Pnuematic Fracturing

Pneumatic or hydraulic fracturing can aid in the removal of contaminants from, or introduction of material to, tight geologic formations. Fracturing is a process where air (or inert gas) is injected into the subsurface at pressures exceeding the natural in situ pressures present in the soil/rock interface (i.e., overburden pressure, cohesive stresses) and at volumes exceeding the natural permeability of the subsurface to propagate fractures outward from the injection point. Fracture propagation may occur at distances up to 30-60 feet from the injection point in rock formations, and up to 20-40 feet in unconsolidated materials such as silts and clays. Relatively low pressures (about 100 psig) are required to initiate fractures, but injection rates are large (several thousand cfm). This technology can be applied to the vadose zone and/or the saturated zone. By increasing the permeability of the formation, the time required for remediation via other technologies (e.g., soil vapor extraction, air sparging, bioremediation) should be reduced. next

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Pnuematic Fracturing