Technical Design Issues

SFI Process

All solid waste material is placed in the Feed Hopper. Liquid waste streams are connected to the 3-stage auger. The waste materials are mixed with water to start the slurrification process in the 3-Stage Auger.
The slurry is then moved into the Shaker Unit, where any oversize material (such as rocks) is removed. The remaining material is moved into the Slurry Mix Unit and mix thoroughly.
The slurry is further moved from Slurry Mix Unit to the Pump Skid using hydraulic pressure from the Hydraulic Skid.
The slurry then goes through the pump skid and is injected down into the disposal well at high rates and pressures.
The injection well (not shown in this photo) has been specifically designed for the SFI process.

Illustration: Kelly Hartman Design Studio

The objective in large-scale waste disposal is to pack as much waste material within the deep target disposal formation as possible. This is best accomplished by packing the waste into short, thick, induced hydraulic fractures and allowing the carrying fluids to bleed off rapidly.

The ideal target disposal formation should have relatively shallow to moderate depths (300 to 2,000 metres); flat lying, laterally continuous strata, and alternating sand/shale stratigraphy. Target formations should be overlain by a thick, impermeable, ductile formation. The primary target intervals should be unconsolidated or weakly cemented, thick (> 30 ft), porous (> 25%), and permeable (> 1 darcy). Highly fractured formations (such as fractured carbonates) may also be suitable disposal zones.

A monitoring program is designed for each project. This program is used to evaluate the formation response to the SFI process and provide effective process control during injection operations.