Oil-water mineral interface modifier for thick oil thermal recovery and preparation method thereof

Abstract

The invention relates to a chemical agent used in a thick oil recovery process, in particular to an oil-water mineral interface modifier which is used in thick oil thermal recovery and has the functions of changing wettability of a reservoir and reducing viscosity by emulsification. The oil-water mineral interface modifier is prepared by the following steps: carrying out free radical polymerization on toluene diisocyanate and polyoxyethylene ether in water to obtain a single polyurethane intermediate; and then carrying out a reaction on the single polyurethane intermediate with polymethylsiloxane to obtain the oil-water mineral interface modifier. The oil-water mineral interface modifier has the advantages of wide raw material source, simple synthesis process, and clean and pollution-freeprocess; the raw materials are easy to obtain, transport and store; and the yield is high and is larger than 99.0%. The oil-water mineral interface modifier can resist to a temperature of 350 DEG C orabove, has mineralization resistance of 100000mg/L or above, can reduce viscosity of common thick oil and extra-thick oil to be 200 mPa*s or below at a concentration of 1000ppm, has a viscosity reduction rate of more than 98%, and has a static oil washing rate of more than 50%.

Description

Technical field [0001] The invention relates to a chemical agent used in the process of heavy oil exploitation, in particular to an oil-water mineral interface modifier with the functions of changing reservoir wettability and emulsification and viscosity reduction in heavy oil thermal recovery. Background technique [0002] With the deepening of my country's petroleum development, the deterioration of petroleum is becoming more and more serious. Heavy oil is one of the typical representatives. my country's heavy oil will become one of the main battlefields of oil exploitation in the future. At present, there are two main development methods: underground crude oil viscosity below 5000 mP·s is often developed by water injection (accounting for about 18% of heavy oil production). The average recovery rate of the development is about 23%; the steam injection method is adopted for the viscosity greater than 5000mPa·s (about 82% of the production of heavy oil). The thermal recovery of h...

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Problems solved by technology

[0003] However, the thermal recovery of heavy oil currently faces the following problems: ① The development method is single, and nearly 95% of the production of thermally recovered heavy oil comes from steam injection huff and puff; 18.1%, nearly 80% of the remaining oil has not been recovered; ③The main heavy oil reservoirs have entered the late stage of multiple rounds of huff and puff, and the huff and puff production effect is poor

[0005] Chemical agents for thermal recovery of heavy oil in my country are developing rapidly. The developed high-temperature oil displacement agent is 300°C, and the interfacial tension is reduced to 10 -3 The ultra-low level of the level, in the field implementation, the first cycle generally has obvious precipitation and oil increase effects, and when the second and third cycles are repeated, there is no obvious effect, and the subsequent further improvement of oil recovery is weak

At the same time, most of the current chemical agents start from reducing the viscosity of heavy oil or improving the sweep efficiency of the reservoir, and have a weak effect on the stripping of crude oil adhering to minerals; currently reported high-temperature resistant chemical agents are relatively expensive and require a large amount on site

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