Seepage pathway assessment for natural gas to shallow groundwater during well stimulation, production and after abandonment

Geo Montréal evaluates the potential pathways of fugitive gas seepage during stimulation and production and concludes that the quality of surface casing and deeper casing installations is a major concern with respect to future gas migration. The pathway outside the casing is of greatest concern, and likely leads to many wells leaking natural gas upwards from intermediate, non-depleted thin gas zones, rather than from the deeper target reservoirs which are depleted during production.