Expandable Tubular Wedge Thread Seal Gap Design

The seal surfaces are designed with a predetermined gap at make-up that is specifically calculated to close during the radial expansion process. This preliminary configuration ensures that the seal surfaces will contact at the optimal moment during expansion, rather than relying on initial contact that would be lost due to differential displacement. The gap distance is pre-calculated based on expected expansion parameters to ensure reliable seal formation.

The invention changes the parameter of seal surface contact timing from immediate contact at make-up to delayed contact during expansion. By introducing a controlled gap that closes as the connection expands radially, the seal surfaces engage at the precise moment when the connection geometry stabilizes, ensuring consistent contact pressure. This parameter change transforms the sealing mechanism from one vulnerable to differential displacement to one that benefits from the expansion process itself.

The seal surfaces are pre-configured with a specific gap distance that is intended to close during the radial expansion process. This preliminary gap ensures that the seal surfaces will contact at the optimal moment during expansion, when the connection geometry has stabilized and uniform contact pressure can be achieved, rather than attempting to maintain contact through the problematic differential displacement phase.

The invention converts the harmful effect of radial expansion (which causes differential displacement and loses preload in conventional seals) into a beneficial force that closes the predetermined gap between seal surfaces. The expansion process itself, which would normally destroy the seal, is harnessed to bring the seal surfaces into contact at the precise moment when contact pressure is maximized and uniform, transforming the expansion-induced displacement from a harmful factor into the mechanism that creates the seal.

The invention changes the sealing parameter from requiring precise initial contact (zero gap) to requiring a specific non-zero gap that closes during expansion. This parameter change simplifies the manufacturing process because the gap can be built into the connection geometry as a standard feature rather than requiring ultra-precise machining to achieve zero clearance. The gap specification becomes a design parameter rather than a tolerance challenge.

The connection structure itself provides the mechanism for seal formation through its geometric design. The predetermined gap is integrated into the basic connection geometry, and the radial expansion process automatically closes the gap and creates the seal without requiring additional components, adjustment mechanisms, or complex control systems. The connection serves its own sealing function through its expanded geometry, eliminating the need for separate sealing devices or complex assembly procedures.