BSI was contracted by an operator to mitigate annular pressure (11 psi buildup over several days shut-in) on the 9-5/8” x 13-3/8” annulus on a well being abandoned in Ohio.

The well was previously bullheaded with an alternative conventional sealant offered by a major service provider, but it was unable eliminate annular gas flow.

TOC was identified at 4.5’ below the casing head valve. The well was then flushed clean to access leakage pathways using fresh water and surfactant.

Injection began by holding rate constant at 1.8 gpm, with pressure quickly rising to 2,100 psi. By the end of day 1 pressure falloff was significantly flatter. The well was then shut in at pressure overnight to allow biomineralization to continue. Pumping resumed with pressure held constant allowing the rate to decrease as leakage pathways constricted. The well was shut in again prior to day 3, during which the rate fell drastically and the well was shut in again. Day 4 consisted of a few more stages, pumping at lower pressure and very low rate.

The final rate was just 0.010 gpm, constituting a 99% decrease. Bubbling ceased after treatment and a 3+ day build-up test showed 0 psi allowing the well to be capped, cut, and approved by ODNR for permanent abandonment.