Degradable Plug Casing Segment for Wellbore Cementing

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Solution Overview

Problem

During wellbore cementing operations, cement composition and debris often obstruct the channels of downhole tools, preventing them from communicating with the interior of the casing, which hampers their operation.

Innovation Solution

The use of degradable plugs within the channels of downhole tools, which are designed to degrade over time due to exposure to specific fluids or environmental conditions, allowing fluid communication to be re-established after the cementing operation is complete, thereby preventing obstruction by cement and debris.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a burst disk is used to prevent cement influx into the channel, then the downhole tool is protected from cement and debris, but the device complexity increases and requires additional activation steps

Engineering Contradiction:

Improveprotection from cement and debrisVSAvoidcomplexity of protection mechanism

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent employs a disposable occlusion device that is discarded after a single use. The device is deployed to occlude the channel during cementing operations, then intentionally allowed to fail or dissolve after serving its protective purpose, eliminating the need for complex retrieval or activation mechanisms

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The occlusion device is pre-positioned within the channel before cementing begins. The channel is pre-occluded to prevent cement and debris ingress during the critical cementing operation, with the occlusion being established in advance rather than requiring activation during or after cementing

Inventive Principle:

Principle #10Preliminary action

2Ease of operation

If the channel is kept open for downhole tool operation, then the tool can function properly, but cement and debris can obstruct the channel during cementing

Engineering Contradiction:

Improveoperation of downhole toolVSAvoidobstruction by cement and debris

Core Design Contradiction:

Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The channel occlusion state is made dynamic rather than static. The occlusion device allows the channel to transition between occluded and open states based on operational requirements - occluded during cementing to prevent contamination, then opened afterward to enable downhole tool function

Inventive Principle:

Principle #15Dynamics

3Ease of operation

If a degradable plug is used to occlude the channel, then the plug can be removed without intervention, but the plug may degrade before the desired time

Engineering Contradiction:

Improveautomatic removal of occlusionVSAvoidtiming of plug degradation

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The degradation characteristics of the occlusion device are controlled by adjusting material parameters such as composition, cross-linking density, or molecular weight. These parameter changes allow tuning of the degradation rate to match the specific timing requirements of different cementing and production schedules

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

A degradable intermediary substance or coating is applied to the occlusion device that controls its degradation timing. This intermediary layer protects the core structure during service then degrades at a controlled rate to allow channel opening without direct operator intervention

Inventive Principle:

Principle #24Intermediary (Mediator)

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 solution ensures that downhole tools can operate effectively by isolating them from cement and debris during cementing, and automatically allowing communication with the casing fluids once the plugs degrade, ensuring uninterrupted functionality.

Implementation Method 1

degradable plugs within the channels of downhole tools, which are designed to degrade over time due to exposure to specific fluids or environmental conditions

Methodology Applied

Scientific EffectDegradation: Decomposition (biological)

Data Source

PatentUS11466535B2Casing segment methods and systems with time control of degradable plugs

Publication Date: 2022.10.11 HALLIBURTON ENERGY SERVICES INC

AI summary

A casing segment comprising a cylinder, a downhole tool, a first channel in the cylinder, a degradable plug wherein the plug degrades when exposed to a degrading fluid, said degrading fluid concurrently not degrading to the cylinder or the downhole tool, and a fluid reservoir that stores the degrading fluid, wherein the fluid reservoir is in fluid communication with the plug. A method comprising obtaining a casing segment having a cylinder, a downhole tool, and a fluid reservoir with degrading fluid, said degrading fluid concurrently not degrading to the cylinder or the downhole tool, wherein the cylinder includes a first channel, installing a degradable plug within the first channel, deploying the casing segment downhole, and exposing the degradable plug to the degrading fluid to cause the downhole tool to be in fluid communication with the interior surface of the cylinder.