Roller Centralizer consists of rigid body, on which machined spiral vanes. There are modified alloy steel, fully heat treated rollers fixed on every spiral vanes. Because of rigid body and rolling friction between the rollers and inside of well or casing.The capability of the roller Centralizer is better than others of all.
Roller centralizers are mainly used for big high Roller, high deviated wells and horizontal wells, to centre casings.Roller Centralizers can also remove wellbore cake and improve mud replacement efficiency etc.Roller Centralizers provide superior wear resistance and have been proven to remain functional throughout the life of the well and can aid in casing/tubing retrieval.
Precision-machined: inside diameter fits over the casing through the complete API tolerance range, providing excellent rotational performance in mud.
When running casing through open hole, the system’s smaller roller-contact area reduces the risk of differential sticking and maintains standoff .The roller/axle relationship ensures that axle shear stresses remain within elastic limits, preventing permanent deformation.
Axles are crimped in place, eliminating the welding process, while ensuring the rollers cannot break free and fall into the wellbore. The system’s high-quality construction materials improve high-pressure/high-temperature capabilities. Roller Centralizers are available in sizes 4½" to 20".Any special sizes are available on request.
Three sets of arms with hard faced rollers at the pivot point are mechanically linked and spring loaded to provide a constant radial force through the full operating diameter. Both upper and lower collars are free to slide on the mandrel to avoid any wedging action. Additional linkage is fitted to the upper arms; this changes the mechanical advantage, affecting closing force requirements when the tool is being pulled up into a restriction.
Each arm has twin rollers which are optimized to give high centering and ultra low rolling frictional forces. The linked pairs of arms ensure accurate positioning while providing an even radial force through the full operating diameter.
To reduce the force required to pull the tool to its minimum diameter, special features are added to the arm profile. The 4-arm Production Roller Centraliser is hard wearing and suitable for Slickline operations.
These six sets of arms provide a constant radial force through the full operating diameter. Both upper and lower collars are free to slide on the mandrel to avoid any wedging action. The rollers enable passage down the well with minimum friction. This tool can also be used as a tubing end locator by observing line tension when pulling into the tubing.
Production Springbow Centralizer
In open hole completed wells the springs enable smooth passage down the well with minimal damage to the formation. The tapered shape of the tool makes it easier to pull into the tubing from casing. Large diameter changes may also be passed through with minimum friction.