Cement plug

Cementing & Well Integrity

A cement plug is a specific volume of cement placed at a desired depth in the wellbore to create a solid set barrier. Unlike primary cementing (which fills the annulus), plugs are placed inside the open hole or casing. They are used for various purposes, including isolating a zone, kicking off a sidetrack (whipstock plug), or permanently abandoning a well (P&A).

Setting a successful plug requires careful calculation of volumes and precise placement techniques (often using a balanced plug method) to prevent contamination by drilling fluids. A 'hard' plug that can withstand weight and pressure is critical for operations like sidetracking.