Systems and methods for multi-fluid geothermal energy systems
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Solution Overview
Problem
Geothermal energy production is limited by insufficient working fluid and pressure depletion, leading to high parasitic costs and reduced flow rates, especially in sedimentary formations where conventional systems are inefficient.
Innovation Solution
A multi-fluid geothermal energy production system using nitrogen (N2) and carbon dioxide (CO2) as supplemental working fluids to augment pressure and enhance flow rates, with a well configuration that includes production, injection, re-injection, and brine production wells to optimize energy extraction and storage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional geothermal systems use single fluid (brine) recirculation, then system simplicity is maintained, but parasitic costs increase and flow rates decrease due to pressure depletion
Solution Approach 1:
The patent combines multiple working fluids (brine, CO2, N2) into a single geothermal system, allowing them to work synergistically. CO2 and N2 are injected to provide pressure support and enhance drive mechanisms, while brine serves as the primary heat transfer fluid. This multi-fluid approach resolves the contradiction by maintaining system productivity through pressure augmentation while reducing parasitic costs through improved natural flow dynamics.
Solution Approach 2:
The patent changes the physical parameters of the working fluid system by introducing gases with different properties (CO2, N2) alongside brine. These parameter changes include viscosity, density, and compressibility variations that create more efficient flow dynamics. The gas fluids provide pressure support and enhance the drive mechanism, reducing the energy required for recirculation while maintaining or increasing flow rates.
2Productivity
If submersible pumps are used to lift brine without sufficient artesian pressure, then flow extraction is achieved, but energy consumption increases significantly
Solution Approach 1:
The patent implements a self-service mechanism where injected CO2 and N2 gases provide natural pressure support and drive mechanisms that automatically lift brine to the surface without requiring external pumping energy. The gases dissolve in brine, creating expansion and pressure differential that drives flow naturally. This eliminates or reduces the need for energy-consuming submersible pumps, resolving the contradiction between maintaining flow rate and reducing electricity consumption.
Solution Approach 2:
The patent replaces the mechanical pumping system (submersible pumps requiring electricity) with a chemical-physical mechanism where CO2 and N2 gases dissolve in brine and provide pressure-driven flow through solution expansion and phase change. This substitution eliminates the need for mechanical energy input while maintaining productivity, directly addressing the contradiction between flow extraction and energy consumption.
3Adaptability or versatility
If geothermal systems are deployed in sedimentary formations with lower permeability, then resource accessibility is limited, but system complexity and development costs increase
Solution Approach 1:
The patent changes the fluid properties by introducing compressible gases (CO2, N2) that can effectively navigate lower permeability formations through pressure dissolution and expansion mechanisms. These parameter changes in fluid behavior allow the system to adapt to sedimentary formations with varying permeability characteristics, enhancing formation compatibility without proportionally increasing system complexity.
Solution Approach 2:
The patent creates a universal system that can operate across different formation types (hydrothermal and sedimentary) by using multi-functional fluids. CO2 and N2 serve multiple functions: pressure support, drive mechanism enhancement, and flow rate augmentation. This multi-functionality allows the same system configuration to adapt to various formation permeabilities, resolving the contradiction between formation compatibility and system complexity.
4Productivity
If working fluid recirculation is enhanced to increase flow rates, then energy production improves, but pressure depletion accelerates and parasitic costs increase
Solution Approach 1:
The patent implements a recovery mechanism where CO2 and N2 gases are injected into the formation, dissolve in brine, and then recovered at production wells through phase separation. The gases provide pressure support during the enhanced recirculation process, preventing pressure depletion. This discard-inject/recover-cycle allows sustained high flow rates without permanent pressure loss, resolving the contradiction between energy production enhancement and pressure maintenance.
Solution Approach 2:
The patent applies preliminary action by injecting CO2 and N2 gases into the formation before significant pressure depletion occurs. These gases pre-establish pressure support and drive mechanisms that maintain reservoir pressure during enhanced recirculation operations. This preliminary pressure augmentation prevents the pressure depletion that would otherwise accompany increased flow rates, resolving the contradiction between productivity enhancement and pressure maintenance.
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 significantly reduces parasitic costs, increases flow rates, and enhances energy storage and production efficiency by using N2 and CO2 to create artesian pressure and drive fluid flow, allowing for flexible energy generation and storage, even in formations with low permeability and scarce water resources.
Implementation Method 1
The supplemental working fluid may be used to augment a pressure in the reservoir formation, to thus drive a flow of the brine out from the reservoir formation and up the production well
Implementation Method 2
using the supplemental working fluid to augment a pressure in the reservoir formation, to thus drive a flow of the brine out from the reservoir formation and up the production well
Data Source
AI summary
A method for extracting geothermal energy from a geothermal reservoir formation. A production well is used to extract brine from the reservoir formation. At least one of nitrogen (N2) and carbon dioxide (CO2) may be used to form a supplemental working fluid which may be injected into a supplemental working fluid injection well. The supplemental working fluid may be used to augment a pressure of the reservoir formation, to thus drive a flow of the brine out from the reservoir formation.