Down Hole Piston Sealing via Segmented Rotation
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Solution Overview
Problem
Existing down hole well tools face challenges in maintaining effective sealing and movement capabilities, particularly in rotating and axially displacing components within the well bore, leading to fluid leakage and inefficient operation during drilling and casing expansion procedures.
Innovation Solution
The implementation of a dual-piston system with radially displaced piston bodies, where the first piston body rotates with the tool unit and the second piston body is positioned between the first piston body and the well bore, utilizing roller bearings for rotation and multiple sealing arrangements to prevent fluid leakage across annulus spaces during axial and rotational movements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single piston is used to divide the well annulus, then the structure is simple, but sealing effectiveness deteriorates during rotation and axial movement
Solution Approach 1:
The piston is divided into two separate piston bodies (first piston body and second piston body) that work together. The first piston body rotates with the tool unit while the second piston body remains stationary relative to the well bore, creating multiple sealing surfaces that maintain effective sealing during both rotation and axial movement operations.
Solution Approach 2:
The first piston body acts as an intermediary between the rotating tool unit and the stationary second piston body. It transfers rotational movement while maintaining sealing contact with the second piston body, allowing the system to accommodate both rotation and axial displacement without compromising seal integrity.
2Ease of manufacture
If the piston is made as a single integrated element, then manufacturing is easier, but the ability to accommodate both rotation and axial movement deteriorates
Solution Approach 1:
The piston functionality is segmented into two distinct piston bodies with different movement characteristics. The first piston body is designed to rotate with the tool unit while the second piston body provides a stationary sealing surface, allowing the system to accommodate both rotational and axial movements that a single integrated piston cannot achieve.
Solution Approach 2:
The system transitions from a static single-piston design to a dynamic two-piston configuration where the first piston body rotates with the tool unit while the second piston body remains relatively stationary. This dynamic arrangement enables the piston assembly to adapt to both rotational and axial movement requirements.
3Reliability
If multiple sealing arrangements are added to prevent fluid leakage, then sealing reliability improves, but device complexity increases
Solution Approach 1:
The sealing function is segmented across two piston bodies, with each body providing its own sealing surface. The first piston body seals against the well bore or casing while the second piston body seals against the first piston body, creating multiple sealing zones that prevent fluid leakage without requiring additional complex sealing components.
Solution Approach 2:
The two piston bodies serve multiple functions simultaneously: they divide the well annulus into separate spaces, accommodate rotational movement, provide multiple sealing surfaces, and enable axial displacement. This multi-functionality achieves reliable sealing without proportionally increasing device complexity.
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
This configuration ensures effective sealing and allows for controlled axial and rotational movements, preventing fluid leakage and enhancing the operational efficiency of the down hole well tool during drilling, casing expansion, and other well operations.
Implementation Method 1
roller bearings for rotation
Implementation Method 2
multiple sealing arrangements to prevent fluid leakage
Data Source
AI summary
A down hole well tool (1) comprising a tool unit comprising at least one first fluid conduit (2) and a return fluid conduit (3) in use forming a well annulus between the tool unit and a well bore, and at least one piston (4) dividing the well annulus into well annulus spaces. The piston comprises at least two piston bodies wherein a first piston body (4a) is arranged to rotate with the tool unit and a second piston body (4b) is arranged in a position in between the first piston body and the well bore. The first piston body is arranged to rotate relative the second piston body and first sealing means are arranged in between the first piston body and the second piston body.