Oil recovery method using hydrothermal cracking combined with downhole authigenic mixed-phase thermal fluid

Abstract

The invention relates to an oil recovery method combining hydrothermal cracking and downhole self-generated miscible thermal fluid, which relates to the field of oil recovery technology. Inject the cracking catalyst and steam into the oil layer through the injection well to trigger the hydrothermal cracking reaction, then carry out the borehole and spontaneous oil recovery, enter the downhole miscible thermal fluid generator in the injection well and complete the well and arrange the supporting ground supply system for displacement oil recovery , this method uses hydrothermal cracking self-spraying oil recovery, which can make the heavy oil near the wellbore that is difficult to flow be recovered, and reduce the injection pressure for the subsequent injection of miscible thermal fluid, and the heavy oil can be effectively improved by injecting miscible thermal fluid. reduce the content of heavy matter, colloid, and asphaltene in the heavy oil, so that the heavy oil in the far-well area can be driven and produced, and the heavy oil in the near-well and far-well areas in the heavy oil reservoir is separated by two methods. Viscosity reduction can effectively increase oil recovery and oil production speed, and reduce the cost of heavy oil and super heavy oil reservoir development.

Description

technical field [0001] The invention relates to the technical field of oil recovery in oilfields, in particular to an oil recovery method combining hydrothermal cracking and downhole self-generated mixed-phase thermal fluid. Background technique [0002] Heavy oil has a high content of heavy components, resulting in high viscosity and poor fluidity. Based on the strong sensitivity of heavy oil viscosity to temperature, thermal oil recovery is generally considered to be the most effective means of exploiting heavy oil reservoirs. Most oil fields in my country use steam huff and puff However, under the condition of steam injection, the viscosity drop of heavy oil is only temporary. With the heat loss and temperature drop in the process of injection and production, the viscosity of heavy oil gradually rises, which gives the wellbore lift and Ground technology presents its own set of difficulties. [0003] Under high temperature conditions above 300°C, heavy components in heavy o...

AI Technical Summary

Problems solved by technology

[0004] The hydrothermal cracking reaction is very slow and complicated. It is difficult to achieve the purpose of upgrading heavy oil by relying on this spontaneous process. Therefore, it is necessary to add a cracking catalyst to change the reaction process and speed up the reaction. For heavy oil hydrothermal cracking technology, many researches at home and abroad have devoted In order to develop high-efficiency transition metal catalysts, under the condition of steam injection, the minerals contained in the formation itself are a kind of cheap catalysts, which can promote the hydrothermal cracking reaction of heavy oil. This kind of mineral-based heterogeneous catalysts is usually used internationally. It is called geological catalysis. Although the catalysis of oil reservoir minerals is small, it has become the frontier topic of hydrothermal cracking technology at present due to its low cost and the synergistic effect of chemical agent catalysis.

Images