Device and method for simulating quantitative flow of downhole liquid under high temperature and high pressure conditions

Abstract

The present invention provides a device and method for simulating quantitative flow of underground liquid under high temperature and high pressure conditions, which relates to the field of experimental devices. The device comprises a high-pressure container, a rock core is fixed at the bottom center of the high-pressure container, an upper cover is arranged on the top of the high-pressure container, the upper cover is provided with an annulus guide assembly and a plunger metering circulation device, the annulus guide assembly is located above the rock core, and the plunger metering circulation device is transmission-connected with a driving assembly; by simulating that the mud in the high-pressure container is pumped to the inlet of the annulus guide assembly through the plunger metering circulation device, and then enters the interior of the device and naturally flows from the lower end outlet to the rock core to complete flushing, the quantitative flow of underground liquid is effectively simulated, the actual flow scene of underground liquid can be simulated more realistically, and more reliable experimental data can be provided for related research.

Description

Technical Field

[0001] The invention relates to the field of experimental devices, and in particular to a device and a method for simulating quantitative flow of underground liquid under high temperature and high pressure conditions. Background Art

[0002] Petroleum products and derived petrochemical products are ubiquitous in today's society. Most of the oil is stored deep underground or under the ocean. To obtain oil, it is necessary to use a series of methods including oil reservoirs, drilling, oil production and ground engineering to extract the oil to the surface.

[0003] The most difficult and dangerous stage is the drilling and cementing stage. In order to make the drilling process safer and smoother, mud will be injected as a lubricant and plugging agent during the drilling stage. Due to the effect of pressure and the extrusion of the drill bit, a mud cake will be formed on the surface of the core of the well wall. The mud cake is beneficial to the construction during the drilling stage, but in the cementing stage, the characteristics of the mud cake will affect the bonding strength between the cement ring and the core, thereby affecting the quality and safety of cementing, and is more likely to affect the quality of oil products in the later oil production.

[0004] In order to solve the above problems, a special flushing fluid is usually added to treat the mud cake on the well wall. The flushing method is to add flushing fluid into the casing, and return it to the ground from the outside of the casing after reaching the bottom of the well. After a period of circulation, the purpose of flushing the mud cake is achieved. However, due to the complex conditions under the formation, due to the depth, pH and formation structure of the formation, different formations require special flushing fluids. In this process, special equipment is needed to simulate the flushing process.

[0005] At present, the devices used to evaluate mud flushing efficiency on the market mainly adopt the following structure: the motor drives the cylindrical blades to rotate radially through the blade shaft, thereby driving the mud in the container to rotate, and the core is fixed to the base and remains motionless, so that the mud forms a relative movement on the cylindrical surface of the core, thereby achieving the purpose of simulating mud cake cleaning; due to the influence of gravity, the rotation speeds of the upper and lower layers of the mud are inconsistent. Under the condition of the same rotation speed, the actual flow speed of muds with different viscosities has a large deviation, and it is impossible to accurately quantify the relationship between the flow rate and the flushing efficiency. In addition, the mud flow direction (radial) and the actual flow direction (axial) are different, and the underground mud flow scene cannot be truly simulated.

[0006] Therefore, there is an urgent need for a device and method for simulating the quantitative flow of downhole liquid under high temperature and high pressure conditions to solve the above problems. Summary of the invention

[0007] The purpose of the present invention is to provide a device and method for simulating the quantitative flow of underground liquid under high temperature and high pressure conditions to solve the problems existing in the above-mentioned prior art.

[0008] To achieve the above object, the present invention provides the following solutions:

[0009] The present invention provides a device for simulating quantitative flow of underground liquid under high temperature and high pressure conditions, comprising a high-pressure container, a rock core is fixed at the bottom center of the high-pressure container, an upper cover is provided on the top of the high-pressure container, the upper cover is provided with an annulus guide assembly and a plunger metering circulation device, the annulus guide assembly is located above the rock core, and the plunger metering circulation device is transmission-connected to a driving assembly.

[0010] Preferably, an air duct is provided on the upper portion of the high-pressure container.

[0011] Preferably, the annular flow guide assembly comprises a flow guide pipe, the top of the flow guide pipe is connected to the plunger metering circulation device, and the bottom of the flow guide pipe is connected to the flow guide tube through a flow guide orifice plate, and the flow guide tube cover is arranged above the core.

