Biomineralization: A Natural Solution to Eliminate Gas Migration

Abstract

A Seneca Resources Company, LLC (Seneca) natural gas well in Pennsylvania was leaking methane from both the 13-3/8 in × 9-5/8 in (55 psi) and the 9-5/8 in × 7 in (85 psi) cemented annuli. Previous attempts to mitigate the problem had proven unsuccessful, which prompted the trial of a new method using the natural process of biomineralization. BioSqueeze Inc. (BSI) was contracted by Seneca to apply their proprietary biomineralization technology to the well. To prepare the well, circumferential notches were cut through all casing strings all the way to the formation to allow fluid injection into the annuli. Biomineralizing fluids were then pumped into the well, where they formed crystalline calcium carbonate in the micro annuli. After 1.5 days of treatment, the injection rate dropped by several orders of magnitude. Subsequent monitoring by a state regulator determined surface pressure had been eliminated and there were no escaping hydrocarbons.