Infiltration experimental device and method for determining infiltration and extraction degree

Abstract

The invention, which relates to the infiltration field, provides an infiltration experimental device and a method for determining the infiltration and extraction degree. The experimental device comprises an infiltration bottle, a micro pressure pump, and a suspension bracket. Water and a core sample are arranged in the infiltration bottle having an open end; a test tube is arranged at the open endand is marked with scale lines from top to bottom; and the water level in the infiltration bottle is not lower than the bottom scale line of the test tube. The micro pressure pump is used for providing water with a predetermined pressure intensity in the infiltration bottle. The suspension bracket is arranged at a gravity sensing device connected with a data acquisition system electrically. A water inlet is formed in the infiltration bottle and is connected with the micro pressure pump by a connecting device; the connecting device includes a hydraulic control valve; when the hydraulic controlvalve detects that the pressure intensities at the two sides are not equal, the valve is opened; and when detecting that the pressure intensities at the two sides are equal, the hydraulic control valve is closed. The infiltration experimental device has advantages of great convenience in assembling, high measurement precision and wide application range.

Description

technical field [0001] The invention relates to the field of imbibition in petroleum engineering, in particular to an imbibition experimental device and a method for determining the recovery degree of imbibition. Background technique [0002] Tight rock reservoirs belong to the type of unconventional oil resources, and they mostly occur in unconventional reservoirs with low porosity and low permeability. Due to the long-term immersion of formation water, underground rocks have shown hydrophilic characteristics. When the two phases of oil and water coexist in the rock pores, the oil-water interface forms a meniscus due to the difference in wettability. The pressure on both sides of the meniscus is unequal, and the oil phase pressure is higher than the water phase pressure to form a pressure difference. The force formed by the pressure difference is the capillary force. Under the action of the capillary force, water will enter the rock pores and the crude oil Displacement is...

AI Technical Summary

Problems solved by technology

[0004] During the measurement process using this method, the amount of oil produced by imbibition is not intuitive enough, and the volume of oil film produced by imbibition cannot be directly measured

In addition, the applicant found that as the imbibition process proceeds, the rock is gradually placed in the mixed solution of formation water and crude oil, and the density of the solution gradually decreases, while the overall volume of the solution remains unchanged, so that the buoyancy on the rock gradually decreases , and the impact of the buoyancy change on the measurement results cannot be measured, resulting in certain errors in the measurement results

At the same time, as the imbibition process proceeds, the formation water continues to volatilize, and the buoyancy on the rock changes with the volatilization of the formation water, which also makes the measurement results inaccurate

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