API Oil Cementing Tool Top and Bottom Cementing Plug / Non-rotating Cement Plug

Typically, the top plug and bottom plug are used in conjunction for cementing operations. To initiate the process, the bottom plug is first placed into the wellbore. It is then pumped down to scrape and clean the hole wall. Once the pump plug is in position, the pressure is increased to 2-4 MPa, breaking the rubber film and establishing circulation.

Subsequently, the cement injection begins. The top plug is inserted and pumping commences. As pressure increases, the cementing process is carried out.

The top rubber plug is engineered with a core made of epoxy coated sand that is compressed into a solid mass. This design enables the plug to withstand shock when pumped to touchdown, while retaining its drillability. The core is fully encased in rubber and features a solid base to prevent separation.

On the other hand, the bottom rubber plug incorporates a cast aluminum core that is PDC drillable. After the plug has completed its wiping of the casing ahead of the cement slurry and is seated at the desired location, additional pump pressure ruptures the rubber diaphragm at the top of the core, allowing the slurry to continue flowing towards its intended destination.