Hydraulic Soil Fracturing and Bio-Net Installation Services

Using Multiple Level Hydrofracturing to Enhance In Situ Remediation

A new method based on hydrofracturing technologies from the oil and gas production industry can now be applied to significantly aid penetration of the formation by in situ chemical and biological treatment materials. The process has three steps:
  • Installation of hydrofracture injectors—nested at multiple levels determined by lithology and contaminant distribution (identified by coring or gamma logging)
  • Fracturing with water & guar, followed by installation of proppant material (sand, Isolite, etc.) to keep fractures open and maintain permeability
  • Injection of chemical or biological treatment material (periodically or continuously)
FIGURE 1 (left): Installing the Bio-Net.
Installing 5-level nested fracture injectors at Pueblo Chemical Depot (PCD). Borings were advanced to depths ranging from 40-60’ below grade. Then, steel injector wells were installed and driven to just above the fracture location, and sealed with grout.

Once the injectors were installed, a high-pressure cutter was used to create a horizontal notch in the formation. The notch focuses subsequent horizontal fracturing.

FIGURE 2 (right): Fracturing and Setting Proppant
The hydrofracturing operation uses a high-pressure progressive cavity pump. The fluid used at PCD was water with a specialized guar and sand, similar to the fracturing methods used in the oil industry. Because of the installation of the injectors, there was no back leakage of fracture fluid to the surface.

FIGURE 3 (left): Injection
The fracture system is set up on a trailer, fully equipped with pumps, mixers, tanks, and both electric and hydraulic power. The unit can deliver 500 gallon batches & 34 ft3 of solids. Additional fluids can be delivered from off-vehicle storage tanks.

Once the fracturing is completed, any vertical rise of the ground-surface can be observed using standard surveying equipment. Then, the site is ready for virtually any bio-enhanced remediation or chemical remediation, whether oxidation or reduction.