A method for recovering in-situ regenerated foam oil in deep heavy oil reservoirs

Abstract

The invention provides a deep heavy oil reservoir in-situ regeneration foam oil exploiting method. The method includes: using vertical wells and / or horizontal wells to form a steam-stimulated well pattern; continuously injecting light alkane solvent into an oil reservoir through the steam-stimulated well pattern to form a first light alkane solvent slug; stopping light alkane solvent injection, and continuously injecting natural gas into the oil reservoir through the steam-stimulated well pattern to form a natural gas slug; stopping natural gas injection, continuously injecting light alkane solvent into the oil reservoir through the steam-stimulated well pattern to form a second light alkane solvent slug; shutting the wells for soaking; and opening the wells for continuous production; wherein the light alkane solvent is preferably alkane with carbon number of 5-8. By the method, foam oil flow can form in oil layers during steam-stimulated recovery, and oil production speed and recovery efficiency of the deep heavy oil reservoir can be increased effectively.

Description

technical field [0001] The invention relates to a mining method for heavy oil reservoirs, in particular to a mining method for deep heavy oil reservoirs, and belongs to the technical field of petroleum exploitation. Background technique [0002] Deep heavy oil reservoirs refer to heavy oil reservoirs whose burial depth is greater than 2000m. There are a large number of reserves distributed in Turpan-Hami and other regions in my country, and the development potential is huge. [0003] Because deep heavy oil reservoirs are buried too deep, conventional steam injection development technologies, such as steam huff and puff, steam flooding, steam-assisted gravity drainage, etc., have too much heat loss along the way during steam transportation from the wellhead to the bottom of the well. , so the thermal efficiency of steam is low, the dryness and specific volume of steam reaching the bottom of the well are low, the swept volume per unit mass of steam is small, and the developmen...

AI Technical Summary

Problems solved by technology

However, due to the large difference in the composition of natural gas and heavy oil in this process, natural gas cannot fully dissolve with crude oil due to the flow resistance of high-viscosity heavy oil after natural gas is injected into the reservoir, and a supersaturated zone is formed near the wellbore. , the undersaturated zone is formed in the area far from the near-well zone. During the huff and puff recovery process, the natural gas dissolved in the crude oil is quickly released to form free gas. Therefore, the ability of the natural gas to carry crude oil into the bottom of the production well will be greatly weakened. The result is the rapid degassing of natural gas, the crude oil production drops rapidly after the rapid degassing, the cycle yield is low, and the economic benefit is poor

[0005] For deep heavy oil reservoirs, there is currently no cost-effective production method

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