Dielectric Cation Exchange Capacity Measurement for Rock Samples

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Solution Overview

Problem

Current methods for determining the cation exchange capacity (CEC) of rock samples are laborious, requiring multiple steps, chemicals, and complex analytical equipment, making them inefficient and impractical for real-time applications in the oil and gas industry.

Innovation Solution

A method involving equilibration of rock samples to relative humidity and performing dielectric permittivity measurements, using handheld probes and equations derived from quartz-smectite mixtures to calculate CEC without the need for chemical-based sample preparation or extensive laboratory settings.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If traditional chemical-based methods are used to determine CEC, then measurement precision is improved, but device complexity and loss of time increase

Engineering Contradiction:

ImproveCEC measurement precisionVSAvoidcomplexity of equipment and chemicals

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces chemical-based measurement systems with a dielectric-based physical measurement system. A handheld dielectric probe measures the dielectric constant of the rock formation, which correlates to CEC values. This substitution eliminates the need for complex chemical saturation and extraction procedures while maintaining measurement accuracy within ±6 meq/100g of laboratory measurements.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent creates a simplified proxy measurement system that copies the essential information needed for CEC determination without replicating the full chemical analysis process. The dielectric constant measurement serves as a proxy that correlates to CEC, allowing rapid assessment without actual chemical extraction and analysis.

Inventive Principle:

Principle #26Copying

2Measurement precision

If traditional laboratory methods are used, then measurement precision is improved, but loss of time increases

Engineering Contradiction:

ImproveCEC measurement precisionVSAvoidtime required for measurement

Core Design Contradiction:

Measurement precisionVSLoss of time

Solution Approach 1:

The patent replaces time-consuming chemical saturation, extraction, and titration processes with an instantaneous dielectric measurement. The handheld probe provides real-time CEC data based on dielectric constant measurements, reducing measurement time from hours or days to seconds while maintaining precision within ±6 meq/100g of laboratory values.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent establishes pre-determined correlations between dielectric constant values and CEC measurements through preliminary calibration against laboratory standards. This allows field measurements to be rapidly converted to CEC values without performing the full chemical analysis procedure each time.

Inventive Principle:

Principle #10Preliminary action

3Productivity

If simplified methods are used, then productivity is improved, but measurement precision worsens

Engineering Contradiction:

Improvespeed of CEC determinationVSAvoidCEC measurement precision

Core Design Contradiction:

ProductivityVSMeasurement precision

Solution Approach 1:

The patent achieves both high productivity and acceptable precision by substituting chemical analysis with dielectric measurement. The method provides rapid CEC determination with precision within ±6 meq/100g of laboratory measurements, which is sufficient for real-time drilling operations and well planning decisions.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the measurement parameter from chemical concentration analysis to dielectric constant measurement. This parameter change enables rapid measurement while maintaining sufficient precision for operational decision-making in hydrocarbon production.

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

This approach simplifies the determination of CEC, providing quick and accurate results that can be used in real-time drilling operations, reducing the need for chemical usage and complex equipment, while maintaining precision within ±6 meq/100g of laboratory measurements.

Implementation Method 1

performing a dielectric permittivity measurement on the rock sample at the relative humidity

Methodology Applied

Scientific EffectDielectric permittivity measurement: Dielectric Permittivity

Data Source

PatentUS11549902B2Determining a cation exchange capacity of a rock sample

Publication Date: 2023.01.10 CHEVRON USA INC

AI summary

Provided herein are various embodiments of determining a cation exchange capacity of a rock sample. One embodiment of a method of determining a cation exchange capacity of a rock sample comprises equilibrating the rock sample to a relative humidity, performing a dielectric permittivity measurement on the rock sample at the relative humidity, and determining a cation exchange capacity of the rock sample based on the dielectric permittivity measurement. One embodiment of a method of determining a cation exchange capacity of a rock sample comprises receiving a dielectric permittivity measurement on the rock sample, and determining a cation exchange capacity for the rock sample based on the dielectric permittivity measurement of the rock sample and a relationship between cation exchange capacity and dielectric permittivity measurements for mineral mixtures corresponding to a range of cation exchange capacity values.