Method for plugging water from oil reservoir fractured water logging oil well developed by injecting water into low-permeable reservoir stratum

Abstract

The invention discloses a method for plugging water from an oil reservoir fractured water logging oil well developed by injecting water into a low-permeable reservoir stratum, which relates to the technical field of reform technologies for controlling water, stabilizing oil and increasing yield on the oil well in the oil exploitation process. The method comprises the following steps of: (1) preparing four plugging agents with different strengths of DQ-1, DQ-2, LDN-1 and LDN-2 on site; continuously pressing the plugging agents of DQ-1 and DQ-2 prepared in the step (1) into a natural micro fracture of the stratum by using an alternate injection process; (3) pressing the plugging agent of LDN-1 prepared in the step (1) into the natural fracture and an artificial fracture; and (4) pressing the plugging agent of LDN-2 prepared in the step (1) into the artificial fracture for sealing. The service temperatures of the four plugging agents are all 0-75 DEG C; the concentrations of the four plugging agents are 0.5-5 percent; and the pump injection pressure of a connecting truck or a fracturing truck is small than 30MPa. By using the invention, the yield increase and the stabilization of the low-permeable reservoir stratum can be effectively realized, the technical effect of the recovery rate of an oil layer can be improved and the effective plugging of the natural fracture and the artificial fracture can be realized.

Description

technical field [0001] The invention relates to the technical field of transformation technology for controlling water, stabilizing oil and increasing production of oil wells in the process of oil exploitation, in particular to a water flooding oil water plugging method for low-permeability reservoir water injection development reservoir fractures. Background technique [0002] In the development process of low-permeability fractured oilfields, due to the long-term water injection development and the influence of formation fractures (natural micro-fractures and artificial fractures), the formation heterogeneity is extremely serious, so that the injected water often flows along high-permeability fractures, while This low-efficiency water injection not only affects the degree of crude oil recovery, but also increases the cost of oil recovery due to energy consumption, treatment of produced fluid, and corrosion of pipelines. [0003] Conventional water plugging technology gener...

AI Technical Summary

Problems solved by technology

It effectively solves the problem that the existing artificial barriers cannot effectively avoid water flooding of oil wells and the problem that the fracturing fluid with diverting agent or temporary plugging agent does not reduce viscosity when it encounters water base and the settlement speed is slow

[0005] On the one hand, this kind of water plugging technology is not suitable for plugging all low-permeability fractured oil layers with a burial depth of 800m-2500m. On the other hand, the plugging agent has a small affected area and a short validity period. , the transformation effect is not good, and the effective sealing of natural and artificial fractures cannot be achieved

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