A spontaneous imbibition measurement device based on capacitive coupling

Abstract

The invention discloses a spontaneous imbibition measurement device based on capacitive coupling. The measurement device comprises a confining pressure control system, a conductivity monitoring systemand a liquid level control system; the confining pressure control system is used for applying a confining pressure to a core; the liquid level control system is used for injecting liquid into the core; the conductivity monitoring system comprises a signal generating and processing system and electrodes; the signal generating and processing system comprises an alternating current excitation source, an inductive module, a signal processing system and a processing imaging and control system, which are electrically connected with each other in sequence; the electrodes comprise multiple pairs of excitation electrodes and detection electrodes, which are distributed on the surface of the core at intervals, the excitation electrodes are electrically connected with the inductive module, and the detection electrodes are electrically connected with the signal processing system. The device disclosed by the invention has a simple structure, is easy to be implemented, can monitor the change condition of saturation with time in a spontaneous imbibition process of the core in real time, and can be used in various spontaneous imbibition displacement modes from piston displacement to non-piston displacement; and saturation cloud charts of the surface and the interior of the rock can be generated in real time.

Description

technical field [0001] The invention relates to a spontaneous imbibition measurement device based on capacitive coupling, which belongs to the fields of oil and gas field development engineering and the research field of porous medium seepage mechanism. Background technique [0002] In the development of unconventional oil and gas resources, fracturing operations are often used to open up the formation, increase the formation diversion effect, and then increase the production. During fracturing, large amounts of water are injected into the formation. The spontaneous imbibition effect is obvious due to the influence of capillary force, salt concentration and pressure difference in unconventional reservoirs. The spontaneous imbibition properties of rocks are one of the important parameters of reservoirs. It provides theoretical basis for oil and gas reservoir screening, reservoir evaluation, technology application and improving oil and gas productivity. [0003] The current...

AI Technical Summary

Problems solved by technology

The above method has the following disadvantages: First, the method generally records page changes through a camera, and the human error factor is obvious

Secondly, if the spontaneous water absorption of the rock is not large, the error defect of this plan will be obvious, because the diameter of the glass tube is limited by the manufacturing process, if it is too thick, the change of the liquid level will not be obvious, if it is too thin, the glass tube itself will produce capillary effect, If the rise of the water surface is too high, and the upper part of the glass tube must be connected to the atmosphere, the water in the tube will inevitably evaporate, which will affect the experimental results.

Thirdly, the rock will expel the gas inside the rock in the form of bubbles during the process of water absorption. From the perspective of the structure of the experimental instrument, it cannot guarantee that the gas bubbles will be discharged from the thin glass tube, which affects the accuracy of the experiment.

Finally, the device can only study the mass of water absorbed throughout the core over time

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