CON F-8310177
PROCEEDINGS OF THE GEOTHERMAL PROGRAM
REVIEW I1
October I 1-1 3, 1983 Washington, D.C.
Coordinated by: US. Department of Energy
Assistant Secretary, Conservation and Renewable Energy
Division of Geothermal & Hydropower Technologies Washington, D.C. 20585
December 1983
CONF-8310177-23
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GEOTHERMAL WORKSHOP SUMMARIES
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DISCLAIMER
This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency Thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof.
DISCLAIMER Portions of this document may be illegible in electronic image products. Images are produced from the best available original document.
WORKSHOP A - HOT DRY ROCK
Moderator: James Bresee Rapporteur: Allan Jelacic
The discussion was led by Dr. John Whetten, Hot Dry Rock Program Manager a t LANL, who introduced various laboratory staff members. Recent results and activities a t the Fenton Hill test s i te were emphasized. Bob Potter, LANL, addressed the problem of fracture orientation in the ttshallowll reservoir a t Fenton Hill. prevented connection of the deep wells. The "barrier" is based on acoustic signals monitored from a nearby well d u r i n g hydraulic pumping. are representative of fracturing events, they show a r a d i a l growth upwards t o the "barrier", whereupon fracture growth stops. acoustic signals plus equipment failures d u r i n g pumping l imit the "barrier's" definition.
He elaborated on a possible tlbarrier't i n the reservoir w h i c h has
I f the signals
Uncertainties in loca t ing the
The prevailing opinion a t LANL is t h a t the pumping has stimulated natural j o i n t sets i n the rock. These j o i n t s are roughly parallel and probably cemented by calcite. James Kelsey, Sandia, suggested tha t acid treatment might be effective i n opening fractures.
Bert Dennis, LANL, gave a quick overview of instrumentation development i n conjunction w i t h the program. a high-temperature 7-conductor line; (2) slim line tools, a set of standard logging tools t h a t have been adapted for narrow-bore wells; (3 ) heat pipe, cooling u n i t for electronics i n downhole tools; ( 4 ) explosive tools, a suite of speci al-purpose detonator packages designed t o sever pipe, perforate, o r i n i t i ate fractures.
Among the items mentioned were: (1) TFE cable,
The considerable difficulties presented by the unexpected presence of hydrogen sulfide and carbon dioxide i n the Fenton Hill reservoir were discussed. John Whetten and Mort Smi th , LANL, indicated stress corrosion cracking was probably responsible for the majority of recent pipe failures. The casing i n bo th wells i s susceptible t o attack by hydrogen sulfide. As a result, considerable time and money have been expended t o acquire new, corrosion-resistant tubul ars. Regrettably, U.S. suppliers were unable t o provide suitable materials, and the 5 1 /2 inch working string had t o be procured from West Germany.
Near-term plans a t Fenton Hill revolve around a major pumping experiment i n EE- 2 well scheduled for mid-November. T h i s experiment will place 4-6 million gallons of water in to the reservoir a t the highest practicable rate. If the experiment succeeds in making a suitable connection, the resulting loop will be circul ated for sufficient time (6-12 months) t o determine reservoir performance characteristics. If the experiment fails , a number of op t ions are available:
Continue pumping, depending on location of acoustic signals;
Pump from EE-3 well t o intersect fractures created around EE-2;
Redrill EE-3 well towards acoustic cloud around EE-2;
Pump bo th we1 1s simultaneously;
Abandon upper reservoir and move downhole.
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Long-term plans, a f t e r operation of the f i r s t c i rcu la t ion loop, ca l l for creation of a f i n a l reservoir system. connections along the open hole sections of the wells. After a su i tab le testing period the reservoir could be turned over t o a pr ivate developer. Plains Elec t r ic Cooperative, a local u t i l i t y , has already expresed interest in acquiring the s i t e .
