Graded displacement oil extraction method for conglomerate oil reservoir chemical flooding reservoir

Abstract

The invention provides a graded displacement oil extraction method for a conglomerate oil reservoir chemical flooding reservoir. The graded displacement oil extraction method comprises the following steps that the pore throat radius of each pervious bed is obtained to obtain a plurality of pore throat radiuses; residual resistance coefficients, corresponding to the multiple pore throat radiuses, of a displacement medium are obtained, and seepage resistance corresponding to each pore throat radius is determined according to capillary pressure of the pore throat radiuses; a displacement pressure gradient is determined according to the parameters of an oil reservoir injection-production system; injection parameters of the displacement medium are determined according to the displacement pressure gradient and the seepage resistances of a plurality of permeable layers; and according to the injection parameters of the displacement medium, the displacement medium is injected into the multiple permeable layers through an injection well, and crude oil in the multiple permeable layers is displaced into an oil producing well to be produced. According to the technical scheme, the problems that in the related technology, chemical agents in the conglomerate oil reservoir easily enter the large pore throats to form high-permeability layer agent channeling and difficultly enter the medium and small pore throats to displace crude oil in medium and low permeability layers are effectively solved.

Description

technical field [0001] The invention relates to the technical field of petroleum development, in particular to a stepwise displacement oil recovery method for chemical flooding of conglomerate reservoirs. Background technique [0002] Chemical flooding refers to the addition of chemical agents into the injected water to change the physical and chemical properties of the displacement fluid and the interface properties between the displacement fluid and crude oil and rock minerals, thereby facilitating the production of crude oil. Chemical flooding mainly includes polymer flooding, polymer / surfactant binary compound flooding, surfactant / polymer / alkali triple compound flooding, etc. Chemical flooding has become an important means to greatly enhance oil recovery in the late stage of water flooding development. How to find a more effective method to displace the remaining oil after water flooding in related technologies is an urgent problem to be solved in chemical flooding. ...

AI Technical Summary

Problems solved by technology

[0009] The present invention aims to provide a stepwise displacement oil recovery method for chemical flooding of conglomerate reservoirs to solve the problem that in the related art, the chemical agents in conglomerate reservoirs easily enter the large pore throats to form high-permeability layer agent channeling, and it is difficult to enter the medium and high permeability layers. The Problem of Small Pore Throats Displacing Crude Oil in Middle and Low Permeability Layers

Images