Fireflooding and flue gas reinjection gravity driving collaborative exploitation method for high-inclination-angle thick oil reservoir

Abstract

The invention provides a fireflooding and flue gas reinjection gravity driving collaborative exploitation method for a high-inclination-angle thick oil reservoir. The exploitation method comprises the following steps: selecting a production block, and respectively arranging a fireflooding linear flooding well pattern and a flue gas reinjection gravity driving well pattern at the middle part and the top of the production block; installing a ground facility, and paving a conveying pipeline; injecting air from a fireflooding gas injection well to an oil layer and igniting, extracting hot oil and flue gas which are generated by combustion from a fireflooding production well, separating and filtering the flue gas, then reinjecting the filtered flue gas into a flue gas injection well, and producing and extracting oil through a gas driving production well. The exploitation method can avoid the shortcomings of non-uniform fire line boosting and small use area due to single fireflooding, and the use area of the oil reservoir is enlarged; under the collaborative action of the fireflooding and flue gas reinjection gravity driving, the oil recovery ratio can be increased; furthermore, through the flue gas generated by the fireflooding, a stable gas source can be supplied to top gas injection; by reinjection of the flue gas, discharge of tail gas can be reduced, the operation cost is reduced, the air pollution is relieved, and the environment is protected.

Description

technical field [0001] The invention belongs to the technical field of oil reservoir exploitation, and relates to a method for synergistic exploitation of fire flooding and flue gas recovery gravity flooding in high-dip heavy oil reservoirs. Background technique [0002] Heavy oil generally refers to crude oil with a viscosity exceeding 50 mPa·s and a relative density greater than 0.920 under formation conditions. The domestic proven heavy oil reserves amount to 1.3 billion tons, accounting for 25-30% of the total domestic oil reserves. Due to the high density, high viscosity and poor fluidity of heavy oil, the development effect of conventional water flooding recovery methods is poor, and fire flooding technology has become one of the main methods to improve heavy oil recovery. For high-dip heavy oil reservoirs, two fire flooding methods are usually adopted: linear flooding at the top of the reservoir and linear flooding in the middle of the oil-rich area of ​​the reservoi...

AI Technical Summary

Problems solved by technology

The top linear flooding method is used for development. When air is injected from the structural high part to the structural low part, the injected air will migrate to the structural high part, causing a large amount of air to flow to the burned area, resulting in waste of air

As the burned area gradually expands, the required air injection rate also increases, increasing operating costs

At the same time, the low part of the reservoir is slow to receive effect, and the development efficiency is not high

However, if the linear flooding in the middle of the oil-rich area of ​​the reservoir is used for development, air is injected from the middle of the oil-rich area, and the upper and lower parts are displaced at the same time, which will lead to uneven advancement of the fire line, resulting in better results in the lower part and better results in the upper part. Poor, the overall production degree of the reservoir is low, and the development effect is not ideal

Images