Wellbore Probe Seal Formation Evaluation Bypassing Invaded Zones
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Solution Overview
Problem
Existing methods for measuring petrophysical parameters in subsurface formations are hindered by the 'damaged zone' and 'invaded zone' created during wellbore drilling, which restrict fluid movement and contaminate fluid samples, making accurate measurements of permeability and saturation challenging.
Innovation Solution
A formation evaluation apparatus that uses a probe seal to establish a localized fluid communication with the formation, allowing for measurements without breaking the seal, and employs sensors to determine petrophysical parameters like saturation levels and resistivity, while injecting or withdrawing fluids, thereby bypassing the damaged and invaded zones.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If conventional wellbore drilling methods are used, then the wellbore can be established for accessing the formation, but the damaged zone and invaded zone are created which restrict fluid movement and contaminate fluid samples
Solution Approach 1:
The wellbore is segmented into different zones: the damaged zone, invaded zone, and undisturbed formation zone. The measurement tool is designed to access only the undisturbed formation zone beyond the damaged and invaded zones, effectively segmenting the measurement location from the contaminated areas.
Solution Approach 2:
A filter or separator mechanism is introduced as an intermediary between the invaded zone and the measurement chamber. This intermediary allows fluid to pass from the formation while blocking contaminants from the damaged and invaded zones, enabling accurate measurement without direct contact with contaminated fluids.
2Productivity
If measurements are taken from the invaded zone, then fluid samples can be obtained easily, but the measurements are contaminated and do not represent the true formation properties
Solution Approach 1:
The measurement system extracts only the clean, undisturbed formation fluids that have passed through the damaged and invaded zones. By taking measurements from fluids that have traveled through the formation and emerged into the undisturbed zone, the system obtains representative samples while excluding contaminated fluids from the measurement process.
Solution Approach 2:
A filtering mechanism acts as an intermediary that separates contaminated fluids from clean formation fluids. The filter allows only undisturbed formation fluids to reach the measurement sensors, ensuring measurement precision while maintaining efficient operation.
3Measurement precision
If the seal is broken to access the undisturbed formation, then accurate measurements can be obtained, but fluid loss and contamination occur
Solution Approach 1:
The measurement chamber is nested within the sealed system, with the seal enclosing the measurement apparatus. The undisturbed formation zone is accessed through the sealed system rather than breaking the seal, allowing measurements to be taken from clean formation fluids while maintaining the integrity of the seal and preventing fluid loss.
Solution Approach 2:
The seal acts as an intermediary barrier that prevents direct contact between the measurement system and the contaminated zones. By routing formation fluids through the seal rather than breaking it, the system maintains measurement precision while preventing fluid loss and contamination.
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
Enables accurate measurement of petrophysical properties representative of the undisturbed formation, improving the determination of permeability and residual oil saturation, and enhancing the assessment of hydrocarbon-bearing formations by minimizing the impact of drilling-related alterations.
Implementation Method 1
a probe seal configured to seal against a wellbore wall to define a sealed-off region
Implementation Method 2
sensors configured to determine petrophysical parameters of the formation proximate the formed hole
Implementation Method 3
induce spin precession in a portion of the formation located around the formed hole, and measure spin echoes
Implementation Method 4
a drill configured to form a hole through the sealed portion of the wellbore wall with the probe seal maintaining its seal against the wellbore wall
Implementation Method 5
injecting or withdrawing fluids, thereby bypassing the damaged and invaded zones
Implementation Method 6
determination of effective permeabilities of water, oil or gas
Data Source
AI summary
Subsurface formation evaluation comprising, for example, sealing a portion of a wall of a wellbore penetrating the formation, forming a hole through the sealed portion of the wellbore wall, injecting an injection fluid into the formation through the hole, and determining a saturation of the injection fluid in the formation by measuring a property of the formation proximate the hole while maintaining the sealed portion of the wellbore wall.