Formation Saturation Parameter Estimation via Probe Mobility
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for determining saturation parameters of an earth formation traversed by a borehole are cumbersome and time-consuming, particularly due to uncertainties associated with the spatial distribution of formation properties like permeability, and require detailed invasion process information.
Innovation Solution
The method utilizes flow rate and pressure data to provide mobility information close to the probe, combined with water fraction data to estimate saturation parameters such as maximum residual oil saturation, connate water saturation, and residual water saturation, using resistivity measurements and simplifying assumptions to bypass the need for invasion details.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If detailed invasion process information is used to determine saturation parameters, then measurement precision is improved, but device complexity and time consumption increase
Solution Approach 1:
The patent extracts only the essential measurements (pressure and water-cut) needed for saturation parameter determination, eliminating the need for complex invasion process modeling while maintaining measurement precision through direct correlation between these measurements and saturation parameters
Solution Approach 2:
The patent segments the determination process into distinct operational phases (drawdown and build-up) with specific measurements taken in each phase, allowing saturation parameters to be determined through systematic analysis of segmented data rather than comprehensive invasion modeling
2Measurement precision
If comprehensive simulation exercises are conducted to parameterize invasion, then measurement precision is improved, but loss of time increases
Solution Approach 1:
The patent performs preliminary measurements of pressure and water-cut during the sampling process itself, preparing the necessary data before formal analysis begins. This preliminary action during drawdown and build-up phases eliminates the need for time-consuming post-processing simulation exercises
Solution Approach 2:
The patent skips the intermediate step of comprehensive simulation exercises by directly correlating pressure and water-cut measurements with saturation parameters through established relationships, rushing through the determination process while maintaining precision
3Measurement precision
If spatial distribution of formation properties is fully considered, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The patent focuses on local measurements at the probe location (pressure and water-cut) rather than attempting to model the entire spatial distribution of formation properties. This local quality approach determines saturation parameters at the specific location of interest without the complexity of comprehensive spatial modeling
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 enables efficient estimation of saturation parameters without requiring detailed invasion information, reducing complexity and uncertainty, and provides accurate results through cross-plot analysis and iterative optimization.
Implementation Method 1
the pressure at the probe may be measured and processed in order to determine formation parameters such as formation permeability
Implementation Method 2
Optical analysis of the fluid may be conducted by a fluid analyzer
Implementation Method 3
resistivity measurements are used to help in the estimation of the saturation parameters
Data Source
AI summary
Methods are provided for determining saturation parameters of a formation while sampling the formation. Flow rate and pressure data may be used in order to provide mobility information close to the probe. In turn, the mobility information may be used in conjunction with at least water fraction information in order to provide an estimation of saturation parameters of the formation such as maximum residual oil saturation Sorm, connate water saturation Swc, and residual water saturation Swr. Resistivity measurements may be used to help in the estimation of the saturation parameters. Initial estimations may be used as the starting parameters for a full parameter inversion. An interpretation scheme in the absence of invasion details is provided.