This system would consis t of multiple
Mr. C. Mac Eddy, General Manager of Navopache Elec t r ic Cooperative, briefed the workshop on Navopachels interest i n building a hot dry rock power plant near '
Springervi l le , Arizona. He expected tha t such a plant would be capable of 40- 50 MW e l e c t r i c power generation and would provide process heat t o a large pulp mil l . He expressed a strong commitment t o hot dry rock technology on the par t of the Cooperative.
Various other problems related t o the Fenton Hil l operation were b r i e f ly touched upon. Those included water ava i l ab i l i t y and water rights, power cycle options, and f r ac tu re stimulation. Inevitably, the discussion returned t o the fascinat ing "barr ier" problem. Gores, cut t ings, and 'logs from the deep wells have proved of l i t t l e value - there a re few indicators of a physical/chemical boundary. One possib y s ign i f icant indicator i s a definite increase i n thermal gradient a t about the depth of the "barr ier" . The next pumping experiment should prove crucial n solving the problem.
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Attendees
Jim Bresee, DOE/HQ Porter Grace, DOE/AL Pauline Labrie, DOE/HQ Steve Kaplan, ORNL C. Mac Eddy, Navopache Elec. Morton C. Smith, LANL Ber t Dennis, LANL Dick Traeger, Sandi a L a r r y Kukacka, BNL Heidi Lee, Meridian Ralph Burr, DOE/HQ D. E. Pyle, Union O i l Janes Kel sey, Sandi a John Whetten, LANL Wilson Pr ichet t , NPECA Robert Gerstein, M i t r e Corp. Andrea Reed, ORNL Robert Potter, LANL A l l a n Jelacic, DOE/HQ Rick Terr io, EER Gwen Redding, DOE/HQ Tony Adduci, DOE/SAN Chin Fu Tsang, LBL
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WORKSHOP B - RESERVOIR PROGRAMS
Moderator: Ron Toms
Rapporteur: Leon Lehr
The Workshop Moderator, Ron Toms, opened the session by calling for discussion on R&D needs i n connection w i t h geothermal reservoirs. He specifically asked t o hear from those who would like t o address reservoir issues t h a t had not been previously addressed d u r i n g earlier sessions. The ensuing discussion focused on six major subject areas as follows:
1. How do we determine what surface treatment should be used prior t o injection?
This subject was introduced by Don Shannon, who pointed out t h a t PNL i s compiling a handbook of injection technologies and has noted a lack of information on the degree of f l u i d treatment needed. is necessary t o know the maximum solids load t h a t will be tolerable for the injection of 20,000 gpm for 30 years.
Specifically, he sa id i t
A number of observations were made on f l u i d treatment, including the following:
Some f lu ids need treatment and others do not. While meters are available for control l ing solids content, acceptable concentrations are a s yet undetermined. Particle size is important, a l though the problem is bigger t h a n particle size alone. A t East Mesa, the particle size t h a t the f i l t e r s will take was reduced t o two microns, a very severe l imitat ion. Treatment i s costly; money should not be spent if i t i s not needed, b u t p lugg ing must be avoided. Considerable literature i s available on o i l and gas treatment practices, b u t those effluents and reservoirs are grossly different from geothermal. The degree of treatment needed i s a site-dependent, geological ly-re1 ated question, and industry will have t o solve the problem as i t comes t o i t a t each site. There i s probably a l o t of industry da ta , b u t i t is generally proprietary. While government funds should not be used t o categorize treatment needs for one reservoir, i t may be appropriate t o use government resources i n the generic area of brine clean-up, such as solids precipitation.
2. What do we learn from Huff P u f f tracer tests?
Marty Malloy of the San Francisco Operations Office invited a discussion on the rationale for the Huff P u f f experiments. of tracers conducted a t R a f t River and East Mesa which uti l ize one well.
