Hydraulic Fracturing to Improve Nutrient and Oxygen Delivery for In situBioreclamation

摘要

A serious problem in the implementation of in situ bioreclamation is the deliveryof nutrients and oxygen to soil of low permeability. The problem commonly requires contaminated soil to be excavated for bioreclamation, resulting in increased exposure to toxic materials, liability and cost. The authors demonstrated that is feasible to create hydraulic fractures at shallow depths (several m) in silty clay till. Fractures created during a recent field test were flat-lying and roughly equant in plan with a maximum dimension of 8 m. Coarse sand was pumped into the fractures to hold them open. The sand was an average of 1.1 cm in maximum thickness. As many as four fractures were created from the same borehole, stacked at vertical spacing of 15 or 30 cm. The technique will be used to deliver slow-releasing granules of nutrients and encapsulated oxygen compounds in an effort to enhance in situ bioreclamation of contaminated soil.