Poroelastic Breakdown Pressure Calculation for Deviated Wellbores

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Solution Overview

Problem

Existing techniques for accurately calculating formation breakdown pressure are deficient, especially for deviated and horizontal wellbores, as they either rely on crude approximations or computationally expensive numerical solutions that do not fully account for underlying physical parameters.

Innovation Solution

A workflow that combines analytical and numerical techniques to accurately calculate formation breakdown pressure, considering a generalized stress model for arbitrary wellbore orientations and incorporating key physical parameters such as rock porosity, permeability, and fracturing fluid properties.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If crude approximation techniques are used to calculate breakdown pressure, then computational complexity is reduced, but calculation accuracy deteriorates

Engineering Contradiction:

Improvecomputational complexityVSAvoidbreakdown pressure calculation accuracy

Core Design Contradiction:

Device complexityVSMeasurement precision

Solution Approach 1:

The patent transforms the breakdown pressure calculation from using crude approximations to incorporating comprehensive physical parameters including rock porosity, permeability, fluid compressibility, and poroelastic effects. This parameter enrichment approach maintains computational tractability while significantly improving accuracy by accounting for the coupled fluid-solid mechanics in porous formations.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent replaces traditional mechanical stress analysis with a poroelastic theory framework that couples fluid flow and solid deformation. This substitution allows the model to capture the interaction between injected fracturing fluids and the porous rock matrix, providing more accurate breakdown pressure predictions without excessive computational complexity.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Measurement precision

If numerical solutions are used to calculate breakdown pressure, then calculation accuracy is improved, but computational cost increases

Engineering Contradiction:

Improvebreakdown pressure calculation accuracyVSAvoidcomputational cost

Core Design Contradiction:

Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The patent segments the complex poroelastic breakdown pressure problem into distinct analytical components: far-field stress calculation, pore pressure diffusion, poroelastic stress adjustment, and near-wellbore stress concentration. Each segment is solved using appropriate analytical or semi-analytical methods, reducing overall computational cost while maintaining accuracy.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent performs preliminary calculations of far-field stresses and initial pore pressure distributions using analytical solutions before proceeding to the breakdown pressure calculation. This preliminary action establishes boundary conditions and initial states that simplify subsequent numerical computations, reducing the overall computational burden.

Inventive Principle:

Principle #10Preliminary action

3Ease of operation

If existing calculation methods are used for deviated and horizontal wellbores, then computational simplicity is maintained, but reliability deteriorates

Engineering Contradiction:

Improvecomputational simplicityVSAvoidbreakdown pressure estimation reliability

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The patent develops a universal breakdown pressure calculation framework based on poroelastic theory that can handle vertical, deviated, and horizontal wellbores through a single set of governing equations. The model incorporates wellbore orientation parameters (inclination and azimuth angles) to account for anisotropic stress fields, providing reliable predictions across all wellbore configurations without requiring separate simplified methods.

Inventive Principle:

Principle #6Universality (Multi-functionality)

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 workflow provides a more accurate and efficient estimation of breakdown pressure, overcoming limitations of existing methods by eliminating empirical parameters and avoiding numerical instability issues, thus enhancing the reliability of hydraulic fracturing operations.

Implementation Method 1

The workflow employs the theory of poroelasticity to compute pore pressures and poroelastic stresses numerically

Methodology Applied

Scientific EffectPoroelasticity:

Data Source

PatentUS20250052141A1Formation breakdown pressure near wellbores

Publication Date: 2025.02.13 SAUDI ARABIAN OIL CO

AI summary

Among other things, methods and systems are described for calculating formation breakdown pressures. A method involves determining, during hydraulic fracturing operations, a pore pressure for a wellbore; determining a poroelastic stress for the wellbore using a poroelastic stress equation and based on the pore pressure; determining, during the hydraulic fracturing operations, a breakdown pressure upper bound for the wellbore; applying, during the hydraulic fracturing operations, a stress correction on the breakdown pressure upper bound based on whether the wellbore is an open hole wellbore or a cemented liner wellbore; and determining, during the hydraulic fracturing operations, a breakdown pressure for the wellbore based on the stress-corrected upper bound breakdown pressure for the wellbore.