HEAVY DUTY HYDRAULIC DISCONNECT

The Heavy Duty Hydraulic Disconnect (HDHD) allows the toolstring to detach at a predetermined point via the deployment of a suitable drop/trip ball through the coiled tubing. The drop ball locates on a piston sleeve creating sufficient back pressure to shear the pins and disconnect the tool. The piston sleeve pushes the tool apart to ensure a clean disconnect. Circulation is immediately returned to the toolstring, providing a surface

indication of a positive disconnect. All piston sleeves and drop balls are returned to surface leaving a standard ‘GS’ internal fish neck for retrieval purposes.

The ‘HDHD’ utilizes a heavy duty, one piece, threaded collet slip to hold the tool together. The collet slip endures higher tensile loading than collet finger type release mechanisms and is far less susceptible to fatigue. The collet slip is backed up with a collet slip sleeve to give maximum tensile strength to the disconnect during heavy jarring operations. Only by dropping a ball and shearing the pins can the collet sleeve shift, allowing the collet and top sub to part. The piston sleeve is pressure balanced, therefore internal pressure does not affect the hydraulic configuration and shear values.

High torque capabilities are achieved through positive torque drive teeth between the top sub and the main body of the tool. The ‘HDHD’ is therefore ideally suited for high torque, heavy duty coiled tubing drilling operations, where maximum performance and durability is essential.

Shear screws can be supplied in either brass or steel to give a comprehensive pressure range to suit virtually any coiled tubing application. Shear screws are also integrally situated to eliminate the possibility of shear screws vibrating free during CT drilling operations.

By interchanging the piston sleeve, the drop/trip ball size can be varied to suit the desired toolstring requirements. This is a particularly useful feature when the ‘HDHD’ is situated below jars and accelerators, and ID restrictions are a factor for consideration. Running

the ‘HDHD’ below jars and accelerators ensures that if disconnection of the toolstring is necessary, a greater proportion of the toolstring is safely returned to surface.

A major design consideration is that of simple field redress. The ‘HDHD’ has been designed to ensure assembly & disassembly of the tool is trouble free. No special assembly tools are required and all seals are standard ‘o’ rings.