Large-liquid-amount constant-pressure displacement indoor physical simulation experiment method

Abstract

The invention discloses a large-liquid-amount constant-pressure displacement indoor physical simulation experiment method. The method sequentially includes the following steps that a large-liquid-amount constant-pressure displacement indoor physical simulation experiment device is installed and detected; water is added into a water container I, and dissolved gas is removed; water is added into a water container II, and dissolved gas is removed; oil saturation is performed on a rock core; oil displacement by water is performed on the rock core; oil and liquid obtained through displacement are counted. The experiment device comprises an automatic water adding device I, an automatic water adding device II, an oil adding device, an impurity removing device I, an impurity removing device II, a pressure collecting device, an oil and water counting device and a rock core clamping device. The automatic water adding devices comprise vacuum pumps, and water adding control buttons and displacement control buttons are further arranged. The experiment method is high in automation degree and operability, integrates multiple functions, can achieve water feeding automatically, meets the using requirement for large-liquid-amount displacement, can effectively remove impurities in the water and oil and meanwhile removes the dissolved gas in the water.

Description

technical field [0001] The invention belongs to the technical field of oil and gas field development, and relates to a core displacement simulation experiment method, in particular to an indoor physical simulation experiment method for large liquid volume and constant pressure displacement. Background technique [0002] In the field of oil and gas field development technology, core flooding experiments are usually used to simulate the actual production process of crude oil in oil and gas fields. This experiment sometimes needs to inject a large amount of displacement fluid (usually water), and the whole experiment generally requires at least half a month of displacement. During the displacement process, it is necessary to continuously replenish the displacement fluid into the intermediate container, which will greatly increase scientific research. Labor intensity of personnel, and affect the progress of the experiment. During the flooding experiment with large liquid vo...

AI Technical Summary

Problems solved by technology

[0003] Although the existing core displacement methods and devices can simulate indoor displacement experiments, they usually simulate displacement experiments with a small amount of liquid. If a displacement experiment with a large amount of liquid is carried out, the displacement fluid needs to be continuously replenished. Every time you add displacement fluid, you need to unscrew the cover on the top of the intermediate container, and then tighten the lid after filling up the displacement fluid, which not only increases the work intensity, but also affects the progress of the experiment; in large-volume displacement experiments , the impact of impurities and dissolved gas in the displacement fluid is constantly accumulating, which has a much greater impact on the experimental results than in general displacement experiments. The existing methods to solve the problem of precipitation and scales entering the core are mainly made of stainless steel intermediate container, or coat the inner wall of the intermediate container with an anti-corrosion layer to prevent the intermediate container from corroding and rusting, but the precipitation and scaling produced by the displacement fluid itself in the container cannot be prevented, which will still cause rock formation. core clogging

The invention patent with the publication number CN102536180A discloses a method and device for preventing impurities from entering the core. The method and device can effectively prevent sedimentation and scaling from entering the core, but there are still many defects that cannot be solved in the prior art. The existing problem is that the patent wraps a filter membrane at the inlet end of the core pipeline to remove impurities, but in the actual operation process, it is impossible to guarantee the hardness of ceramics and cemented quartz sand described in the patent by simply wrapping. The material is in full contact with the pipeline without leaving a large gap, so impurities and dissolved gas cannot be effectively removed; in this patent, the pipeline wrapped with a filter membrane is arranged at the bottom of the intermediate container, which makes it difficult to replace the filter membrane on the one hand, and on the other hand. When the piston of the intermediate container moves to the bottom, either the piston is stuck by the pipeline wrapped with the filter membrane, or the pipeline wrapped with the filter membrane is broken, so the operability is very poor

In addition, when carrying out large-volume displacement experiments, it is necessary to accurately measure the volume of oil and water. In the existing technology, test tubes are mostly used for liquid measurement, and the errors generated by each reading continue to accumulate, resulting in large errors in the final results. The entire experiment For at least half a month of displacement, the test tube needs to be replaced continuously, and the workload is very large; in the displacement experiment, when the displacement liquid is added to the intermediate container, it is easy to vibrate, and a large amount of gas dissolves in the liquid. The existing technology does not take measures for this. Any measure, which will greatly affect the experimental results

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