Ultra-deep ultra-thick oil thermal steam-gas (CO2 and N2) well bore viscosity reduction and oil production technology

Abstract

The invention relates to a technology for producing ultra-deep and ultra-heavy oil. An ultra-deep and ultra-heavy oil hot steam-gas (CO2 and N2) shaft body viscosity reduction oil production technology is the oil production technology for replacing 'less thin oil' or 'no thin oil'. The principle is to inject steam, CO2 and N2 which are prepared together by a steam-gas generator into a shaft body simultaneously with a continuous and disconnected process. The steam, the CO2 and the N2 are circulated in the shaft body to achieve the processes of injection, viscosity reduction, circulation, lifting and production at the same time. The technology has a normalized injecting flow of the steam, the CO2 and the N2 without building a ground flow, has wide adaptability to the production of the ultra-deep and ultra-heavy oil, and provides a novel technical support and technical reserve for the large scale development and production of the ultra-deep and ultra-heavy oil in China. With the technology to produce the ultra-deep and ultra-heavy oil, the cost can be greatly reduced and the benefit can be greatly improved.

Description

technical field [0001] The invention relates to a heavy oil recovery technology, especially ultra-deep ultra-heavy oil [burial depth of 5000-6500m, surface crude oil viscosity of 900-1.8×10 6 mPa.s(50℃)] mining technology. Background technique [0002] Petroleum is a non-renewable resource that plays a pivotal role in the current political and economic structure of the world. With the exhaustion of thin oil production, the requirements for the quantity, scale and efficiency of heavy oil production will become higher and higher. [0003] Countries rich in heavy oil resources in the world include Canada, Venezuela, the United States, the former Soviet Union, etc., and the buried depth of heavy oil in foreign countries is 0-1000m. my country's heavy oil resources are widely distributed, and more than 70 heavy oil fields have been discovered. The buried depth of the oil reservoir is 300-6500m, the Liaohe River is 800-2700m, the Tuha is 3500m, the Tarim is 5000m, and the Tahe R...

AI Technical Summary

Problems solved by technology

The disadvantages of previous heavy oil thermal recovery (formation viscosity reduction) technology are: first, the application depth is less than 2000m, and if the depth exceeds 2000m, the heavy oil can only flow into the wellbore, but not the wellhead; second, due to the characteristics of wet saturated steam and Wellbore engineering and surface engineering such as ultra-deep heat insulation and ultra-deep steam injection are difficult to realize, which also restricts the application of such technologies in ultra-deep and ultra-heavy oil production; third, in terms of steam source generation, large-scale steam Boiler supply, this equipment requires a large investment, high energy consumption, and high risk, and it can only be supplied in a centralized manner, which is not suitable for decentralized oil well exploitation; economy

There are obvious deficiencies in this method: restricted by thin oil resources, ultra-deep and ultra-heavy oil cannot be exploited without thin oil resources or shortage; when thin oil is mixed with heavy oil, sales revenue will decrease; Thin oil has poor viscosity reduction effect, which may easily cause breakage, detachment and jamming of the mechanically pumped well, and increase the difficulty of artificial lifting

[0013] So far, apart from mixing thin oil, there is no other better way to reduce the viscosity of ultra-deep and ultra-heavy oil, and many domestic oil fields are facing the dilemma of shortage of thin oil resources

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