Hydraulic Fracturing Capsule
Hydraulic fracturing informally referred to as “fracking,” is an oil and gas well development process that typically involves injecting water, sand, and chemicals under high pressure into a bedrock formation via the well. This process is intended to create new fractures in the rock as well as increase the size, extent, and connectivity of existing fractures. Hydraulic fracturing is a well-stimulation technique used commonly in low-permeability rocks like tight sandstone, shale, and some coal beds to increase oil and/or gas flow to a well from petroleum-bearing rock formations. A similar technique is used to create improved permeability in underground geothermal reservoirs.
Advantages of Fracking
1- It provides us with cleaner energy access.
2. It has encouraged clean-capture technologies.
3. It is not as dangerous as it may appear.
4. It does not affect groundwater.
5. It does not use as much water as other forms of energy.
6. It reduces domestic reliance on foreign energy products
7. It is a major jobs creator.
Disadvantages of Fracking
1. Hydraulic fracturing encourages us to use fuels that are finite.
2. It may produce ozone.
3. Hydraulic fracturing may provide us with unknown long-term consequences.
4. Hydraulic fracturing encourages us to consume more fossil fuels.
5. Hydraulic fracturing is a leading contributor of methane in our atmosphere.
6. Hydraulic fracturing puts unknown chemicals into the ground.
7. Hydraulic fracturing may cause earthquakes.
8. Hydraulic fracturing changes property ownership standards.
9. Hydraulic fracturing prevents innovation in other industries.
10. Hydraulic fracturing requires water, which could be used in other ways.
Fracturing additives
|
ADDITIVE TYPE |
DESCRIPTION OF PURPOSE |
EXAMPLES OF CHEMICALS |
| Proppant | “Props” open fractures and allow gas/fluids to flow more freely to the wellbore. | Sand [Sintered bauxite; zirconium oxide; ceramic beads] |
| Acid | Cleans up perforation intervals of cement and drilling mud prior to fracturing fluid injection, and provides the accessible path to formation. | Hydrochloric acid (HCl, 3% to 28%) or muriatic acid |
| Breaker | Reduces the viscosity of the fluid in order to release proppant into fractures and enhance the recovery of the fracturing fluid. | Peroxydisulfates |
| Bactericide / Biocide | Inhibits the growth of organisms that could produce gases (particularly hydrogen sulfide) that could contaminate methane gas. Also prevents the growth of bacteria which can reduce the ability of the fluid to carry proppant into the fractures. | Glutaraldehyde; 2-Bromo-2-nitro-1,2-propanediol |
| Buffer /
PH Adjusting Agent |
Adjusts and controls the pH of the fluid in order to maximize the effectiveness of other additives such as crosslinkers. | Sodium or potassium carbonate; acetic acid |
| Clay Stabilizer / Control | Prevents swelling and migration of formation clays which could block pore spaces thereby reducing permeability. | Salts (e.g., tetramethyl ammonium chloride) [Potassium chloride] |
| Corrosion Inhibitor | Reduces rust formation on steel tubing, well casings, tools, and tanks (used only in fracturing fluids that contain acid). | Methanol; ammonium bisulfate for Oxygen Scavengers |
| Crosslinker | The fluid viscosity is increased using phosphate esters combined with metals. The metals are referred to as crosslinking agents. The increased fracturing fluid viscosity allows the fluid to carry more proppant into the fractures. | Potassium hydroxide; borate salts |
| Friction Reducer | Allows fracture fluids to be injected at optimum rates and pressures by minimizing friction. | Sodium acrylate-acrylamide copolymer; polyacrylamide (PAM); petroleum distillates |
| Gelling Agent | Increases fracturing fluid viscosity, allowing the fluid to carry more proppant into the fractures. | Guar gum; petroleum distillate |
| Iron Control | Prevents the precipitation of carbonates and sulfates (calcium carbonate, calcium sulfate, barium sulfate) which could plug off the formation. | Ammonium chloride; ethylene glycol; polyacrylate |
| Solvent | An additive that is soluble in oil, water & acid-based treatment | Various aromatic |
| Fluids are used to control the wettability of contact surfaces or to prevent or break emulsions. | hydrocarbons | |
| Surfactant | Reduces fracturing fluid surface tension thereby aiding fluid recovery. | Methanol; isopropanol; ethoxylated alcohol |
Potential environmental impacts
The actual practice of fracking is only a small part of the overall process of drilling, completing, and producing an oil and gas well. However, since fracking involves injecting a chemical solution into the ground to free up oil and gas resources, there are some potential environmental impacts related to this process. These include:
• spills of chemicals at the surface
• surface-water-quality degradation from waste fluid disposal
• groundwater quality contamination
• induced seismicity from the injection of waste fluids into deep disposal wells
