Plug

Cement displacement plugof CDP-C type is used during the cementing (plug) operations, and aimed at:

• Bottom plug (B) is used to scrape a clay cake from inner surface of the casing string, as well as to divide cement slurry and spacer and prevent them from mixing.
• Top plug (T) – traditionally used – necessary to obtain pressure jump Stop;, which signals the end of the cementation process, and to divide cement slurry and displacement fluid (mud fluid), pumped into the casing string, and prevent them from mixing.

Plugs clean the inside of the casing pipes from the remains of mud fluid or cement slurry.

CEMENTING PLUGS TYPE CP Cementing plugs are used for casing cementing and division of the cement slurry, spacer, and chaser in order to prevent them from mixing with each other. Bottom plug CPB is designed to remove the clay skin of mud fluid from the surface of the casing string.

Top plug CPT is used to obtain a pressure jump (the signal “Stop”, signaling the end of the cementation process), landing it on the bottom plug or plug seat, or valve packing nut of type CКОDМ (CКОDU),when no bottom plug is used.