A method for water flooding under microfracture pressure in low/ultra-low permeability reservoirs

Abstract

The invention relates to the technical field of oil recovery, in particular to a method for water flooding and oil displacement in low / ultra-low permeability reservoirs under microfracture pressure. According to the characteristics of low / ultra-low permeability reservoirs, intelligent software is used for online real-time dynamic monitoring and automatic control of water injection pressure, water injection volume and temperature, so that a large number of micro-fractures are formed in the formation, and water is injected under micro-fracture pressure to make the formation full of micro-fractures. If some micro-fractures and natural fractures are connected in series to form high-permeability channels, the plugging agent is injected immediately for plugging. The final result is that the formation is full of micro-fractures, and the injected water can be easily injected without rushing along the high-permeability channels. Improve the sweep coefficient of injected water and enhance the recovery factor.

Description

technical field [0001] The invention relates to the technical field of oil recovery, in particular to a method for water flooding and oil displacement in low / ultra-low permeability reservoirs under microfracture pressure. Background technique [0002] Low / ultra-low permeability reservoirs are characterized by low permeability, low porosity, and high seepage resistance. The characteristics of the mine field are "no injection, no production". The development reflects the low single-well production and rapid decline in production capacity of oil wells , difficult to stabilize production, difficult to replenish energy and low recovery. [0003] The conventional method is to perform fracturing on the formation of low / ultra-low permeability reservoirs, that is, to open artificial fractures inside the formation to improve the conductivity of the formation. Although this method can achieve the purpose of increasing production in a short period of time, it is easy to form high-permea...

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Problems solved by technology

[0003] The conventional method is to perform fracturing on the formation of low / ultra-low permeability reservoirs, that is, to open artificial fractures inside the formation to improve the conductivity of the formation. Although this method can achieve the purpose of increasing production in a short period of time, it is easy to form high-permeability fractures. The channel causes water flooding, and the goal of enhancing oil recovery will not be achieved in the long run

[0004] At present, the productivity, inflow performance, seepage characteristics, fracturing methods and well type selection of low / ultra-low permeability reservoirs have been extensively studied, but the water flooding technology under the micro-fracture pressure of low / ultra-low permeability reservoirs has not been studied. is researched and is a gap in the field of research

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