CN116556937A - Coal-bed gas well exploitation evaluation system and evaluation method - Google Patents

Abstract

A coalbed methane well mining evaluation system provided by the present invention includes a model device, a gas injection device, a liquid injection device, a confining pressure control device, a pressure control device, a vacuum device, a extraction device, a gas-liquid-solid separation device, and data acquisition and processing device etc. During the test, firstly use the confining pressure control device to apply confining pressure around the model device; then vacuumize the system; then use the gas injection device and liquid injection device to inject the gas and liquid contained in the simulated formation into the simulation device respectively; The sampling device extracts the mixed medium from the model device, and the gas-liquid-solid separation is carried out through the gas-liquid-solid separation device; at the same time, during the test process, the parameters of each device in the entire system are collected by the data acquisition and processing device. The present invention also provides an evaluation method of the above-mentioned coalbed gas well mining evaluation system, which is used to evaluate the sand control effect under different well completion modes, sand control parameters, temperature, ground stress and other conditions.

Description

A Coalbed Gas Well Exploitation Evaluation System and Evaluation Method

technical field

The invention belongs to the technical field of coal bed gas mining and gas control, and in particular relates to a coal bed gas well mining evaluation system and evaluation method.

Background technique

In the prior art, in the process of coalbed methane surface well mining or gas treatment, due to the influence of well completion methods, formation characteristics, production pressure difference, flow rate and other factors, it is easy for coal powder or sand to get stuck in the pump, resulting in production reduction or even shutdown. Therefore, the mechanism of pulverized coal or sand stuck in the pump needs to be further studied, so as to adjust production measures and improve production efficiency.

Therefore, how to simulate factors such as different well completion methods and sand control parameters, coal and rock types, in-situ stress, formation temperature, formation pressure, gas flow rate in the formation, liquid flow rate in the formation, coal powder or sand concentration, pump displacement, etc. It is a problem to be solved urgently by those skilled in the art to find out the law of the coal powder or sand carried and migrated by the fluid contained in the formation, and to provide the test data under the working state.

Contents of the invention

The purpose of the present invention is to provide a coalbed methane well exploitation evaluation system and evaluation method, which can simulate the working state of the well under a certain well completion mode, and provide test data under the working state.

In order to solve the above technical problems, the present invention provides a coalbed methane well mining evaluation system, including: a model device, a gas injection device, a liquid injection device, a confining pressure control device, a drainage device, a gas-liquid-solid separation device, and a data acquisition and processing device;

The model device is used for simulating well bores and formations under different sand control completion methods;

The gas injection device is used to inject the gas contained in the simulated formation into the model device;

The liquid injection device is used to inject the liquid contained in the simulated formation into the model device;

The extraction device is used to extract the mixed medium in the model device;

The confining pressure control device is used to simulate and provide the formation stress suffered by the model device underground;

The gas-liquid-solid separation device is used to separate the mixed medium extracted by the extraction device;

The data acquisition and processing device is used to measure and collect data of the formation simulation device, the gas injection device, the liquid injection device and the gas-liquid-solid separation device.

Optionally, in the above-mentioned coalbed methane well production evaluation system, the model device includes a core chamber, a cushion block, a rock sample wrapped with a core sleeve and a wellbore that are sequentially set from outside to inside, and the core chamber and the cushion block There is a first cavity between them, the core casing, the pad and the wellbore are all provided with through holes, the outlet ends of the gas injection device and the liquid injection device go through the core chamber and the pad block and communicates with the second chamber formed between the pad and the rock sample, the output end of the confining pressure control device is set in the first chamber and is used to apply formation stress to the pad, so One end of the wellbore is inserted into the rock sample, and the other end of the wellbore is exposed outside the model device and connected with the extraction device and the gas-liquid-solid separation device.

Optionally, in the above coalbed methane well production evaluation system, the model device further includes a rotating support, and the rotating support can rotate the connected core chamber.

