API Oilfield Download Drillable Oil / Gas Well Cementing Tools Cementing / Cement Plug

Top Plugs:The Top Cementing Plug is designed to exert continuous pressure on the casing wall. The core is made of special materials such as Plastic, Aluminium or Phenolic depending on the application and well conditions. The tapered base fits the cavity of the top plug initiating a positive seal. A solid rubber top plug is also available.

Bottom Plugs:Like the Top Cementing Plug, the fins and tail section provide positive wiping action. Fins also serve as a seal while cementing. The core of the bottom plug also made of special materials such as Plastic, Aluminium or Phenolic depending on the application and well conditions. A rubber diaphragm at the top of the plug ruptures after the plug is seated allowing cement to flow through.

The cementing plug is used to separate the cement slurry from the mud. It can prevent the mud from blending into the cement slurry to influence the cementing quality.

Structure:

conventional cementing plug & special cementing plug

Conventional cementing plug is divided into top plug and bottom plug. Special plug has top/middle/bottom plug used in two-stage cementing, drill pipe plug and hollow plug used in drilling liner cementing and composite plug used in composite casing.