Abstract
In recent years polymer flooding has been field tested extensively and has succeeded in many Enhanced Oil Recovery (EOR) projects. The use of synthetic polymers in EOR is undesirable from an environmental perspective. Further, due to limitations of the existing synthetic polymers in high temperature and high salinity conditions, thermal degradation among other drawbacks, biopolymers have attracted the attention of the petroleum Industry. Recently, the use of biopolymer schizophyllan for polymer flooding operations has been found to have advantages such as stability under high temperature and high salinity conditions. This biopolymer is commercially produced from the fungus schizophyllum commune using glucose as a carbon source via fermentation process and is currently available in small quantities as an expensive purified pharmaceutical and cosmetic grade material. Our study aims to utilize locally available sources in Malaysia to synthesize the above biopolymer making it cost effective. The fungus schizophyllum commune commonly known as "cendawan kukur" in Malaysia was used as a starting material. Different production media containing carbon and nitrogen sources, required for the growth of the fungus, were utilized for the biopolymer production. Initial viscosity studies carried out using rheometer showed that, the production media comprising sago starch as the carbon source and potato extract as the nitrogen source, showed the highest viscosity value of 0.12 Pa-s at 30°C. Therefore, this media was chosen as the most favorable media for the biopolymer production. Further, the biopolymer extracted from this media was identified by Fourier Transform Infrared (FTIR) spectroscopy which showed similarity in chemical structure with reference to commercial schizophyllan data from the literature. The results from Thermo Gravimetric (TG) analysis showed that the biopolymer was thermally stable at higher temperatures similar to that of the commercial schizophyllan. This study would develop the utilization of locally available sources to produce schizophyllan for polymer flooding operations by explaining various characteristics so as to meet the expected requirements for it to be applied in an oil field.
