facility to Study Two-Phase Steam/Water Flow in Porous Media (open access)

Design and Development of a Test Facility to Study Two-Phase Steam/Water Flow in Porous Media

The concept of relative permeability is the key concept in extending Darcy's law for single phase flow through porous media to the two-phase flow regime. Relative permeability functions are needed for simulation studies of two-phase geothermal reservoirs. These are poorly known inspite of considerable theoretical and experimental investigations during the last decade. Since no conclusive results exist, many investigators use ad hoc parametrization, or adopt results obtined from flow of oil and gas (Corey, 1954). It has been shown by Reda and Eaton (1980) that this can lead to serious deficiencies. Sensitivity of the relative permeability curves for prediction of mass flow rate and flowing enthalpy into geothermal wells has been studied by many investigators (e.g. Eaton and Reda (1980), Bodvarsson et al (1980), Sun and Ershagi (1979) etc.). It can be concluded from these studies that the beehavior of a two-phase steam/water reservoir depends greatly on the relative permeability curves used. Hence, there exists a need for obtaining reliable relative permeability functions.
Date: December 15, 1983
Creator: Verma, Ashok K.; Pruess, Karsten; Bodvarsson, G. S.; Tsang, C. F. & Witherspoon, Paul A.
System: The UNT Digital Library
Interpretation of Interference Data from the Klamath Falls, Oregon Geothermal Resource (open access)

Interpretation of Interference Data from the Klamath Falls, Oregon Geothermal Resource

Data from a seven week pressure interference test in the Klamath Falls, Oregon geothermal resource have been analyzed. The data indicate that productive wells are fed by a highly permeable fracture network and that the less permeable matrix blocks contribute significantly to the reservoir storage capacity. Detailed analysis of data from two wells is presented. Data from both of the wells yield a reservoir permeability-thickness (kh) of approximately 1.3x10{sup 6} md-ft and a storativity of 6.8x10{sup -3} ft/psi. The parameters ({lamda} and {omega}), which are determined by the distribution of permeability and storativity between the matrix and fractures, vary by more than an order of magnitude. A sensitivity study shows that for these wells, the pressure transients are not very sensitive to the distribution of permeability and storativity between the fractures and matrix blocks. No hydrologic boundaries were detected during the test. This indicates that the fault which supplies hot water to the shallow hydrothermal system does not behave according to the cassical model of either a barrier or constant potential boundary.
Date: December 15, 1983
Creator: Benson, S.M.
System: The UNT Digital Library
Pressure Transient Analysis for Large Scale Hydraulic Injections in the Carnmenellis Granite, England (open access)

Pressure Transient Analysis for Large Scale Hydraulic Injections in the Carnmenellis Granite, England

Large volume hydraulic injections into the Carnmenellis granite have been completed at the CSM Hot Dry Rock Project during the period October 1982 to July 1983, with small volume injections before and after this period. The effects of the injections on the hydraulic properties of the rock mass have been estimated by pressure transient analysis. The growth of the reservoir zone was tracked with microseismic locations, and the growth mechanism modeled with the computer program FRIP. The limited duration of the transients amenable to analysis and the tendency for growth below the injection zone meant that the interpretations could only describe hydraulic conditions within about 100 m of the wellbores. The effect of the large volume injections was to increase permeability values from less than 100 {micro}d to greater than 5 md, and to decrease skin values from about -3 to about -6. The FRIP modeling explained the observed reservoir growth in plan with reference to measured in-situ stresses, jointing and rock properties and showed some of the limitations of continuum modeling.
Date: December 15, 1983
Creator: Pine, R. J.
System: The UNT Digital Library
PLEIADES: High Peak Brightness, Subpicosecond Thomson Hard-X-ray source (open access)

PLEIADES: High Peak Brightness, Subpicosecond Thomson Hard-X-ray source

The Picosecond Laser-Electron Inter-Action for the Dynamic Evaluation of Structures (PLEIADES) facility, is a unique, novel, tunable (10-200 keV), ultrafast (ps-fs), hard x-ray source that greatly extends the parameter range reached by existing 3rd generation sources, both in terms of x-ray energy range, pulse duration, and peak brightness at high energies. First light was observed at 70 keV early in 2003, and the experimental data agrees with 3D codes developed at LLNL. The x-rays are generated by the interaction of a 50 fs Fourier-transform-limited laser pulse produced by the TW-class FALCON CPA laser and a highly focused, relativistic (20-100 MeV), high brightness (1 nC, 0.3-5 ps, 5 mm.mrad, 0.2% energy spread) photo-electron bunch. The resulting x-ray brightness is expected to exceed 10{sup 20} ph/mm{sup 2}/s/mrad{sup 2}/0.1% BW. The beam is well-collimated (10 mrad divergence over the full spectrum, 1 mrad for a single color), and the source is a unique tool for time-resolved dynamic measurements in matter, including high-Z materials.
Date: December 15, 2003
Creator: Kuba, J.; Anderson, S. G.; Barty, C. J.; Betts, S. M.; Booth, R.; Brown, W. J. et al.
System: The UNT Digital Library
Gas Chemistry in Geothermal Systems (open access)

