Thermo-Settable Cross-Linked Polymer System For Optimization Of Wellbore Stability And Zonal Isolation

For decades the industry recognized cement slurry as a common and universally accepted solution for zonal isolation. This technology has been used for several decades and it has been fine tuned to the limit of its possibility. There are several pluses to be recognized: it is economically favourable and thanks to several additives is able to give different properties which are not usually associated with cement, such as flexibility, self-healing capabilities to mention few. Traditional cement it is limited on other aspects such as the density ranges; it is possible now to reach density below 16.0 lbs/gal however other issues are derived from this procedure. Cement has high viscosity which will lead to high ECD, particularly important when dealing with a narrow wellbore pressure window. Other well known issues are thin windows of thermal activation and incompatibilities with oil-based mud systems, to mention few. Polymer composites have been introduced in the field to address all the shortcomings of the cement. This paper will present a new polymer/monomer composite that is activated by thermally-dependant initiator for free-radical polymerization. The system boasts a rheology comparable to drilling fluids at a set density; it can be designed to cover any mud weight from 9.0 lbs/gal to 16.0 lbs/gal and still keep mechanical properties superior to cement at any of those densities. The thermo settable polymer described in this paper can be customized to set at certain temperatures ranging between 90°F and 200°F within a desiderate time frame between 2 and 12 hours consistently. Other properties of the system include stability with drilling fluid and cement, low HMIS, and a low ECD.