Fluid dynamic annular space cavitation device

Abstract

The invention relates to a fluid dynamic annular space cavitation device. The fluid dynamic annular space cavitation device comprises a cylindrical shell body, a spherical dynamic body, a stop plate and a bracket; the cylindrical shell body is internally provided with a working area, and the spherical dynamic body is disposed in the working area in the cylindrical shell body; a channel for fluid flowing is formed between the outer wall of the spherical dynamic body and the inner wall of the cylindrical shell body, and fluid flowing through the channel is subjected to cavitation; the stop plateis disposed on the top of the cylindrical shell body and used for preventing the spherical dynamic body from escaping from the upper part of the cylindrical shell body, so that the spherical dynamicbody is operated within the working area in the cylindrical shell body; and the bracket is disposed at the inner bottom of the cylindrical shell body for preventing the spherical dynamic body from coming out of the lower portion of the cylindrical shell body. The fluid dynamic annular space cavitation device has the beneficial effects of small volume, wide application range and safety and reliability.

Description

technical field [0001] The invention relates to a hydrodynamic annular gap cavitation device. Background technique [0002] In the oilfields developed and produced in the early stage, the comprehensive recovery rate is generally low due to factors such as formation pressure attenuation and oil layer plugging. At present, there are two common technologies for enhancing oil recovery, one is hydraulic fracturing technology, and the other is ultrasonic cavitation technology. [0003] Hydraulic fracturing technology is an enhanced oil recovery technology that injects fracturing fluid into the oil layer to create fractures and change the liquid state of the oil flow. This technology is an important technical means for the development of oil and gas wells, especially low-permeability oil and gas, and is currently widely used in various oil fields across the country. The technical principle is to inject liquid (water, fracturing fluid) into the oil well at a displacement exceeding ...

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Problems solved by technology

(2) Serious pollution to oil well formation

If the fracturing fluid for hydraulic fracturing is improperly selected, it may cause formation clay minerals to swell, crude oil to emulsify, and precipitation due to incompatibility with formation water, etc., which will damage the original physical properties of the formation; for acid fracturing, the acid will Harm to the formation, acid may also corrode construction equipment and pipe strings

At the same time, the fracturing operation is a high-pressure operation, and various acidification agents may pose a serious threat to the construction personnel and the surrounding ecological environment during the construction process.

(3) Water fracturing is extremely destructive to oil wells and formations. If fracturing is not done properly, it may cause severe consequences of violent water flooding and reactive water injection of oil wells, and may also depress the top of adjacent aquifers or gas-bearing layers.

(4) The artificial fractures or channels created by hydraulic fracturing aggravate the heterogeneity of the reservoir, seriously affect the full production of crude oil in the reservoir, which itself may have an adverse effect on reservoir development

[0006] Ultrasonic cavitation has the following disadvantages: (1) This technology can only be used for unblocking the formation near the wellbore. The cavitation effect of the liquid medium requires the ultrasonic wave to reach a certain intensity. The higher the ultrasonic power, the better the unblocking effect. However, the attenuation speed of the ultrasonic wave is extremely fast. Some studies have shown that the ultrasonic intensity at the well wall has been attenuated to 45% of the sound source, and the ultrasonic intensity at the radius of the geometric model of the void medium is 1 meter attenuated to 10% at the well wall.

Therefore, the ultrasonic cavitation effect is limited to the formation near the wellbore, and the maximum operating radius is only 15 meters, so the operating effect is limited

(2) The ultrasonic cavitation operation area is in a non-flowing state, and the cavitation area around its converter is limited. With the increase of external pressure, no new cavitation will be formed under the high pressure of deep well static water

In deep wells and extended pipelines, cavitation effects may not be obtained under high external hydrostatic pressure

(3) Limited by the processing time, the operation effect is limited

The cumulative ultrasonic treatment time is the key to the effect of ultrasonic cavitation, but a lot of practice has proved that after the cumulative ultrasonic treatment time exceeds 1 hour, the increase in its effect will no longer be obvious; the higher the ultrasonic frequency, the greater the attenuation during the propagation process, which will also affect its effect. job effect

(4) The technical supporting equipment is complicated, the cost is high, and the requirements for the working environment are also high

(5) This technology is not suitable for oil wells and horizontal wells with an inclination greater than 45 degrees

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