He was referring t o the field tests
Mike Wright of UURI, who helped design the tests, responded, n o t i n g that, he d i d not realize the severity of the credibility gap on this issue. He described the procedure as a powerful technique for o b t a i n i n g new information on f l u i d flow not currently available from geothermal wells. information i s being published, he said, offering t o meet fo r explanatory sessions w i t h DOE personnel and others.
A great deal of
The advantages of a one-well tracer test , he said, are t h a t , generally speaking, ('...you have only one hole t h a t you can meaningfully tes t in a geothermal field. Early on, you only have one hole i n the f i r s t place, and, i n other cases, there may be no communication between two wells.". However, he said, two-hole tracer tes ts such as those conducted by Stanford, have a
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defini te place and will work if there i s communication between wells.
He i l lus t ra ted the types of f l u i d flow data curves generated by the Huff Puff t e s t s and discussed the i r significance. thermal breakthrough calculations; determination of heat-transfer coefficients; identification of waterhock interactions; characterization of the nature, direction, and velocity of f lu id flow at depth; pressure profiles; and monitoring the ultimate effect of injection on wells. data is ongoing.
Dr. Wright supported the LBL reservoir modeling program and development of lab data, b u t emphasized the need for f i e l d observation. Actual measurements can be made w i t h H u f f P u f f t es t s , which he said are not new, and he encouraged others to help exploit t h i s 'I.. .powerful technique.. .in a number of reservoirs t o b u i l d up a body of these data...to use i n models.".
The purposes of the t e s t s include:
Analysis of the t e s t
A workshop participant doubted, however, t h a t Huff P u f f observation would prove a f i e l d for power production, and others f e l t that excessive f u n d s ($300,000 each fo r R a f t River and East Mesa) have been spent on an "ill-posed problem". I t was contended that research needs and objectives were n o t suff ic ient ly well defined prior t o the t e s t s , and tha t f u n d s should n o t be expended on further tests of this k i n d without more p l a n n i n g and data analysis. Further related comments led t o the next major topic.
3.
An industry participant pointed out that II...y ou only need the years of research t h a t your plant needs...in convincing u t i l i t i e s (of reservoir productivity and longevity) .'I. Another suggested that smal 1 business needs borrowing capacity rather than Huff-Puff-type information.
How do we predict f i e l d lifetime?
I t was then noted that the necessity of productivity for 20-30 years represents a ". . . false se t of payback c r i t e r i a " -- that payback usual ly occurs i n seven years, and rather than "... looking for in f in i t e l i f e , you are looking for f ive t o ten years.". Then, as noted above, i t was observed that H u f f P u f f t e s t s do l i t t l e t o prove a f i e l d for power generation.
An i n d u s t r y spokesman observed t h a t p l a n t operators a t present are se l f - financed and only need data on their own f i e l d for their own information. They do not need the voluminous objective data required to convince investors of the v iab i l i ty of the i r project. t h a t ''...you need the sane k i n d of data t o convince yourself.n.
Another industry representative noted, however,
4. 3-Dimensional Modeling
A participant stated that he was s t a r t l ed by LBL's comment that a f te r having studied the Cerro Prieto f i e l d for years, the longevity of the f i e l d cannot be determined without 3-D modeling. other reservoirs) that we have on Cerro Prieto, the best known f i e ld . If we can ' t do i t there, will we ever be able t o do i t?"
He said, "We will not have the data ( for
DOE was urged not t o stop analysis of data from Cerro Prieto at t h i s time because of i t s s imilar i ty t o the Imperial Valley.
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5. What about low-temperature resources?
The Moderator noted that the DOE program , s not accenting t,,e use of low-to- moderate-temperature hydrothermal reservoirs in direct-applications, and it is not clear whether it should. Another alternative is to leave development of this portion of the resource to the private sector and local communities.
One spokesman responded that while it is important to take advantage of opportunities (in this area), the opportunities are probably not all that numerous. first (for power generation).'I.
