Intelligent Monitoring and Controlling Technology of Water Injection in Ultra-low Permeability Reservoir of Ordos Basin

The main reservoir of Ordos Basin, China’s second largest sedimentary basin, has three low characteristic, low permeability, low pressure, and low richness, which accounts for about a third of ultra-low permeability reservoirs. In recent years, based on the better understanding of ultra-low permeability reservoirs gradually, Changqing oilfield forms the core technology system to enhance developing ability, such as fine water injection, fracturing. By 2013, the oil equivalent is more than 50 million tons. Because of Ordos ultra-low permeability reservoir waterflood development characteristics, small directional well, low injection water volume, and regular water injection technology are pointed out high cost of supporting, complication of artificial operation, and fast falling of zonal water injection rate, so that this paper presents the intelligent injection monitoring technique. The technology including downhole automatic control water distributor, ground transmission control integration device and remote monitoring system, uses fluid wave code telecommunication and downhole flow intelligent control theory, implements the downhole separated flow automatic test, automatic adjustment, dynamic data test and stored for a long time, the ground and downhole remote wireless data transmission, oilfield digital system real-time monitoring, and other functions. This technique had been applied in profile control test in five wells in special test area of block Changqing Huaqing and success rate is 100%. Qualified rate of water injection increases to 95.0%. The result shows that the intelligent injection monitoring technique can satisfy to the fine water distribution, effective controlling of monolayer onrush, reducing invalid water cycle and mastering the dynamic process of reservoir development truly, and lay a foundation for realizing the integration of reservoir geology and engineering.