The Installation of "Intelligent Switch" in Oil Reservoir of Xinjiang Oilfield Has Remarkable Effect on Oil Stability and Water Control
As of April 19, the integrated technology of "plugging, regulating and flooding" of strong heterogeneous conglomerate reservoir developed by Xinjiang Oilfield Experimental Testing Research Institute has been applied in 7 strong heterogeneous conglomerate blocks in Xinjiang Oilfield, including Kexia and Zhongxia, and the cumulative oil increase has reached 297,100 tons, and the effect of water control and oil increase is remarkable.
In the process of waterflood development, the strong heterogeneous conglomerate reservoir is easy to form a channeling channel, which leads to inefficient or ineffective circulation of displacement fluid, and it is difficult to effectively expand the swept volume. Since 2018, the recovery efficiency research team of Xinjiang Oilfield has carried out research and development in the aspects of quantitative identification of channeling channel, optimization of the formula system of blocking-regulating flooding, and supporting technologies related to blocking-regulating flooding, aiming at the problems and difficulties faced in the process of profile regulation and flooding in the recession-controlling reservoir.
At present, the scientific research team has independently created three key technologies, such as ineffective water circulation channel and quantitative classification technology of remaining oil, and for the first time created a formula matching chart for different levels of channeling channel in conglomerate reservoir, forming a channel quantitative comprehensive characterization method integrating "geological static, production dynamic and numerical simulation". The formula system adapted to complex channels has been developed, and supporting technologies such as "well selection - early warning - tracking evaluation" have been established. This innovative technology is equivalent to the installation of a "smart switch" in the reservoir flow direction, which continuously triggers the "OFF key" in the high permeability area and the "UP key" in the low permeability area to achieve the purpose of oil stability and water control in the double high reservoir.
This technology is mainly applied to three types of conglomerate reservoirs with high permeability, low permeability and high viscosity in Xinjiang oilfield. Aiming at the difficulty of spreading and spreading in the late stage of water drive development in the middle permeable conglomerate reservoir of Class I Badaowan Formation, Qizhong District, the newly developed formula system has broken through the bottleneck of the incompatibility between injection and plugging of traditional gel-type profile control agent, and effectively solved the problem of "unplugging" of deep formation large pores. The oil increase efficiency of 27 oil Wells is up to 81.5%, and the increase in oil recovery rate in this block is up to 5.5 percentage points.
The new formula and new technology have the advantages of controllable crosslinking time, adjustable strength, variable viscosity, and wider application range of reservoir temperature and salinity, and the average efficiency of sealing strong cross-flow well groups is 86%, reaching the international advanced level.
