Tubular Centralizer Segmented Sleeve for Wear Reduction
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Solution Overview
Problem
Existing centralizers for tubulars in wellbores are prone to failure and costly to replace due to wear, particularly in horizontal wellbores where directional changes cause increased wear and grinding, leading to inefficiencies and operational disruptions.
Innovation Solution
A centralizer design featuring a resilient inner sleeve with protruding members and a tubular outer support body, where the inner sleeve is retained by end collars, allowing for the replacement of only the worn components, thereby minimizing the risk of failure and reducing replacement costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a centralizer with multiple connectors (hinged segments, pins, bolts) is used to secure the tubular, then the centralizer can be robustly retained about the tubular, but the risk of failure increases with repeated use and the number of connectors
Solution Approach 1:
The centralizer body is divided into multiple segments that can be independently replaced. The resilient inner sleeve is segmented into multiple replaceable elements, while the outer support body remains as a single durable component. This segmentation allows replacement of only the worn inner sleeve segments rather than the entire centralizer assembly.
Solution Approach 2:
The resilient inner sleeve and outer support body are combined into a composite centralizer structure where the inner sleeve provides wear resistance and compliance while the outer support body provides structural strength. This merging creates a system where the durable outer body can retain the replaceable inner sleeve segments with minimal connectors.
2Reliability
If the entire centralizer is replaced when components wear, then sufficient standoff is maintained, but replacement costs increase and operational disruptions occur
Solution Approach 1:
The resilient inner sleeve is divided into multiple independent segments that can be replaced individually. When wear occurs, only the affected segment(s) need to be replaced rather than the entire centralizer assembly, significantly reducing replacement time and cost.
Solution Approach 2:
The durable outer support body and end collars are recovered and reused after the inner sleeve segments wear out. Only the worn inner sleeve segments are discarded and replaced, maximizing component utilization and minimizing waste.
3Strength
If hard-faced drill pipe tool joints are used to prevent wear, then tubular strength is improved, but grinding of the casing occurs when the hard-faced portions contact the wellbore walls
Solution Approach 1:
The resilient inner sleeve acts as an intermediary between the hard-faced drill pipe tool joints and the wellbore/casing walls. This compliant intermediate layer absorbs the contact stresses and prevents direct grinding between the hard tubular surfaces and the wellbore, reducing casing damage while maintaining tubular protection.
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 design reduces the risk of centralizer failure and minimizes replacement costs by allowing for the replacement of only the worn components, maintaining effective tubular positioning and reducing wear on wellbore and casing walls.
Implementation Method 1
a resilient inner sleeve having a central bore formed therethrough for receiving the tubular therein
Data Source
AI summary
A centralizer is provided for centralizing a tubular, such as a drill pipe, in a wellbore. The centralizer comprises a resilient inner sleeve comprising three or more protruding members extending radially outwardly from an outer surface of the inner sleeve. The inner sleeve receives the tubular and spaces the tubular from the wellbore. The centralizer further comprises an outer support body for receiving the outer surface of inner sleeve. When the inner sleeve is retained between the support body and the tubular, the protruding members project out through windows formed in the support body. The support body and the inner sleeve are retained about the tubular with a pair of annular end collars. A method for replacing worn components of the centralizer is also provided.