A Viscoelastic Foam Flooding Method for Developing Deep Heavy Oil Reservoirs

Abstract

The invention belongs to the technical field of heavy oil exploitation and discloses a method for viscoelastic foam flooding development of a deep heavy oil reservoir. The method includes steps: (1) water flooding development of the deep heavy oil reservoir; (2) high-concentration sacrifice agent slug injection; (3) nitrogen and foaming agent solution slug alternate injection stage; (4)nitrogen and foaming agent solution slug simultaneous injection stage; (5) solid-phase particle strengthened nitrogen foam displacement stage; (6) nitrogen and production alternate conduction stage. By iscoelastic foam flooding, development effects after water flooding of the deep heavy oil reservoir can be effectively improved, the conformance efficiency is increased while displacement efficiency is improved, and the recovery ratio is increased by 8.0%-15.0%.

Description

Technical field [0001] The invention relates to the technical field of heavy oil exploitation, in particular to a method for viscoelastic foam flooding to develop deep heavy oil reservoirs. Background technique [0002] Heavy oil is a crude oil with higher asphaltene and gum content and higher viscosity. The viscosity of the degassed crude oil at the original reservoir temperature is greater than 100 mPa.s. my country’s heavy oil resources are widely distributed. Onshore heavy oil resources account for more than 20% of the total oil resources. The proven geological resources are 7.98 billion tons. The annual output exceeds 28 million tons, accounting for 14% of the domestic crude oil output. An important part of my country's crude oil production. Further increasing the production of heavy oil is an important guarantee for maintaining the stability of our domestic oil production and maintaining national energy security. [0003] The development of deep heavy oil reservoirs with a b...

AI Technical Summary

Problems solved by technology

However, for deep heavy oil reservoirs, due to the deep burial depth, high steam injection pressure, and increased heat loss in the wellbore and formation, deep heavy oil reservoirs cannot be developed with steam huff and puff.

Especially if the solid-phase particle water blocking slug, foam slug, nitrogen slug, and sealing slug are injected before the steam huff and puff, the formation pressure will be increased, making it impossible to inject steam, so the method cannot be used in deep thick layers. oil reservoir development

Images