The centralizer, also known as the guide, is a centralizer that is installed on the outer surface of the casing to ensure that the running casing string is located in the center of the wellbore.

The use of centralizers in oil and gas drilling and production can improve the working stability of the drill bit, thereby prolonging the service life of the drill bit.
Rigid centralizers are usually of one-piece construction for higher strength and are usually attached to stop rings or to casing with set screws. Rigid centralizers provide maximum recovery and improved fluid flow and improved cementing quality. Straight or swirling types are available in aluminum alloy and cast steel.
The rigid centralizer can freely rotate and slide up and down on the casing, or it can be fixed to a certain part of the casing with a set screw or a fixing ring.
Compared with the elastic centralizer, the rigid centralizer has obvious advantages. In vertical wells, if the casing is required to rotate during cement injection to improve the displacement efficiency, then the rigid centralizer is the best choice. In inclined wells and horizontal wells, leaf spring centralizers can no longer support heavy casing strings. If the casing in the cemented section is required to rotate, rigid centralizers are the only choice.