Gas Chemistry in Geothermal Systems

Five new gas geothermometers are introduced. They are useful for predicting subsurface temperatures in water dominated geothermal systems. The geothermometers use data on CO{sub 2}, H{sub 2}S and H{sub 2} concentrations in fumarole steam as well as CO{sub 2}/H{sub 2} and H{sub 2}S/H{sub 2} ratios. It is demonstrated that the gas composition of fumarole steam may be used with or withour drillhole data to evaluate steam condensation in the upflow zones of geothermal systems. Uncertainty exists, however, in distinguishing between the effects of steam condensation and phase separation at elevated pressures. The gas content in steam from discharging wells and the solute content of the water phase can be used to evaluate which boiling processes lead to "excess steam" in the discharge and at which temperature this "excess steam" is added to the fluid moving through the aquifer and into the well. Examples, using field data, are given to demonstrate all the mentioned applications of geothermal chemistry.
Date: December 15, 1983
Creator: Arnorsson, Stefan & Gunnlaugsson, Einar
System: The UNT Digital Library
Nonisothermal Injectivity Index can Infer Well Productivity and Reservoir Transmissivity (open access)

Nonisothermal Injectivity Index can Infer Well Productivity and Reservoir Transmissivity

In geothermal wells injection tests are commonly used to obtain well and reservoir data. These tests are typically conducted in a series of step rates followed or preceded by a complete shutin. Usually the temperature of the injected fluid is different from that of the reservoir fluid. Because of the strong temperature dependence of fluid viscosity and to a lesser extent, fluid density, nonisothermally related pressure responses must be considered. The nonisothermal isjectivity index obtained from these tests depends on the mobility ratio of the cold region to the hot reservoir and the extent of the cold spot. This paper proposes a method which accounts for these effects and relates the nonisothermal injectivity index to the isothermal injectivity index.
Date: December 15, 1983
Creator: Sigurdsson, Omar; Bodvarsson, Gudmundur S. & Stefansson, Valgardur
System: The UNT Digital Library
Analysing Spinner Measurements from Well Tests Using Computerized Interpretation Techniques (open access)

Analysing Spinner Measurements from Well Tests Using Computerized Interpretation Techniques

The development of reliable spinner tools may help avoid much of the ambiquity which often accompanies well tests in geothermal wells, due to interlayer flows through the well bore. However, the use of both pressure and flow rate changes requires new methods of well test interpretation. The Stanford Geothermal Program has been developing microcomputer-based techniques for the simultaneous analysis of pressure and flow rate measurements. There are two key steps in the procedure. Firstly, the non-linear regression is achieved by calculating the gradients of the response (with respect to the unknown reservoir parameters) in Laplace space, and inverting numerically. Secondly, the variable flow rate is represented in terms of a superposition of many step changes - this was found to work better than a spline fit to the data. One problem was encountered when attempting to analyze data in which the spinner "stalled", causing a jump to zero flow rate. The method shows great promise in that the degrees of freedom on the interpretation are greatly reduced, the well bore storage effect disappears, and inter-feed flows do not affect the results.
Date: December 15, 1983
Creator: Horne, Roland N.; Guillot, Alain & Rosa, Adalberta
System: The UNT Digital Library
Geothermal Field Developments in Japan (open access)

Geothermal Field Developments in Japan

The present situation of the geothermal field developments in Japan is such that eight geothermal power stations are being operated, while there are sill many geothermal areas to be explored. Up to this day, the target of geothermal exploration has mainly been the areas by surface geological survey and the existing geothermal reservoirs are located not deeper than 1,500m depth. Recent geothermal energy development shows a trend from the study on vapor dominated of liquid dominated hydrothermal resources in shallow zones to that on hydrothermal resources in deeper zones. Exploration wells of 3,000m depth class have been drilled in Japan.
Date: December 15, 1983
Creator: Hirakawa, Seiichi
System: The UNT Digital Library
Geothermal Field Development in the European Community Objectives, Achievements and Problem Areas (open access)

Geothermal Field Development in the European Community Objectives, Achievements and Problem Areas

