Heavy oil reservoir water-coning-control water plugging method

Abstract

The invention provides a heavy oil reservoir water-coning-control water plugging method. The method comprises the following steps: determining a water-outlet oil layer caused by bottom water coning; injecting gas with predetermined quantity into the water-outlet oil layer; and injecting a chemical water plugging agent into the water-outlet oil layer injected with the gas for selective water plugging. Wherein the chemical water plugging agent is composed of a first slug and a second slug; and according to the mass percent concentration, the first slug comprises 0.4-0.5% polyacrylamide, 2-3% rubber particles and 1-3% tanning extract powder, and the second slug is an aqueous solution prepared from 15-25% resin and fly ash. According to the heavy oil reservoir water-coning-control water plugging method provided by the invention, before the chemical water plugging agent is injected into the water-outlet oil layer caused by bottom water coning for selective water plugging, the gas with a certain pressure is injected into the water-outlet oil layer in advance, and the injected gas preferentially occupies the top space of the water-outlet oil layer to drive heavy oil at the top of the oil layer to move downwards, so that rapid water coning control is realized.

Description

technical field [0001] The invention belongs to the technical field of oil reservoir water shutoff, in particular to a method for pressing cone water shutoff in heavy oil reservoirs. Background technique [0002] Bottom water reservoirs account for a large proportion of oil reservoirs in my country, and their reserves are quite abundant. In addition to a large number of natural bottom-water reservoirs, as oilfields enter secondary and tertiary production, the development characteristics of more oilfields tend to be bottom-water reservoirs. Bottom water reservoirs have the characteristic that all oil-bearing areas are in contact with bottom water. This is not only the advantage of bottom water reservoirs in development than other reservoirs, but also the difficulty in the development of bottom water reservoirs. The large contact area between the reservoir and the bottom water greatly enhances the ability of the bottom water to invade the reservoir, and the formation energy c...

AI Technical Summary

Problems solved by technology

Before adopting the selective water shutoff process for water shutoff, usually the bottom water should be crushed when the cone enters a certain height, and the current commonly used method for crushing the cone is shutting down the well and crushing the cone. The effect is generally unsatisfactory. Not only will the oil production of the oil well be affected during the well shut-in period, but the water content of the oil well will quickly rise to the level before the well shut-in and pressure cone after the well is opened; Due to the poor gravity of medium oil and water, affected by factors such as salinity and long-term contact of bottom water with heavy oil, the density of bottom water will tend to increase in the direction of heavy oil density, resulting in a smaller oil-water density difference and a decrease in cone pressure. Extended cone time and shut-in time, ultimately impacting production

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