Scavanger used to counter Hydrogen Sulphide formation in the upstream.

Hydrated Lime (Calcium Hydroxide) holds the formula Ca(OH)2 and has many Niche uses across the industry. It is more commonly used in both water treatments.

A group of sheet silicates characterized by a platy appearance and basal cleavage most common in igneous and metamorphic rocks. Several clay minerals, such as chlorite and glauconite, are closely related to the mica group.

A hydrophilic polysaccharide from the seed of the guar plant. It is a galactomannan type of saccharide that is highly dispersible into water and brines of various types and salinity. Its water solutions are non-Newtonian and also can be cross-linked by borax to give very high gel strength for suspension. Such a structure is easily broken by breakers in fracturing fluids, so it serves as a carrier for placing sand far back into fractures. It is also used as a top-hole drilling fluid. Disadvantages of using guar gum include its lack of thermal stability and sensitivity to high pH and bacterial fermentation.

Oxalic acid is an organic compound with the formula H2C2O4. It is a colourless crystalline solid that forms a colourless solution in water. Its condensed formula is HOOCCOOH, reflecting its classification as the simplestdicarboxylic acid. Its acid strength is much greater than that of acetic acid. Oxalic acid is a reducing agent

Paraformaldehyde (PFA) is the smallest polyoxymethylene, the polymerization product of formaldehyde with a typical degree of polymerization of 8–100 units.

Polyol is low toxic, versatile cloud point glycols for shale control designed for low to high salinity water level system and can be used in well with low, moderate and high formation temperature in isolation or in combination with salts and polyamines.

Another term for sodium carbonate, a chemical with the formula Na2CO3. It is called soda ash at the drilling rig and is used to treat most types of calcium ion contamination in freshwater and seawater muds. For cement contamination, sodium bicarbonate is used. Calcium ions from drilling gypsum or anhydrite, CaSO4, cause clay flocculation and polymer precipitation and lower pH.

A chemical with the formula NaHCO3. It is called bicarb at the drilling rig and is used to treat cement contamination in watermud. When cement hydrates, substantial amounts of lime, Ca(OH)2, are produced. As the cement sets, less free lime is available. When partially set cement is drilled with a water mud.

A compound with the chemical formula NaOH. It is commonly known as caustic soda and used in most water-base muds to increase and maintain pH and alkalinity. It is a hazardous material to handle because it is very caustic and gives off heat when dissolved in water. Proper training and equipment are needed to handle it safely.

Formed by dissolving silica or silicate minerals in NaOH solutions. The silicate anion, SiO4-4, is found in solutions of sodium silicate. Silicate anions form polysilicates, or colloidal silica gel. A silicate mud is a type of shale-inhibitive water base drilling fluid that contains sodium silicate or potassium silicate polymeric ions. These ions adsorb on the shale surface and form a semipermeable osmotic membrane that prevents the transport of water and ions internal to the shale structure. This physicochemical barrier helps improve wellbore stability and provides in-gauge holes through troublesome shale sections that otherwise might require a nonaqueous drilling fluid.

A small volume or pill of fluid placed in a wellbore annulus to free differentially stuck pipe. Oil-base mud is the traditional stuck-pipe spotting fluid. Speed in mixing and placing the spot is of primary importance to successfully freeing pipe. Because of concern about mud disposal, spots used offshore are either synthetic-based emulsions or benign water-base formulations. Each type is supplied as prepackaged concentrate designed for rapid access and mixing at the rig. A spot frees pipe by covering the stuck region. It presumably breaks up the filter cake, allowing the spot to migrate into cracks in the cake and between the pipe and the cake, reducing the stuck area and allowing pipe to be pulled free.

An asphaltic mud additive that has been reacted with sulfite to add anionic sulfonate groups to the complex molecular structure. Sulfonate groups make an additive water dispersible, depending on the extent of sulfonation. Such an additive is used to stabilize wellbores and as a filter-cake additive for water- and oil-base muds.

A polysaccharide secreted by the bacteria genus Xanthomonas campestris, also known as xanthan gum. XC in water muds provides non-Newtonian mud rheology, highly desirable because of the flat velocity profile it produces in annular flow, which is required for efficient cuttings lifting in lower density muds. XC polymer is anionic, with tolerance for salinity and fair tolerance for hardness ions. XC is a finely powdered material that can vary in the amount of residual bacteria debris and the ease with which it disperses into water. Temperature tolerance varies with water-phase components, but starts to degrade around 200 to 250°F [93 to 121°C]. Extreme pH or hardness are not well-tolerated by XC polymer and it is susceptible to bacterial attack.

An asphaltic mud additive that has been reacted with sulfite to add anionic sulfonate groups to the complex molecular structure. Sulfonate groups make an additive water dispersible, depending on the extent of sulfonation. Such an additive is used to stabilize wellbores and as a filter-cake additive for water- and oil-base muds.

An additive that kills bacteria. Bactericides are commonly used in water muds containing natural starches and gums that are especially vulnerable to bacterial attack. Bactericide choices are limited and care must be taken to find those that are effective yet approved by governments and by company policy. Bactericides, also called biocides, can be used to control sulfate-reducing bacteria, slime-forming bacteria, iron-oxidizing bacteria and bacteria that attacks polymers in fracture and secondary recovery fluids. In polymers, the degradation of the fluid is controlled, thus avoiding the formation of a large biomass, which could plug the formation and reduce permeability.