A method to reduce the risk of emulsification of heavy oil during steam stimulation

Abstract

The present invention discloses a method of reducing the risk of thick oil emulsification in the process of steam throughput, including the following steps: analyzes the glue and asphalt content of thick oil samples, and determines the emulsification mechanism of the target oil field through experiments;Self -spray 不同 Pump to produce the heat loss rate indicators at different stages to determine the best time to increase the speed of oil well production; evaluate the diameter of the stratum crude oil flow based on the injection temperature and cyclical vapor injection volume, and use the sand out of the target oil field. c As the highest value of the volume of liquid liquid; after the well finish, spray self -spray, gradually let go of the oil mouth, and make the Nissan fluid speed Q as much as possible L Maximum (requiring Q L << c ); After the self -spray is ended, add the electric submarine pump, and gradually increase the frequency of pumps in time after the pump is enabled to use the maximum Nissan liquid ability Q Lmax Return to high temperature liquid (requiring Q Q Lmax << c ); According to CMG digital mold software, quantitative evaluation of different drainage speed Q L The impact on cyclical oil production, and predict the flow temperature at the bottom of the well at different discharge speed T BHP And select high temperature resistance pump (electric pump temperature resistance T max T BHP To.

Description

technical field [0001] The invention belongs to the technical field of petroleum exploitation, and particularly relates to a method of adjusting the frequency of an electric submersible pump and the size of an oil nozzle according to the effective free flow radius of the formation and the critical sand production rate in the optimal time window for steam injection thermal recovery wells. Without increasing the risk of sand production, increase the daily liquid production rate of the oil well, thereby reducing the risk of emulsification of heavy oil during steam stimulation. Background technique [0002] Thermal oil recovery technology (such as steam huff and puff, steam flooding, steam-assisted gravity drainage, etc.) is an effective technology that can greatly improve the recovery of heavy oil fields, and is an effective means of onshore heavy oil development. The Bohai Sea has a large scale of heavy oil reserves and a wide range of heavy oil viscosities (the viscosity of c...

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Problems solved by technology

[0003] The reports of existing patents and scientific literature mainly focus on the emulsification mechanism and treatment after emulsification in the process of heavy oil cold recovery development, and solve the problem of emulsification of heavy oil in the wellbore after emulsification, but it is not effective for the problem of formation emulsification solve

In the process of steam stimulation, due to the high temperature of the injected fluid (usually around 300°C) and frequent operations (steam injection first, then spraying, and then pump production), the risk of heavy oil emulsification is accelerated. The existing cold recovery process It is difficult to solve the emulsification problem of steam huff and puff wells in heavy oil reservoirs

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