Glass Barrier Plug
Accessories
Autofill Sub
The TCO Autofill Sub is a downhole completion tool designed to allow the tubing to self-fill with well fluid during run-in-hole (RIH), thereby simplifying operations and eliminating the need for external fluid-filling systems. Installed above a glass plug such as the TDP-PO, the Autofill Sub provides a temporary open flow path between the annulus and the inside of the tubing string. This allows the completion string to fill naturally with well fluid as it is lowered into position.
When the completion reaches depth, hydrostatic and surface pressure activation closes the flow path – creating creating a reliable VO barrier that maintains well integrity and allows activation of the glass plug below under pressure.
The Autofill Sub is designed to operate in high-temperature and pressure environments (up to 5,000 psi) and can be built from material configurations suited for the well conditions to provide durability, corrosion resistance, and performance consistency. Once the sleeve has closed, it provides a permanent seal that isolates the tubing from the annulus pressure.
Designed to integrate directly into the completion string, the Autofill Sub enhances TCO’s portfolio of completion technologies, providing a fully compatible solution that complements our laminated glass plugs. This allows operators to execute safer, faster completions while reducing dependence on third-party autofill systems.
Features
Six inlet nozzles for efficient annulus-to-tubing self-filling during RIH
Pressure-activated sliding sleeve closure
Dual elastomer sealing elements for high-integrity isolation
Shear pins for controlled sleeve actuation
Snap ring for permanent sleeve locking in the closed position
Optional closure via B shifting tool (standard industry tool)
ISO 14998 VO certified
Benefits
Enables tubing self-filling, reducing rig time and operational complexity
Forms a permanent, high-integrity barrier once closed
Fully compatible with TCO’s laminated glass plug systems
Enhances safety and efficiency by minimizing dependence on third-party autofill systems
Provides durable, corrosion-resistant performance tailored to specific well conditions
Applications
Tubing self-filling during run-in-hole operations
Completion strings utilizing laminated glass plug systems
Subsea and deepwater completions where rig time and efficiency are critical
Wells requiring barrier formation without post-installation intervention
Integration into full-bore tubing strings with premium thread connections
Self Calibrating Cycle Open Toe Valve
Our Self Calibrating Cycle Open Toe Valve eliminates the need for tubing conveyed perforation of the toe stage and enables a full pressure casing test without a time limit. The intervention less activation is controlled by pressure cycles at surface. After a predetermined number of cycles, the valve activates allowing infectivity into the formation.
The self-calibrating feature eliminates the need to change burst values based on depths and pressures. Multiple valves may be placed and opened simultaneously to act as a frac stage or independently to avoid pressuring out due to debris. The toe valves may be used in both cemented and open hole completions.
Technical Specifications
No time limit on casing pressure test
Torque through mandrel
Tested to over 15,000 psi burst at temperature
Multiple valves can be placed to simulate 1st stage frac clusters
Redundant opening mechanisms
Cemented and open hole completions
Activation with pressure on the casing improves connectivity to payzone compared to opening on release of surface pressure
Independent of TVD or formation pressures
