LABORATORY STUDY OF INVESTIGATING NUTRIENT CONCENTRATION ON MICROBIAL ENHANCED OIL RECOVERY USING IMBIBITION METHOD OF WELL BN-38, BENTAYAN FIELD

• Main Author: Immanuel, Yeremia
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/35940
• Institution: Institut Teknologi Bandung

The declining crude oil production in Indonesia leads to the application of EOR (Enhanced Oil Recovery) method. MEOR (Microbial Enhanced Oil Recovery) is one of the newest and cheapest method that make use of microorganisms. In this research, bio-stimulation method is done by adding nutrients into the well to increase the indigenous bacteria growth. Bio-stimulation will influence the bacteria community dynamics and help metabolism of bacteria so they could produce products that support the increasing of oil recovery. For those reasons, MEOR is starting to be applied in Indonesia and in this research, on well BN-38, Bentayan Field. The objectives of this research is to understand the nutrients for MEOR, its compositions, and the field wise implementation on well BN-38. Reservoir screening confirms that MEOR is applicable in well BN-38. Bio-stimulation had been done to well BN-38 and by laboratory analysis, it had reported that the optimum nutrients concentration is 5% of molasses, 0.25% of DAP, and 0.25% of NPK. It is proved that bio-stimulation had been successfully applied by looking at bacteria growth, decreasing viscosity and interfacial tension, and the increasing oil recovery. This research is done to obtain the effect of nutrients addition to the well which bio-stimulation had been done before. The examination is done in laboratory scale with artificial cores using imbibition process. Imbibition is applied to five different cores but the rock properties are relatively near to field condition. Each core is soaked in nutrient fluid for 14 days which the molasses concentration be the independent variable. Molasses concentration value is obtained by referring to the applied bio-stimulation to well BN-38 (4%, 5%, 6%, 8%, 10%). Imbibition result shows that nutrient concentration variation will have impact to the oil recovery factor. The optimum molasses concentration is 6%, which is not so far from the value obtained in previous research, with the highest oil recovery factor is 5.441%. This indicates that applying imbibition into well BN-38 increases oil recovery. Sample from well BN-38 contains grown bacteria so the addition of nutrients will push the bacteria’s metabolism up.