[0012] Preferably, the number of the flow guide pipes is 2 and they are axially symmetrically distributed.

[0013] Preferably, it further comprises an input pipe, the top of which is connected to the plunger metering circulation device, and the bottom of which is suspended in the high-pressure container.

[0014] Preferably, the number of the input pipes is 2 and they are distributed axially symmetrically.

[0015] Preferably, the driving assembly comprises a motor, and a power output end of the motor is transmission-connected to the plunger metering circulation device via a magnetic driving device.

[0016] The present invention also provides a method for simulating the quantitative flow of downhole liquid under high temperature and high pressure conditions, comprising the following steps:

[0017] Step 1: first, remove the upper cover (1) and the plunger metering circulation device (4) from the high-pressure container (10) and place them elsewhere, fix the core (8) with the mud cake on the bottom of the high-pressure container (10), introduce the flushing liquid into the high-pressure container (10), until the liquid level reaches the top of the core (8), and then install the upper cover (1) and the plunger metering circulation device (4) on the top of the high-pressure container (10) and tighten them;

[0018] Step 2: High-pressure nitrogen is injected into the high-pressure container (10) through the air guide pipe above the high-pressure container (10). After the plunger metering circulation device (4) is opened, the flushing liquid enters the plunger metering circulation device (4) through the input pipe (9) and is quantitatively pumped into the guide pipe (5). The flushing liquid enters the annular space between the guide tube (7) and the core (8) through the guide orifice plate (6), and finally returns to the high-pressure container (10), completing the quantitative flow of the flushing liquid under high temperature and high pressure.

[0019] Compared with the prior art, the present invention has achieved the following beneficial technical effects:

[0020] The present invention provides an apparatus and method for simulating quantitative flow of downhole liquid under high temperature and high pressure conditions. The apparatus comprises a high-pressure container, a core is fixed at the bottom center of the high-pressure container, an upper cover is provided on the top of the high-pressure container, the upper cover is provided with an annulus guide assembly and a plunger metering circulation device, the annulus guide assembly is located above the core, and the plunger metering circulation device is transmission-connected to a driving assembly; by simulating that the mud in the high-pressure container is pumped to the inlet of the annulus guide assembly through the plunger metering circulation device, and then enters the interior of the device and naturally flows from the lower end outlet to the core to complete flushing, the quantitative flow of downhole liquid is effectively simulated, and the actual flow scene of downhole liquid (slurry) can be simulated more realistically, providing more reliable test data for related research. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0022] Figure 1 A schematic diagram of the structure of the device for simulating the quantitative flow of downhole liquid under high temperature and high pressure conditions provided by the present invention;

[0023] Figure 2 A partial cross-sectional view of an annular flow guide assembly in a device for simulating quantitative flow of downhole liquid under high temperature and high pressure conditions provided by the present invention;

[0024] In the figure: 1: upper cover, 2: magnetic drive device, 3: motor, 4: plunger metering circulation device, 5: flow guide pipe, 6: flow guide orifice plate, 7: flow guide tube, 8: core, 9: input pipe, 10: high pressure container. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] The purpose of the present invention is to provide a device and method for simulating the quantitative flow of underground liquid under high temperature and high pressure conditions, so as to solve the problems existing in the prior art.

[0027] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0028] Embodiment 1:

[0029] This embodiment provides a device for simulating the quantitative flow of downhole liquid under high temperature and high pressure conditions, such as Figure 1 and 2 As shown, it includes a high-pressure container 10, a core 8 is fixed at the bottom center of the high-pressure container 10, an upper cover 1 is provided on the top of the high-pressure container 10, and the upper cover 1 is provided with an annulus guide assembly and a plunger metering circulation device 4, the annulus guide assembly is located above the core 8, and the plunger metering circulation device 4 is transmission-connected to the driving assembly.

[0030] As an implementation mode, an air duct is provided at the upper portion of the high pressure container 10 so as to simulate a high pressure environment.

[0031] As an implementation mode, the annulus diversion assembly includes a diversion pipe 5 , the top of which is connected to the plunger metering circulation device 4 , and the bottom of which is connected to the diversion tube 7 through the diversion orifice plate 6 , and the diversion tube 7 is covered above the core 8 .

[0032] As an implementation method, the number of the flow guide pipes 5 is two and they are axially symmetrically distributed, so as to solve the flow balance problem to the greatest extent.