Optionally, in the above coalbed methane well development evaluation system, the gas injection device includes gas cylinders, a first valve, a gas booster pump, a first buffer tank, a first one-way valve and a first back pressure valve connected in sequence , the gas cylinder is used to contain the gas contained in the simulated formation, and the outlet end of the first back pressure valve communicates with the air inlet of the model device.

Optionally, in the above coalbed methane well development evaluation system, the liquid injection device includes a liquid tank, a first injection pump, a second valve, a piston container, a second one-way valve and a second back pressure valve connected in sequence, so that The liquid tank is used to store the liquid contained in the simulated formation, and the outlet port of the second back pressure valve is connected with the liquid inlet port of the model device.

Optionally, in the above coalbed methane well development evaluation system, it further includes a pressure control device for controlling the valve opening of the first back pressure valve and the second back pressure valve, and the pressure control device includes a second An injection pump, a second buffer tank, a third valve and a fourth valve, the second injection pump is connected to the inlet of the second buffer tank, the outlet of the second buffer tank is connected to the third valve and the fourth valve respectively The inlet of the fourth valve is connected, and the outlets of the third valve and the fourth valve are respectively communicated with the set pressure chambers of the first back pressure valve and the second back pressure valve.

Optionally, in the above coalbed methane well development evaluation system, the gas-liquid-solid separation device includes a gas-liquid separator, a desiccant bottle, a second flow meter, a gas collection tank, a liquid storage tank, and an electronic scale, and the model device The wellbore outlet of the gas-liquid separator communicates with the inlet of the gas-liquid separator, the gas outlet of the gas-liquid separator communicates with the gas collection tank through the desiccant bottle and the second flow meter, and the gas-liquid separator The liquid outlet is in communication with the liquid storage tank, and the electronic scale is used to weigh the liquid storage tank.

Optionally, in the above coalbed methane well development evaluation system, a vacuuming device for vacuuming the interior of the model device is also included;

And/or, the confining pressure control device includes a confining pressure pump, the output end of the confining pressure pump is a piston, and the piston is used to provide formation stress to the model device.

Optionally, in the above coalbed methane well production evaluation system, the extraction device is a pumping unit, or an electric submersible pump, or a jet pump, or a screw pump.

The present invention also provides a coalbed methane well mining evaluation method, which uses the above-mentioned coalbed methane well mining evaluation system, comprising the following steps:

S1. Clean and assemble the model device, fill the model device with corresponding rock samples according to the formation to be simulated and the completion method, and arrange the wellbore according to the completion method;

S2. Install the model device, the gas injection device, the liquid injection device, the confining pressure control device, the extraction device, the gas-liquid-solid separation device, and the data acquisition and processing device, and check Airtightness, and vacuumize the model device, and then load the confining pressure;

S3. Turn on the gas injection device, the liquid injection device, the extraction device, the gas-liquid-solid separation device, and the data collection and processing device; the gas injection device and the liquid injection device send to the The model device injects formation gas and formation liquid respectively, and maintains the required injection pressure, temperature and flow rate during the test. The data acquisition and processing device monitors the outlet of the gas injection device and the pressure in the wellbore of the model device. difference, and the pressure difference between the outlet of the liquid injection device and the wellbore of the model device, the flow rate and total amount of the injection medium at the gas inlet and the liquid inlet, and the weight of the gas separated by the gas-liquid-solid separation device and flow, and the weight of solid particles and liquid separated by the gas-liquid-solid separation device, the data acquisition and processing device records the temperature, pressure, and flow dynamic parameters in the test process, and each item in the coalbed methane well development evaluation system The parameters were analyzed and compared.

