Experimental device for improving gas injection recovery ratio through low-frequency voltage transformation

Abstract

The invention provides an experimental device for improving the gas injection recovery ratio through low-frequency voltage transformation. The experimental device comprises a rock model, an autoclave, a low-frequency voltage transformation device, an ultrasonic transmitting and receiving device and a gas injection oil displacement device, wherein the rock model is located in the autoclave and simulates an actual oil reservoir stratum; a low-frequency voltage transformation well and an ultrasonic probe are arranged in the rock model; a hole is formed in the lower section of the low-frequency voltage transformation well and communicates with an actual oil reservoir simulated by the rock model; the ultrasonic probe is connected with the ultrasonic transmitting and receiving device; the gas saturation change process is monitored through the change of the ultrasonic attenuation amplitude; the low-frequency voltage transformation device is used for changing the distribution state of remaining oil in the rock model; and the gas injection oil displacement device conducts gas injection oil displacement after the rock model reaches the oil saturation state and the distribution state of the remaining oil is changed, and the improvement rate of the gas injection recovery ratio is determined according to two times of gas injection oil displacement. According to the scheme, pressure change is caused between an injection well and a production well, the remaining oil in oil reservoir pores is affected by pressure, and therefore the recovery rate of the remaining oil is increased.

Description

technical field [0001] The invention relates to the technical field of oilfield development, in particular to an experimental device for improving gas injection recovery by low-frequency variable pressure. Background technique [0002] Gas flooding technology is an advantageous technology in the late stage of water flooding development and the development of low-permeability reservoirs. It has the advantages of low seepage resistance, fast recovery of formation pressure, and obvious oil displacement effect. The channel flows along the high-permeability channel in the reservoir. Once the gas is pointed and forms a channel in the reservoir, after the production from the production well, the gas injected later will hardly play the role of oil displacement. However, in the oil reservoir, some pores including channeling channels still contain residual oil with relatively high saturation. The existing technology has methods to block part of the channeling channels, but usually it ...

AI Technical Summary

Problems solved by technology

[0003] The embodiment of the present invention provides an experimental device for improving gas injection recovery with low-frequency variable pressure, which solves the technical problem in the prior art that the remaining oil recovery in channeling channels and surrounding pores cannot be improved

Images