At some point in the life of the well, even if only at the end of life, a chemical (cement or resin) plug will be used. The particular challenge of setting a chemical plug is that a relatively small volume of cement or resin is placed in a wellbore already containing a large volume of fluid. Considerations for achieving a successful plug operation include (but are not limited to): temperature, stability of the well architecture, stability of the formation, displacement of existing fluid, avoiding contamination of the chemical material, compatibility with existing fluids, a reasonably short wait-on-set time, achieving sufficient mechanical and chemical strength and long-term resiliency.
Cementing plugs are used for:
- Securing formation fluids in the originating strata and sealing off selected intervals of
- A depleted well;
- An exploration well;
- A dry hole;
- To meet regulatory specifications for plug-to-abandon.
- Stabilizing the whipstock tool or simply setting a kick-off plug used to guide a change of direction for the drill bit
- Toward an otherwise inaccessible target;
- For shoreline drilling;
- Relief-well drilling;
- Drilling under salt domes;
- Enhanced reservoir contact.
- Isolation of a specific zone that presents a concern such as
- A water zone
- A zone prone to lost circulation such as a depleted zone or an unconsolidated formation strata
- Formation testing when the reservoir zone is significantly above the bottom of the well and it is not practical or possible to set a bridge plug or a sidewall anchor in the open-hole section below (if it is a long open hole section).