Sensor Assembly Centering Device for Deviated Wellbore Logging
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Wireline logging tools face challenges in descending deviated wells due to high friction and drag forces, which can prevent them from reaching the desired depth, especially at angles greater than 60 degrees from the vertical, leading to delays and increased costs in hydrocarbon exploration.
Innovation Solution
A centralizing device with arm assemblies and wheels is designed to maintain the tool string centered by adjusting its arm configuration and using springs to bias the arm assemblies radially outward, ensuring the wheels contact the wellbore wall effectively, reducing friction and allowing the tool string to descend even in deviated wells.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the tool string is lowered into deviated wells, then the logging operation can access target depth, but friction and drag forces increase preventing the tool from reaching desired depth
Solution Approach 1:
The centralizing device divides the tool string into multiple segments with individual arms that can independently adjust their position. Each arm assembly includes wheels that contact the wellbore wall separately, allowing localized friction reduction while maintaining overall centralization. This segmentation enables the device to handle high friction conditions in deviated wells more effectively than a rigid centralized structure.
Solution Approach 2:
The centralizing device employs dynamic arms that can pivot and adjust their radial position in response to wellbore conditions. The arms are connected through pivot joints that allow them to move between extended and retracted positions, enabling the device to adapt to varying friction and drag forces encountered during descent into deviated wells. This dynamic adjustment capability allows continuous optimization of the centering force to maintain descent speed.
2Adaptability or versatility
If bow-springs are used to provide centering force, then the device can maintain centering in smaller diameter wellbores, but the device cannot be oversized for larger diameter wellbores without causing excessive drag
Solution Approach 1:
The device uses dynamic arms with pivot joints that allow the arm assemblies to extend radially outward in smaller diameter wellbores to maintain centering, and retract in larger diameter wellbores to minimize drag. This dynamic adjustment enables the same device to adapt to a wide range of wellbore diameters without requiring multiple specialized devices, resolving the contradiction between adaptability and drag force.
Solution Approach 2:
The centralizing device changes its effective outer diameter by adjusting the radial position of its arm assemblies. In smaller diameter wellbores, the arms extend to provide sufficient centering force, while in larger diameter wellbores, the arms retract to reduce the device's profile and minimize drag. This parameter change capability allows the device to optimize its performance for different wellbore conditions, achieving both adaptability and reduced drag when appropriate.
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 device effectively reduces friction and allows the tool string to maintain centering in a wide range of wellbore diameters and angles, enhancing the reliability and efficiency of wireline logging operations by minimizing stick-slip and data invalidation issues.
Implementation Method 1
one or more spring elements to bias the arm assemblies radially outward so that the wheel of each arm assembly contacts the wellbore wall
Implementation Method 2
reducing friction and allowing the tool string to descend even in deviated wells
Data Source
AI summary
A device for centering a sensor assembly in a bore comprises a plurality of arm assemblies connected between first and second support members. Each arm assembly comprises a first arm pivotally connected to the first support member by a first pivot and a second arm pivotally connected to the second support member by a second pivot joint. A beam is connected between the first and second arms, the first arm pivotally connected to the beam by a third pivot joint and the second arm pivotally connected to the beam by a fourth pivot joint. A wheel is rotationally mounted to the beam on a rotational axis located axially between the third and fourth pivot joints to contact a wall of the bore in use. A third arm is pivotally connected to the first support member by a fifth pivot joint having a fifth pivot axis axially spaced from the first pivot axis, and is pivotally connected to the beam by a sixth pivot joint having a sixth pivot axis. The third arm is configured so that the wheel is maintained at a radial extremity of the device as the first arm and second arm pivot relative to the first and second support members to move the wheel between a maximum outer diameter and a minimum outer diameter of the device.