Historical Background of Database - PowerPoint

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					Historical Exploration and Drilling
Data from Geothermal Prospects
and Power Generation Projects in
    the Western United States


           Jim Combs, Ph.D.
     Geo Hills Associates, Reno, NV

     GRC 2006 Annual Meeting Technical Program
      September 13, 2006 in San Diego, California
                Motivation
• In 2005, Idaho National Laboratory was
 studying historical geothermal exploration
 practices and success ratios for DOE.

• GHA was contracted to accumulate copies of
 published literature, internet information, and
 unpublished geothermal exploration data on
 currently operating geothermal projects and
 undeveloped geothermal prospects.
                                              2
                Motivation
• Since 1992, no new geothermal reservoir
 has been developed for power production in
 the United States.

• The U.S. geothermal industry is in need of
 exploration and development for new power
 projects to respond to current demand and
 growing need for secure, environmentally
 benign, domestic, base-load, renewable
 geothermal electricity.
                                               3
      Historical Background
• Many prospective geothermal areas were
 being explored and drilled in the 1950s,
 1960s, and early 1970s in the western
 United States.

• In the mid- to late-1950s, Magma Power
 Company drilled wells near most hot
 springs in the western U.S. and in 1960
 initiated their paying geothermal assets
 with development of a steam field in The
 Geysers for a initial PG&E power plant.
                                            4
       Historical Background
• During the 1970s and 1980s in response
 to the oil crises, at least 19 oil and gas and
 mining companies were involved in the
 exploration for geothermal resources and
 their combined expenditures were at least
 a billion nominal dollars.

• During the period from 1976 to 1985, U.S.
 Department of Energy (DOE) had a well-
 funded ($827 million for 10-year period)
 and focused geothermal R&D program.          5
        Historical Background
• The oil and gas companies included Phillips
 Petroleum, Chevron Resources, Unocal
 Geothermal, Santa Fe Geothermal, Shell Oil,
 Aminoil USA, Burma Oil & Gas, ARCO
 Petroleum, Anadarko Petroleum, Occidental
 Petroleum, Getty Oil, Signal Oil & Gas, Earth
 Power Resources, Hunt Energy, Hunt Oil,
 and Southland Royalty.

• The most prominent mining companies were
 Amax Exploration and Kennecott Mining.         6
            Historical Background
•   Reasons for the oil and gas industry withdrawing in
    late 1980s from the geothermal industry included
    the low cost of petroleum power generation fuels.
•   Few potential geothermal reservoirs had been
    identified with temperatures greater than 200°C at
    depths less than 2,000m.
•   A lack of power purchase agreements (i.e., market)
    for geothermal power generation projects.
•   Binary power generation technologies were not
    proven; thus, petroleum firms essentially exited the
    domestic geothermal industry.
                                                      7
                                     Historical Background
                                            DOE Geothermal R&D Funding 1976-1985
                               180
                                                           157
Geothermal R&D Funding ($MM)




                               160                                 150
                                                                         137
                               140

                               120                  108
                               100

                               80                                               73

                               60            53                                        50
                                     43
                               40                                                                    33
                                                                                              23
                               20

                                0
                                     1976    1977   1978   1979   1980   1981   1982   1983   1984   1985
                                                                  Fiscal Year


                                                                                                            8
           Historical Background
•   In late 1977, DOE initiated an Industry-Coupled
    Drilling Program with geothermal industry entities to
    accelerate development of high-temperature
    geothermal resources for power generation.

•   The program was intended to obtain and release to
    the public confidential industry data with respect to
    geothermal exploration and drilling in return for
    DOE funding deep exploration wells on designated
    geothermal prospects of which there were 14 in the
    Basin and Range Physiographic Province of Utah
    and Nevada.                                         9
Historical Background




                        10
           Historical Background
•   The resulting database for the 14 geothermal areas
    included total DOE funding over a 4-yr period from
    1978 to 1981 of about $14.5 million with industry
    contributing an estimated $17 million (Fiore, 1980).

•   The program contributed directly to new
    geothermal power generation projects at Beowawe,
    NV and Cove Fort-Sulphurdale, UT as well as
    supported power development at Roosevelt Hot
    Springs, UT; Dixie Valley, NV; Soda Lake, NV;
    Stillwater, NV; and Empire, NV.
                                                     11
          Historical Background
In his critique of the U.S. DOE Geothermal Program
Review IX, Combs (1991) identified the following
classic geothermal paradox:

   “Some companies have found and do find themselves
     in a position of having to prove a viable geothermal
    resource with little capital to make a long-term power
       sales contract secure, which in turn, can be used
     to finance the drilling and testing programs to prove
    viability of the geothermal power generation project.”