Another participant, from the Klanath Falls, Oregon project, took the opposing view that if there is not enough energy in the resource for power generation, it should be used for something else. He said there are large load areas for space and process heat that can be satisfied with geothermal temperatures ranging from 4OoF to the boiling point. continue to intensify on the use of alternative sources of energy, and that DOE should change its direction to include direct-heat research and development.
He contended that "...we should learn to explait the best resource
He added that pressures will
Another suggestion was that while Federal technology is not needed for "mom-and- pop"-type direct applications, a Federal role in monitoring and predicting the effect of additional wells on existing wells may be desirable, noting current litigation in this regard. The Moderator commented that this type of Federal activity could provide scientific data to the regulators.
A comparison was made of energy values involyed in power generation (retail value of electricity) and direct use. (marginal cost of using geothermal or next alternative). Another spokesman said that individuals do not figure payout by corporate methods -- they want it to last a lifetime. A two-focus R&D program was suggested,-- i.e;, technology for the most efficient, thorough, and economic means of utilizing the resource for power production and then direct use. cascade use of low-temperature fluids from power plants, including questions on cost-effectiveness, cost of relocating, and problems in fluid hand1 ing and systems i ntegr at i on.
Some cautions were offered, however, on
6. Should deep Salton Sea well be fractured?
The pros and cons of stimulating the deep well to be constructed at the Salton Sea were discussed. One view held that an artificially induced fracture will interfere with the other scientific purposes of the well and create unnecessary risks -- that the money should be spent for more tests and good instruments. The opposing view was that tremendous economic benefits can accrue if the production of the well is doubled, and that no harm will be done to other research in connection with the well. To the question.of the relevance of fracturing to the deep well project, the response was that, for experimental purposes, a well with a long open-hole interval in a fractured reservoir is - needed during the drilling phase. It was suggested that other wells could be- available. A brief discussion on drilling procedures and the depth at which fracture tests will be performed followed.
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Miscellaneous Discussion
Earlier in the workshop discussions, Marcel0 Lippmann o f LBL listed areas o f research he feels are needed for fractured reservoirs. These included: heat/mass transfer, two-phase flow, relative permeability, theoretical curves, i nstrument at ion, and monitoring techniques.
The Moderator noted that he has heard this list advanced since 1975 and that it changes very little. the past has not accomplished much -- that the history of reservoir studies is not very good. The Division is hoping, he said, that the deep well at the Salton Sea in conjunction with a power plant will provide the opportunity to build a data base on a U.S. reservoir over a long period. DOE will have access to the data on all wells for the 25 MWe power plant and it will be up to Republic and Parsons as to whether tracer and other studies can be carried out. dispersion studies, the Moderator observed that GHTD cannot put much money into projects outside the country.
As a result, he is concerned that what GHTD has done in
When it was noted that Cerro Prieto would be a good place for mixing/
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Attendees
H. R. H i l k e r , ID0 Jack Rmstha le r , E G U i Paul Lienau, OIT W i 11 i an Ogl e, Energy Systems Mar ty Molloy, SAN John Crawford, SAN P h i l i p M. Wright, UURI Joseph Moore, UURI Leon Lehr, DOE/HQ Gene Bee1 and, Mer id i an Corp. Don Shannon, PNL Marcel o L ippann, LBL Norman Go1 ds te i n, LBL T i f f any Ne1 son, SDG&E Bob Ver i ty , Republic Geothermal Rol and Horne, Stanford R. J . Hanol d, LANL Thomas F lynn, U n i v e r s i t y o f Nevada Dennis Trex le r , U n i v e r s i t y o f ’ Nevada Andrea Reed, ORNL Bob Robertus, PNL Ray Wall ace, USGS Jim Combs, G R I Deepak Kenkermath, Mer id ian Corp. C. Carson, Sandia Marianne G u f f an t i , USGS J. H. Weare, U n i v e r s i t y o f Calif./SD Bob Morton, U n i v e r s i t y o f Texas Hank Cof fe r , C. K. GeoEnergy Corporat ion Doug1 as Medvi 11 e, M i t r e D. van Rooyen, BNL Chr is Amundsen, Technicon Research Lew Pratsch, DC€/HQ Ron Toms, DOE/HQ
I
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WORKSHOP C - GEOPRESSURED
Moderator: Dave Lombard
Rapporteur: Henry Coffer
Dr. Dave Lombard opened the workshop by reviewing the current status of the DOE Geopressured Geothermal Resource Evaluation Program.
