Frangible Sealing Members for Wellbore Isolation
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Solution Overview
Problem
Existing downhole tools face challenges in effectively sealing wellbores under high differential pressures and efficiently removing sealing solutions without generating debris or restricting fluid communication, particularly in deviated or horizontal wellbores.
Innovation Solution
A downhole tool featuring frangible and/or decomposable sealing members with a curved surface design, capable of withstanding high pressures and being selectively removable through solvent degradation or fracturing, utilizing materials like ceramics, engineered plastics, and soluble components to ensure reliable sealing and easy removal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If non-retrievable plugs made of brittle materials are used for sealing, then the sealing reliability is improved, but the removal process becomes complex and time-consuming due to binding and rotation issues
Solution Approach 1:
The plug is divided into two distinct parts: a retrievable body and a non-retrievable sealing element. The sealing element can be physically separated from the body through fracturing or dissolving, allowing the body to be retrieved while the sealing element remains in place. This segmentation resolves the contradiction by enabling reliable sealing through the non-retrievable element while allowing quick removal of the body component.
Solution Approach 2:
The sealing element's material properties are changed from traditional brittle materials to materials that can undergo phase changes or chemical transformations. This includes using soluble materials that dissolve in specific solvents or frangible materials that can be fractured by controlled impact. These parameter changes enable the sealing element to be removed through simple dissolution or fracturing rather than complex drilling operations.
2Ease of operation
If retrievable plugs with anchors and sealing elements are used, then the ease of removal is improved, but the reliability of sealing under high differential pressures deteriorates
Solution Approach 1:
The plug system is segmented into a retrievable body and a non-retrievable sealing element. The sealing element is designed to remain in the wellbore after the body is retrieved, ensuring that the sealing function is permanently established while the body can be easily removed through simple withdrawal operations.
Solution Approach 2:
The sealing element is designed as a disposable component that is intentionally made to remain in the wellbore after serving its sealing function. This disposable approach ensures reliable sealing while eliminating the need for complex retrieval operations, as the sealing element is left in place and the body is simply withdrawn.
3Productivity
If sealing disks are physically fractured using weighted bars, then the removal speed is improved, but debris is generated that can accumulate and interfere with future operations
Solution Approach 1:
The sealing element is designed to change its physical or chemical state during removal. Instead of fracturing brittle materials that generate debris, the sealing element can dissolve in a solvent or decompose through chemical action. This parameter change eliminates debris generation while maintaining quick removal capability, as the sealing element simply disappears through dissolution rather than fragmentation.
Solution Approach 2:
The mechanical fracturing method using weighted bars is replaced with chemical dissolution or decomposable materials. The sealing element is made from materials that can be dissolved by circulating solvents or that can decompose through chemical reactions. This substitution eliminates the mechanical impact that generates debris while achieving rapid removal through chemical action.
4Ease of operation
If soluble or frangible sealing members are used, then the ease of removal is improved, but the ability to withstand high differential pressures deteriorates
Solution Approach 1:
The plug is segmented into a body and a sealing element with different functional requirements. The body is made of strong, pressure-resistant material to withstand high differential pressures during sealing operations. The sealing element is made of soluble or frangible material that can be easily removed. This segmentation allows each component to be optimized for its specific function without compromising the other.
Solution Approach 2:
The plug system uses composite construction combining different materials for different components. The body is made of strong, pressure-resistant material while the sealing element is made of soluble or frangible material. This composite approach allows the system to simultaneously withstand high differential pressures during sealing and enable easy removal through dissolution or fracturing of the sealing element.
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 tool provides effective sealing and quick, reliable removal of sealing solutions without debris, maintaining full fluid communication and reducing operational time and costs by using soluble or frangible materials that can be dissolved or fractured as needed.
Implementation Method 1
The one or more sealing members can be soluble, frangible, or decomposable. In one or more embodiments, the one or more sealing members can be soluble in a common solvent, permitting the removal of all sealing members within a single wellbore by circulating the solvent through the wellbore.
Implementation Method 2
Other plugs have employed sealing disks partially or wholly fabricated from brittle materials that can be physically fractured by dropping a weighted bar via wireline into the casing string to fracture the sealing disks.
Data Source
AI summary
Downhole assemblies and methods for isolating a wellbore. A downhole tool can include a body having a bore or flowpath formed therethrough, and one or more sealing members disposed therein. The one or more sealing members can include an annular base and a curved surface having an upper face and a lower face, wherein one or more first radii define the upper face, and one or more second radii define the lower face, and wherein, at any point on the curved surface, the first radius is greater than the second radius. The sealing members can be disposed within the bore of the tool using one or more annular sealing devices disposed about the one or more sealing members.