Method for exploiting heavy oil reservoir by strengthening in-situ oil combustion

Abstract

The invention provides a method for exploiting a heavy oil reservoir by strengthening in-situ oil combustion. The method includes: arranging a vertical injection-production well pattern including an injection well and a production well in an exploiting area of the heavy oil reservoir; lighting oil layers by means of chemical ignition or electric ignition; continuously injecting air from the vertical injection well to maintain combustion; continuously exploiting through the production well; injecting 1-3m<3> of hydrogen peroxide slug 30-50% in mass concentration when every 100000-150000Nm<3> of air is injected in the injection well, and alternately injecting in this way; and closely monitoring oxygen content and temperature of gas produced by the production well, and timely adjusting slug injection parameters. Hydrogen peroxide rapidly decomposes at high temperature in the oil layers, so that a large amount of heat and oxygen is provided for oil layer combustion, strengthened combustion is achieved, heavy oil combustion rapidly and favorably crosses a low-heat area to enter a high-temperature combustion area, and continuous oil combustion exploiting is achieved.

Description

technical field [0001] The invention relates to a method for injecting hydrogen peroxide to intensify the exploitation of heavy oil reservoirs by burning oil layers, and is mainly used for the development of heavy oil reservoirs to increase the recovery rate of crude oil. Background technique [0002] The main development technologies of heavy oil reservoirs are steam injection development technology (steam huff and puff, steam flooding, steam assisted gravity drainage) and air injection high temperature combustion development technology (combustion reservoir recovery technology). Steam injection development technology, due to the large heat loss along the steam injection process from the outlet of the surface boiler to the bottom well reservoir, the dryness of the steam entering the heavy oil reservoir, especially the medium and deep heavy oil reservoir is low, and the steam spreads The volume is often small, resulting in high energy consumption for steam injection developm...

AI Technical Summary

Problems solved by technology

However, in the combustion oil layer recovery technology, according to the heat release test results of the oxidation reaction of crude oil in different temperature ranges, it is shown that the combustion of crude oil needs to start from the low temperature (oxidation) zone (see figure 1 Region A in the region, where heavy oil undergoes low-temperature oxidation reaction) jumps to the high-temperature (combustion) region (see figure 1 The area C in the middle, in which the high-temperature combustion reaction of heavy oil occurs) can achieve successful high-temperature combustion, and the temperature range between the low-temperature area and the high-temperature area (see figure 1 The area B in the middle, hereinafter referred to as: low-heat area), is affected by the oxidation reaction components in this area, and the heat release of crude oil is significantly reduced. If it reaches the ignition point, the surrounding crude oil will not be able to ignite. At the same time, if the oxygen concentration in this area does not reach the minimum oxygen concentration required for combustion, the combustion will be extinguished, the continuous combustion process will stop, and the mine test will fail.

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