Oil layer gas injection method

Abstract

The invention discloses an oil layer gas injection method. The oil layer gas injection method comprises the following steps: injecting a foaming agent water solution into an oil layer to be mined through an injection well; injecting air into the oil layer to be mined through the injection well after the foaming agent water solution is injected, wherein the injection speed of the foaming agent water solution is 150-300 cubic meters per hour, the injection time of the foaming agent water solution is 2-5 hours, and the injection speed of the air is that 200-300 normal cubic meters of air is injected into the oil layer with the thickness of every one meter every day; stopping injection of the air when the volume ratio of the air injected inside the oil layer to be mined to the combusted crude oil is 200-500. Through the oil layer gas injection method provided by the invention, the producing extent of each oil layer is balanced during multi-layer burning.

Description

technical field [0001] The invention relates to the field of oil recovery by burning oil layers, in particular to a gas injection method for oil layers. Background technique [0002] At present, the technology of burning the oil layer is usually used to extract oil. The technology of burning the oil layer is to inject air into the oil layer and ignite the oil layer, and then reduce the viscosity of the crude oil through the heat generated by the combustion of the oil layer to extract the crude oil. Combustion technology usually includes single-layer fire and multi-layer fire. Since there are different oil layers at different depths of the oil reservoir, there is an interlayer between the oil layers to separate them. When the longitudinal thickness of the interlayer is greater than 3 meters, the oil layer can be separated by the packer lowered in the gas injection well, and oil can be exploited by single-layer burning after being separated by the packer. When the longitudin...

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Problems solved by technology

In the subsequent multi-layer fire, the injected air has a relatively low specific gravity, and the injected air will preferentially enter the large pores, and most of the injected air will enter the upper oil layer, leaving less air in the lower oil layer, or even The ignition conditions cannot be met, which leads to the fact that some oil layers have a higher degree of production and some oil layers have a lower degree of production during multi-layer fires, resulting in unsatisfactory production effects

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