The invention provides a coalbed gas well mining evaluation system and evaluation method, the beneficial effects of which are:

During the test, firstly use the confining pressure control device to apply confining pressure around the model device; then vacuumize the system; then use the gas injection device and liquid injection device to inject the gas and liquid contained in the simulated formation into the simulation device respectively; The sampling device extracts the mixed medium from the model device, and the gas-liquid-solid separation is carried out through the gas-liquid-solid separation device; at the same time, during the test process, the data acquisition and processing device is used to collect the parameters of each device in the entire system. The present invention also provides an evaluation method of the above-mentioned coalbed gas well mining evaluation system, which is used to evaluate the sand control effect under different well completion modes, sand control parameters, temperature, ground stress and other conditions.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only It is an embodiment of the present invention, and those skilled in the art can also obtain other drawings according to the drawings provided by the present invention without any creative effort.

Fig. 1-Fig. 2 is the system flowchart of a kind of coalbed methane well mining evaluation system provided by the embodiment of the present invention (the external appearance of model device is cube rock sample or columnar rock sample, piston is not shown in the figure);

Fig. 3 is a schematic structural view of a vertical well and a drainage device provided by an embodiment of the present invention;

Fig. 4 is a schematic structural view of a horizontal well and a drainage device provided by an embodiment of the present invention;

5 is a schematic diagram of the internal structure of a cube model device using a single wellbore provided by an embodiment of the present invention (only showing the confining pressure control device in one direction);

6 is a schematic diagram of the internal structure of a cube model device using a double wellbore provided by an embodiment of the present invention (only showing the confining pressure control device in one direction);

Figure 7 is a schematic diagram of the internal structure of the cylinder model device provided by the embodiment of the present invention (only showing the confining pressure control device in one direction);

Fig. 8 is a schematic structural diagram of a model device and a rotating support provided by an embodiment of the present invention.

In the picture above:

Gas injection device: 101-gas cylinder; 102-first valve; 103-gas booster pump; 104-air compressor; 105-first buffer tank; 106-first one-way valve; 107-first back pressure valve ;

Liquid injection device: 201-liquid tank; 202-first injection pump; 203-second valve; 204-piston container; 205-first flow meter; 206-second one-way valve; 207-second back pressure valve;

Pressure control device: 301-second injection pump; 302-second buffer tank; 303-third valve; 304-fourth valve;

Model device: 401-core chamber; 402-pad; 403-rock sample; 404-wellbore; 405-temperature control box; 406-rotary support;

Vacuum device: 501-vacuum pump;

Confining pressure control device: 601-confining pressure pump; 602-piston;

Gas-liquid-solid separation device: 701-gas-liquid separator; 702-desiccant bottle; 703-second flow meter; 704-gas collection tank; 705-liquid storage tank; 706-electronic scale; 707-third one-way valve ;

8- Extraction device.

Detailed ways

Embodiments of the present invention are described in detail below, examples of which are shown in the drawings, wherein the same or similar reference numerals designate the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the figures are exemplary only for explaining the present invention and should not be construed as limiting the present invention.

The core of the present invention is to provide a coalbed methane well mining evaluation system and evaluation method, which can simulate the working state of the well under a certain well completion mode and provide test data under the working state.

In order to enable those skilled in the art to better understand the technical solutions provided by the present invention, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

Please refer to Fig. 1-Fig. 8, a coalbed methane well production evaluation system provided by the present invention, including: model device, gas injection device, liquid injection device, confining pressure control device, vacuum device, extraction device 8, gas-liquid-solid Separation device and data acquisition and processing device.

The model device is used to simulate the wellbore and formation under different sand control completion methods.

The gas injection device is used to inject the gas contained in the simulated formation into the model device.

The liquid injection device is used to inject the liquid contained in the simulated formation into the model device.

The vacuum unit is used to evacuate the system.

The extraction device 8 is used to extract the mixed medium in the model device.

The confining pressure control device is used for simulating and providing the formation stress suffered by the model device underground (in all directions).

The gas-liquid-solid separation device is used to separate the mixed media extracted by the extraction device 8 .

The data acquisition and processing device is used for measuring and collecting data of the model device, the gas injection device, the liquid injection device and the gas-liquid-solid separation device.

