BioSqueeze Inc. was contracted by an operator in the Utica Shale of Ohio to remediate sustained casing pressure on a well in the process of being plugged. The well had sustained casing pressure on both the 5-1/2” x 9-5/8” – 863 psi and the 9-5/8” x 13-3/8” – 257 psi annuli.

A spectral acoustic noise log was run to determine the source(s) and leakage pathway(s) allowing gas to migrate up the well. Analysis of the log revealed the source of gas as the Marcellus/Big Lime on the outside of the 9-5/8” casing with gas traveling to surface through the 9-5/8” x 13-3/8” annulus and also crossing over through a leak in the 9-5/8” casing around 5,747’ – 6,011’ into the 5-1/2” x 9-5/8” annulus and to surface.

Raw data from an existing radial cement bond log (RCBL) was then reprocessed in the form of Advanced Cement Imaging (ACI™) to further inform the intersection strategy. The ACI™ revealed a debonded interval near the top of the section where the noise log identified a leak through the 9-5/8” casing.

Three sand notches were then cut between 5,758’ and 5,760’ at 90 degree phasing through both the 5-1/2” and 9-5/8” casings out to the formation face to seal both annuli with a single Downhole BioSqueeze^®. In preparation for treatment a retrievable bridge plug was set at 5,764’, with a tension set packer at 5,749’, and tubing run to 5,759’.

Treatment consisted of six stages of our low-viscosity, biomineralizing fluids injected into leakage pathways in the annuli over the course of 48 hours. The initial injection rate achieved in stage one was 0.138 gpm and fell to 0.004 gpm at the conclusion of the sixth stage with 109 gallons injected. This 97% reduction in the injection rate was indicative of sealing and prompted the conclusion of treatment.

The flowrate on the 9-5/8” x 13-3/8” annulus increased during treatment before dropping to no flow less than 2 days later.

The flowrate on the 5-1/2” x 9-5/8” annulus remained unchanged throughout treatment and for several days after.

Several long-term (4+ days) pressure build-ups were then recorded with the highest being less than 0.2 psi (99.9% reduction) with the well subsequently approved for permanent abandonment.