Achievements and problem areas are reviewed with respect to various engineering implications of geothermal field development in the European Community (EC). Current and furture development goals address three resource settings. (a) low enthalpy sources (30-150{degrees}C), an outlook common to all Member states as a result of hot water aquifers flowing in large sedimentary units with normal heat flow, widespread thoughout the EC; (b) high enthalpy sources (<150{degrees}C) in areas of high heat flow which, as a consequence of the geodynamics of the Eurasian plate, are limited to Central and South-West Italy and to Eastern Greece; (c) hot dry rocks (HDR), whose potential for Europe, and also the difficulties in implementing the heat mining concept, are enormous. A large scale experiment conducted at medium depth in Cornwall (UK) proves encouraging though. It has provided the right sort of scientific inputs to the understanding of the mechanics of anisotropic brittle basement rocks.
Date: December 15, 1983
Creator: Ungemach, Pierre
System: The UNT Digital Library
Mapping the Acid Stimulation in the Beowawe Geothermal Field Using Surface Electrical Potentials (open access)

Mapping the Acid Stimulation in the Beowawe Geothermal Field Using Surface Electrical Potentials

A surface electrical potential system was fielded during the chemical stimulation of the Rossi 21-19 well in the Beowawe Geothermal Field. The technique, which measures variations in resistivity resulting from the flow of conductive fluid into the reservoir, was not only shown to be highly sensitive, not only to the chemical treatment, but also to the in situ conductive zones before any acid injection. A review of the experiment and a preliminary interpretation of the data are presented. The data provide convincing evidence that it should be possible to map the treated zone as well as the primary pretreatment in situ conductive zones.
Date: December 15, 1983
Creator: Hart, Carolyne M.; Engi, Dennis & Morris, Harris E.
System: The UNT Digital Library
A Status Report on the Exploitation Conditions of the Ahuachapan Geothermal Field (open access)

A Status Report on the Exploitation Conditions of the Ahuachapan Geothermal Field

The present exploitation conditions of the Ahuachapan field are discussed. The high well density in a small area has resulted in a significant reservoir pressure decrease due to the inherent reservoir over-exploitation. The average pressure in the exploitation zone has decreased from the 1975 value of 34 kg/cm{sup 2} to the May 1983 value of 23 kg/cm{sup 2}. The production decline characteristics of the Ahuachapan wells were examined, concluding that all wells but Ah-22 show exponential decline. The cumulative production-reinjection for the field up to April 1983 is 159.090 x 10{sup 6} tons, and 37.592 x 10{sup 6} tons, respectively. The effect of reinjection upon field behavior is evident when observing the pressure decline characteristics of the field. It is seen that for indection fraction related to total mass extracted above 30 percent, the average decline pressure in the production area becomes approximately stabilized. If this condition is not met the reservoir pressure decreases sharply. From this finding it is concluded that a careful and properly planned reinjection program is a must for the field. The observed temperature reduction in some of the wells seems to be the result of two operating mechanisms. First, we have the pressure decline that …
Date: December 15, 1983
Creator: Rivera-R., Jesus; Vides-R., Alberto; Cuellar, Gustavo; Samaniego-V., Fernando & Neri-I, Gustavo
System: The UNT Digital Library
Cosmological Consequences of String Axions (open access)

Cosmological Consequences of String Axions

Axion fluctuations generated during inflation lead to isocurvature and non-Gaussian temperature fluctuations in the cosmic microwave background radiation. Following a previous analysis for the model independent string axion we consider the consequences of a measurement of these fluctuations for two additional string axions. We do so independent of any cosmological assumptions except for the axions being massless during inflation. The first axion has been shown to solve the strong CP problem for most compactifications of the heterotic string while the second axion, which does not solve the strong CP problem, obeys a mass formula which is independent of the axion scale. We find that if gravitational waves interpreted as arising from inflation are observed by the PLANCK polarimetry experiment with a Hubble constant during inflation of H{sub inf} {approx}&gt; 10{sup 13} GeV the existence of the first axion is ruled out and the second axion cannot obey the scale independent mass formula. In an appendix we quantitatively justify the often held assumption that temperature corrections to the zero temperature QCD axion mass may be ignored for temperatures T {approx}&lt; {Lambda}{sub QCD}.
Date: December 15, 2005
Creator: Kain, Ben
System: The UNT Digital Library
Radial Flow of Pressured Hot Water Through Narrow Cracks (open access)

Radial Flow of Pressured Hot Water Through Narrow Cracks

Geothermal wells discharging hundreds of tons/hour of steam-water mixtures may be supplied at depth from one very narrow crack of width 1 to 2 mm, or alternatively, from some hundreds of hairline cracks. In the former case, turbulent flow takes place out to tens of meters from the well while the sum of frictional and kinetic pressure-drop indicates the flashing distance to be of the order of 10 cm from the well wall for pressure-temperature equilibrium. However it is unlikely that equilibrium obtains because of the high water velocity (order of 100 m/s) near the well giving no time for bubble nucleation. Flashing and hence mineral deposition are therefore not at all likely in the crack but can occur within the well from the crack horizon upwards. In the case of a multitude of fine cracks giving the same total flow, streamline conditions prevail over the flow path with the flash front a meter or so from the well, hence deposition is a possibility.
Date: December 15, 1983
Creator: James, Russell
System: The UNT Digital Library