Method for using gel foaming agent for suppressing bottom water coning of heavy oil thermal recovery

Abstract

The invention discloses a method for using a gel foaming agent for suppressing the bottom water coning of heavy oil thermal recovery, and belongs to the field of oilfield exploitation and oilfield chemical technology. The method comprises the following steps: 1) when the periodic comprehensive water content of a production well is greater than 90%, injecting nitrogen into the production well to form a front nitrogen slug; 2) continuing injecting a mixed system of nitrogen and a gel foaming agent solution into the production well to form a nitrogen-gel foam main slug; 3) injecting nitrogen intothe production well to form a replacing nitrogen plug; and 4) injecting steam. The front nitrogen slug can push the water in a wellbore and in the immediate vicinity of the wellbore to an oil layer to balance formation pressure, the nitrogen-gel foam main slug can suppress the bottom water intrusion, and the replacing nitrogen slug can push a gel foam plugging agent out of a screen tube and a near-wellbore zone so as to prevent the plugging agent from consolidating in the vicinity of the wellbore and blocking the steam injection and oil production passages. The method can delay the bottom water coning speed, improves a steam wave sweep coefficient and a utilization rate, and improves the development effect of a reservoir.

Description

[0001] This application is a divisional application of the following application, [0002] The filing date of the original application: August 23, 2016, [0003] The application number of the original application: 201610709754.3, [0004] Invention title of the original application: a method for thermal recovery of heavy oil by gel foam suppressing bottom water coning. technical field [0005] The invention relates to a method for using a gel foam agent for suppressing bottom water coning in thermal recovery of heavy oil, and belongs to the technical fields of oilfield exploitation and oilfield chemistry. Background technique [0006] Heavy oil is also called heavy crude oil or high viscosity crude oil, crude oil d 4 20 >0.92. In heavy oil, especially straight-chain waxy hydrocarbons, the content of light distillates is low, the content of colloids and asphaltene is high, the content of elemental compounds such as sulfur, oxygen, nitrogen, and metal components such as...

AI Technical Summary

Problems solved by technology

This method is suitable for high water-cut or ultra-high water-cut horizontal wells. It can achieve high-strength deep sealing, effectively reduce the water content of horizontal wells, and increase the productivity of oil wells. To seal the water outlet point, only general plugging measures can be taken, and selective plugging agent must be used, and due to the influence of the completion method of the screen, it is impossible to use granular plugging agent to plug the bottom water

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