Abstract

The advantages of oil as primary energy source are still unsurpassed by any other source. After primary and secondary recovery, approximately 50% to 70% original oil in-place is left in reservoirs. The oil left is unrecoverable by conventional means. Enhanced oil recovery or tertiary oil recovery indeed is a very promising effort for the future.

The goal of this research is to develop chemicals produced from local materials and physical or chemical processes which can be used to optimize recovery and minimize residual oil in the reservoir by lowering the oil/water interfacial tension and improving mobility ratio. A laboratory experiment has been carried out to simulate the process.

The porous media used in the oil displacement process was prepared from two glass plates with dimension about 20 cm × 8 cm × 0.3 cm containing fine quartz sands. Initially it is 100% saturated with brine water and oil is then injected until water saturation (S_wc) is minimized. Then water is again injected until oil saturation (S_or) is minimized. From this point, various chemicals are then injected to flush out the remaining oil in the medium. The results are then analyzed and compared.

The experimental results show that some chemicals found in the Indonesian market can be used as EOR chemicals (surfactants, cosurfactants and polymers). The EOR chemicals can also be developed from isolating lignin from waste of pulp industries. Several other chemicals have also been developed by many processes such as pyrolysis, sulfonation, chlorination and sulfatation. The oil displacement experiments show that as much as 20% to 80% of remaining oil (after water flood) can be recovered by flooding with these chemicals. The results also show that the oil recovery depends on the chemical, the chemical concentration, the pressure and temperature, the crude oil and the brine used.