The present invention provides a coalbed methane well mining evaluation system. During the test, firstly, the confining pressure control device is used to apply pressure to the surroundings of the model device; the system is then vacuumed; The gas and liquid are respectively injected into the simulation device; then the mixed medium is extracted from the model device through the extraction device, and the gas-liquid-solid separation is carried out through the gas-liquid-solid separation device; The parameters of each device are collected. The present invention also provides an evaluation method of the above-mentioned coalbed gas well mining evaluation system, which is used to evaluate the sand control effect under different well completion modes, sand control parameters, temperature, ground stress and other conditions.

In a specific embodiment, the model device includes a core chamber 401 , a pad 402 , a rock sample 403 wrapped with a core casing, and a wellbore 404 , which are sequentially fitted from outside to inside, and a first cavity is arranged between the core chamber 401 and the pad 402 . The core sleeve wrapped around the rock sample 403 is a mesh structure material with certain elasticity, which is used to prevent the rock sample 403 from being broken under high pressure and causing blockage inside the model device. Both the pad 402 and the wellbore 404 after simulating a certain well completion mode are provided with through holes. The outlet ends of the gas injection device and the liquid injection device pass through the core chamber 401 and the pad 402 , and communicate with the second cavity formed between the pad 402 and the rock sample 403 . The output end of the confining pressure control device is set in the first cavity and is used to apply formation stress to the pad 402. One end of the wellbore 404 is inserted into the inside of the rock sample 403, and the other end of the wellbore 404 is exposed outside the model device and is connected with the extraction device. 8 is connected with the gas-liquid-solid separation device.

The above-mentioned device and the confining pressure control device are convenient for applying pressure from the cushion block 402 . When the wellbore 404 is completed with a screen, specifically, the screen type may include high-quality screens such as slotted, wound wire, metal mesh, and metal wool.

The core chamber 401 is provided with an air inlet that communicates with the gas injection device. There may be multiple air inlets, and one gas injection device communicates with the air inlet through multiple air inlet pipes. The air inlets can be evenly distributed around the core chamber 401 . Similarly, the core chamber 401 is provided with a liquid inlet connected to the liquid injection device. There may be multiple liquid inlets, and one liquid injection device communicates with the liquid inlet through multiple liquid inlet pipes. The liquid inlets can be evenly distributed around the core chamber 401 . There are multiple air inlets/liquid inlets of the model device, and the valves can be connected in series, and it is only necessary to selectively open all or part of the corresponding valves. Of course, the number of gas inlets and liquid inlets can also be designed to any value according to actual conditions, so that formation gas and formation liquid can be evenly injected from around the simulation device.

In order to simulate the influence of formation dip angles of different angles, the model device further includes a rotating support 406 , which can rotate the connected rock core chamber 401 . The angle-adjustable support includes a frame, casters, a rotating shaft and a drive mechanism. The bottom of the frame is provided with castors. The frame and the core chamber 401 are rotatably connected by the rotating shaft. The driving mechanism is used to drive the core chamber 401 to rotate relative to the frame.

As shown in Figure 3, the connection mode of the model device and the drainage device 8 is the connection situation when simulating a vertical well, and as shown in Figure 4, the connection mode of the model device and the drainage device 8 is the connection situation when simulating a horizontal well.

The model device also includes a temperature control box 405 covering the outside of the core chamber 401 . The model device can be put into the temperature control box 405 as a whole to heat up. The rock sample 403 is heated quickly, and is heated through the temperature control box 405 to ensure rapid heating to the required experimental temperature. The system controls the temperature and pressure accurately, which makes the measurement accuracy of the experimental results high.

In a specific embodiment, when the shape of the model device is a cube, the shapes of the rock core chamber 401 and the rock sample 403 are both cubes, and one end of the wellbore 404 passes through one side of the cube of the model device and is inserted into the inside of the rock sample, and another One end is exposed outside the model device and is connected with the extraction device 8 and the gas-liquid-solid separation device.

