Core Sample Slabbing Force Measurement for Rock Friction

Solution Overview

Problem

Existing methods for characterizing the mechanical properties of formation rocks from subsurface hydrocarbon reservoirs are time-consuming and costly, often failing to meet urgent operational needs for well completion, well testing, and stimulation due to separate testing procedures before or after slabbing.

Innovation Solution

A computer-implemented method and system that characterizes mechanical properties of formation rock in real-time during the slabbing process by measuring forces applied to the core sample and forming ratio measures to indicate strength and internal friction, using a processor, memory, and output device to record and display these properties.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If separate testing procedures are conducted before or after slabbing, then rock mechanical properties can be characterized, but the process becomes time-consuming and costly

Engineering Contradiction:

Improverock mechanical properties characterizationVSAvoidtesting time

Core Design Contradiction:

Measurement precisionVSLoss of time

Solution Approach 1:

The patent combines the slabbing process with mechanical property testing into a single integrated operation. The slabbing machine is equipped with sensors that measure forces during cutting, and a processing system that calculates mechanical properties (compressive strength, tensile strength, elastic modulus, Poisson's ratio, and angle of internal friction) from these force measurements. This eliminates the need for separate pre- or post-slabbing tests, reducing both time and cost while maintaining measurement accuracy.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The slabbing machine is transformed into a multi-functional device that simultaneously performs cutting and mechanical property characterization. The system uses the slabbing process itself to generate data for calculating multiple mechanical properties, making the equipment serve dual purposes rather than requiring dedicated testing equipment.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Measurement precision

If separate testing procedures are conducted before or after slabbing, then rock mechanical properties can be characterized, but the cost increases

Engineering Contradiction:

Improverock mechanical properties characterizationVSAvoidtesting cost

Core Design Contradiction:

Measurement precisionVSLoss of energy

Solution Approach 1:

The patent combines the slabbing process with mechanical property testing into a single integrated operation. The slabbing machine is equipped with sensors that measure forces during cutting, and a processing system that calculates mechanical properties (compressive strength, tensile strength, elastic modulus, Poisson's ratio, and angle of internal friction) from these force measurements. This eliminates the need for separate pre- or post-slabbing tests, reducing both time and cost while maintaining measurement accuracy.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The slabbing process itself generates the data needed for mechanical property characterization. The force measurements taken during the cutting process are directly used to calculate the mechanical properties, eliminating the need for additional energy expenditure on separate testing operations.

Inventive Principle:

Principle #25Self-service

3Measurement precision

If existing methods are used, then rock strength can be determined, but urgent operational needs for well completion and stimulation are not met

Engineering Contradiction:

Improverock strength determinationVSAvoiddata delivery speed

Core Design Contradiction:

Measurement precisionVSProductivity

Solution Approach 1:

The patent performs mechanical property characterization during the slabbing process itself, obtaining results before the core sample is fully processed. The force measurements are continuously collected and processed in real-time, providing preliminary mechanical property data that can be used immediately for well completion and stimulation planning, rather than waiting for separate post-slabbing tests.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system maintains continuous measurement and calculation of mechanical properties throughout the slabbing process. The force sensors continuously monitor the cutting forces, and the processing system continuously calculates mechanical properties, ensuring an unbroken data stream that delivers results as soon as the slabbing is complete, meeting urgent operational timelines.

Inventive Principle:

Principle #20Continuity of useful action

Data Source

PatentUS8738294B2Determination of angle of internal friction of formation rock while slabbing core samples

Publication Date: 2014.05.27 SAUDI ARABIAN OIL CO

AI summary

Mechanical properties of formation rock from a subsurface reservoir are measured with a computerized system while a core sample from the formation is being cut, during a process known as slabbing, for other analytical purposes. Forces exerted during cutting of the slab from the original core sample are sensed and stored in the computer system. The recorded force data, cutting time and dimensions of the core sample and the cut slab are processed in the computer system. Measures of characteristics and mechanical properties of the rock, such as rock strength and angle of internal friction, are obtained with the computer system. Separate and specialized testing procedures performed on test core plugs using samples specially extracted from the original core sample are not required.