[0033] As an embodiment, it further includes an input pipe 9 , the top of which is connected to the plunger metering circulation device 4 , and the bottom of which is suspended in the high-pressure container 10 .

[0034] As an implementation method, the number of input pipes 9 is two and they are axially symmetrically distributed, thereby solving the flow balance problem to the greatest extent.

[0035] As an embodiment, the drive assembly includes a motor 3, and the power output end of the motor 3 is connected to the plunger metering circulation device 4 through a magnetic drive device 2. Since the volume of liquid that can pass through the plunger metering circulation device 4 per rotation is certain, the flow rate through the plunger metering circulation device 4 can be accurately controlled by precisely controlling the rotation speed of the motor 2. At the same time, since the area of ​​the annulus between the guide tube 7 and the core 8 is known, the speed of the mud flowing through the surface of the core 8 can be calculated when the flow rate is known.

[0036] This embodiment also provides a method for simulating the quantitative flow of downhole liquid under high temperature and high pressure conditions using the above device, comprising the following steps:

[0037] Step 1: first remove the upper cover 1 and the plunger metering circulation device 4 from the high-pressure container 10 and place them elsewhere, fix the core 8 with the mud cake at the bottom of the high-pressure container 10, introduce the flushing liquid into the high-pressure container 10, and the liquid level reaches the top of the core 8, then install the upper cover 1 and the plunger metering circulation device 4 on the top of the high-pressure container 10 and tighten them;

[0038] Step 2: Inject high-pressure nitrogen into the high-pressure container 10 through the air guide pipe above the high-pressure container 10. After opening the plunger metering circulation device 4, the flushing liquid enters the plunger metering circulation device 4 through the input pipe 9 and is quantitatively pumped into the guide pipe 5. The flushing liquid enters the annular space area between the guide tube 7 and the core 8 through the guide orifice plate 6, and finally returns to the high-pressure container 10, completing the quantitative flow of the flushing liquid under high temperature and high pressure.

[0039] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core ideas of the present invention. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scopes. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. Equipment for simulating the quantitative flow of underground liquid under high temperature and high pressure conditions, characterized by: The invention comprises a high-pressure container (10), a core (8) is fixed at the bottom center of the high-pressure container (10), an upper cover (1) is provided on the top of the high-pressure container (10), the upper cover (1) is provided with an annular flow guide assembly and a plunger metering circulation device (4), the annular flow guide assembly is located above the core (8), and the plunger metering circulation device (4) is in driving connection with a driving assembly; The annular flow guide assembly comprises a flow guide pipe (5), the top of the flow guide pipe (5) is connected to the plunger metering circulation device (4), and the bottom of the flow guide pipe (5) is connected to the flow guide tube (7) through a flow guide orifice plate (6), and the flow guide tube (7) is covered above the core (8); The number of the flow guide pipes (5) is 2 and they are axially symmetrically distributed; It also includes an input pipe (9), the top of which is connected to the plunger metering circulation device (4), and the bottom of which is suspended in the high-pressure container (10); The number of the input pipes (9) is 2 and they are axially symmetrically distributed; The driving assembly comprises a motor (3), and the power output end of the motor (3) is transmission-connected to the plunger metering circulation device (4) via a magnetic driving device (2).

2. The device for simulating quantitative flow of downhole liquid under high temperature and high pressure conditions according to claim 1, characterized in that: An air guide pipe is provided on the upper part of the high-pressure container (10).

3. A method for simulating the quantitative flow of downhole liquid under high temperature and high pressure conditions, characterized in that: The following steps are involved: Step 1: first remove the upper cover (1) and the plunger metering circulation device (4) from the high-pressure container (10) and place them elsewhere, fix the core (8) with the mud cake at the bottom of the high-pressure container (10), introduce the flushing liquid into the high-pressure container (10), until the liquid level reaches the top of the core (8), and then install the upper cover (1) and the plunger metering circulation device (4) on the top of the high-pressure container (10) and tighten them; Step 2: High-pressure nitrogen is injected into the high-pressure container (10) through the air guide pipe above the high-pressure container (10). After the plunger metering circulation device (4) is opened, the flushing liquid enters the plunger metering circulation device (4) through the input pipe (9) and is quantitatively pumped into the guide pipe (5). The flushing liquid enters the annular space between the guide tube (7) and the core (8) through the guide orifice plate (6), and finally returns to the high-pressure container (10), completing the quantitative flow of the flushing liquid under high temperature and high pressure.

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