Method for increasing recovery ratio of thick oil

Abstract

The invention provides a method for increasing the recovery ratio of thick oil. The method comprises the following specific steps of: injecting a steam injection string; connecting a ground steam injection pipeline with a subcritical steam-water two-phase flow meter, scanning the steam injection pipeline, testing the pressure of a well mouth and judging the pressure to be qualified if no pressure leaks after three minutes; inversely injecting a casing pipe; injecting steam into an oil pipe; after the steam is injected, mounting a temperature-resistant pressure gauge at the well mouth and starting to soak the well; and spraying by using an oil nozzle. Due to the utilization of gas, chemical and heat energy and actions of three substances, the mixed mass transfer action of the three substances in the longitudinal and transverse actions of an oil layer are exerted, the production pressure difference is reduced, the flowability of crude oil is improved, the oil-displacement power is increased, steam waves and the radius are increased, the saturation of residual oil is reduced and the aims of increasing the recovery ratio and improving the development effect are finally achieved.

Description

technical field [0001] The invention relates to an oil recovery method, in particular to a heavy oil recovery method, and belongs to the technical field of heavy oil development. Background technique [0002] Oilfields in my country have now entered the middle and late stages of development. In order to increase and stabilize production, each oilfield will continue to increase the production rate of heavy oil resources and invest a lot of money to support the development of heavy oil. Currently, it has been discovered in Shengli Oilfield, Liaohe Oilfield, and Xinjiang Oilfield. Large-scale heavy oil reservoirs have been discovered, and those with large reserves, shallow burial, and relatively low viscosity have been developed; since the viscosity of heavy oil is very sensitive to temperature, as long as the temperature rises (8-9°C), its viscosity will decrease. Therefore, it is often used to inject high-pressure saturated steam into the oil layer, swallow first and then spit ...

AI Technical Summary

Problems solved by technology

Effectively solve problems such as failure to inject steam (high steam injection starting pressure), difficulty in steam injection (high steam injection pressure), low oil-steam ratio, low recovery water rate, large amount of emulsified water in the produced oil, post-treatment Difficulty and other issues