Composite Settable Well Tool Slips for Restricted Casing
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Solution Overview
Problem
Current settable well tools, particularly those with cast iron slips, are difficult to drill up in horizontal wells due to limited weight application, leading to slow operation and increased wear on bits, and existing composite tools lack sufficient expansibility to navigate restricted casing sections or patches, hindering efficient well maintenance and production in tight formations.
Innovation Solution
Designing a composite settable well tool with increased radial expansibility, featuring a drillable metal skin on the expander cone and thicker, fracturable slips that break into smaller pieces for easy circulation, allowing the tool to pass through restricted sections and expand securely within the casing, while maintaining drillability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If cast iron slips are used in settable well tools, then the tool can expand securely into gripping engagement with casing, but the tool becomes difficult and time-consuming to drill up, especially in horizontal wells where little weight can be applied to the bit
Solution Approach 1:
The slip body is divided into multiple segments that can fracture independently during drilling operations. This segmentation allows the slips to maintain their gripping function while enabling easier removal by drilling, as the segmented structure can break apart more readily than a solid cast iron slip
Solution Approach 2:
The invention uses composite materials for the slip body that combine the strength needed for secure gripping engagement with properties that facilitate drilling removal. The composite structure allows the slips to expand and grip casing effectively while being more easily drilled up compared to conventional cast iron slips
2Loss of time
If the settable well tool is made with composite materials for increased drillability, then the tool becomes easier to drill up, but the tool lacks sufficient expansibility to navigate restricted casing sections or patches
Solution Approach 1:
The settable well tool incorporates dynamic expansion capabilities where the slip structure can transition from a compact configuration for passing through restricted sections to an expanded configuration for secure gripping engagement. This dynamic behavior allows the tool to adapt to varying casing conditions while maintaining drillability
Solution Approach 2:
The use of composite materials provides both the drillability needed for easy removal and the structural properties required for sufficient expansibility. The composite construction allows the tool to expand radially to engage restricted casing sections while remaining easier to drill up than conventional metal slips
3Reliability
If conventional cast iron bridge plugs are used in horizontal wells, then the tool can be set against casing, but drilling up multiple plugs completely wears out bits and debris from upper plugs interferes with drilling up lower plugs
Solution Approach 1:
The segmented slip structure allows debris to pass through the segments more easily during drilling operations, reducing interference between upper and lower plugs. The segmentation also facilitates more efficient removal of multiple plugs by allowing the drilling bit to progress through the fractured slip pieces without complete wearout
Solution Approach 2:
The invention applies different material properties to different parts of the slip structure, with harder materials in areas requiring gripping strength and more drillable materials in areas that contact the drilling bit. This local differentiation maintains setting reliability while improving drilling efficiency and reducing bit wear
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 achieves enhanced drillability and expansibility, enabling efficient passage through restricted casing patches and sections, facilitating faster well maintenance and production by expanding up to 20-25% more than conventional tools, allowing for easier circulation of slip pieces without further reduction, thus reducing operational costs and increasing production efficiency.
Implementation Method 1
a conical expander for pushing the slips radially outward to secure the tool in position
Implementation Method 2
thicker, fracturable slips that break into smaller pieces for easy circulation
Data Source
AI summary
A settable down hole tool is of increased drillability and/or of increased expansibility. The improvement in drillability can be caused by fracturing cast iron slips into a large number of small pieces that can be circulated out of a well without further reduction in size. The improvement in expansibility can be partially caused by providing an expander cone of increased hardness thereby allowing an increased angle on the expander cone and slips. The improvement in expansibility can be partially caused by increasing the thickness of the slips.