Geothermal Resources Suitability for Desalination in New Mexico

Transcription

1 GEOTHERMAL EXPLORATION, MCGREGOR RANGE, NEW MEXICO Geothermal Resources Suitability for Desalination in New Mexico JAMES C WITCHER WITCHER AND ASSOCIATES LAS CRUCES, NM Witcher

2 CAPACITY FACTORS Wind Solar Hydro Average Biomass Fossil Geothermal

3 WHAT DEFINES GEOTHERMAL WATER? Anomalous temperature? Temperature that is is sufficient for a particular use?

4 REGIONAL GEOLOGIC SETTING Rio Grande Rift High Heat Flow Neogene Tectonism Neogene Volcanism Modified from Baldridge and others (1995)

5 HEAT FLOW Lillie (1999) q = K (dt/dz) Witcher

6 GEOTHERMAL RESOURCE CLASSIFICATIONS TEMPERATURE THERMAL REGIME SALINITY AND CHEMISTRY GEOLOGIC Well testing AmeriCulture Well, Animas Valley, Lightning Dock KGRA, NM

7 Red Convective Systems Light Blue Deep Conductive Systems in Tertiary Basins Dark Blue Deep Conductive Systems in Paleozoic and Mesozoic Basins CONDUCTIVE SYSTEMS

8 GENERALIZED GEOLOGIC CROSS SECTION BENEATH MESA DEL SOL May and Russell (1994)

9 GEOPHYSICAL LOG BOTTOM HOLE TEMPERATURES

10 SUBSURFACE TEMPERATURE ESTIMATES BENEATH MESA DEL SOL RESERVOIR TEMPS MESA DEL SOL Mean Annual Temp 13.8 o C Background Heat Flow 85 mw/m 2 Formation Thickness Thickness Depth est Tcond Tgrad T T + MAT T + MAT BHT model BHT model ft m ft W/m o K o C/km o C o C o F uncorr o C uncorr o F Upper Santa Fe 2, , Lower Santa Fe 2, , Galisteo 2, , Menefee 1, , Crevasse Canyon , Mancos , Dakota , Morrison/Brushy Basin , Morrison/Salt Wash , Summerville , Todilto , Entrada , Chinle/Petrified Forest 1, , Chinle/Aqua Zarca , San Andres LS , Glorieta SS , Yeso/San Ysidro , Yeso/Meseta Blanca , Abo , Madera Group/Bursum , Madera Group/Wild Cow , Madera Group/Los Moyos , Sandia , Arroyo Penasco , TD 14,980 total 172.3

11 ESTIMATED MESA DEL SOL RESERVOIR CHARACTERISTICS matix permeability CORE/DST est est min est T-TDScorr T-TDScorr RESERVOIR LITH THICK TEMP TDS HCOND K TRANS T ft o F mg/l ft/d ft2/d CREVASSE CAN/DALTON SS SAND , DAKOTA SAND , MORRISON (SALT WASH) SAND ,000 ENTRADA SAND , AQUAZAR/SAN ANDRES/GLOR LIME/SAND , DECHELLY/MESETA BLANCA SAND , MADERA LIME/SAND , solution/fracture permeability PUMP TEST est est min est T-TDScorr T-TDScorr RESERVOIR LITH THICK TEMP TDS HCOND K TRANS T ft o F mg/l ft/d ft2/d CREVASSE CAN/DALTON SS SAND ,000 DAKOTA SAND , MORRISON (SALT WASH) SAND , ENTRADA SAND , AQUAZAR/SAN ANDRES/GLOR LIME/SAND , , DECHELLY/MESETA BLANCA SAND ,000 MADERA LIME , ,244.64

12 Red Convective Systems Light Blue Deep Conductive Systems in Tertiary Basins Dark Blue Deep Conductive Systems in Paleozoic and Mesozoic Basins CONVECTIVE SYSTEMS

13 CONVECTIVE GEOTHERMAL SYSTEM q z = k(dt/dz) q z conductive heat flow(mw/m 2 ) k thermal conductivity (W/m o K) dt/dz temperature gradient ( o C/km) k = 1.8 W/m o K basin fill k = 2.2 W/m o K volcanics Q= q z da - q b da Q total system heat loss q b regional heat flow (70 to 100 mw/m 2 ) da area of integration (km 2 ) Assumptions: All heat is lost by conduction over top of outflow plume. Estimated thermal conductivity does not introduce excessive error. Borehole density is adequate to characterize system.

