Partially Bonded Wellbore Seals for Pressure-Compensating Sealing
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Solution Overview
Problem
Fully bonded elastomeric and metal-to-metal seals in wellbore systems experience degradation due to radially inward deformation under high pressures, leading to a drop in seal contact stress and potential leakage.
Innovation Solution
Adaptive partially bonded seals with a mix of bonded and unbonded surfaces, utilizing fluid conduits to allow pressure engagement and radially outward deformation of the unbonded portion to compensate for inward deformation, maintaining seal contact stress and preventing leaks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If fully bonded elastomeric or metal-to-metal seals are used, then initial seal contact stress is achieved, but radially inward deformation under high pressure causes stress drop and potential leakage
Solution Approach 1:
The seal is designed with a dynamic unbonded portion that can deform radially outward in response to internal pressure, transitioning from a static bonded configuration to a dynamic adaptive state that maintains seal contact stress under varying pressure conditions
Solution Approach 2:
The seal utilizes parameter changes by allowing the unbonded portion to change its radial position and deformation state based on internal pressure levels, enabling the seal to adapt its geometric parameters (radial outward deformation) to compensate for the carrier's radially inward deformation and maintain effective seal contact stress
2Strength
If the seal carrier deforms radially inward under high pressure, then structural integrity is maintained, but seal contact stress decreases leading to leakage
Solution Approach 1:
The seal is segmented into a bonded portion (attached to the seal carrier) and an unbonded portion (free to deform), allowing different segments to perform different functions: the bonded portion maintains structural attachment while the unbonded portion provides pressure-compensating deformation to maintain seal integrity
Solution Approach 2:
Different portions of the seal have different bonding characteristics - the bonded portion provides structural attachment to the carrier while the unbonded portion provides local adaptive deformation capability, creating local quality differentiation that simultaneously achieves structural integrity and seal reliability under pressure
3Manufacturing precision
If a rigid seal structure is used, then manufacturing precision is achieved, but adaptability to pressure-induced deformation is reduced
Solution Approach 1:
The seal transitions from a rigid static structure to a dynamic system where the unbonded portion can adapt its shape and position in response to pressure changes, enabling the seal to maintain manufacturing precision in its installed state while gaining adaptability to pressure-induced deformation through controlled radial outward movement
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 adaptive seals effectively resist high pressures up to 10000 PSI by self-energizing, maintaining seal contact stress and preventing leakage, while being cost-effective and scalable.
Implementation Method 1
the radially outward deformation of the unbonded portion of the sealing element compensates for the radially inward deformation of the seal carrier
Implementation Method 2
When actuated against another surface... fluid pressure may be communicated through one or more passageways into the unbonded portion of the sealing element
Data Source
AI summary
Various seals for wellbore systems include a partially bonded seal configured to be actuatable to provide a fluid seal between a first conduit and a second conduit positioned within a wellbore. The partially bonded seal may comprise a hanger body and a sealing element, the sealing element positioned in contact with and arranged to encircle an outer surface of the hanger body for some longitudinal distance along the hanger body. A first portion of the sealing element adjacent to the outer surface of the hanger is bonded to the outer surface of the hanger body, and a second portion of the sealing element adjacent to the outer surface of the hanger body is not bonded to the outer surface of the hanger body.