CHARACTERIZATION OF PARTICLE STABILITY AND POLYMER REOLOGY OF NANOHYBRID NANOSILICA/ PARTIALLY HYDROLYZED POLYACRYLAMIDE FOR ENHANCED OIL RECOVERY (EOR) APPLICATION

• Main Author: Rabriella, Nisa
• Format: Theses
• Language: Indonesia
• Subjects: Kimia
• Online Access: https://digilib.itb.ac.id/gdl/view/55113
• Institution: Institut Teknologi Bandung

Currently, oil prices are increasing due to declining oil production worldwide, so there is a need for alternatives to increase oil production. Oil is still a source of energy that plays an important role throughout the world so that consumption and demand is still high. One way that is being developed is by using used oil wells that have undergone primary and secondary recovery, namely Enhanced Oil Recovery (EOR). A method that is being developed and is receiving more attention is chemical injection, specifically known as polymer flooding. Polymers commonly used in this application are partially hydrolyzed polyacrylamide or commonly known as partially hydrolyzed polyacrylamide (HPAM). Unfortunately, there are still deficiencies in terms of resistance to extreme conditions in oil wells, namely high temperatures and salinity. For this reason, the development of HPAM was carried out by adding nanoscale materials in the form of nanosilica particles, so that a nanohybrid polymer was formed. In addition, to increase the economic value, this material must also produce high oil yield by increasing the ability of the solution to sweep the oil and replace the pore surface of the sand grains that were originally wet with oil to become wetted with water. First, characterization was carried out by observing the effect of particle size (30 and 70 nm) and ultrasonication time (20 and 40 minutes) during the disperse process on the increase in viscosity value. Furthermore, to see the stability of the dispersion of silica nanoparticles in the HPAM polymer solution, characterization of the hydrodynamic diameter, transmittance, and zeta potential was carried out focused on the size of the nano silica particles of 30 nm and the ultrasonication time of 20 minutes with concentrations varied from 0.1 – 1,6 % w/v. The hydrodynamic diameter can describe the amount of cluster formation when the temperature conditions or the dispersing medium are different. Transmittance can describe the occurrence of a sedimentation process when the cluster diameter reaches its critical point. Then to describe the interaction of van der Waals forces between particles and the magnitude of the charge density of the interactions between the particles, a zeta potential value test is carried out. Furthermore, to see the flow and deformation properties of the nanohybrid polymer solution, it was also carried out to characterize its rheological properties. The rheological properties based on the viscosity data can identify the flow properties and resistance of the nanohybrid polymer solution to mechanical forces in the form of varied shear rates. This viscosity value can be processed using the Carreau-Yasuda model to see the plateau value of viscosity with shear forces close to zero (?0), infinite viscosity (? ), relaxation time (?), and flow properties (n). Then the rheological properties based on the shear modulus data can identify the structural conformation schemes that are formed between the silica nanoparticles and the HPAM solution. The results of the characterization of the dispersion stability through testing the hydrodynamic diameter, transmittance, and zeta potential showed that silica nanoparticles were well dispersed and homogeneous in the HPAM solution. This applies equally to the conditions of the test temperature of 20 and 80 °C and the dispersing medium in the form of water and 1 % w/v NaCl. The results of rheological characterization based on viscosity data showed that the nanohybrid polymer with a concentration of 0.8 % w/v had resistance to shear rates and high temperatures of up to 90 °C in water and 1 % w/v NaCl. This is due to the formation of a net structure between HPAM and nanosilica through covalent and hydrogen bonds, which was confirmed by the results of the rheological properties test based on the shear modulus value. Thus, it can be concluded that a nanohybrid polymer composition with high mechanical and chemical resistance has been obtained.