Through-Rotary Centralizer for Torque Transmission and Bit Centering
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing centralizers for downhole operations cannot transmit torque or rotation through their center and often rotate with the drill bit, causing wear or damage to the tubular components.
Innovation Solution
A through-rotary centralizer with a rotatably mounted sleeve and sliding floating hubs, allowing centralizing arms to extend and contract, providing centering force while independently rotating from the drill bit, thus transmitting torque through a mandrel.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a centralizer is fixedly mounted to the milling string or bit tool, then it provides stable centralization, but it rotates with the drill bit causing wear or damage to the tubular components
Solution Approach 1:
The centralizer is divided into two independent rotating systems: the outer sleeve that contacts the tubular and remains stationary relative to it, and the inner mandrel that rotates with the drill bit. This segmentation allows each component to perform its function independently - the outer sleeve provides stable centralization without rotating with the bit, while the inner mandrel transmits rotational power to the drill bit through the sleeve's bearing surface.
2Manufacturing precision
If a centralizer is located close to the drill bit for effective centralization, then it improves bit positioning, but it cannot transmit torque through its center
Solution Approach 1:
The sleeve acts as an intermediary element between the rotating inner mandrel and the stationary outer structure. It contains a bearing surface that allows the inner mandrel to rotate relative to it while transmitting torque through its thickness to the drill bit. This intermediary structure enables both close positioning to the bit for effective centralization and torque transmission through its center.
3Force
If the outer diameter of a slipover centralizer is increased to provide better centralization, then it improves centering force, but the milling string cannot pass through narrow tubulars
Solution Approach 1:
The centralizer employs a dynamic structure where the outer sleeve can rotate independently on the inner mandrel, allowing the assembly to flex and adapt to varying tubular diameters. The sleeve's bearing surface accommodates rotational movement while maintaining contact with the tubular wall, enabling the centralizer to provide effective centering force in larger tubulars while still fitting through narrow tubulars during installation.
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 centralizer maintains the drill bit centered within the tubular, preventing damage while effectively transmitting power to the downhole tool, even in deviated wellbores.
Implementation Method 1
a floating hub slidably mounted around the sleeve
Implementation Method 2
Coil springs may be installed around the sleeve to provide centralization force for the centralizing arms
Data Source
AI summary
Devices, systems, and methods are provided for a through-rotary centralizer for downhole operations. The through-rotary centralizer assists with centralizing a tool operating downhole, such as a bit. The through-rotary centralizer has a mandrel, a sleeve rotatably mounted around the mandrel, a floating hub slidably mounted around the sleeve, and centralizing arms mounted to the sleeve and floating hub. The centralizing arms extend to exert force against the inner wall of a tubular, such as wellbore casing, thereby providing stability to the downhole tool. Because the sleeve is rotatably mounted to the mandrel, the mandrel rotates within the sleeve and is able to transmit power or torque to the downhole tool, such as a bit. The centralizing arms are not required to rotate with the mandrel due to the rotatably mounted sleeve. A surface system may be used to control the position of the through-rotary centralizer.