Subsurface Energy Storage in Overpressure Formations
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Solution Overview
Problem
Traditional pumped hydro storage systems are limited by their dependence on elevated terrains and struggle to expand into areas with overpressure conditions, which introduce mechanical instability and require effective management of higher pressure variations, limiting their applicability in balancing grid fluctuations and storing excess energy generation.
Innovation Solution
A method involving the injection of an incompressible working fluid into a subsurface formation under pressure, storing it for a period, and then reducing pressure to produce the fluid for power generation, suitable for formations with overpressure conditions, isolated traps, depleted oil and gas fields, or dry holes, using techniques like expanding the wellbore contact area and employing proppants to reduce friction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If traditional pumped hydro storage systems are used, then energy storage capability is achieved, but the system is limited to elevated terrains and cannot operate in overpressure environments
Solution Approach 1:
The patent changes the fundamental operating parameters of pumped storage systems by transitioning from gravity-dependent elevated terrain operations to pressure-driven subsurface formations. This includes operating in overpressure environments where fluid pressures exceed hydrostatic equilibrium, and managing pressure variations throughout the working cycle. The system adapts to different geological conditions (overpressure systems, isolated traps, depleted fields) by modifying injection and production pressure parameters rather than relying on elevation differences.
2Adaptability or versatility
If geomechanical pumped storage systems are developed in overpressure environments, then geographical footprint is expanded, but mechanical instability and pressure variation management challenges increase
Solution Approach 1:
The patent applies preliminary actions by conducting extensive formation evaluation and characterization before implementing energy storage operations. This includes assessing overpressure conditions, mechanical properties, and fluid conductivity to identify suitable formations. The system performs preliminary injection and production cycles to establish stable operating parameters and monitor formation response, ensuring mechanical stability is maintained throughout the working cycle.
3Quantity of substance
If working fluid is injected into overpressure formations, then energy storage capacity increases, but friction and pressure loss increase
Solution Approach 1:
The patent introduces wellbore proppants as intermediary materials to reduce friction between the working fluid and formation boundaries. These proppants create a low-friction pathway that facilitates efficient fluid injection and production, minimizing pressure losses. The proppants act as a mediator between the high-pressure injection system and the formation, enabling effective energy storage while reducing energy dissipation through friction.
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
Enables energy storage and generation in a wider range of geological conditions, including overpressure environments, by efficiently managing pressure variations and reducing friction, thus expanding the suitability of geomechanical pumped storage systems beyond traditional limitations.
Implementation Method 1
injecting an incompressible working fluid into a subsurface formation under pressure through a well to store energy
Implementation Method 2
storing the working fluid within the formation under the pressure for a period of time; overpressure environments, where fluid pressures exceed hydrostatic equilibrium
Implementation Method 3
reducing the pressure so as to produce a portion of the fluid up the well and using the produced fluid to generate power
Implementation Method 4
using techniques like expanding the wellbore contact area and employing proppants to reduce friction
Data Source
AI summary
Methods for developing geomechanical pumped energy storage systems whereby energy is stored as mechanical energy by injecting a working fluid into a formation and producing the working fluid from the formation while generating power or performing work. The method is particularly adapted to storage of large amounts of energy such as in grid-scale electric energy systems. The formation may exhibit overpressure conditions, may comprise isolated stratigraphic or structural traps of reasonable size, or may comprise depleted oil and gas assets repurposed for storing energy.