Poroelastodynamic Rock Property Inversion for Fracturing Accuracy
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing theories of elasticity fail to account for the viscoelastic behavior and frequency dependence of poromechanical properties in fluid-saturated rock, making it difficult to determine accurate values for poromechanical properties essential for well trajectory and hydraulic fracturing plans.
Innovation Solution
A method involving well data analysis using a poroelastodynamic relationship and vector operators to determine poromechanical properties, such as shear modulus and Biot's modulus, by linking deformations to fluid-saturated rock properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the theory of elasticity is used to model formation rock, then the model is simple and treats rock as homogenous isotropic media, but it fails to account for poromechanical properties, viscoelastic behavior of fluid-saturated pores, and frequency dependence
Solution Approach 1:
The patent transitions from the theory of elasticity to the theory of poroelasticity, fundamentally changing the physical parameters and assumptions of the model. This includes incorporating porosity, fluid saturation, and frequency-dependent properties to accurately represent formation rock behavior while maintaining model tractability through established poroelastic equations
Solution Approach 2:
The patent replaces the simple elastic mechanical model with a poroelastic model that couples solid matrix deformation with fluid flow behavior. This substitution introduces pore pressure, Biot coefficients, and viscoelastic parameters to capture the complex interaction between rock framework and saturating fluids
2Measurement precision
If the theory of poroelasticity is used to model formation rock, then poromechanical properties and frequency dependence are considered, but the model complexity increases compared to elasticity theory
Solution Approach 1:
The patent utilizes poroelastic parameters such as Biot coefficients, porosity, and frequency-dependent moduli to accurately represent formation rock properties. These parameter changes enable precise characterization of viscoelastic behavior and fluid-rock interactions while maintaining a structured modeling approach
Solution Approach 2:
The poroelastic model serves multiple functions simultaneously: it describes static stress-strain relationships, dynamic wave propagation, fluid flow behavior, and frequency-dependent property variations. This multi-functionality justifies the increased complexity by providing a comprehensive framework for various well operations analysis
3Measurement precision
If well data is substituted into the vector-operated poroelastodynamic relationship, then accurate poromechanical property values are determined in situ, but the computational process becomes more complex
Solution Approach 1:
The patent employs inversion techniques where the poroelastic model uses measured well data (seismic velocities, density, porosity) to automatically determine poromechanical properties. The system self-calibrates by fitting model predictions to observed data, reducing the need for complex manual calculations while maintaining high accuracy
Solution Approach 2:
The computational process incorporates feedback loops where initial poromechanical property estimates are refined iteratively by comparing model predictions with actual well data. This feedback mechanism ensures accurate property determination while systematically managing computational complexity through controlled iteration
Data Source
AI summary
Systems and methods are disclosed. The method includes obtaining well data for a fluid-saturated rock and obtaining a poroelastodynamic relationship linking a deformation of the fluid-saturated rock to a poromechanical property of the fluid-saturated rock. The method further includes determining the poromechanical property of the fluid-saturated rock by applying a vector operator to the poroelastodynamic relationship. The method still further includes determining a value of the poromechanical property by substituting the well data into the vector-operated poroelastodynamic relationship.