Various oil production processes, including well drilling, crude oil storage and refining are associated with serious issues. Today a biocide, polyhexamethylene guanidine chloride (PHMG chloride) is actively used to solve such issues.
This substance can improve well deliverability. It is a highly-efficient anti-corrosion and anti-deposit agent. In addition, it facilitates separation of oil from salt water and is used to control oil viscosity in oil-in-water systems. Further, PHMG is actively used to protect petroleum products against biological degradation (degradation caused by microorganisms).
‒ Role of PHMG at the Well Drilling Stage:
Expendables, such as pipes, packing cement and drilling fluids are rather essential for drilling.
Thus, packing cement used to seal drilled wells after installation of piping must be highly spreadable, since it is important that it seals all narrow gaps between the pipes and rock. Furthermore, it should be highly strong hen set as the pressure in wells is high.
All the above characteristics can be significantly improved by adding PHMG chloride to packing cement in proportion 100 (mass) fractions of packing Portland cement to 0.2-2.0 (mass) fractions of PHMG chloride.
Further, in the process of oil well drilling fluids is used to cool drill bits and to wash over the well. Clay-based fluids are widely used in drilling. Such fluids are aqueous colloidal bentonite clay solutions. In aggressive saline media (NaCl and CaCl2), such fluids are stabilized using hydrophilic polyelectrolytes the action of which can also be enhanced by their combination with PHMG solutions.
In most cases, oil penetrates into porous strata in producing formations from which it is displaced by purpose-specific prepared highly viscous flooding polymer solution displacing oil without mixing with it since oil viscosity is lower than that of such solution. For this purpose, oil producers often use cheap acrylamide polymers partially hydrolyzed with sodium hydroxide, which are characterized by the highest possible molar mass (about 107) and high viscosity.
However, it should be noted that polyacrylamide is highly instable in its properties and is rather easily degradable by microorganisms and, therefore, it can get deteriorated in the midst of a very important process. Such deterioration results in crucial drop in its molar mass and the viscosity it creates.
That is why high-efficient biocide preparations, and namely PHMG, are used to protect polyacrylamide against microorganisms inhabiting formations.
If PHMG is added to polyacrylamide, the biocide not only inhibits formation microflora but also “cures” gaps in polyacrylamide macromolecules (by chemical interaction), which results in higher fluid viscosity and improved oil recovery.
‒ PHMG for Separation of Oil from Salt Water:
Oil produced from a well always comes as trolly oil containing mineral salts in high concentrations. Therefore, it must be dehydrated and de-mineralized before refining.
This complex process of separation of oil from salt water can also be facilitated by adding PHMG used as an auxiliary polymer reagent.
‒ High Anti-Corrosion Properties of PHMG:
PHMG has an additional advantage – it is a high-efficient anti-corrosion agent essential for crude oil. Its high anti-corrosive activity is explained by presence of hydrogen sulfide and sulfate-reducing bacteria in its composition. The crude distillation process is associated with conditions favourable for distillate vapour condensation and corrosion of rectifying plants even if the oil is preliminarily de-mineralized and dehydrated.
PHMG (5-20 g of PHMG per ton of the resulting distillate) is successfully used to prevent corrosion – efficiency of the biocide reaches 95-98%.
PHMG hydrochloride is not an oxidant and does not cause corrosion. However, its biocidal properties provide for killing a wide variety of microorganisms inhabiting inner and outer surfaces of oil pipes, which affect metals in a negative way.
PHMG:
- Protects walls of oil pipes against rare types of corrosion, including sulfide cracking and embrittlement;
- Protects equipment against acidic and hydrogen sulfide corrosion – it kills all pathogenic bacteria.
‒ PHMG is an effective biocidal agent preventing biological degradation:
In the process of storage, crude oil and refined petroleum products are prone to biological degradation caused by biocenoses of bacteria, fungi, algae and other microorganisms, which forms in them. In most cases, such biocenosis forms at the border of petroleum products and formation water due to temperature fluctuations in the process of storage. If such biocenosis is large, petroleum products can get jellified.
PHMG preparations are rather efficient as biocidal agents preventing biological degradation of both crude oil and refined petroleum products (such as diesel fuel, gasoline and lubricants) in the process of storage.
PHMG has a major advantage compared to other biocidal agents – it is neither toxic nor combustible (the flash point is higher than 400°C), and it burns down completely without ash.
In order to protect petroleum products against biological degradation, it is advisable to add polyethylene glycol (molar mass = 300-500) and polydimethyl diallyl ammonium chloride to PHMG salt (chloride, carbonate, oleate, stearate etc).
If added to the PHMG-based agent, polyethylene glycol facilitates homogenization and solubility of the agent in petroleum products. Polydimethyl diallyl ammonium chloride, in turn, enhanced biocidal properties of PHMG salt (10-100-fold synergistic effect).
The enhanced biocidal agent is added to petroleum products in proportion 2-50 (mass) fractions to 106 (mass) fractions of petroleum product. The agent easily blends with petroleum products and has no effect on their physical and chemical properties and performance characteristics. In addition, it ensures efficient biocidal protection of fuel and the “formation water” accumulating beneath its layer.
Conclusion: Thus, on the basis of test results and experience of commercialization of PHMG-based biocidal compositions, which have been carried out by Research Institute for Drilling Equipment of Research and Production Association “Nefteotdacha”, by Laboratory of Institute for Petroleum Chemical Synthesis, and at drilling sites if Ural-Povolzhye Oil District, it has been showcased that use of PHMG at all stages of oil production increases oil delivery rate by at least 40% and improves the oil produced by solving a wide variety of issues oil and gas companies are facing.
“Alterhim-Pro” LLC majors in production of polyhexamethylene guanidine chloride (PHMG chloride), a biocidal substance confirming to all applicable quality standards set forth in GOSTs.
For detailed information about our products in the form of crystals and solutions, go to >>> PHMG-HC >>>.
On matters of wholesale, please contact us by tel.: +7 (831) 274-66-84, or email us: office@alterhim-pro.ru.
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