Multi-Fluid Geothermal Storage Wells for Dispatchable Power
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Solution Overview
Problem
Geothermal energy systems face challenges such as high costs and risks in prospecting and well drilling, parasitic power costs, and geographical limitations, while renewable energy sources like wind and solar have diurnal and seasonal variability, requiring backup power sources that emit CO2, complicating climate change mitigation efforts.
Innovation Solution
A multi-fluid geo-energy system using concentric rings of wells for working fluid injection and brine production, incorporating supplemental fluids like CO2 and N2, and thermal energy storage to enhance geothermal energy production and storage, allowing for efficient energy dispatch and grid stabilization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional hydrothermal geothermal power systems are used, then reliable and predictable power is generated, but geothermal resources remain underutilized due to high prospecting and drilling costs, parasitic power costs, and geographical limitations
Solution Approach 1:
The system divides the geothermal fluid circulation into separate functional zones: an inner ring of production wells extracts hot brine, while outer rings of injection wells reinject cooled fluid and CO2 at different locations. This segmentation allows independent optimization of each zone for its specific function, improving overall system productivity while managing complexity through modular well arrangements.
Solution Approach 2:
The system combines multiple functions into a single integrated geothermal system: electricity generation, thermal energy storage, CO2 sequestration, and working fluid recirculation all occur within the same subsurface reservoir structure. This merging eliminates the need for separate systems for each function, reducing overall device complexity while maximizing geothermal resource utilization.
2Productivity
If fluid recirculation is implemented to sustain geothermal production, then continuous energy generation is achieved, but parasitic power costs increase
Solution Approach 1:
The system uses the geothermal reservoir itself to provide the recirculation function. Hot brine rises naturally through production wells due to buoyancy forces, and the injected CO2 creates pressure differentials that drive fluid circulation without requiring external pumping. This self-service approach maintains continuous energy generation while minimizing parasitic power costs by eliminating or reducing the need for mechanical recirculation pumps.
Solution Approach 2:
The system employs pneumatic principles by injecting CO2 gas into the reservoir to create pressure differentials that drive hydraulic flow of the brine through the formation. The gas phase provides the driving force for fluid circulation, replacing energy-intensive mechanical pumping with a more efficient gas-driven hydraulic system that reduces parasitic power consumption.
3Ease of manufacture
If geothermal systems are deployed in geographically limited settings, then existing technology can be utilized, but the range of viable locations is restricted
Solution Approach 1:
The system design creates a universal geothermal platform that can function in various geological settings by performing multiple functions simultaneously: power generation, thermal storage, CO2 storage, and fluid management. This multi-functionality allows the same basic system architecture to be adapted to different geographical locations and reservoir characteristics, expanding the versatility of where geothermal systems can be deployed while maintaining deployment feasibility through standardized components.
Solution Approach 2:
The system adjusts operational parameters such as injection rates, pressures, and well depths to match specific geological conditions at different locations. By changing these parameters rather than the fundamental system design, the same multi-functional platform can be adapted to various geographical settings, from high-temperature hydrothermal reservoirs to lower-temperature aquifer systems, thereby expanding geographical range while maintaining ease of deployment.
4Object-generated harmful factors
If CO2 is captured from exhaust streams for storage, then CO2 emissions are reduced, but the cost of supplying CO2 increases
Solution Approach 1:
The system merges CO2 sequestration with geothermal fluid circulation by injecting the captured CO2 directly into the geothermal reservoir where it serves dual purposes: storing the greenhouse gas and acting as a working fluid to drive brine circulation and enhance heat transfer. This merging eliminates the need for separate CO2 storage infrastructure and reduces supply costs by utilizing the CO2 as a functional component of the geothermal system itself.
Solution Approach 2:
The system converts the captured CO2, which would otherwise be a waste product requiring costly disposal, into a beneficial resource that enhances geothermal productivity. The injected CO2 creates pressure differentials for fluid circulation, improves heat transfer coefficients, and provides additional working fluid for power generation, thereby transforming a harmful emission into an asset that reduces overall system costs while achieving emissions reduction goals.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The system increases geothermal energy efficiency, reduces parasitic loads, and provides dispatchable power generation, mitigating CO2 emissions by leveraging existing geothermal technology and reducing reliance on fossil fuels.
Implementation Method 1
at least one compressed fluid injection well in communication with the storage zone for injecting an unheated, compressed working fluid into the storage zone
Implementation Method 2
The unheated, compressed working fluid further assists with a withdrawal of pressurized brine residing below and/or to the side of the storage zone
Implementation Method 3
storing thermal waste heat or excess heat in a storage zone of the reservoir formation
Implementation Method 4
at least one fluid injection well in communication with the storage zone for injecting a heated working fluid laden with thermal waste heat into the storage zone
Implementation Method 5
a geo-energy production system for extracting thermal energy from a reservoir formation
Data Source
AI summary
A geo-energy production system and method extracts thermal energy from a reservoir formation, and stores either thermal waste heat or excess heat in a storage zone of the reservoir formation. A compressed fluid injection injects an unheated, compressed working fluid into the storage zone. A fluid injection well injects a working fluid laden with thermal waste heat or excess heat into the storage zone. The storage zone is located below a caprock layer and above a native brine zone of the reservoir formation and is partially circumscribed by a hot brine storage zone. The compressed working fluid assists with a withdrawal of pressurized brine residing below and/or to the sides of the storage zone. A compressed CO2, N2, or air production well helps to remove compressed working fluid from the storage zone for use in power production.