Rotary Steerable Drilling Assembly with Non-Rotating Biasing Control
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Solution Overview
Problem
Existing directional drilling systems face challenges in efficiently controlling the direction of the drill bit with high power demand and complex mechanical interactions, particularly due to the rotational coupling of biasing elements with the drill shaft, leading to inefficient steering and increased operational costs.
Innovation Solution
A self-contained, modular steering assembly with a non-rotating sleeve and integrated sensors and controllers that allow for independent control of biasing elements using energy harvested from the drill string rotation, enabling precise directional control with reduced power consumption and simplified maintenance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If biasing elements are rotationally coupled with the drill shaft to enable directional control, then the drill bit direction can be changed, but the system experiences high power demand and complex mechanical interactions
Solution Approach 1:
The system is divided into rotating and non-rotating sections. The non-rotating section houses the biasing elements that apply steering forces to the borehole wall, while the rotating section contains the drill shaft. This segmentation allows directional control without requiring the biasing elements to rotate, thereby reducing power demand and mechanical complexity.
Solution Approach 2:
A bearing is introduced as an intermediary component between the rotating and non-rotating sections. This bearing enables relative rotation while allowing the non-rotating section with biasing elements to remain stationary relative to the borehole wall, achieving directional control without high power demand.
2Ease of operation
If a non-rotating sleeve with biasing elements is used to steer the drill bit, then directional drilling is achieved, but the mechanical interactions become complex
Solution Approach 1:
The system replaces complex mechanical coupling between rotating and non-rotating sections with a bearing interface. This substitution simplifies the mechanical interactions by allowing independent rotation of the drill shaft while maintaining the stationary position of the biasing elements relative to the borehole wall.
3Use of energy by moving object
If the rotating section is decoupled from the non-rotating section to reduce power consumption, then energy efficiency improves, but relative rotation sensing becomes more difficult
Solution Approach 1:
A bearing serves as an intermediary that physically decouples the rotating and non-rotating sections while allowing relative rotation. This mechanical intermediary enables independent motion while maintaining a defined interface for sensing relative rotation through the bearing's internal geometry.
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 system achieves efficient directional drilling with lower power requirements and facilitates quick module exchange for maintenance, reducing operational costs and enhancing drilling precision.
Implementation Method 1
a bearing between the rotating section and the non-rotating section that allows relative rotation between the rotating section and the non-rotating section
Implementation Method 2
at least one relative rotation sensor configured to generate signals representative of a rotation of the rotating section relative to the non-rotating section
Implementation Method 3
at least one orientation sensor configured to generate signals representative of an orientation of the non-rotating section relative to a selected frame of reference
Implementation Method 4
devices for generating forces against a borehole wall
Data Source
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AI summary
An apparatus for use in a wellbore includes a non-rotating section disposed along the drill string. The non-rotating section has a bore and at least one biasing member engaging an adjacent wall. A rotating section is disposed in the bore of the non-rotating section and a bearing is positioned between the rotating section and the non-rotating section. The apparatus also includes a relative rotation sensor that generates signals representative of a rotation of the rotating section relative to the non-rotating section, an orientation sensor that generates signals representative of an orientation of the non- rotating section relative to a selected frame of reference, and a controller in signal communication with the at least one relative rotation sensor and the at least one orientation sensor. The controller adjusts a force applied by the at least one biasing element, and/or a position of the at least one biasing element in response to the generated signals from the at least one relative rotation sensor and the generated signals from the at least one orientation sensor.