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.
Multiple-stage cementing tools are recommended for the following circumstances:
Two types of multiple-stage cementing tools are available: plug-opened (free fall) or hydraulically-opened (pump down). All of Halliburton's stage cementing tools are rated for continuous service up to 275°F (135°C).