Pressure return device for water plugging profile control physical simulation experiment and use method of pressure return device

Abstract

The invention discloses a pressure return device for a water plugging profile control physical simulation experiment and a use method of the pressure return device. The pressure return device comprises a pressure sensor and a stop valve, and is characterized by also comprising an intermediate container, pistons, a four-way valve and a high-pressure pulsation-free pump, wherein the intermediate container is internally provided with two pistons, a working liquid is filled in a space between the two pistons, the left side of the intermediate container is connected with an outlet pipe of a core barrel, a space for filling a plugging agent can be formed between the left piston and the intermediate container, and the right piston is connected with a fine tuning hand wheel and a working liquid inlet pipe. Through controlling the pressure of the working liquid between the two pistons, an actual stratum pressure born by a water shutoff profile control agent in a mine field is simulated. The pressure return device has the advantages of simple structure and convenience for use, is easy to dismantle for cleaning and maintaining, and difficult to plug, and has reliable performance to easily maintain the stability of return pressure on the outlet end of the core barrel; return pressure is high to meet the demand of experiments on high return pressure; and an obtained sample is not sheared by a return pressure device.

Description

technical field [0001] The invention relates to a back pressure device used in a physical simulation experiment of water plugging and profile control and a using method thereof. Background technique [0002] In the petroleum industry, before injecting the gel-type water plugging agent (hereinafter referred to as the plugging agent) into the formation, the gel-type plugging agent should be evaluated indoors. In general, jelly-type plugging agents are evaluated using a single-tube core under the condition that the outlet end is vented. This evaluation condition is different from that of the jelly plugging agent entering the formation, and the evaluation result may be different from its performance in the formation, because the formation has a certain pressure. In order to simulate the formation conditions more realistically, the back pressure generated by the piston back pressure valve is used to simulate the formation pressure conditions, and the jelly plugging agent is eval...

AI Technical Summary

Problems solved by technology

However, when using the piston back pressure valve for experiments, it was found that the structure of the piston back pressure valve is relatively complicated, and the jelly blocking agent entering the back pressure valve is not easy to remove, and it will also cause blockage in the valve, making the experiment impossible; The jelly plugging agent obtained from the outlet of the piston back pressure valve is severely sheared, and the result of sampling and analysis is not true; when the piston back pressure valve is working, it is constantly suppressing and releasing pressure, causing pressure fluctuations, which leads to the failure of the core tube outlet. End back pressure cannot be constant, affecting experimental data processing

In order to better evaluate jelly-type blocking agents, a back pressure device is now developed to overcome the shortcomings of currently used devices in evaluating jelly-type blocking agents

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