Method for controlling bottom water fingering by foam

Abstract

The invention discloses a method for controlling oil well bottom water coning by foam. In the method, a mass of foam is injected at the oil-water boundary of an oil well so that a foam plugging area is formed. In the technical technology of controlling oil well bottom water coning by foam in the invention, a mass of foam is injected at the oil-water boundary of the oil well so that a stable foam plugging band is formed. The injected foam has the characteristic of selective water plugging that the foam is broken when meeting oil and is stable when meeting water, so that the foam is comparatively stable at the oil-water boundary and is not easy to be broken and raising of bottom water can be efficiently plugged; and at an oil reservoir, the foam stability becomes weakened due to damage of the oil to the foam, and the foam is easy to be broken, but the output of crude oil in the oil layer is not influenced.

Description

technical field [0001] The invention relates to a method for controlling water coning at the bottom of an oil well during oil field exploitation. Background technique [0002] With the continuous development of oilfields, the water content of many old oilfields continues to rise, especially for oilfields with bottom water reservoirs. After the oilfields are put into production, with the gradual release of reservoir pressure, the pressure of the reservoirs gradually decreases, and the energy of the bottom water is greater than the energy of the reservoirs. At the same time, due to the difference in oil-water viscosity, the bottom water gradually penetrates into the oil layer. For a single oil well, the water cut will rise sharply, and for the entire oilfield, the oil-water interface will rise as a whole, the water cut will continue to rise, and the oil production will continue to decline. yield. Especially for some bottom water reservoirs with high crude oil viscosity, the w...

AI Technical Summary

Problems solved by technology

This mining method is easily restricted by well conditions. Once the wellbore has problems such as casing deformation and dislocation, large tools such as packers cannot be lowered into the wellbore.

In addition, the mechanical water plugging method only seals the lower water outlet layer in the wellbore, but cannot seal the bottom water outside the wellbore. If the properties of the interlayer between the oil and water layers are not good, the Continue to produce, the bottom water will continue to cone along the formation to the oil well

Therefore, the mechanical water plugging method cannot achieve the desired effect on oil wells with bottom water coning