Cement Stage Collar  API Standard

Drilling stage cementing tool is a special equipment which divided the cementing job for twice.It’s mainly used for the following condition.

 Cementing tool The DCFZ-A hydraulic stage cementing collar feature inner closing structure,opening through pressure difference.The closing plug drives the closing sleeve down and then shuts circulating port. This stage cementing collar is used to cement upper sections of the casing string after displacing cement around the lower section.

The Multiple Stage Cementing Collar provides a means of opening and closing port holes for cement displacement and positive containment of the cement after displacement. All internal parts are drillable, and are held from rotating during drilling.

The port closing sleeve is positively locked in position after cementing.

When running the Collar, it is advisable to place Casing Centralizers above and below the tool, and to run a Cementing Basket below the cementing ports.

 After running the Collar to setting depth, the lower section is cemented in the conventional manner, except the cement is displaced with the flexible cementing plug furnished with the collar. This is bumped against the shut-off Baffle which is also included.

A slight pressure build-up of 300-400 PSI will help to seat the plug in the Baffle. The port holes in the Multiple Stage Cementing Collar are opened for the second stage by dropping the trip bomb and applying approximately 800-1000 PSI pressure . The second stage is displaced with the closing plug, which is also furnished with the Tool. When the closing plug bumps approximately 800-1000 PSI, the pressure will close the port holes.

Description

The multi-stage cementing collar provides an effective, economical way to cement one or more specific casing intervals or to cement upper zones after a lower zone has been cemented. The collar should be used with centralizers aboce and below and a cementing basket positioned below the ports. The operation of the collar is simple and reliable. It features a double locking mechanism consisting of a snap ring lock and ball lock system to assure that the ports are permanently locked closed after cementing is completed. Internal parts are designed to lock to prevent rotation during drill out and are constructed of easily drillable materials.

Features

1. Opening pressure can be adjusted and it is not subjectiveto hole angle.

2. The pressure-relief design prevents fluid trapping and compression during the closing phase of the tool's operation. 3. The I.D of upper/lower sub is the same as that of casing, but smaller than that of closing sleeve, whcih can minimize chances of damages to the closing sleeve.

4. The inner seats are made of an easily drillable butyronitrile rubber/ aluminum materail.Both the opening and closing seats lock against rotation for easy drill-out.

Features:

1,Openging pressure can be adjusted and it is not subjective to hole angle or mud properties for operation.

2,The pressure-relief design prevents fluid trapping and compression during the closing phase of the tool's operation.

3,The I.D.of upper/lower sub is the same as that of casing ,but smaller than that of closing sleeve,which can minimize chances of damages to the closing sleeve

4,The inner seats are made of an easily drillable butyronitrile rubber/aluminum material.Both the opening and closing seats lock against rotation for easy drillout.