When the shape of the model device is a cylinder, the shape of the rock core chamber 401 is a cylinder, the shape of the rock sample 403 is a cube or a cylinder, and one end of the wellbore 404 passes through an end face of the cylinder of the model device and is inserted into the inside of the rock sample , and the other end is exposed outside the model device and is connected with the extraction device 8 and the gas-liquid-solid separation device.

In a specific embodiment, the gas injection device includes a gas cylinder 101, a first valve 102, a gas booster pump 103, a first buffer tank 105, a first one-way valve 106 and a first back pressure valve 107 connected in sequence, the gas cylinder 101 is used to hold the simulated formation gas, and the outlet end of the first back pressure valve 107 communicates with the air inlet of the model device. One side of the gas booster pump 103 is also provided with an air compressor 104 . The air compressor 104 and the gas booster pump 103 pressurize the gas in the gas cylinder 101 and store it in the first buffer tank 105. The first buffer tank 105 is used to buffer the gas and prevent the pressure from directly impacting the first back pressure valve 107. , the pressure stability of the first back pressure valve 107 can be improved. A pressure regulating valve may also be provided between the first buffer tank 105 and the first back pressure valve 107 to adjust the pressure range of the entire gas injection pipeline.

The liquid injection device includes a liquid tank 201, a first injection pump 202, a second valve 203, a piston container 204, a second one-way valve 206 and a second back pressure valve 207 connected in sequence, and the liquid tank 201 is used to hold the simulated formation liquid , the outlet port of the second back pressure valve 207 communicates with the liquid inlet port of the model device. A first flow meter 205 is also arranged between the piston container 204 and the second one-way valve 206, which can effectively control the liquid flow on the liquid injection pipeline.

The present invention also includes a pressure control device for controlling the valve opening of the first back pressure valve 107 and the second back pressure valve 207, the pressure control device includes a second injection pump 301, a second buffer tank 302, a third valve 303 and The fourth valve 304, the second injection pump 301 is connected to the inlet of the second buffer tank 302, the outlet of the second buffer tank 302 is connected to the inlet of the third valve 303 and the fourth valve 304 respectively, the third valve 303 and the fourth valve The outlets of 304 communicate with the set pressure chambers of the first back pressure valve 107 and the second back pressure valve 207 respectively.

It should be noted that the working principle of the back pressure valve is to realize the action through the elastic force of the built-in spring: when the system pressure is smaller than the set pressure of the back pressure valve set pressure chamber, the diaphragm blocks the pipeline under the action of the spring force; When the system pressure is higher than the set pressure of the set pressure chamber of the back pressure valve, the diaphragm compresses the spring, the pipeline is connected, and the liquid passes through the back pressure valve. The second buffer tank 302 is used for buffering the pressure control medium.

In a specific embodiment, the gas-liquid-solid separation device includes a gas-liquid separator 701, a desiccant bottle 702, a second flow meter 703, a gas collection tank 704, a liquid storage tank 705, and an electronic scale 706. The inlet of the liquid separator 701 is connected, the gas outlet of the gas-liquid separator 701 is connected with the gas collection tank 704 through the desiccant bottle 702 and the second flow meter 703, the liquid outlet of the gas-liquid separator 701 is connected with the liquid storage tank 705, and the electronic The scale 706 is used to weigh the solid-liquid mixed medium in the liquid storage tank 705 .

In order to prevent some coal powder or sand and other particles and liquids in the model device from settling to the bottom of the wellbore inside the model device and not being extracted by the extraction device, another discharge pipe can be set up, and one end of the discharge pipe is connected to the outside of the core casing. The first chamber communicates with the other end of which communicates with the reservoir through the third one-way valve 707 or a common valve. When the third one-way valve 707 is used, the third one-way valve 707 is connected in one direction from the wellbore to the reservoir, and the direction from the reservoir to the wellbore is blocked. Close the third one-way valve 707 or the common valve during the test, after the test is over, shut down each device, open the third one-way valve 707 or the common valve, and the liquid remaining at the bottom of the first cavity can enter the storage tank under the action of gravity. In the liquid pool, to provide the accuracy of the test. The remaining particles such as coal powder in the well shaft 404 can be poured out from the well shaft after the test is completed, placed on the electronic scale 706 to measure the coal powder particles or sand particles, and measure the total sum of the two. By comparing the amount of sand produced, the total amount of particles and sand particles under the same conditions and their impact on the sand control effect are evaluated. Specifically, the criteria for judging the sand control effect are: under the same conditions, the less sand produced, the better the sand control effect; on the contrary, under the same conditions, the more sand produced, the worse the sand control effect.

