Modification and viscosity reduction method of thickened oil

Abstract

The invention discloses a modification and viscosity reduction method of thickened oil. The modification and viscosity reduction method comprises the steps that an injection-production pattern is arranged in a to-be-exploited thickened oil reservoir exploitation region and comprises working wells and producing wells, and the bottoms of the producing wells communicate with the bottoms of the working wells; hot water and inert gas are injected into an oil reservoir adjacent to the working wells through the working wells to form a near-critical water environment, the temperature of the hot water and the inert gas is 300 DEG C or above, the temperature of the near-critical water environment ranges from 200 DEG C to 300 DEG C, and the pressure of the near-critical water environment ranges from 5 MPa to 10 MPa; when the injected hot water submerges the oil reservoir adjacent to the working wells, the injection-production pattern is sealed; and the injection-production pattern keeps sealed, the oil reservoir of the working wells is in the near-critical water environment for 3 h to 5 h, and crude oil with viscosity reduced is finally formed in the injection-production pattern. Through the modification and viscosity reduction method of the thickened oil, the viscosity of the thickened oil can be reduced to a large degree.

Description

technical field [0001] The application relates to the field of petroleum exploitation, in particular to a method for upgrading and reducing viscosity of heavy oil. Background technique [0002] With the continuous development of petroleum, the resources of thin oil continue to decrease. Although heavy oil resources are abundant, it is difficult to develop and utilize them, mainly because of the complex composition of heavy oil, high content of heavy components (bitumen, colloid, etc.), high viscosity, and poor fluidity, which lead to difficulties in mining, gathering, transportation, and processing. In my country, heavy oil refers to crude oil with a viscosity greater than 50 millipascal seconds (mPa·S) at the reservoir temperature. The key to improving the recovery rate of heavy oil and solving the problem of gathering and transportation is to reduce the viscosity of heavy oil. For this reason, people have developed a series of heavy oil viscosity reduction technologies, m...

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Problems solved by technology

In actual oil field production, the viscosity rate of heavy oil is less than 10% by using the above-mentioned hydrothermal cracking upgrading technology, and the degree of viscosity reduction is low, and the effect on increasing heavy oil production and reducing the difficulty of heavy oil processing is weak, so it is urgent Need a method that can reduce the viscosity of heavy oil to a greater extent

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