Elevator Roller Insert Reduces Torque for Tubular Rotation
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Solution Overview
Problem
In the oil and gas industry, maintaining proper thread integrity and rotating heavy tubulars within single joint elevators is challenging due to high torque requirements and safety concerns, often resulting in galled or destroyed connections and potential equipment failure.
Innovation Solution
Integration of multiple rollers with radial and thrust bearings into existing elevators, allowing tubulars to rotate with reduced torque, eliminating the need for pneumatic or hydraulic control lines, and enabling safe handling of heavy tubulars by reducing friction and preventing disconnection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If conventional elevators without rollers are used to rotate heavy tubulars, then the elevator can maintain structural simplicity, but the torque required to rotate the tubular increases significantly and connection failures occur
Solution Approach 1:
The elevator contact surface is segmented into multiple rollers (typically 3-6 rollers arranged circumferentially) that independently rotate to support the tubular. This segmentation distributes the rotational force across multiple points, reducing the torque required at each contact point and preventing galling of the tubular threads.
Solution Approach 2:
The rollers are designed to rotate freely within the elevator body, transforming the static friction contact into dynamic rolling contact. This dynamic element allows the tubular to rotate with minimal resistance, as the rollers spin on their own axes rather than sliding against the tubular surface.
2Ease of operation
If rollers with bearings are integrated into the elevator, then the friction and torque required to rotate the tubular is reduced, but the device complexity and manufacturing cost increase
Solution Approach 1:
Rollers serve as intermediary elements between the elevator body and the tubular. These rollers mediate the contact interaction, providing a rolling interface that reduces friction. The rollers are typically simple cylindrical shapes that can be manufactured using standard machining processes, and they incorporate conventional bearing assemblies that are off-the-shelf components.
Solution Approach 2:
The roller system is designed to be self-lubricating through the inherent properties of the bearing assemblies, which contain lubricant reservoirs or use self-lubricating materials. The rollers automatically adjust their rotation to match the tubular's rotation speed, requiring no external control mechanisms or additional actuators.
3Reliability
If heavy tubulars are rotated using conventional elevators, then the elevator structure remains simple, but connection integrity is compromised due to high torque and galling
Solution Approach 1:
The contact interface is segmented into multiple discrete rollers rather than a single continuous contact surface. This segmentation prevents concentration of stress and friction at any single point, eliminating the galling that occurs with conventional elevators and protecting the tubular threads from damage.
Solution Approach 2:
The transition from static friction to dynamic rolling contact fundamentally changes the interaction mechanics. The rollers rotate freely on their bearings, creating a low-friction interface that allows heavy tubulars to be rotated without exceeding the thread strength limits, thereby ensuring connection integrity.
4Force
If multiple rollers are used to reduce friction, then the torque required decreases, but the manufacturing precision requirements for roller alignment increase
Solution Approach 1:
The rollers are designed with universal mounting features that allow them to be installed in various configurations (different numbers of rollers, different angular positions) while maintaining functionality. The bearing assemblies are standardized components that can accommodate minor alignment variations, reducing the precision requirements compared to custom-fitted components.
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
Enables tubulars to be rotated with minimal torque, reducing connection failures, operational time, and safety risks, allowing for efficient and safe handling of heavy tubulars without additional control lines, and minimizing downtime and costs.
Implementation Method 1
Integration of multiple rollers with radial and thrust bearings into existing elevators
Implementation Method 2
Integration of multiple rollers with radial and thrust bearings into existing elevators
Data Source
AI summary
A device, system, and/or method for reducing friction required to rotate a tubular within an elevator during the process of running tubulars in an oil and gas well are provided. An elevator roller insert may be used in conjunction with an elevator, such as a single joint elevator. Such an insert may comprise upper and lower rollers which are positioned on upper and lower roller sets or a combination roller set containing multiple upper and/or lower rollers. The result is the provision of a plurality of rollers which bear the weight of a tubular yet still allow the tubular to rotate rather freely, facilitating the maintenance of proper thread integrity of the connections while making up a stand to a string of tubulars as well as preventing the loss of resources due to galled or crushed threads or a tubing segment or stand falling to the rig floor.