                                                             12
    Geothermal Exploration and Drilling Data
•   Using the Excel format in the next slide, Combs
    (2005) gathered exploration and drilling data on 22
    geothermal power generation projects. In addition,
    some 315 geothermal prospects are included in the
    GHA database.

•   The 337 geothermal areas can be compared to the
    140 geothermal resource sites, forming the basis of
    the Western Governors’ Association Geothermal
    Task Force Report (2006).

                                                     13
Required Information for Historical
Geothermal Exploration and Drilling




                                  14
Partial Table of Historical Data




                                   15
    Geothermal Exploration and Drilling Data
•   These published data should be thoroughly
    evaluated before new surveys and investigations
    are planned, funded, and conducted. In fact, the
    historical data may
    •   be the least cost exploration information that can be
        obtained;
    •   eliminate the need to conduct certain surveys; and
    •   assist in the interpretation of other data collected during
        the course of the geothermal exploration activities of a
        geothermal developer.
•   With the 315 identified geothermal prospects, new
    exploration ventures should carefully consider the
    historical exploration and drilling databases.
                                                                 16
    Geothermal Exploration and Drilling Data
•   Under a separate INL contract to SAIC of which the
    author is a member of the team, as shown earlier
    Pritchett (2006) noted, based on a series of
    theoretical calculations, that shallow heat flow is
    essentially useless for delineating “hidden basin
    and range type” geothermal resources and thus
    citing successful geothermal wells.

•   It appears that the best way to find “hidden”
    geothermal reservoirs is to reexamine geothermal
    prospects, which have anomalous thermal
    gradients and conduct SP, MT, and DC resistivity
    surveys.
                                                    17
    Geothermal Exploration and Drilling Data
•   Under a separate INL contract to SAIC the team is
    to use existing historical data sets from operating
    Basin and Range geothermal reservoirs to test the
    utility of electrical surveys for characterizing the
    subsurface and the geothermal reservoir (Garg, et
    al., 2006).

•   Garg and coworkers (2006) earlier presented the
    results from their analysis and evaluation of the
    Dixie Valley Geothermal Project to verify results
    from theoretical calculations of Pritchett (2006).
    The Beowawe Geothermal Project is now being
    examined by the SAIC team.
                                                         18
Exploration and Drilling Data on Geothermal
      Prospects and Power Projects




                                        19
    Geothermal Exploration and Drilling Data
•   The California Division of Oil, Gas and Geothermal
    Resources database contains 3,914 well records;
    however, only 3,427 could be examined. The other
    487 deep wells are presently confidential but will be
    reclassified as open to public during next few years.

•   Imperial Valley had 1,481 well records, 298 were
    identified as thermal gradient holes, and 421 were
    slim holes, exploration and/or commercial wells all
    being associated with geothermal power projects.
    Locations for another 770 thermal gradient/heat
    flow boreholes were not located in the database.
                                                      20
    Geothermal Exploration and Drilling Data
•   The 770 thermal gradient holes in the Imperial Valley were
    drilled and reported by Chevron Geothermal (435), Unocal
    Geothermal (131), Phillips Petroleum (71), Republic
    Geothermal (69), Occidental Geothermal (30) and the USGS
    (34). These holes should be located and the temperature-
    depth data carefully reviewed.

• There are 2,737 thermal gradient holes in the GHA database
    for Nevada; however, of the 122 geothermal prospects and
    power projects only 39 have data on slim holes, exploration,
    and/or commercial wells.Thus, there are as many as 83
    potential geothermal projects that need confirmation with
    electrical geophysical surveys, slim holes and exploration
    wells to define possible geothermal reservoir.
                                                             21
            Acknowledgments



Thanks to Joel Renner of the Idaho National Laboratory
(INL) who was conducting a study of past exploration
practices and success rates for geothermal resources
identification for having the management and operations
contractor for INL, i.e., Battelle Energy Alliance, LLC
(BEA), to subcontract with Dr. Jim Combs of Geo Hills
Associates to assist in the INL efforts (BEA Contract No.
00047375).

                                                        22

				
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