Petroleum Science: Green Biofracturing Fluid System

China's petroleum scientists and technicians are making efforts to comprehensively innovate the drilling fluid system, and the bio-fracturing fluid system developed has the advantages of environmental protection, increased production and efficiency, and energy conservation and emission reduction.

The clean fracturing fluid viscoelastic surfactant (VES) technology has been successfully applied in fracturing fluids. It is a micellar solution of a quaternary ammonium salt cationic surfactant dissolved in saline. The micelles are mainly in the form of pods or flexible oblong rods, highly intertwined with each other to form a reversible three-dimensional network structure, and exhibit a special rheological, viscoelastic and high viscosity under low shear and shear dilution, thixotropy. Wait. Because it does not contain polymer, the system itself has clay anti-expansion ability, and it can break rubber when it meets oil and water.

However, such fracturing drilling fluids still cannot use a large number of environmentally unfriendly chemical aids. The use of a large number of surfactants brings great difficulties to the environmental protection of the ground. At the same time, the amount of fracturing works is large, the construction conditions are harsh, and the requirements of on-site equipment are high. Unclean water or base tanks will affect the construction results, and surfactant filter cakes will be formed under high pressure. Currently, there is no effective gelation solution to relieve the damage. Plugging means. In addition, the use of some inferior chemicals not only brings great harm to the reservoir, but also adds cost to the environmental treatment of the fracturing fluid discharged to the ground.

In traditional guar drilling fluid systems, due to incomplete gel breakage, except for guar gum, the main well-introducing fluid components are organic and inorganic hard-to-degrade harmful substances. Both returning and re-injecting have adverse consequences on both the reservoir and the environment.

Relevant scientific researchers in China have made in-depth studies and understanding of various types of drilling fluid systems, and have made changes to the existing fracturing systems. The green bio-fracturing system uses bio-fractured materials instead of toxic and hazardous chemical materials, which has significant environmental advantages, as well as the ability to restore the original physical properties of the formation and activate the oil reservoir productivity.