Rotary Steerable Cutters Axial Positioning
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional rotary steerable systems face limitations in achieving precise directional control and increased dogleg severity due to the distance between cutting structures and steering actuators, leading to reduced dogleg capability and potential micro spiraling and doglegs, especially in abrasive formations.
Innovation Solution
The rotary steerable tool incorporates cutters placed at a distance from the steering actuators, with the cutters being above the drill bit and at or beyond the bit gage diameter, reducing the distance L1 and increasing dogleg severity by positioning the cutting structure closer to the steering assembly, thereby improving wellbore quality and durability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the cutting structure is positioned farther from the steering actuator, then the device can accommodate more components and maintain structural integrity, but the dogleg capability is reduced and micro spiraling occurs
Solution Approach 1:
The patent repositions the cutters from a conventional distant location to a location closer to the steering actuator, specifically at a distance L1 of 0 to 6 inches. This dimensional change in the axial position of the cutters enables better dogleg capability while the radial position maintains the necessary structural integrity. The cutters are positioned at a radial distance R from the tool axis that accommodates both the steering actuator proximity and structural requirements.
Solution Approach 2:
The patent changes the critical parameter L1 (axial distance from cutter to steering actuator) from conventional larger values to a reduced range of 0 to 6 inches. This parameter change directly improves dogleg capability by reducing the lever arm that causes micro spiraling. The radial parameter R is also optimized to maintain structural integrity while allowing the cutters to be positioned closer to the steering actuator.
2Reliability
If the cutters are positioned closer to the steering actuator, then dogleg capability is improved, but the structural integrity and durability of the steering assembly may be compromised
Solution Approach 1:
The patent resolves the strength concern by utilizing the radial dimension. The cutters are positioned at an optimized radial distance R from the tool axis, which provides sufficient structural support and durability while maintaining axial proximity (L1 = 0 to 6 inches) to the steering actuator for improved dogleg capability. This two-dimensional positioning allows both requirements to be satisfied simultaneously.
Solution Approach 2:
The patent optimizes both parameters L1 (axial distance) and R (radial distance) to achieve the desired balance. By setting L1 to 0-6 inches and optimizing R, the system achieves improved dogleg capability while maintaining the structural integrity and durability of the steering assembly through appropriate dimensional selection.
3Manufacturing precision
If the distance L1 is reduced, then dogleg severity is increased and wellbore quality is improved, but the risk of micro spiraling and doglegs increases
Solution Approach 1:
The patent changes parameter L1 to a specific optimized range of 0 to 6 inches, which reduces the lever arm sufficiently to minimize micro spiraling and doglegs while maintaining enough distance to prevent direct contact between the steering actuator and the cutting structure. This parameter optimization achieves improved wellbore quality (increased dogleg severity) while controlling harmful effects.
Solution Approach 2:
The patent introduces the radial distance R as an intermediary parameter that mediates between the axial proximity of the cutters to the steering actuator and the prevention of harmful effects. By optimizing R, the system allows L1 to be reduced for better wellbore quality while the radial positioning prevents direct interference that would cause micro spiraling and doglegs.
Data Source
AI summary
A rotary steerable tool may include a tool body with an upper end and a lower end. Additionally, the tool body may include at least one steering assembly extending from the tool body and includes at least one steering actuator configured to extend beyond other portions of the steering assembly. Furthermore, at least one cutter may be disposed on the rotary steerable tool a distance from the at least one steering actuator.