Sand Screen Assembly Using Rotating Protrusions
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Solution Overview
Problem
Existing well screen assembly methods require secondary manufacturing steps like radial expansion or swaging, which increase manufacturing time and cost, induce stress on materials, and can compromise the effectiveness and longevity of the screen due to welding or bonding processes, especially when using wire mesh filter layers.
Innovation Solution
A method where an inner and outer tubular member with radial protrusions are positioned concentrically, allowing a filter layer to be sandwiched between them by rotating the members to align protrusions, eliminating the need for secondary manufacturing steps and ensuring a tight, stress-free assembly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If secondary manufacturing steps like radial expansion or swaging are used, then the screen assembly achieves a tight fit, but manufacturing time and cost increase, and stress is induced on materials
Solution Approach 1:
The inner and outer tubular members are pre-formed with radial protrusions that are misaligned during assembly. The filter layer is positioned between them, and then the members are rotated to align the protrusions, creating a tight fit without requiring secondary expansion or swaging operations. This preliminary preparation of the protrusion geometry enables the tight fit to be achieved during the primary assembly process itself.
Solution Approach 2:
The assembly process utilizes rotation of the tubular members to transition from a misaligned state to an aligned state. The dynamic rotation action allows the protrusions to move from a clearance-position to a contact-position, eliminating the need for static secondary manufacturing steps like radial expansion. This dynamic alignment process achieves the tight fit while reducing manufacturing time.
2Reliability
If welding or bonding operations are performed on wire mesh filter layers, then the filter layer is sealed against sand migration, but the wire mesh becomes more susceptible to corrosion and long-term usefulness is reduced
Solution Approach 1:
The patent replaces welding or bonding operations with a purely mechanical interference fit system. The radial protrusions on the inner and outer tubular members contact the filter layer, creating a mechanical seal through physical contact and friction. This mechanical sealing mechanism eliminates the need for thermal welding or chemical bonding processes that would compromise the wire mesh integrity and increase corrosion susceptibility.
3Reliability
If swaging is performed on the screen jacket, then the filter layer is sealed, but stress concentrations are imparted on the filter layer
Solution Approach 1:
The sealing function is segmented and distributed across multiple radial protrusions rather than concentrated in a single swaging operation. Each protrusion contacts the filter layer at a discrete point, and the collective action of multiple protrusions provides the seal. This segmentation distributes the contact forces and eliminates the stress concentrations that would result from uniform radial compression during swaging.
4Manufacturing precision
If the shroud is plastically deformed radially inwardly to reduce inner diameter, then the filter layer can expand against the shroud, but the shroud is deformed putting additional stresses on the shroud and affecting its material makeup
Solution Approach 1:
Instead of deforming the outer shroud radially inward to create a tight fit, the patent inverts the approach by using fixed-dimensional inner and outer tubular members with protrusions that create the tight fit through their geometric configuration. The filter layer expands against the stationary inner shroud and is contained by the stationary outer shroud, eliminating the need to deform the shroud and thereby avoiding additional stresses on the shroud material.
Data Source
AI summary
A method of assembling a sand screen assembly includes the steps of providing inner and outer shrouds having radial protrusions, such as ribs, louvers, splines, etc., that are radially unaligned during a first assembly step thereby providing clearance for positioning of a filter layer between the shrouds. The outer or inner shroud is then rotated until the protrusions are aligned and the clearance between the shrouds and filter layer is eliminated to provide a tight fit between the layers.