An Overview of DOE-Funded Geothermal R

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An Overview of DOE-Funded Geothermal RD
Programs at the University of Utah

• Peter Rose and Jeff Hulen
• Energy and Geoscience Institute
• at the University of Utah
• Geothermal Program Briefing
• Lawrence Berkeley National Laboratory
• March 16, 2004

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AGENDA

• Tracer Technology, Chemical Stimulation,
  Electrical Geophysics, Two-Phase Flow
  MeasurementPeter Rose
• Geology, Hydrothermal Alteration, Geochemistry,
  Remote Sensing..Jeff Hulen

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Tracing Fluid Flow in Geothermal Reservoirs
Peter Rose and Mike Adams

• Objective
• To develop tools for tracing injected fluids and
  interpreting fluid-flow processes

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Tracer Technology AccomplishmentsPeter Rose and
Mike Adams

• Liquid-phase tracers
• Laboratory development and field testing of a
  family of eight fluorescent tracers for use in
  high temperature (gt300oC) reservoirs
• Detection limits reduced by a factor of 100 to 40
  parts per quadrillion through laser-induced-fluore
  scence detection
• The development and demonstration of the use of
  fluorescent compounds as thermally reactive
  tracers
• The evaluation of analytical methods for
  estimating reservoir pore volume from tracer data
• Vapor-phase tracers
• Laboratory development and field testing of
  several tracers for application in
  steam-dominated reservoirs
• Solubility modeling for the interpretation of
  return-curve patterns
• Reduction of detection limit by factor of 100
  using solid-phase micro-extraction

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Technology Transfer Adoption of the Naphthalene
Sulfonate Tracers by Geothermal Operators
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Follow-On Tracer Research

• Develop adsorptive tracers for characterizing
  reservoir fracture surface areas
• Develop and demonstrate two-phase tracers for
  measuring flow processes in liquid-depleted
  reservoirs

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National Laboratory and Industry Collaboration

• Paul Spielman, Coso Operating Company
• Mike Shook, Idaho National Energy and
  Environmental Laboratory

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Chemical Stimulation of Wellbores and
Near-Wellbore FormationsPeter Rose and Mike Adams

• Objectives
• To design and evaluate chemical dissolution
  agents for use in wellbore stimulation
• Evaluate the feasibility of using chemical agents
  for stimulating near-wellbore formations as an
  alternative to hydraulic and thermal stimulation
  approaches

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Chemical Stimulation of Wellbores and
Near-Wellbore Formations (Cont.)Peter Rose and
Mike Adams

• Approach
• Determine the decay kinetics and reactivity of
  candidate dissolution agents under conditions
  that simulate a geothermal environment
• Strong mineral acids with improved acid
  inhibition
• Weak organic acids
• Chelating agents
• Conduct wellbore field experiments to verify the
  laboratory experiment
• Model the wellbore mineral dissolution process
  using reactive-transport models and calibrate
  using field data
• Develop models of near-wellbore stimulation
  processes and conduct experiments to verify
  models

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Strong University, National Laboratory, and
Industry Collaboration

• Derek Elsworth, Penn State
• Joe Moore, U of U
• Carol Bruton, LLNL
• Karsten Pruess and Tianfu Xu, LBNL
• Paul Spielman, COC

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Measuring Two-Phase Flow Rates at Geothermal
WellheadsPeter Rose and John Stodt

• Objective To design, fabricate and evaluate
  electrical-resistivity methods and
  instrumentation for measuring two-phase flow
  rates (and thereby enthalpy) continuously and in
  real time at geothermal wellheads

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Prototype Resistivity Meter Designed and
Fabricated by Paul Spielman at Coso Operating
Company
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Controller and Data Logger Designed and
Fabricated by John Stodt at EGI
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Electrical GeophysicsPhil Wannamaker

• Objectives
• Integrated geothermal systems modeling
  (Karaha-Telaga Bodas andesitic analog)
• Resolving system structural ambiguities (Dixie
  Valley single/multi fault controversy)
• New-generation EM surveying technology brought to
  geothermal (MT/DC multi-profile array system from
  mining industry)

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Electrical Geophysics (contd) Phil Wannamaker

• Objectives and New Directions
• Integration with 3D reservoir modeling (STAR and
  TETRAD simulators)
• Merging EM resolution principles with inversion
  regularization (2D 3D)
• Economical, reliable, publicly available 3D
  imaging for industry needs

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