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Six Oil and Gas Districts. Three Geothermal Districts. Oversight of Geothermal Well Operations. Drilling, operation, maintenance, plugging, and abandonment of geothermal wells on state and private lands to ensure public safety and protect underground and surface waters.
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Oversight of Geothermal Well Operations Drilling, operation, maintenance, plugging, and abandonment of geothermal wells on state and private lands to ensure public safety and protect underground and surface waters.
California is the United States' largest generator of electricity from geothermal energy • 650 active, high-temperature geothermal wells (with fluids over 212° F) • 280 injection wells • 4.5% of Electrical Energy 13k Gigawatt-hours)
The Geysers • 45 square miles • 15 power plants • 335 steam wells • 53 injection wells • 360 degree average steam temperature • 75 psi average steam pressure • 20,000,000 gallons/day wastewater injection • Southeast Geysers Effluent Pipeline
State-Wide Seismicity All Eqs 7 days Source: usgs.gov
Induced Seismicity Source: usgs.gov
Salton Sea Field • High pressure • High temperature (600 degrees Fare height) • High permeable sedimentary basin • Onshore resource potential – 1,400 MW • 11 power plants operating in onshore area - 380 MW cumulative capacity
Hudson Ranch 1Salton Sea Geothermal Plant • High temperature flash technology • First stand alone geothermal energy source plant built in Salton Sea field in last 20 years. • Three production well, four injection wells • Two wells produce 40 MW each
Plant Details • High pressure brine separator – steam flash • Steam scrubber (remove impurities) • Steam turbine • Brine sent to standard pressure crystallizer (steam separation - standard pressure steam) • Low pressure separator (final stage steam separation) • Clarifier tanks to separate out suspended silica, then reinjected
Make-Up Water • Well produce brine • Water from Imperial Valley Irrigation District used to make-up for water lost in operations • Brine treated and reinjected
Geothermal’s Future Short –Term Long-Term Benefits Drawbacks
Increase permeability of oil-/gas-bearing formations • Use of water, proppant, and chemicals to open fissures to allow oil/gas to flow to well • Recent development? Combination of multi-stage HF in long, horizontal formation • “Tight” shales or other types of formations require HF What is Hydraulic Stimulation ? Source: http://today.uconn.edu/blog/2011/12/fracking-%E2%80%93-good-news-or-bad-for-america%E2%80%99s-energy-needs/
Hydraulic Stimulation -- Last 2 months www.conservation.ca.gov
Historic Regulation • Well Construction Standards • Focus on competent well bores • Ensure “zonal isolation” • Facilities regulation • Covers pipelines, collection/separation vessels / tanks • Includes Spill Prevention and Contingency Planning Department of Conservation
Interim Regulations • Requires: • Neighbor notification • Pressure testing of well and surface • equipment • Water quality monitoring plans • Disclosure of HF fluid content • Public disclosure
Permanent Regulations • Will require: • Permit from DOGGR • Neighbor notification • Pre-WST evaluation of formation & well • Monitoring during and after WST • Water quality monitoring plans and water • management plans • Public disclosure of job and chemicals used • Process for adoption