
Hydraulic fracturing and the chemicals used
When the natural rate of gas production from a well is low, sometimes companies use a technique called hydraulic fracturing to improve gas flows.
Hydraulic fracturing has been used in the oil and gas industry for more than 50 years and in Australia for several decades.
when drilling wells, grout or cement is pumped between the well casing (a steel tube) and the hole back to the surface. This forms a barrier between the coal seams and any nearby aquifers.
Hydraulic fracturing involves mostly water and sand that is injected into wells at high pressure to crack the coal seams so gas can flow more freely. The sand holds open the cracks. The process is designed to only affect the target coal seam. Like farmers who use chemicals on crops, QGC uses chemicals with extreme care.
The small proportion of chemical additives in hydraulic fracturing fluid are needed to reduce friction, remove bacteria, dissolve some minerals and enhance the fluid’s ability to transport sand. They consist mainly of commonly used compounds like:
- Surfactants (in soap or toothpaste)
- Guar gum (in ice cream)
- Sodium hypochlorite (in swimming pools)
- Hydrochloric acid (also in swimming pools)
- Acetic acid (basis of vinegar)
All chemicals are handled according to strict procedures by trained personnel and are used in concentrations so low as to cause no adverse environmental impact. The chemical product safety data sheets (SDS) are supplied in Table 1 below. Table 2 provides stimulation chemical risk assessments, prepared by an independent and qualified consultancy, that:
- identify the hazards associated with proposed stimulation chemicals;
- consider potential exposure pathways and the risk of potential impacts; and,
- determine the required management measures.
Service Company Name or Handling Name (links to SDS) | Main chemical components | Common uses | Main CAS# |
---|---|---|---|
Function: Biocide | - | - | - |
BE-09 | Tributyl tetradecyl phosphonium chloride | Biocide used industrial cleaning, oil field waters, papermaking | 81741-28-8 |
BE-6 | Bronopol | Eliminates bacteria in water | 52-51-7 |
Magnacide 575, M298L | Tetrakis (hydroxymethyl) phosphonium sulfate | Eliminates bacteria in water for farming uses | 55566-30-8 |
M275, BPA68915 | 3:1 CIT/MIT biocide, Magnesium Nitrate | Eliminates bacteria in water | 55965-84-9 |
Sodium Hypochlorite, BE-7, M091 | Sodium hypochlorite | Household bleach, disinfectants | 7681-52-9 |
M300A | Glutaraldehyde | Industrial water treatment, disinfectant | 111-30-8 |
Clay control | - | - | - |
KCL, M117 | Potassium chloride | Fertilisers | 7447-40-7 |
L071, ClayCare, ClayTreat-2C, Choline chloride | Choline chloride | Agricultural feed additive | 67-48-1 |
Corrosion inhibitor | - | - | - |
B499, Gelatine | Gelatine | Marshmallows, canned hams, desserts and dairy products, pharmaceuticals | 9000-70-8 |
L058 | Sodium erythorbate | Food additive used predominantly in meats, poultry, and soft drinks | 6381-77-7 |
U042 | Tetrasodium ethylenediaminetetraacetate | Food perservative, shampoo products, dentistry, cosmetics | 64-02-8, 1310-73-2, 5064-31-3 |
Crosslinker | - | - | - |
XLW-10A | Borax, also known as sodium borate, sodium tetraborate, di-sodium tetraborate | Detergents, soaps | 1330-43-4, 107-21-1, 1310-73-2 |
J480 | Aliphatic acid salt | Fish bait additive, food preservatives | N/A . |
J610 | Potassium hydroxide | Manicure treatments, hair removal, soft soaps | 1310-58-3 |
J604 | Ethane-1,2-diol, Sodium tetraborate | Corrosion protection, antifreeze | 107-21-1, 1330-43-4 |
Gel | |||
J580 | - | Food thickening agent | N/A |
J594 | Carbohydrate polymer derivative | None. Considered non hazardous. | - |
J596, J450 | 2,2',2"-nitrilotriethanol | Laundry detergents, dishwashing liquids, general cleaners, shaving cream. | 102-71-6, 1330-43-4, 7699-43-6 |