He briefly mentioned the Wells of Opportunity program, wherein wells were taken over from o i l industry operators who had penetrated attractive aquifers i n their drilling for oil and gas. T h i s program has shown the widespread existence of high-temperature aquifers i n the G u l f Coast and has indicated t h a t the brine from such aquifers i s usually saturated with methane. one well a h i g h methane content (oversaturated) which increased with production led t o coning i n a gas well which i s now being produced by the original o i l company.
In fact, in
Four design wells were drilled and tested w h i c h yielded large-volume reservoirs t h a t had the capabi l i ty of h i g h brine flow rates. Thus , the wide extent and the large size of the methane resource has been established. Now we need t o know the economics of such hot brine production through long-range test programs t o determine the problems w h i c h must be solved i n order t o routinely produce such hot , high-volume wells.
Three of the original design wells are being readied for long-term testing. These are the Sweet Lake, the Gladys McCal1, and the Pleasant Bayou. A t meeting time, the Gladys McCal1 was back under flow testing a t h i g h rates and appeared t o be an excellent large reservoir w i t h h i g h flow capacity.
All three of the design wells have been plagued by pipe problems. Production of large volumes of hot brine i s hard on tubular goods, and extensive care must be taken i n pipe and thread selection t o prevent corrosion problems. The Sweet Lake and Pleasant Bayou wells should also be on strean by the end of the year and plans are t o determine what k i n d of problems, if any, accompany the long- term test programs.
There have been some surprises i n the DOE program. The sensitivity of pipe hardness and thread design t o corrosion was not expected. be controlled by careful selection and handling of the tubing and couplings.
Such corrosion can
Several interesting results are coming from the DOE program. puzz l ing i s the increasing concentration of aromatic hydrocarbons i n the brine w i t h brine production. Another is the observed evidence t h a t the aquifers produce more brine t h a n expected, which means water i s coming i n from dewatering of shales or i n t r u d i n g across f a u l t s t h a t bound the reservoirs.
The DOE program has concentrated, t h u s far, only on the methane content o f the hot brine. No attempt has been made t o utilize two other energy components, the heat and the pressure of the brine. An experiment has been proposed by the Electric Power Research Institute (EPRI) t o convert the total energy content of the brine t o electrical energy. They would plan t o utilize the pressure t o generate electricity, burn the methane t o drive a generator, and use the heat from the brine and the waste heat from the generator t o drive a binary-cycle turbine t o convert the heat i n t o electricity. In cooperation w i t h DOE, they would install such a binary system a t the wellhead a t the Pleasant Bayou well
Among the most
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t o determine the o v e r a l l e f f i c i e n c y o f t he combined e l e c t r i c a l generation package. 1984.
Fo l low ing t h e rev iew o f problems and pro jec ted plans f o r t h e DOE program, the group was asked by Dave t o discuss areas t h a t should be emphasized o r had been overlooked.
If a l l goes as planned, the experiment should be ready t o go e a r l y i n
The f o l l o w i n g suggestions were made:
Look a t o f fshore resources. The G u l f Coast sands cont inue o f fshore and genera l l y tend t o thicken. Thus, t he rese rvo i r s should be l a rge r and conta in more energy.
Resource assessment work should continue and be enlarged, since t h i s i s a f u t u r e resource of 1 arge magnitude.
Data bases a t LSU, t he U n i v e r s i t y o f Texas, and Bay S t . Louis should be combined and made a v a i l a b l e t o everyone.
