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;
◦Sidetracking;
◦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).
For more specifications:
http://www.halliburton.com/en-US/ps/cementing/deep-water-cementing/plug-setting.page?node-id=hsx1li0e
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;
◦Sidetracking;
◦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).
For more specifications:
http://www.halliburton.com/en-US/ps/cementing/deep-water-cementing/plug-setting.page?node-id=hsx1li0e