The present invention also includes a vacuum device for vacuuming the interior of the model device, and the vacuum device includes a vacuum pump 501 .

The confining pressure control device includes a confining pressure pump 601, which is equivalent to a jack mechanism. The output end of the confining pressure pump 601 is a piston 602, and a first chamber is arranged between the rock core chamber 401 and the pad 402, and the piston 602 is arranged in the first chamber of the model device for providing the model device (that is, the pad 402). Formation stress. The first cavity of the model device can be provided with a piston 602 in multiple directions, so as to realize uniform pressure around the model device. It is sufficient that the pressure provided by the confining pressure pump 601 is consistent with the pressure of the simulated completion formation. Of course, the confining pressure control device may also include a pressure gauge for detecting the output pressure of the confining pressure pump 601 . The number of confining pressure control devices can also be designed to be multiple, and confining pressure control devices can be installed on each surface of the model device, and the loading confining pressure can be independently controlled in multiple spatial directions of X, Y, and Z.

In a specific embodiment, the extraction device 8 is a pumping unit, or an electric submersible pump, or a jet pump or a screw pump.

For vertical wells, pumping units can be selected, electric submersible pumps, jet pumps or other pumps can also be selected. For horizontal wells, electric submersible pumps, jet pumps or other pumps can be used. It can dynamically simulate the dynamic pumping process of vertical wells, horizontal wells or directional wells, and directly observe and study the process of pumping and draining.

The pumping unit mainly includes a burner head, a connecting rod reciprocating mechanism, a counterweight mechanism, a reduction box, a frequency modulation motor, a frequency modulation device and a cabinet support, etc. The pumping unit belongs to the power source of the up and down reciprocating motion of the vertical well simulation device. According to the working principle of the pumping unit, it takes the beam pumping unit as the prototype and scales it down into an experimental pumping unit. When the electric work of the pumping unit is reciprocating, it drives the plunger pump in the vertical well to move up and down, so that the liquid can be truly pumped out. Since the pumping unit belongs to the prior art, no more details are given here.

The above-mentioned devices are controlled and detected by various types of valves, temperature sensors and pressure sensors.

The data acquisition and processing device mainly includes: acquisition device, acquisition control and processing software, computer, etc. Timely collect the pressure, temperature, gas flow, liquid flow in each device, feedback control the pressure of the injection pump, and control the start and stop of each component. The data collected by the computer can be processed to generate raw data reports, analysis reports and graphs, etc., so that users can use them flexibly.

The evaluation device of the present invention considers the similarity between the model device and the actual formation in many aspects, carries out scheme design on the spot of the coal seam according to similar proportions, and performs physical simulation by means of the latest achievements of modern science and technology. An overall evaluation experiment of simulating the core casing 402 and the wellbore 404 under different well completion methods, sand control parameters, and different temperature and in-situ stress conditions. It can simulate the process of slowly producing sand or pulverized coal from the reservoir, so as to study the blockage of the well and the amount of sand or pulverized coal produced.

Completion methods include: open hole screen completion, open hole gravel packing completion, screen completion in casing, gravel packing completion in casing, and perforation completion; the optional screen types for core casing 402 and wellbore 404 include: High-quality screens such as slotting, wire wrapping, metal mesh and metal wool, etc. The through-holes on the completed wellbore 404 are adaptively designed in different shapes according to the above-mentioned screen pipe types.