Service Company Name or Handling Name (links to SDS) | Main chemical components | Common uses | Main CAS# |
Function: Gel breaker | - | - | - |
GBW-30 | Carbohydrates, hemicellulase enzyme | Food additives, coffee processing | 9012-54-8 |
J218, J479, GBW-5 | Diammonium peroxidisulphate | Hair bleach, household cleaners, etching copper, printed circuit boards | 7727-54-0 |
J134 | Hemicellulase enzyme | Food additives, coffee processing | 9012-54-8 |
J318 | 2,2`,2"-nitrilotriethanol | liquid laundry detergents, dishwashing liquids, general cleaners, hand cleaners, polishes, metalworking fluids, paints, shaving cream and printing inks | 102-71-6 |
J481, J490 | Sodium bromate | Hair pigments, clothes dyeing | 7789-38-0 |
Gel stabiliser | - | - | - |
J589 | Propan-2-ol | Keyboard, LCD screen, whiteboard and eyeglasses cleaner | 67-63-0 |
J511 | Aliphatic polyol | N/A. | N/A. |
Friction Reducer | - | - | - |
FRW-16 | 1-Propanesulfonic acid, 2-methyl-2-[(1-oxo-2-propen-1-yl)amino], sodium salt (1:1) homopolymer | Water treatment, Thickener, Personal care products | 35641-59-9 |
J353L | Sodium thiosulphate | Preservative, stain remover, bleach and chlorine remover | 7772-98-7 |
J568 | Butyl Diglycol | Printing ink, surface cleaners, foam fire extinguishers | 112-34-5 |
J599 | Tetraethylenepentamine | Adhesives, agriculture, veterinary and detergents | 112-57-2, 4067-16-7, 112-24-3 |
Other | - | - | - |
Nitrogen | Nitrogen | Refrigeration, supercooling, inert gas | 7727-37-9 |
Carbon Dioxide | Carbon Dioxide | Dry ice | 124-38-9 |
Sodium Chloride, Rock Salt, D044 | Sodium chloride | Table salt | 7647-14-5 |
Fluorobenzoic acids | Fluorobenzoic acids | Groundwater tracers | 385-00-2, 445-29-4, 1583-58-0 |
Oxygen Scavenger | - | - | - |
Oxygon | Organic acid salt | Removal of dissolved oxygen in fluids, meat processing | 6381-77-7 |
J528 | Organic polymer | Biodegradable plastics (eg. Biodegradeable plastic bags, sheets, cups) | 9051-89-2 |
J554 | Aliphatic synthetic polymer | Carpenters glue | N/A |
pH buffer | - | - | - |
M003, Soda Ash | Sodium Carbonate | Neutralise acids, water softening | 497-19-8 |
Sodium Hydroxide, U028 | Sodium Hydroxide | Manufacturing of paper, textiles, drinking water, soaps, detergents, drain cleaner | 1310-73-2 |
BF-3 | Sodium Bicarbonate | Baking soda | 144-55-8 |
BF-7L | Potassium carbonate | Additive in soaps, wines, dyes, glass | 584-08-7 |
Acetic Acid, BF10L, L401 | Acetic acid | Vinegar | 64-19-7 |
HCL | Hydrochloric Acid | Swimming pool pH control | 7647-01-0 |
FE-300 | Citric Acid | Naturally occurring in citrus fruits, flavouring, cosmetics | 77-92-9 |
Scale inhibitor | - | - | - |
L065 | Calcium Chloride, 1,2-Ethanediol | Brine, desiccant | 10043-52-4, 107-21-1 |
Surfactant | - | - | - |
F112 | Polyethylene glycol monohexyl ether | Cleaning fluids, paints, coatings, silk screening inks | 31726-34-8 |
Foam Stabiliser | - | - | - |
B271 | beta-Alanine, N-coco alkyl derivs., sodium salts | Carwash foams | 68608-68-4, 111-76-2, 67-63-0 |
Proppant | - | - | - |
Sand | quartz | Construction | 14808-60-7 |
Carboprop | Corundum, Mullite | Ceramics | 1302-93-8 |
NRTCarboprop | - | - | - |
Type | Title |
---|---|
Main text | Stimluation Chemical Risk Assmt (Golder 2014) |
Addendum | Urea sulphates polymer |
Addendum | Glutaraldehyde |
Addendum | Butenedioic acid polymer |
Addendum | Fluorobenzoic acid |
Addendum | Xanthan gum, sorbitol, ethane-diol, borate |
Addendum | Acetates, amines, tetrafluoroethylene |
Addendum | Boronatrocalcite, fumarate, diutan |
Addendum | Propenoic acid, calcium chloride, oxydiethanol |
Note: The above tables are periodically updated with new chemical products and also to remove some that are obsolete. Chemical products are retained on the QGC website for at least a year following their use in hydraulic fracturing. For information about historical chemicals used in hydraulic fracturing please contact us.
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