Po ten t i a l energy i n b r i nes i n shales should be studied. l a r g e enough i n massive shales t o a l low f a i r l y r a p i d production.
Need add i t i ona l temperature logs i n shales and more shale core i n the geopressured are as.
Why n o t look a t hydropressured r e s e r v o i r s too? They are u s u a l l y l ess s a l i n e and conta in l a rge mounts o f methane.
Fundamental rock s tud ies need t o be increased.
Permeab i l i t y i s
Resource base eva lua t ion has shown extens ive r e s e r v o i r s o f energy. more work needs t o be done on qecovery fac to rs and economics.
Coproduction and use of a l l t h e energy contained i n the hot b r i n e stream should be emphasized.
But
(Th is i s contemplated i n t h e E P R I experiment.)
Everyone was pleased a t DOE'S dec is ion t o take over H u l i n we l l . Th is i s probably t h e way i n d u s t r y w i l l ge t invo lved i n geopressured geothermal product ion ... by d r i l l i n g f o r o i l - o r gas and then dec id ing t o get t h e incremental geothermal energy from aquifers penetrated i n t h e i r quest f o r o i l and gas.
I n general, t h e i n t e r e s t was h igh and everyone agreed DOE had an exce l l en t p r o g r m going. They were pleased by DOE'S apparent turn-around where t h e program would be maintained and poss ib l y expanded f o r a f u l l e r eva lua t ion o f t h i s l a r g e energy source.
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Attendees
Gene Beeland, Mer id ian Rick Ter r io , EER Andrea Reed, ORNL Paul ine Labrie, DOE/HQ Jim Bresee, DOE/HQ Ray Wallace, USGS Leo Rogers, G R I Bob Clarke, DOE/NV Clay Durham, Magma Gulf/Technadri l J. H. Weare, UCSD Bob Morton, U n i v e r s i t y o f Texas Norm Goldstein, LBL Hank Cof fer , C. K. GeoEnergy Corp. Doug1 as Medvi 11 e, M i t r e Gwen Redding, DOE/HQ T. David Riney, S-Cubed Ralph Burr, DOE/HQ Dave Lombard, DOE/HQ
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WORKSHOP D - COMPONENT AND DRILLING RESEARCH
Moderator: David Allen
Rapporteur: Ray LaSal a
Dave Allen defined the session as a forum for critique of current DOE programs and recommendations for future efforts. transfer was stressed.
I n p u t on industry needs and technology
Dri 11 ing Program
The hard rock penetration program consists of three program elements:
0 systems (Carson) 0 Program (Kel sey) 0 Stimulation (Allen)
Janes Kelsey was asked t o present a task l i s t for Sandia. T h i s includes cont inuing work and new initiatives.
-Mechanics of Rock Penetration
e Rock/Cutter Interaction - analysis/experimentation o f the mechanisms and effects of the breakage of rocks.
0 Carbide Fracture Toughness Experiments - test of toughness and hardness o f carbides.
0 Electo - Wear Experiments - research a t the University of Arizona has demonstrated reduced wear i n d r i l l bits i n the l a b when stimulated by DC current. These bits will also be field tested.
0 Modified Pressure Pulse Loading - stimulation usually produces parallel fractures. The pulse pressure loading technique i s an attempt a t radi a1 f r ac tu r ing .
-Borehole Mapping
0 Lost Circulation Zone Mapping Tool - uses an acoustic borehole televiewer.
Far Wellbore Fracture Mapping - used for fractures t h a t d o n ' t intersect the well.
0
0 Evaluation of Mapping Techniques - a paper study.
-Dr i l l ing Instrumentation
0 High-Temperature Cement Bond Log Tool - good a t temperatures up t o 275OC, project completion, December 1983.
resistant too l for !emperature, pressure, and flow measurement. ' High-Temperature Combination Tool - development o f a high-temperature-
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0 Feasibi l i ty Studies of High Data Rate Systems - development of an improved way of transmitting data; this i s a new in i t ia t ive .
