The laboratory performance properties of the colloidal dispersion system are described in the proposed paper. This paper deals with the improvement and application of a new technology to EOR. This technology is applicable to high salinity, high temperature and severe heterogeneity reservoir.
The essence of this technology is to decrease the water cut of production wells and attain the result of oil production and recovery enhancement by injecting an improved micelle dispersions system. According to lab test, this colloidal dispersion system is a pseudoplastic fluid with temperature tolerance, salinity tolerance, shearing resistance, stability and low cost. The lab experiment result shows oil recovery is improved by 8—10%.
The information of lab study and field application relative to this technology has been presented at the 2000 International Symposium on Petroleum Engineering. The previous technology has a defect of crosslinking to polymer's wide applicability, now this system has been improved in its properties. The new micelle dispersions system can satisfy all polymer in use and form stable weak gel system. It can keep stable when reservoir temperature is 90°C, water salinity is 80000mg/L (Ca2++Mg2+≤ 2000mg/L).
A pilot was conducted in fault—block Xin 50 of Dongxin oil field. There are 4 injection wells and 7 corresponding production wells.in the area The viscosity of aimed formation oil is 80mPa.s, the temperature is 90 °C, the salinity of reservoir is 44100mg/L, well spacing is 300m. Some production wells were effective after 2 months injection during the successive injection of this improved micelle dispersions system. Water cut of typical effective well was decreased by 34.1%. Oil production per day increased 30 ton.
Pilot test shows that this technology has better enlarge commercial application potentiality and economic value. It will be applied in others similar blocks on great scale in the future.