Multiple-stage cementing tools allow for selected intervals around the casing string to be cemented at separate times or in stages. Two-stage cementing is the most common of the multiple-stage cementing techniques, but a three-stage method can be used. New technologies and techniques have led to the use of lightweight cement solutions in some situations that would conventionally call for multiple-stage cementing.
5 1/2" Hydraulic Stage Cementing for Oil Drilling
1. Opening pressure can be adjusted and it is not affected by the 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.