Variable Bore Production Tubing for High-Pressure Gas Erosion

The production tubing is divided into multiple sections with different diameters (narrow-bore section, intermediate section, wide-bore section) rather than using a single uniform diameter. This segmentation allows each section to be optimized for specific functions: the narrow-bore section resists erosion in high-velocity flow, the intermediate section provides transition, and the wide-bore section maximizes flow capacity. The segmentation principle directly resolves the contradiction by creating a complex multi-section structure that achieves superior reliability against erosion and corrosion.

Different sections of the tubing are given different local qualities through varying diameters and materials. The narrow-bore section has smaller diameter and erosion-resistant properties for high-velocity flow areas, while the wide-bore section has larger diameter for maximum flow capacity. This local quality differentiation allows the tubing to simultaneously achieve erosion resistance where needed and high flow capacity where appropriate, resolving the contradiction between reliability and structural complexity.

The tubing is segmented into narrow-bore, intermediate, and wide-bore sections to optimize flow characteristics. The narrow-bore section maintains high velocity for efficient gas lifting while resisting erosion, the intermediate section provides smooth transition to reduce turbulence and pressure losses, and the wide-bore section maximizes overall flow capacity. This segmentation enables the system to achieve high productivity (300-500 MCFD) while minimizing erosion and pressure losses that would occur in uniformly large-diameter tubing.

The tubing diameter varies dynamically along its length rather than remaining static, with the diameter profile optimized for different flow conditions at different locations. The narrow-bore section handles high-velocity erosive flow, the intermediate section transitions to reduce turbulence, and the wide-bore section accommodates high flow rates. This dynamic diameter variation resolves the contradiction by adapting the tubing geometry to local flow conditions, achieving both high productivity and reduced harmful effects.