Method for producing fractured buried hill reservoir with high yield

Abstract

The invention relates to a method for producing a fractured buried hill reservoir with high yield, and belongs to the technical field of oil displacement of oil reservoirs of oil fields. According tothe method, crude oil in the fractured buried hill oil reservoir is extracted with a three-dimensional injection-production method of low-position water injection, high-position gas injection and middle oil production. According to the three-dimensional injection-production method of low-position water injection, high-position gas injection and middle oil production, the density difference betweengas and water is fully utilized, the injected gas migrates to the upper part of the oil reservoir so as to displace high-position crude oil which cannot be moved by water injection, and the injectedwater migrates to the low position of the oil reservoir, so that the low-position crude oil is moved. In addition, the diameter of gas molecules is far smaller than that of water molecules, and therefore, gas can enter tiny apertures so as to displace crude oil which cannot be moved by water injection.

Description

technical field [0001] The invention belongs to the technical field of oil field oil displacement, and relates to a method for fractured buried hill oil reservoirs with high yield. Background technique [0002] With the development of oil exploration technology and the continuous expansion of exploration fields, carbonate buried hill reservoirs have become an important type of oil and gas reservoirs in my country. Most of the buried hills discovered so far have experienced multi-stage tectonic movements, forming multi-system fracture storage spaces, and experienced differential chemical filling effects such as calcite and anhydrite, forming a fracture system with very strong heterogeneity. [0003] Because in the process of oil field development, the oil production of buried hill reservoirs is generally very high. Due to the influence of lithology, the crude oil in reservoirs composed of massive buried hills exists in dense cracks and fractured pores, and the production depe...

AI Technical Summary

Problems solved by technology

[0003] Because in the process of oil field development, the oil production of buried hill reservoirs is generally very high. Due to the influence of lithology, the crude oil in reservoirs composed of massive buried hills exists in dense cracks and fractured pores, and the production depends on buried hills. The bottom water energy drives the oil layer, but as the bottom water rises, the production will continue to decline. In order to improve the recovery rate, the current method of injecting water into the bottom of the buried hill to push the bottom water upwards can increase the recovery rate, but With this water injection method, when the bottom water rises to the top of the buried hill, the water content in the well can reach more than 95%, and Russian crude oil cannot be effectively produced in the high parts, small fractures and matrix pores, that is, the crude oil in the oil well cannot be exploited. The remaining oil existing in the buried hill becomes a dead oil zone