Method for thermal profile control and energy recovery in geothermal wells

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Solution Overview

Problem

Current geothermal energy production technologies face challenges in managing thermal losses and optimizing heat extraction along the length of geothermal wells, particularly due to temperature variations and inefficient heat transfer, leading to reduced energy recovery and increased costs.

Innovation Solution

The implementation of a wellbore configuration network with interdigital disposition of horizontal sections and controlled working fluid flow to achieve thermal equilibrium, combined with sealing and additive compositions to enhance thermal conductivity and wellbore integrity, allowing for dynamic adjustment of thermodynamic parameters to maximize energy recovery across varying geothermal gradients.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If traditional geothermal well configurations are used, then heat extraction is simplified, but thermal losses increase and energy recovery efficiency decreases

Engineering Contradiction:
Improvethermal lossesVSAvoidenergy recovery efficiency
Core Design Contradiction:
Loss of energyVSProductivity

Solution Approach 1:

The well system is divided into multiple horizontal wellbores arranged in an interdigital pattern, with each wellbore segment handling specific flow directions. This segmentation allows optimized thermal interaction with the formation while reducing overall thermal losses through distributed heat extraction points.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Multiple horizontal wellbores are combined into an integrated network system where injection and production wells work in coordination. The merged system creates enhanced thermal interference patterns in the formation that improve overall energy recovery efficiency while managing thermal losses across the entire wellpad.

Inventive Principle:
Principle #5Merging (Combining)

2Productivity

If heat extraction is maximized along the well length, then energy recovery improves, but temperature variations create thermal inefficiencies and 'dead spots'

Engineering Contradiction:
Improveheat extraction efficiencyVSAvoidtemperature variations
Core Design Contradiction:
ProductivityVSTemperature

Solution Approach 1:

The interdigital arrangement inverts the traditional parallel well configuration by alternating injection and production wellbores in an interlaced pattern. This inversion creates more uniform temperature distribution by preventing thermal short-circuiting and eliminating dead spots where temperature variations would otherwise create inefficiencies.

Inventive Principle:
Principle #13The other way round (Inversion)

Solution Approach 2:

Each wellbore location is optimized for its specific function (injection or production) based on its position in the interdigital pattern. This local optimization ensures that heat extraction occurs where most efficient, while injection zones are strategically positioned to maintain thermal equilibrium, reducing overall temperature variations.

Inventive Principle:
Principle #3Local quality

3Productivity

If multiple branched horizontal wells are used to enhance heat mining, then energy recovery increases, but the footprint and construction costs increase

Engineering Contradiction:
Improveheat mining rateVSAvoidwellpad footprint
Core Design Contradiction:
ProductivityVSArea of stationary object

Solution Approach 1:

The system transitions from vertical well configurations to horizontal wellbores that extend in the subsurface plane. This dimensional change allows multiple wellbores to be arranged in a compact interdigital pattern, achieving enhanced heat mining rates while minimizing the surface footprint of the wellpad.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

4Productivity

If working fluid flow rate is increased to enhance heat transfer, then energy recovery improves, but pressure losses and pump requirements increase

Engineering Contradiction:
Improveheat transfer rateVSAvoidpressure losses
Core Design Contradiction:
ProductivityVSStress or pressure

Solution Approach 1:

The system optimizes working fluid flow parameters by distributing flow across multiple wellbores in the interdigital network. This parameter optimization allows adequate heat transfer rates to be achieved while maintaining manageable pressure losses through the distributed flow paths, reducing pump power requirements.

Inventive Principle:
Principle #35Parameter changes

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

This approach enhances heat extraction efficiency, reduces well construction costs, and minimizes 'dead spots' by maintaining thermal equilibrium and optimizing energy recovery regardless of geothermal gradient quality or formation characteristics, making geothermal energy production more economically viable.

Implementation Method 1

heat exchange is enhanced between the hot surrounding rock formation through long horizontal segments of a closed loop well using specific working fluids

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Implementation Method 2

in geothermal energy heat is continually generated within the magma layer through radioactive decay

Methodology Applied
Scientific EffectRadioactive decay: Radioactive Decay

Data Source

PatentEP3611441B1Method for thermal profile control and energy recovery in geothermal wells
Publication Date: 2024.08.21 EAVOR TECH INC
  • EP3611441B1 patent drawingFigure 1~2
  • EP3611441B1 patent drawingFigure 3~5
  • EP3611441B1 patent drawingFigure 6~7

AI summary

A method for controlling temperature maxima and minima from the heel to toe in geothermal well lateral sections. The method includes disposing at least a pair of wells proximately where thermal contact is possible. Working fluid is circulated in one well of the pair in one direction and the working fluid of the second well is circulated in as direction opposite. to the first. In this manner temperature equilibration is attainable to mitigate maxima and minima to result in a substantially more uniform temperature of the working fluids in respective wells and the rock formation area there between. Specific operating protocol is disclosed having regard to the temperature control for maximizing thermal energy recovery.