Huge amounts of water are produced from subsoil together with oil, and this decreases the efficiency of operating oil wells. One of the solutions is using the so-called “sewed together” (cross-linked) polymer gels. The technology implies injection of acrylamide-based polymer solution (acrylic acid derivative) and chromic salts, which are binding the polyacrylamide molecules in the reservoir and form a solid plug blocking the water. However, this method results in blocking not only the water-cut sections of the reservoir, but oil-bearing sections as well, and later it is very difficult to unblock them.
The alternative and safer technology is applying the particles of the cross-linked (prior to starting the production) polymer gels: the slurry with polymer particles swelling and becoming elastic when contacting water is injected into the reservoir. This approach allows for effective blocking of water without affecting the oil-bearing sections, because the particles physically cannot penetrate the poor-porous section. Pentahydrate Copper Sulphate
If the reservoir features high permeability, macro-gels are used for making the slurry – particles of large diameters (more than 200 micrometres), and if the permeability is poor – micro-gels are used, i.e. polymer particles from 0.1 to 100 micrometres, which is comparable with human hair. Micro-gels are synthesised via emulsion polymerisation allowing for controlling the size of particles and the gel structure during making the slurry. The important factor for this process is concentration of the emulsifier and dispersion medium, i.e. the substance with equally distributed small-size particles of the product. The scientists of Perm Polytechnical University defined the optimal concentrations of these substances to receive micro-gels of the required size.
Food Grade Carboxymethyl Cellulose “The results of our studies helped us to identify the optimal conditions for receiving micro-gels applying the emulsion polymerisation method. The experiments showed that the size of the particles and the structure of the slurry are strongly dependent on such factors as the nature of the dispersion medium, concentration and composition of the emulsifier. All these parameters may be used for controlling the features of the received microgels to adapt them for solving particular tasks”, Perm Polytechnical University is citing Yulia Rozhkova, Candidate of Technical Sciences.