Method for improving shale oil reservoir recovery efficiency by cracking reservoir through catalytic oxidation combustion

Abstract

The invention discloses a method for improving shale oil reservoir recovery efficiency by cracking a reservoir through catalytic oxidation combustion. The method comprises the following steps that a catalyst is selected; a mixture slug of a catalyst and an organic solvent is injected into a shale oil reservoir subjected to staged fracturing of a horizontal well, and the well is soaked for a period of time; and then air is injected into the shale oil reservoir, the shale reservoir is fractured through catalytic oxidation / combustion, and the flow conductivity of shale oil is enhanced. By means of the method for improving the shale oil reservoir recovery efficiency by cracking the reservoir through catalytic oxidation combustion, the shale oil reservoir ignition difficulty can be obviously reduced, the combustion efficiency and the combustion front edge stability can be improved, the shale is fractured by fully utilizing the oxidation / combustion chemical effect, the synergistic effect is generated with an existing hydraulic fracturing method, the reservoir pore-fracture structure is improved, and the recovery efficiency is improved.

Description

technical field [0001] The invention relates to the technical field of shale oil development, in particular to a method for improving the recovery rate of shale oil reservoirs by catalyzing oxidative combustion to crack reservoirs. Background technique [0002] According to the evaluation results of the International Energy Agency, China has abundant shale oil reserves, with recoverable resources reaching 43.52×108 tons, ranking third in the world. However, due to the poor physical properties of shale oil reservoirs, extremely low pore-throat ratio and permeability, and various pore types and fluid occurrence states, it is difficult to implement water flooding and chemical flooding technologies, and conventional gas injection is limited; shale reservoirs are thin The development of interbeds and bedding makes it difficult to form a complex fracture network in fracturing, and the recovery degree of volume fracturing is low (5%-10%). In 2018, Sheng Jiaping and others first pr...

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Problems solved by technology

However, due to the tight nature of shale reservoirs and the presence of kerogen, the method was directly introduced into shale reservoirs and found that its impact on recovery and combustion front stability was not stable, high and low at times, and difficult to predict. It is not suitable for shale oil reservoirs, so we conducted further research on the basis of this patent and perfected the method to make it suitable for shale oil reservoirs

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