Long-term zonal isolation issues with oilfield cement annuli commonly result from cyclic temperature and pressure loading during the lifetime of the well.
Cement mechanical properties such as brittleness and low tensile strength affect the long-term durability of the cement seal.
Remediation of zonal isolation failures, such as microannuli, can be both costly and challenging to execute successfully. The relatively large particle size of conventional cement compared to a microannulus means that it is difficult for the cement to penetrate far enough to create an effective seal.
Tight casing leaks, wellhead and tubing hanger leaks, small fractures, channels, or microannuli.
Zonal isolation/shut off water and gas.
Plugging of hydraulic control line.
Temporary Plugging.