-Non-Conventional Dril l ing Techniques
0 Cavitating Jet Research - hydraulic je t for rock cutting, eliminates mechanical cutting.
D r i l l i n g S t r i n g Dynamics - development o f an understanding o f d r i l l dynamics and directional d r i l l i ng application.
0
0 High-temperature Elastomeric Liner - BNL i s doing this s tudy t o provide a borehole l iner t o prevent los t circulation during dr i l l ing.
System Study of Spallation Dril l ing - Los Alanos i s beginning t h i s new study w i t h the use of a flane j e t .
0
-High-Temperature F l u i d Loss Control
0 Lost Circulation Test Fac i l i ty - operates under downhole conditions of 280 GPM, 4OO0F and 1000 ps i .
0 Casing Stress Analysis - l ab tes t ing t o assess casing fatigue and thermal s t ress .
0 Clay-to-Cement Conversion Studies - lab studies t o convert the in-hole clay t o cement.
0 Aqueous Foam Studies - testing the use of aqueous foam as an al ternate d r i l l i ng f l u i d t o air because of the corrosion problems associated w i t h a i r used as a d r i l l i ng f luid.
0 Encapsulation Methods for Lost Circulation Control - BNL study t o p l u g f ractures t o control l o s t circulation problems; this is a new ini t i ative.
Mr. Bert Dennis from Los Alanos National Laboratory was asked t o describe current research and instrumentation needs. Los Alanos i s responsible f o r t h e Hot Dry Rock Demonstration Project a t Fenton Hill. There have been some unexpected resu l t s i n d r i l l i n g ; the actual temperature i s 32OoC instead of the predicted 25OoC, which p u t s added stress on instrumentation. research includes:
Present
-Higher-Temperature-Resistant Downhole Instruments
0 0 0 0 0 0 0 0 0 0
Caliper tool for borehole d i meter Spinner tool for gamma ray radiation' t racer f racture studies Geophones fo r f racture studies Explosives and detonators fo r f racture mapping Acoustic transceiver Piso-electric receiver for formation identification Fluoro-dye t racer injector Borehole televiewer Seals, 0 rings, connectors Less-expensive cable (using TFE materia? by Rochester currently, i t works b u t costs $5/foot)
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/ /
-Slimline Tools due t o Small Borehole T u b i n g I
0 Above instruments apply, especially the spinner, temperature probe, i' 1 geophone detector, and gamma detector
-Better Computer System for Fracture Growth Monitoring
D. E. Pyle from Union Oil was asked to share his concerns i n the d r i l l i n g research area. He determined that well casings and pipe threads were the l i m i t i n g materials currently. They have only a 6-month cycle.- Lost.; circulation and directional equipment f a i lu re under high-temperature conditions are also problems. w i t h high-speed bearing seals. The best motor available is the Russian direct drive motor, b u t i t has not been adapted t o the high-temperature environment yet.
High-RPM bits are needed (8-10 hour l i f e currently) along
Dave Allen then opened the discussion t o constructive cri t icism of the progrm. h igh- r i sk R&D and effect ive technology transfer t o industry are opposing goals. Industry is more appli,cations-oriented, more intereted i n short-term f i e l d tes t ing resu l t s than long-term analysis and lab testing. pointed out t h a t both could be'accomplished under the current DOE policy, since the emphasis i s s h i f t i n g from theoretical analysis t o hardware applications.
