The rigid centralizer can be freely turned and slid up and down on the casing, or it can be fixed to a certain part of the casing with a fixing screw or a fixing ring. When casing into the well, it can scrape mud cake, clean the well wall, make the cement slurry swirl, improve the displacement efficiency, in inclined Wells and horizontal Wells, it can support the casing to center the casing, and play the role of a sliding bearing when the casing is required to rotate.
Work Principle
In vertical Wells where cementing requires casing rotation to improve displacement efficiency, rigid centralizer is the best choice. In inclined and horizontal Wells, spring plate centralizers can no longer support the heavy casing string, and rigid centralizers are the only option when casing rotation is required in the cement-sealed section.
Technical Parameters
| Specification | Ontology style | OD (mm) | ID (mm) | Length (mm) |
|---|---|---|---|---|
| 4 1/2″×6″ | I、II、III | 145 | 116.5 | 100 or 150 |
| 5″×6″ | I、II、III | 145 | 129 | 100 or 150 |
| 5 1/2″×8 1/2″ | I、II、III | 205-210 | 142 | 100 or 200 |
| 6 5/8″×8 1/2″ | I、II、III | 205-210 | 171 | 100 or 200 |
| 7″×8 1/2″ | I、II、III | 205-210 | 181 | 100 or 200 |
| 7″×9 1/2″ | I、II、III | 225-235 | 181 | 100 or 200 |
| 7″×9 5/8″ | I、II、III | 225-235 | 181 | 100 or 200 |
| 9 5/8″×12 1/4″ | I、II、III | 300-305 | 248 | 100 or 200 |
| 10 3/4″×14 3/4″ | I、II、III | 365-370 | 278 | 100 or 200 |
Characteristics
- The rigid centralizer is made of all steel.
- The inner diameter is usually 1-4mm larger than the outer diameter of the casing, which is easy to install on the casing.
- The outer diameter of the body is smaller than the outer diameter of the casing coupling, so that there is enough flow area, the outer diameter of the centralizer has a variety of specifications, and is generally 2-10mm smaller than the hole when used. The length of the centralizer is available for users to choose.
- Both ends of the righting bar have large chamfer.