PERFORMANCE IMPROVEMENT OF PARTIALLY HYDROLYZED POLYACRYLAMIDE (PHPAM) BY MODIFIED ORGANOSILANE FOR ENHANCED OIL RECOVERY (EOR) APPLICATION

• Main Author: Arifin, Ihsan
• Format: Theses
• Language: Indonesia
• Subjects: Kimia
• Online Access: https://digilib.itb.ac.id/gdl/view/55388
• Institution: Institut Teknologi Bandung

In old oil wells, there is a decline in oil production so that the exploitation process is considered uneconomical. Therefore, it is necessary to increase oil recovery, called as Enhanced Oil Recovery (EOR). In the EOR technique, injection fluid such as surfactant solution or polymer solution is carried out. Both types of fluid have a role as a displacing agent for the remaining oil between the rock gaps. Until now, the most widely used polymer in EOR is polyacrylamide (PAM) and its derivatives due to its wide application and ease of modification of its compounds. Partially hydrolyzed polyacrylamide (PHPAM) is a PAM derivative which is proven to have high viscosity at low concentrations. However, PHPAM has a weakness in the form of its vulnerability to high salinity and temperature. In order to improve its thermal resistance and salinity properties, various modifications were carried out to PAM, such as adding sulfonate groups, grafting, and copolymerization. In addition to the above modifications, currently nanoparticles are also being developed as a mixture of EOR agents to improve polymer characteristics. Silica (nanosilica), alumina, and titanium oxide nanoparticles are some examples of nanoparticles that are often studied for their potential as EOR agents. Nanosilica can be used as an additive in EOR injection solutions, because it can interact with polymer molecules via hydrogen bonds and van der Waals interaction. Thus, the viscosity and thermal resistance of the polymer solution are expected to also increase. In addition to thermal and salinity resistance, it turns out that nanosilica can also increase the wettability of the rock surface by forming a nano-layer between the rock surface and the oil. This property can be analyzed by testing the contact angle alterations of the solution on a polar solid surface such as glass (SiO2). Increased wettability can reduce the adsorption rate of oil by rocks and facilitate oil mobility. In this study, a partially hydrolyzed polyacrylamide (PHPAM) was synthesized using the radical polymerization method (addition polymerization) and the partial hydrolysis method with alkaline solutions. The viscosity of the 1000 ppm PHPAM solution at 20 °C was measured at 166.69 mPa.s then increased to 173.48 mPa.s when 0.8% (w / w) of nanosilica was added. At a temperature of 80 °C, the viscosity of the solution with nanosilica reaches 147.14 mPa.s and only 120.8 mPa.s without nanosilica. To improve its characteristics, in this study a nanosilica surface modification was carried out with 3-aminopropyl triethoxysilane (APTES) and the optimum composition of this modification was obtained in the nanosilica mole ratio: APTES 0.021: 0.0005. The success of this modification was confirmed by measuring the Fourier transform infrared (FTIR) spectrum with the appearance of new signal peaks such as a vibration signal at a wave number of ~ 950 cm-1 which showed a reduction in the intensity of the silanol (Si-OH) bending vibration signal, NH2 bending vibration and CH2 is in the wave number range of 1450-1600 cm-1, and the stretching vibration of CH is in the range of 2900-3000 cm-1. The contact angle test on the glass surface of aqua dm, PHPAM solution and PHPAM solution with nanosilica gave a contact angle of 57.7; 55.4; and 36.1° respectively. PHPAM hybrid solution with nanosilica (polymer nanohybrid) has a stable dispersion stability in 1% (w / w) NaCl solution. The viscosity of a 1000 ppm PHPAM solution in 1% NaCl was measured at 7.61 mPa.s. The addition of 0.8% (w / w) nanosilica was proven to maintain the viscosity of the polymer solution at 90.24 mPa.s. This result shows that nanosilica can improve thermal and salinity resistance of polymer solutions. In addition, comparison tests with two types of commercial polymers A and B show that the nanosilica-PHPAM hybrid solution has a higher viscosity in the room temperature range up to 80 °C.