Plugging agent with double plugging function and filling method thereof

Abstract

The invention provides a plugging agent with a double plugging function and a filling method thereof. The plugging agent comprises a foaming agent, a foam stabilizer, a cross-linking agent, gas and water, wherein the foaming agent is sodium dodecyl sulfate as an anionic surfactant, the foam stabilizer is water-soluble polyacrylamide with relative molecular mass of 11.6*106, and the cross-linking agent is a chromium cross-linking agent and comprises Na2Cr2O7 and Na2SO3. The filling method comprises the following steps: sequentially filling a far-well foaming liquid comprising the foaming agent, the foam stabilizer and the cross-linking agent, transition-area foaming liquid and near-wall foaming liquid; then, filling HPAM (hydrolyzed polyacryamide) over-top replacing liquid and nitrogen; and finally, filling clear water as the over-top replacing liquid for completely replacing the nitrogen into a layer of the earth. The gel foam plugging agent not only has Jamin effect of nitrogen foam, but also has a selective plugging function of polymer gels, improving foam stability by using the gel as an outer phase and increasing the effect and the effective period of a plugging measure.

Description

Technical field: [0001] The invention relates to an oilfield chemical agent and an injection method thereof, in particular to a chemical agent and an injection method for water plugging of high water-cut oil wells. technical background: [0002] At present, after most oilfields enter the high water-cut or ultra-high water-cut water injection development stage, the injected water and edge water often break into the oil well along the high permeability layer, resulting in a decline in oil well productivity and seriously affecting the water flooding development effect. Conventional oil well water plugging technologies such as mechanical sealing of high aquifers, chemical water plugging, etc., due to the artificial abandonment of the remaining geological reserves of high water-bearing layers, small plugging radius, and insufficient plugging depth, oil well water plugging measures decline rapidly. Failure to fully develop the potential of oil layers will greatly affect the improv...

AI Technical Summary

Problems solved by technology

[0002] At present, after most oilfields enter the stage of high water-cut or ultra-high water-cut water injection development, the injected water and edge water often break into the oil well along the high permeability layer, resulting in a decline in oil well productivity and seriously affecting the water flooding development effect

Conventional oil well water plugging technologies such as mechanical sealing of high aquifers, chemical water plugging, etc., due to the artificial abandonment of the remaining geological reserves of high water-bearing layers, small plugging radius, and insufficient plugging depth, oil well water plugging measures decline rapidly. The potential of oil layers cannot be fully utilized, which greatly affects the improvement of oilfield water flooding recovery

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