Tips for selecting right rigid centralizers

In cementing process, we often need rigid centralizers which are used to center the casing in the hole and allow the mud flow around the casing. The design of the kinds of rigid centralizers is completely different from bow spring centralizers. Generally speaking, we have two kinds of technologies to manufacture them, one is casting by wax model, the other is seamless steel pipe and then the blade welded on the pipe. In order to make the rigid centralizers beautiful and dust-proof on the centralizer body, we often utilize the powder coating technology in the high temperature, which is to put the powder melting and then sucking on the rigid centralizers body.

 

In fact, API do not give strict standard for rigid centralizers, only for bow spring centralizers. So many centralizer manufacturers have different appearances, but basic bodys are almost the same. There are two usual classifications, one is from material, the other is from blade types. For example, we often call the solid rigid centralizers which are composite of steel body and aluminum body centralizer. The aluminum rigid centralizers have some features like light weight, anti-corrosion, without coating, higher tensile and yield strengths. According to the blade difference, we have straight blade or spiral blade rigid centralizers, they are used in different mud density well , straight blade centralizer in low density mud, spiral one in high density mud.

 

 

In China, there are many API certified casing centralizer manufacturers who often supply bow spring centralizers and rigid centralizers. Because the rigid centralizers are provided with some features themselves like shock, impact and corrosion resistant, high tensile and yield strengths, easy installing and so on. They also select the rigid centralizers in cementing job.

 

Puyang zhongshi group is one of the professional rigid centralizers manufacturers. It supplies the centralizer size from 4-1/2 to 20inch, its rigid centralizers are used in deviated or horizontal holes. They also provide special size rigid centralizers according to different casing sizes. In order to keep the rigid centralizers fixed on the casing, we need use the stop collar with integral screws. Usually the rigid centralizers are installed between stop collars which reducing the risk of sliding from casing.

 

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