Methods and systems to control flow and heat transfer between subsurface wellbores connected hydraulically by fractures

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Solution Overview

Problem

Existing geothermal energy systems face issues of thermal breakthrough and heterogeneity in formations, leading to inefficient resource recovery and premature cooling, which has hindered the adoption of geothermal energy as a clean energy source.

Innovation Solution

Implementing a system with optimized well designs and hydraulic fracturing techniques, including cased and cemented completions, multistage multicluster hydraulic fracture treatments, and uniform perforation patterns, to establish a substantially uniform tortuous flow path and manage thermal distribution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If hydraulic fracturing is performed to enhance resource recovery, then fluid flow between wellbores is improved, but thermal breakthrough occurs prematurely due to direct flow paths

Engineering Contradiction:

Improveresource recovery rateVSAvoidthermal breakthrough timing

Core Design Contradiction:

ProductivityVSTemperature

Solution Approach 1:

The patent applies the curvature principle by designing tortuous (curved) flow paths through strategic perforation patterns and fracture geometry control. Instead of straight direct paths, the fluid is guided through curved routes that extend the thermal contact time between the geothermal fluid and formation rocks, thereby preventing premature thermal breakthrough while maintaining enhanced resource recovery

Inventive Principle:

Principle #14Spheroidality (Curvature)

Solution Approach 2:

The patent implements preliminary action by pre-planning and executing specific perforation patterns and fracture treatments before production begins. The tortuous flow path geometry is established in advance through controlled hydraulic fracturing and perforation configurations, ensuring that thermal management is built into the system structure before operational issues arise

Inventive Principle:

Principle #10Preliminary action

2Ease of manufacture

If conventional well completions are used, then installation is simpler, but flow distribution is heterogeneous leading to inefficient heat extraction

Engineering Contradiction:

Improvewell completion installationVSAvoidheat extraction efficiency

Core Design Contradiction:

Ease of manufactureVSProductivity

Solution Approach 1:

The patent applies local quality by varying perforation characteristics (size, spacing, orientation) at different locations along the wellbore to optimize flow distribution. Each local section is tailored with specific perforation patterns that account for local formation properties, ensuring uniform heat extraction across the entire well interval while maintaining overall system feasibility

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent implements parameter changes by systematically adjusting perforation parameters (diameter, spacing, density, orientation) to transform the flow regime from heterogeneous to uniform. These parameter modifications are made within the constraints of conventional completion technologies, achieving improved heat extraction efficiency without fundamentally changing the installation process

Inventive Principle:

Principle #35Parameter changes

3Speed

If direct flow paths are created between wellbores, then fluid circulation rate increases, but thermal contact time with formation rocks decreases

Engineering Contradiction:

Improvefluid circulation rateVSAvoidthermal contact time

Core Design Contradiction:

SpeedVSDuration of action of moving object

Solution Approach 1:

The patent resolves this contradiction by introducing curved tortuous flow paths that increase the effective travel distance of the fluid without proportionally increasing the straight-line distance between wellbores. This curvature extends the thermal contact time between fluid and formation rocks while still maintaining high circulation rates, as the fluid velocity remains high even though the path length is extended through multiple bends and turns

Inventive Principle:

Principle #14Spheroidality (Curvature)

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

Enhances geothermal well performance by maintaining consistent fluid flow and temperature, supporting long-term commercial power generation and reducing greenhouse gas emissions.

Implementation Method 1

hydraulically fracturing the formation by pumping a fracturing fluid under pressures in excess of the fracture pressure of the formation

Methodology Applied

Scientific EffectHydraulic fracturing: Fracture Mechanics

Implementation Method 2

pumping a heat transfer fluid down a production well and through the formation and back up an injection well

Methodology Applied

Scientific EffectHeat transfer: Conduction (thermal)

Data Source

PatentUS20260078658A1Methods and systems to control flow and heat transfer between subsurface wellbores connected hydraulically by fractures

Publication Date: 2026.03.19 FERVO ENERGY CO

AI summary

A controlled rate of propagation of the fluid saturation front or thermal front is desired in may oil and gas and geothermal operations. Natural fractures and fractures created during hydraulic stimulation may have heterogeneous hydraulic properties resulting in uneven flow distributions, therefore leading to short-circuiting and breakthrough issues. The present invention relates to wellbores connected hydraulically by multiple fracture zones; methods are directed to control for even flow distribution among fractures, regardless of heterogeneities in fracture hydraulic properties, and to control propagation of saturation fronts and thermal fronts in subsurface reservoirs.