Janes Kelsey made the observation that the DOE goals of+ long-range,
R q y LgSala
Heat Cycle Research
The heat cycle research program fo r FY84 emphasizes binary-cycle research i n the 300-400°F range. Ray LaSal a wrote a 1 i s t of program options on the board, asking the audience which subjects other than binary cycles should be covered:
0 High s a l in i ty 0 Smal l/well head plants 0 Heat rejection/cool i n g water 0 0 Total flow 0 Other
Hybr i d/cogener a t i on
The audience recommended that more money be spent on downhole pump research. Better materials are needed. Parallel tes t ing instead of the current sequential tes t ing a t the new pump t e s t fac(i1ity would speed resul ts . There was some controversy over whether other manufacturing firms besides REDA should be contracted t o tackle the pump problems. Competition might encourage answers and lower the f ina l cost of the product, b u t i t also migh t water down research results. There also isn' t another manufacturing firm that has the knowledge and experience that REDA has i n the geothermal f ie ld .
The most pressing problem w i t h downhole pumps, according to Bob Hanold, i s brine in f i l t r a t ion through the cable. The motor u n i t i s working well. A new metal sheath i s being t r i ed on the cables t o prevent this problem.
I t was mentioned tha t l ine and s h a f t turbine pumps could be modified and used instead of downhole pumps. conditions though, and the i r technology has been picked up by industry and therefore won't receive DOE fund ing .
They have only proven effective under shallow, "mild
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Materials research and f l u id handling were the other areas suggested by the audience as needing more funding. Two-phase measurements are needed for reservoir characterization under full-flow conditions. Larry Kukacka l i s ted the materials research ongoing a t BNL, b u t mentiond that f u n d i n g was being curtailed i n FY84.
BNL Materials R&D:
0 Sta t i c Seals - now commercially available
0 Dynanic F l u i d s - material curing by microencapsulation or chemical reaction
0 Utilization of Geothermal Wastes - f i n d i n g ways t o reuse d r i l l i n g f lu ids and scale
0 Non-Metallic Casing - ceramics
0 Thermally-Conductive Deposits - used for heat exchanger tubes
0 Corrosion Rates of Metals - measurement of metal corrosion ra tes i n binary f l u i d s and i n brines
Cathodic Protection - used i n well casing and energy extraction cycle 0
0 Pipe Liners - production side
0 Polymer Concrete - now commercially available
Leon Lehr gave an update on the Environmental Control Technology Progran which is i n closeout mode. The only ongoing project i s a t LNL, w i t h f l u i d migration surface modelling. This work is be ing transferred t o the Injection Progran.
Bob Verity from Republic Geothermal, Inc. reported on the i r reservoir stimulation effor ts . Results have shown t h a t stimulation is viable where wells penetrate naturally-fractured reservoirs, b u t control of the direction of fracturing i s needed.
Ron Toms addressed the subject o f hybrid power plants, especially the combination of f lash and binary systems. He suggested t h a t research might be useful i n assessing the optimum hybrid geothermal p l a n t . The audience pointed out that each plant i.s s i te-specif ic i n terms o f water quality, quantity, and temperature, making a generic p l a n t d i f f i cu l t t o apply t o a specific si tuation.
The f ina l discussion concerned Technology Transfer. The main complaint was t h a t technology transfer needed t o go one more step and assure that industry can have a material or piece of equipment on the shelf for order.
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Attendees
Thomas Goebel, Technadril - Fenix & Scisson Stephen I. Kaplan, ORNL Dr. Janes R. Kelsey, Sandia Rick Murphy, ORNL W i l l i a m Ogle, Energy Systems, Inc. Marty Mol loy, DOE/SAN Thomas Turner, Phi 11 i p s Petroleum Co. Porter Grace, DOE/AL P h i l i p M. Wright, UURI Anthony Adduci, DOE/SAN Robert Potter, LANL Don Shannon, PNL Lew Pratsch, DOE/HQ D. E. Pyle, Union O i l Bob Verity, Republ i c Geothermal Bob Robertus, PNL Ron Toms, DOEIHQ Jim Combs, G R I Deepak Kenkeremath, Meridi an R. J. Hanold, LANL C. Carson, Sandi a L. Lehr, DOE/HQ Robert Gerstein, M i t r e D. van Rooyen, BNL Chris Amundsen, Technecon Research L a r r y Kukacka, BNL Paul Lienau, OIT
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