14 McGREGOR HEAT FLOW Maximum Heat Flow 454 mw/m 2 Area of Heat Flow over 90 mw/m km 2

15 HYDROGEOLOGIC WINDOWS Structure highs. Provide rapid vertical flow past regional aquitards. Relatively low elevation. On or near regional drainage. Feed geothermal outflow plumes. Rincon Radium Springs Las Cruces East Mesa

16 HIGHLY GENERALIZED TERTIARY SUBCROP MAP Precambrian and Paleozoic subcrop (brown) Convective geothermal systems (black squares) Associated with Laramide and Late Paleozoic Basement Uplifts

17 STRUCTURE CONTROL Laramide uplifts. Rift horst blocks. Ring fracture zones of mid-tertiary cauldrons. Pleistocene faults. Fault transfer zones. Modified from Seager and Mack (2003)

18 Extensive opal and siliceous deposits RINCON GEOTHERMAL SYSTEM Total heat loss >10 MWt > 150 o C geothermometer temperatures

19 RINCON CROSS SECTION Laramide subsurface structure inferred from overturned limestone outcrop 4 miles to north Hydrogeologic windows between Paleozoic carbonates and Tertiary Thurman Formation Tertiary Palm Park Formation forms confining cap rock Cross section in Tertiary rocks based upon Seager and Hawley (1973)

20 COMPARISON OF CONDUCTIVE AND CONVECTIVE SYSTEMS CONDUCTIVE Very deep reservoirs Higher cost and risk Very large reservoirs Suitable for large scale desalination Greater salinity Most applicable for brine disposal Stratigraphic reservoir CONVECTIVE Comparatively shallow and smaller reservoirs Lower cost and risk Much smaller reservoirs Suitable for smaller scale desalination Brackish water most common Structural reservoir

21 RESOURCE EVALUATION CONVERT EXPLORATION AND TESTING BUDGET INTO USEABLE HEAT Reservoir Geology Structure Stratigraphy Geophysics Direct Method (heat flow) Proxy Methods (resistivity, SP) Structural Methods (gravity, seismic) Geochemistry Geothermometry (Qtz, Chal) Soil Hg, Rn gas APPROACH Rincon 1, Rincon, New Mexico Witcher

22 WHERE IS THE GEOTHERMAL RESERVIOR? Structure controls Example Resource and Exploration Model Aquifers(reservoirs) Properties Aquitards (caps) Hydrogeology Flowpath Heat Sources Thermal Sweep? Witcher

23 COMMON COMPONENTS WELLS HEAT EXCHANGERS PIPELINES Drilling AmeriCulture State 2, Lightning Dock, Animas, New Mexico, AmeriCulture Geothermal Tilapia Farm Witcher

24 HEAT EXCHANGERS Prevent scaling and corrosion Isolate geothermal fluids from heating equipment and environment Plate and frame heat exchangers are very efficient NMSU Haslego and Polley (2002)

25 PRODUCTION WELLS AND INJECTION WELLS Drilling Masson Federal 36, Radium Springs, New Mexico, Masson Geothermal Greenhouse LARGE DIAMETER DESIGNED TO HOST PUMP EQUIPMENT DRILLED TO MINIMIZE FORMATION DAMAGE Witcher COST HIGHLY VARIABLE ($75 TO $400/ft)

26 BINARY-CYCLE POWER USDOE Soda Lake, Nevada, 26.1 MWe Binary Power Plant Witcher Witcher

27 TEMPERATURE AND PRODUCTION RATE REQUIREMENTS BarberNichols

28 COMPARATIVE ADVANTAGES OF GEOTHERMAL DESALINATION High Capacity Factor Electrical power for pumps and possibly RO units Source of thermal energy for process heat in distillation or other desalination technology Saline water source Heat Flow Units mw/m 2 Process brine sink via injection into reservoir

29 COMPARATIVE DISADVANTAGES OF GEOTHERMAL DESALINATION Greater Investment Risk Alpine Geothermal Test Hole, Alpine, Arizona Longer Time Frames and More Regulation Geothermal Lease Permitting Production and Injection Wells High Silica Content Witcher

30 A GEOTHERMAL PROJECT PERMITTING RESOURCE OWNERSHIP WATER RIGHTS Alligator Aquaculture, Mosca, Colorado ENGINEERING FEASIBILITY BUSINESS AND MARKETING PLAN FINANCING RESOURCE ASSESSMENT AND RESERVOIR CONFIRMATION PRODUCTION/INJECTION WELLS NREL RESOURCE MANAGEMENT PLAN ENVIRONMENT AND PUBLIC RELATIONS