Heavy oil thermal recovery method using foamed gel to inhibit bottom water coning

Abstract

The invention discloses heavy oil thermal recovery method using foamed gel to inhibit bottom water coning and belongs to the technical field of oilfield exploitation and oilfield chemistry. The method includes the steps of firstly, injecting nitrogen into a producing well to form a front nitrogen slug when the period comprehensive water content of the producing well is larger than 90%; secondly, injecting a mixed system of nitrogen and a foamed gel solution to form a nitrogen-foamed gel main slug; thirdly, injecting nitrogen into the producing well to form a replacing nitrogen slug; fourthly, injecting steam, wherein the front nitrogen slug can push water of a shaft and a stratum in an area near the well to an oil layer and balance stratum pressure, the nitrogen-foamed gel main slug can effectively inhibit bottom water invasion, and the replacing nitrogen slug can replace a foamed gel blocking agent in a screen pipe and an area in near the shaft to prevent the blocking agent from solidifying near the shaft and blocking a steam injecting pipeline and an oil extraction pipeline. By the method, bottom water coning speed can be reduced, steam wave coefficient and utilization rate can be increased, and oil reservoir exploitation effect can be improved.

Description

technical field [0001] The invention relates to a heavy oil thermal recovery method in which gel foam suppresses bottom water coning, and belongs to the technical fields of oilfield exploitation and oilfield chemistry. Background technique [0002] 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 nickel and vanadium is also relatively high, so it has a large specific gravity and high viscosity. It has the characteristics of high temperature and low freezing point, and it has the characteristics of Newtonian fluid in a wide temperature range. Due to the high viscosity of heavy oil at the formation temperature, it is difficult to flow autonomously in the original formation, and there a...

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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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