Creating injection slurries for disposal of oil and gas field waste is standard practice for managing solid waste in environmentally sensitive regions:

  • Offshore
  • Tundra
  • Marsh
  • Remote areas

Otherwise, waste would be left in reserve pits, land-farmed, or discharged into the ocean, damaging the environment and threatening the health of the human population.

Slurry injection relies on hydraulic fracturing science to create subsurface voids for storing solids.

Key Concerns about Injection

  • Containment of injection waste
  • Prevention of humanly perceived seismic activity

Appropriate design standards and constant monitoring of controlling parameters will mitigate much of the concern.

Safe operations are always the highest priority for well operators.

Both surface and subsurface risks must constantly be evaluated using real-time well surveillance to ensure the surface pressures and subsurface behaviors are within bounds. Problems can be managed when you base your planning and operations on understanding subsurface behavior.

Best Practice: Proper Site Research, Construction, and Operation

Determine workflow based on:

  • Well logs
  • Offset well performance
  • Geomechanics
  • Fracture simulation and optimization

Perform proper zonal selection and well construction and remodel the initial parameters once the well is drilled.

Build safe margins into your operating procedures using:

  • Log analysis
  • Break down and fall-off tests
  • Fracture and flow simulations

Best Practice: Manage Injection Fluids to Prevent Formation Damage

Matrix injection is prone to plugging – you need to monitor for fractured injection sites.

Typical Causes of Near-well Damage:

  • Oilfield bacteria
  • Calcium carbonate
  • Sulfates
  • Iron compounds
  • NORM – naturally occurring radioactive materials such as Ra-226 and Ra-228

Monitor your formation after drilling at all times.

Best Practice: Use Injection Diagnostics to Predict Failure Before It Happens

Safe operations require real-time monitoring – continually monitor both the surface pressure and subsurface fracture behavior to assure containment.

Typical Injections:

Diagnostic tests forecast injection performance trends that indicate potential types of damage and when work-overs may be required.

Fall-Off Test
  • Perform daily
  • Conduct after shut-in
  • Analyze for information on fracture containment in-zone, near-well damage, and reservoir properties
Step-Rate Test
  • Perform quarterly
  • Conduct at different rates to determine when fracturing occurs, in-situ stress, and rock strength
  • Interpret fracture closure and propagation pressures to confirm fracture geometry and injection zone

Best Practice: Minimize All Magnitudes of Seismic Activity

There is a complex web of potential causes, two of which are injection near crystalline basements and the use of high rate injection.

Nearly all cases of suspected injection-induced seismic activity perceived by humans have involved communication between disposal zones and basement faults.

Operators must avoid activation of faulted basement rock:

  • Injection in strata near crystalline basements
  • Injection zones proximal to faults penetrating into basement

Studies show high injection rates (>300,000 bbl per month) are much more likely to be associated with induced seismic events and includes propagation into faults or other wells.

Advantek Waste Management Services has helped clients inject 1.5 billion barrels of oilfield and other hazardous waste for more than 50 of the biggest national and international oil companies.

Hydraulic Fracturing Library

Technical papers related to hydraulic fracturing, including case studies, advances in model building, and other topics.