Oil Field Chemicals

1. Surfactant for mining heavy oil

Due to the heavy viscosity and poor fluidity of heavy oil, it brings many difficulties to mining. In order to extract these heavy oils, it is sometimes necessary to inject an aqueous solution of the surfactant into the well to convert the high-viscosity heavy oil into a low-viscosity oil-in-water emulsion and draw it to the ground. The surfactant used in the heavy oil emulsification viscosity reduction method is sodium alkyl sulfonate, polyoxyethylene alkyl alcohol ether, polyoxyethylene alkyl phenol ether, polyoxyethylene polyoxypropylene polyene polyamine, polyoxygen Sodium vinyl alcohol ether sulfate sodium salt. The oil-in-water emulsion produced requires separation of the water and the use of some industrial surfactants as a demulsifier for dewatering. These demulsifiers are water-in-oil emulsifiers. Commonly used are cationic surfactants or naphthenic acids, asphaltic acids and their polyvalent metal salts. Special heavy oil can not be used in conventional pumping unit mining methods, and steam injection is required for thermal recovery. To increase the thermal recovery effect, a surfactant is required. Injecting foam into the steam injection well, that is, injecting a high temperature resistant foaming agent and non-condensable gas is one of the commonly used modulation methods.

Commonly used foaming agents are alkylbenzene sulfonate, α-olefin sulfonate, petroleum sulfonate, sulfoalkylated polyoxyethylene alkyl alcohol ether and sulfoalkylated polyoxyethylene alkyl phenol ether, special Gemini surfactants, etc. Fluorosurfactants are ideal high temperature foaming agents due to their high surface activity and stability to acids, bases, oxygen, heat and oil. In order for the dispersed oil to easily pass through the pore throat structure of the formation, or to make the oil on the surface of the formation easy to be driven out, it is necessary to use a surfactant called a film diffusing agent. Commonly used are gemini surfactants and alkylated phenolic resin polymeric surfactants.

2. Surfactant for mining waxy crude oil

Mining waxy crude oil requires frequent waxing and wax removal. The surfactant can be used as an anti-waxing agent and a wax removing agent. Anti-wax used is oil-soluble surfactants and water-soluble surfactants. The former can act as an anti-wax by changing the properties of the surface of the wax crystal. Commonly used oil-soluble surfactants are petroleum sulfonates and amine surfactants. Water-soluble surfactants act as waxes by altering the properties of the surface of the wax, such as tubing, sucker rods and equipment surfaces. Usable surfactants are sodium alkyl sulfonate, quaternary ammonium salt, alkane polyoxyethylene ether, aromatic polyoxyethylene ether and their sodium sulfonate salts and so on. The surfactants used for dewaxing are also divided into two aspects: oil-soluble is used for oil-based dewaxing agents while water-soluble sulfonate type, quaternary ammonium salt type, polyether type, twain type, OP type surfactant, sulfuric acid ester salinization or sulfonated alkylated pingplus surfactant and OP type surfactant are used for water-based dewaxing agents. In recent years, the anti-wax has been organically combined at home and abroad, and an oil-based wax remover and a water-based wax remover are organically combined to produce a mixed wax remover. The clear waxing agent uses an aromatic hydrocarbon and a mixed aromatic hydrocarbon as an oil phase, and an emulsifier having a wax removing action as an aqueous phase. When the emulsifier selected is a nonionic surfactant having a suitable cloud point, it can be brought to or above its cloud point at temperatures below the waxing section of the well. Therefore, the mixed type wax clearing agent is broken before entering the wax forming section, and two kinds of wax removing agents are separated, and at the same time, the wax is removed.

3. Surfactants used to stabilize clay

Stabilized clays can be divided into two aspects: preventing the expansion of clay minerals and preventing the migration of clay mineral particles. Cationic surfactants such as an amine salt type, a quaternary ammonium salt type, a pyridinium salt type, and an imidazoline salt etc. can be used to prevent swelling of the clay. Fluoride-containing nonionic-cationic surfactants are useful for preventing migration of clay mineral particles.

4. Surfactants used in acidification measures

In order to improve the acidification effect, various additives are generally added to the acid solution. Surfactants that are compatible with acid and easily absorbed by the formation can be used as acid retarders. Surfactants that can be compatible with acid and easily absorbed by strata can be used as acidification retarders, such as cationic surfactant aliphatic amine hydrochloride, quaternary ammonium salt, pyridine salt and amphiphilic surfactant sulfonation, carboxymethylation, phosphate ester salinization or sulfuric acid ester salinization polyoxyethylene alkyl phenol ether and so on. Some surfactants, such as dodecyl sulfonic acid and its alkylamine salts, can emulsifie an acid solution in an oil to produce an oil-in-water emulsion, and the emulsion acts as an acidifying industrial liquid, which also acts as a slowing action.

Some surfactants can be used as acidifying agent emulsifiers, and branched surfactants such as polyoxyethylene polyoxypropylene propylene glycol ether and polyoxyethylene polyoxypropylene pentaethylene hexamine can be used as acidification and emulsifier. Some surfactants can be used as a spent acid drainage agent, such as amine salt type, quaternary ammonium salt type, pyridinium salt type, nonionic type, amphoteric and fluorosurfactant.