Layered electric ignition method for multilayer gas injection of fire flood

Abstract

The invention belongs to the field of fire flooding process, in particular relating to a layered electric ignition method for multilayer gas injection of fire flood, comprising the following steps: (1) placing a gas injection tubular column in a fire flooding gas-injection well; (2) continuously injecting air into the gas injection tubular column; (3) determining a main gas-entry layer by means of a main gas-entry profile; (4) heating the air until the temperature of the air is above 450 DEG C, and ensuring the contents of the oxygen in tail gases of surrounding production wells to be less than or equal to 2%; (5) injecting high-temperature foams into the fire flooding gas-injection well, and when pressure increases 1-4Mpa, determining the main gas-entry layer by the means of the main gas-entry profile; (6) increasing the air injection amount by 30%, electrifying to heat the injected air until the temperature of the injected air is above 450 DEG C, and ensuring the contents of the oxygen in the tail gases of the surrounding production wells to be less than or equal to 2%; and (7) continuing to inject the high-temperature foams, ensuring the air injection intensity, and determiningthe main gas-entry layer by means of the main gas-entry profile when the pressure increases, as well as detecting the compositions in the tail gases of the surrounding production wells. According to the invention, the fire flood is utilized to realize multilayer combustion, multilayer effectiveness and high mining efficiency.

Description

technical field [0001] The invention belongs to the field of fire flooding oil production technology, and in particular relates to fire flooding under the condition of multi-layer general gas injection in fire flooding oil production. Due to the difference in air absorption capacity between layers, the gas intake volume between layers is adjusted to achieve multi-layer fire burning and multi-layer effect. Multilayer gas injection layered electric ignition method for oil production. Background technique [0002] Before fire flooding in heavy oil reservoirs, steam injection thermal recovery is generally carried out. Due to the difference between layers, the steam injected by steam injection thermal recovery is only absorbed by the oil layer with high permeability, and the other parts of the oil layer Then there is no steam, so that the high-viscosity heavy oil in the ground cannot be heated and cannot be extracted. After switching to the development mode of fire flooding, if ...

AI Technical Summary

Problems solved by technology

After switching to the development mode of fire flooding, if the general gas injection is used, the layer with high permeability tends to absorb more gas, while the layer with low permeability absorbs less gas, resulting in uneven gas absorption in each layer, which will inevitably affect the performance of oil recovery by fire flooding. Development effect

[0003] In the prior art, multi-layer reservoirs generally inject air, that is, inject gas to several development layers at the same time. Due to the differences in formation pressure, permeability, and crude oil physical properties of each layer, the air absorption between layers is uneven, and even occurs. The combustion zone in a certain layer advances sharply, which intensifies the air overlay and single-layer intrusion, reduces the vertical sweep efficiency, and affects the recovery effect of the incinerated oil layer