Frangible Disc Plug Assembly for Oil Well Pressure Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing plug assemblies for petroleum well boreholes are not robust enough and often have many movable parts, leading to malfunctions in harsh well conditions with high pressure and corrosive fluids, and they lack reliable mechanisms for controlled and predictable opening.
Innovation Solution
A plug assembly with a frangible disc that can be opened by a controlled pressure differential, featuring a breaker object and a seat that supports the plug, ensuring the plug remains stationary and intact until broken at a predetermined pressure threshold, with safety measures to prevent accidental actuation and ensure complete opening without debris entry into the wellbore.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If existing plug assemblies with many movable parts are used, then they can be designed to block fluid flow, but they are not robust enough and lead to malfunctions in harsh well conditions
Solution Approach 1:
The plug assembly is divided into distinct functional segments: a frangible disc for fluid blocking, a breaker object for controlled destruction, and a support structure. This segmentation allows each component to be optimized independently, reducing overall complexity while improving reliability through specialized function distribution.
Solution Approach 2:
The frangible disc is extracted as a separate, replaceable component from the plug assembly. This allows the disc to be designed specifically for fluid blocking without the complexity of integrated movable parts, while the remaining assembly provides support and control functions.
2Productivity
If existing plug assemblies are removed using coiled tubing or wireline, then they can be retrieved from the well, but this damages the tubing and takes up valuable rig time
Solution Approach 1:
The frangible disc is designed as a disposable component that is destroyed in place within the wellbore. This eliminates the need for retrieval operations using coiled tubing or wireline, thereby preventing tubing damage and avoiding loss of rig time. The disc is replaced by installing a new assembly rather than retrieving the old one.
Solution Approach 2:
The mechanical retrieval system (coiled tubing, wireline) is replaced by a chemical/breaking system where the frangible disc is destroyed using a breaker object. This substitution eliminates the harmful mechanical forces that damage tubing during retrieval operations.
3Reliability
If frangible materials like glass or ceramics are used for the plug, then they are insensitive to pressure, temperature and chemical corrosion, but they are relatively easy to destroy and may break into small pieces
Solution Approach 1:
The frangible disc is designed with non-uniform local properties: the bulk material provides high strength and resistance to pressure, temperature, and corrosion, while specific localized regions contain stress concentrators or weakened zones that initiate controlled breaking. This allows the disc to withstand harsh well conditions during operation but break predictably when activated.
Solution Approach 2:
The frangible disc is pre-conditioned during manufacturing with inherent weaknesses or stress concentrators in specific locations. These preliminary modifications ensure that when the breaker object applies force, the disc breaks in a controlled manner at predetermined locations rather than shattering randomly, preventing debris entry into the wellbore.
4Ease of operation
If explosives are used to break the frangible disc, then the plug can be opened, but there is a risk of undetonated explosives remaining and safety conditions complicate transport and handling
Solution Approach 1:
The breaker object is designed as a disposable, single-use component that is activated only when needed to break the frangible disc. After activation, it serves its purpose and is discarded, eliminating the long-term safety risks associated with storing and transporting explosives. The breaker object replaces explosives with a simpler, safer activation mechanism.
Solution Approach 2:
The invention converts the potential harm of unpredictable plug breaking into a benefit by designing a controlled breaking mechanism. The breaker object applies force through a defined path to break the frangible disc in a predictable manner, ensuring complete opening without debris entry. The controlled breaking process transforms a potentially harmful random shattering event into a beneficial, predictable operation.
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
The solution provides a robust and reliable mechanism for maintaining pressure integrity until the plug is safely opened, ensuring complete and predictable breaking of the frangible disc, preventing debris entry and maintaining fluid flow without partial opening or leakage.
Implementation Method 1
A plug assembly with a frangible disc that can be opened by a controlled pressure differential
Data Source
AI summary
A plug system including: a plug tubular including a tubular body, an upstream tubular connection, and a downstream tubular connection; wherein: the upstream tubular connection and the downstream tubular connection are openings at opposite ends of the tubular body; and a plug assembly arranged in a housing including: a plug; a breaker object; and a seat; wherein: the plug is supported by the seat; the plug assembly has a first position and a second position; wherein in the first position, the plug intact; and in the second position the plug has been broken by the breaker object; wherein: the plug is stationary with respect to the housing in both the first and second position; there is a fluid connection between the upstream tubular connection and the downstream tubular connection: and the tubular body is a single continuous piece; and wherein the plug assembly is entirely arranged within the plug tubular.