Deep profile control method for fractured oil reservoir

Abstract

The invention relates to a deep profile control method for a fractured oil reservoir. By the method, the recovery ratio of crude oil can be increased. Four sections of plugs are provided for plugging different types of fluid-channeling channels, wherein in the first section of plug, a high-strength solidification system is used for plugging fracture; in the second section of plug, inorganic gel is used for plugging microfracture or large pores; in the third section of plug, a water drive flow direction changing agent and weak gel are used for further filling the fracture and the pores so as to displace residual oil in the pores; and in the fourth section of plug: a strong gel YQY plugging agent is used for plugging the fracture near the wellbore. By the method, the problem that the oil well is flooded by water caused by the fracture of the fractured oil reservoir water injection well can be effectively solved; the water absorption condition of a storage layer is changed; the utilization ratio of the injected water is increased; the swept volume is enlarged; and the oil displacement efficiency is improved finally.

Description

technical field [0001] The invention relates to a deep profile control method of a fractured oil reservoir for increasing the recovery rate of crude oil. Background technique [0002] Changqing Oilfield carried out technical research on water flooding flow direction changing agent + hydrophobic association polymer deep composite profile control system, and achieved certain breakthroughs. Through practical application, it has become an important means of controlling oil well water in Triassic fractured reservoirs and Jurassic large-pore high-permeability reservoirs. However, the application situation shows that the effect of these technologies is better in the initial stage, and the effect of the later stage is getting lower and lower, mainly because the selection of the measure wells follows the principle from easy to difficult. As the complexity of formation water flooding increases, plugging adjustment technology shows inadaptability. [0003] The water flooding flow dir...

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Problems solved by technology

However, the application situation shows that the effect of these technologies is better in the initial stage, and the effect of the later stage is getting lower and lower, mainly because the selection of the measure wells follows the principle from easy to difficult. As the complexity of formation water flooding increases, plugging adjustment technology shows inadaptability

[0003] The water flooding flow direction changing agent + hydrophobic association polymer system is mainly used in profile control of fractured water injection wells, in which the water flooding flow direction changing agent mainly plays a blocking role in the fractures, and has the characteristics of blocking but not dead, but because its underground form is between Between colloids and solids, the underground migration distance is limited by the formation to a certain extent, and deep profile control cannot be realized

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