Endothermic Wellbore Composition for Thermal Shock Fracturing

Solution Overview

Problem

Unconventional subsurface formations with low permeability and porosity require high pressures and large fluid volumes for hydraulic fracturing, leading to increased costs and material needs.

Innovation Solution

Thermal shocking of subsurface formations using an endothermic fluid composition comprising ammonium chloride and sodium hydroxide, which reacts to produce ammonia, reducing the formation's compressive strength and Poisson's ratio, thereby lowering the required hydraulic fracturing pressure and fluid volume.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If hydraulic fracturing is performed on unconventional subsurface formations, then fractures can be created to enable fluid production, but high pressures and large fluid volumes are required due to low permeability and porosity

Engineering Contradiction:

Improvefluid production capabilityVSAvoidfluid volume required

Core Design Contradiction:

ProductivityVSQuantity of substance

Solution Approach 1:

The patent applies preliminary action by introducing an endothermic fluid composition before hydraulic fracturing to pre-soften the subsurface formation. This preliminary thermal treatment reduces the compressive strength and Poisson's ratio of the formation, creating conditions that require less fluid volume and pressure for subsequent fracturing operations.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent changes physical parameters by using an endothermic chemical reaction to temporarily alter the temperature and mechanical properties of the subsurface formation. The endothermic fluid composition undergoes a temperature decrease that induces thermal shock, softening the rock and reducing its strength parameters, thereby enabling more efficient fracturing.

Inventive Principle:

Principle #35Parameter changes

2Productivity

If hydraulic fracturing is performed on unconventional subsurface formations, then fractures can be created to enable fluid production, but high pressures are required to overcome the formation breakdown pressure

Engineering Contradiction:

Improvefluid production capabilityVSAvoidhydraulic fracturing pressure

Core Design Contradiction:

ProductivityVSStress or pressure

Solution Approach 1:

The patent applies preliminary action by introducing an endothermic fluid composition before hydraulic fracturing to pre-soften the subsurface formation. This preliminary thermal treatment reduces the compressive strength and Poisson's ratio of the formation, creating conditions that require less fluid volume and pressure for subsequent fracturing operations.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent changes physical parameters by using an endothermic chemical reaction to temporarily alter the temperature and mechanical properties of the subsurface formation. The endothermic fluid composition undergoes a temperature decrease that induces thermal shock, softening the rock and reducing its strength parameters, thereby enabling more efficient fracturing.

Inventive Principle:

Principle #35Parameter changes

3Productivity

If high pressures and large fluid volumes are used for hydraulic fracturing, then fractures can be created in low permeability formations, but cost and material needs increase substantially

Engineering Contradiction:

Improvefluid production capabilityVSAvoidcost and material efficiency

Core Design Contradiction:

ProductivityVSEase of manufacture

Solution Approach 1:

The patent applies preliminary action by introducing an endothermic fluid composition before hydraulic fracturing to pre-soften the subsurface formation. This preliminary thermal treatment reduces the compressive strength and Poisson's ratio of the formation, creating conditions that require less fluid volume and pressure for subsequent fracturing operations.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent changes physical parameters by using an endothermic chemical reaction to temporarily alter the temperature and mechanical properties of the subsurface formation. The endothermic fluid composition undergoes a temperature decrease that induces thermal shock, softening the rock and reducing its strength parameters, thereby enabling more efficient fracturing.

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

The method reduces the hydraulic fracturing pressure and fluid volume needed, achieving cost and material savings while inducing fractures in the subsurface formation.

Implementation Method 1

reacting the ammonium chloride and sodium hydroxide, thereby decreasing a temperature of the endothermic fluid and producing ammonia

Methodology Applied

Scientific EffectEndothermic reaction: Endothermic Reaction

Implementation Method 2

exposing the reacted endothermic fluid composition to the subsurface formation, thereby thermally shocking at least a portion of the subsurface formation and inducing one or more fractures in the same

Methodology Applied

Scientific EffectThermal shock: Thermal Shock

Data Source

PatentUS20260015927A1Methods and compositions for thermally shocking subsurface formations

Publication Date: 2026.01.15 SAUDI ARABIAN OIL CO

AI summary

A method of thermally shocking a subsurface formation may comprise introducing an endothermic fluid composition into a wellbore fluidly connected to the subsurface formation, the endothermic fluid composition comprising an aqueous solution, ammonium chloride, and sodium hydroxide; reacting the ammonium chloride and sodium hydroxide, thereby decreasing a temperature of the endothermic fluid and producing ammonia; and exposing the reacted endothermic fluid composition to the subsurface formation, thereby thermally shocking at least a portion of the subsurface formation and inducing one or more fractures in the same.