Hydrostatically Actuatable Bottom-Hole Assembly for Shock Damping
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Solution Overview
Problem
Existing drilling systems face issues with shock amplification and reduced component lifespan due to inadequate securing mechanisms for internal components, leading to potential failure from lateral shock and vibration during wellbore creation.
Innovation Solution
A hydrostatically-actuatable assembly and passive structures are used to secure the central body within the outer body, utilizing hydrostatic pressure to lock the central body in place, reducing lateral shock and vibration through a combination of piston bodies and passive structures that absorb and dampen drilling-induced forces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If traditional through-bolts are used to mount internal components to the collar, then the components are secured in place, but stress concentration is created that leads to fatigue cracks under bending or torsional loading
Solution Approach 1:
The invention extracts the mounting function from the drill pipe collar structure itself and relocates it to self-contained anchor mounts that attach to the collar's internal surface without penetrating the pipe wall. This removes the stress concentration source from the critical drill pipe structure while maintaining component securing.
Solution Approach 2:
The anchor mount acts as an intermediary component between the internal components and the collar. It provides a secure mounting interface for components while attaching to the collar through a mechanism that does not create stress concentrations in the drill pipe, thus mediating between securing needs and structural integrity.
2Strength
If a locking nut is used to apply axial pressure on internal components, then the components are locked against a fixed shoulder, but thermal expansion differences between the collar and components are restricted
Solution Approach 1:
The anchor mount uses a dynamic expansion mechanism where the body expands radially outward in response to axial pressure from the set screw, rather than relying on a fixed rigid lock. This dynamic adjustment allows the mounting interface to adapt to thermal expansion differences while maintaining secure attachment.
Solution Approach 2:
The invention changes the mounting parameters from a fixed rigid connection to a controllable expansion mechanism. The anchor mount's radial dimension can change in response to axial loading, allowing adjustment to accommodate thermal expansion variations between different materials.
3Ease of operation
If radial clearance is provided between spacer mounts and the collar to allow assembly and disassembly, then tolerance stack up is accommodated, but shock amplification occurs when lateral shock is transmitted from the collar to the internal assembly
Solution Approach 1:
The anchor mount is pre-loaded through axial pressure on the set screw, which creates initial radial expansion and contact force against the collar before any shock occurs. This preliminary action ensures that the mounting interface is already engaged and shock-resistant, rather than relying on clearance that allows movement.
Solution Approach 2:
The friction interface between the anchor mount body and collar, established through pre-loading, acts as a cushioning mechanism that absorbs and dampens shock forces before they can amplify and damage the internal components.
4Strength
If the collar locking features are matched to specific length of the internal assembly, then the components are securely locked, but changes in length to add additional components become more challenging
Solution Approach 1:
The anchor mount provides a universal mounting interface that is not dependent on specific assembly length. The self-contained design with adjustable expansion allows the same mounting mechanism to securely hold components regardless of the overall assembly length or the number of components added.
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 effectively secures internal components, reducing shock amplification and extending their lifespan by providing a stable interface that withstands drilling-induced vibrations and impacts, enhancing the reliability of measurement devices.
Implementation Method 1
at least one piston body exposed to hydrostatic pressure; exposing the piston body to hydrostatic pressure such that the piston body causes the at least one hydrostatically-actuatable assembly to contact an inner surface of the outer body
Implementation Method 2
reducing lateral shock and vibration through a combination of piston bodies and passive structures that absorb and dampen drilling-induced forces; reducing shock amplification
Data Source
AI summary
A system, such as a bottom hole assembly, having a central body, at least one hydrostatically-actuatable assembly configured to extend radially outward from the central body, the hydrostatically-actuatable assembly having at least one piston body exposed to hydrostatic pressure; a plurality of passive structures, each of which is: configured to extend radially outward from the central body; and circumferentially spaced from the at least one hydrostatically-actuatable assembly and another one of the plurality of passive structures.