In addition, the present invention also provides a coalbed methane well mining evaluation method, using the above coalbed methane well mining evaluation system, including the following steps:

S1. Clean and assemble the model device, fill the model device with corresponding rock samples according to the formation to be simulated and the completion method, and arrange the wellbore 404 according to the completion method;

S2. Install the model device, gas injection device, liquid injection device, confining pressure control device, extraction device 8, gas-liquid-solid separation device and data acquisition and processing device, and check the air tightness, and vacuumize the model device, and then load Confining pressure;

S3. Turn on the gas injection device, liquid injection device, extraction device 8, gas-liquid-solid separation device, and data acquisition and processing device. The gas injection device and the liquid injection device inject formation gas and formation liquid into the model device respectively. Maintain the injection pressure, temperature (the core chamber 401 can heat and control the temperature of the rock sample 403 inside it) and flow rate required for the test, and the data acquisition and processing device monitors the pressure difference of the model device (respectively referring to the outlet of the gas injection device and the model device). The pressure difference in the wellbore of the device, and the pressure difference between the outlet of the liquid injection device and the wellbore of the model device), the flow rate and total amount of the injected medium at the gas inlet and liquid inlet, and the weight of the gas separated by the gas-liquid-solid separation device and flow rate, as well as the weight of solid particles and liquid separated by the gas-liquid-solid separation device, the data acquisition and processing device records the dynamic parameters such as temperature, pressure and flow rate during the test, and analyzes and compares the parameters in the coalbed methane well development evaluation system .

Through the above method, the present invention can change the completion mode and sand control parameters, coal rock type, ground stress, formation temperature, formation pressure, formation coalbed gas production, formation water flow rate, concentration of coal powder or sand, pump in the extraction device, etc. Displacement and other factors, analyze the influence of coal dust or sand being carried and migrated, and provide test data under working conditions.

The judgment method for evaluating the influence of each parameter on the sand control effect is: under the same conditions (that is, under the same premise of other parameters, by adjusting the value of a certain parameter), the less sand produced, the better the sand control effect; on the contrary, the same Under certain conditions, the more sand produced, the worse the sand control effect.

The functions of the coalbed methane well mining evaluation system and evaluation method mainly include:

(1) According to the displacement mechanism and similarity principle, adopt advanced technology and control means to simulate formation pressure, stress and temperature conditions, and use the latest achievements of modern science and technology, such as computer technology, advanced sensor technology, automatic control technology, etc., to carry out Physical simulation test.

(2) It can dynamically simulate the dynamic pumping process of vertical wells, horizontal wells or directional wells, and visually observe and study the process of pumping and draining;

(3) The working principle of the pumping unit can be visually and visually simulated, and the water absorption and permeability of the coal seam plates in vertical wells, horizontal wells, and directional wells can be directly studied and observed, and the coal powder is carried and migrated in the well.

(4) Visually observe the carrying and migration of coal powder or sand in vertical wells or horizontal wells or directional wells, as well as the phenomenon of stuck pumps and blocked pipes, and study the causes of pump stuck and blocked pipes; in-depth study of sand control pipes The clogging mechanism can quickly gain regularity.

(5) Study the dynamic changes and influencing factors of coal powder or sand output in coalbed methane extraction. Study different completion methods and sand control parameters, coal sample types, in-situ stress, formation temperature, formation pressure, coalbed methane content, formation water flow rate, coal powder or sand concentration, pump displacement and other factors. Carryover and Migration Influence Laws.

In the description of this application, multiple means more than two. If the first and second are described for the purpose of distinguishing technical features, it cannot be understood as indicating or implying relative importance or implicitly indicating The number of technical features or implicitly indicates the order of the indicated technical features.

As indicated in this application and claims, the terms "a", "an", "an" and/or "the" do not refer to the singular and may include the plural unless the context clearly indicates an exception. Generally speaking, the terms "comprising" and "comprising" only suggest the inclusion of clearly identified steps and elements, and these steps and elements do not constitute an exclusive list, and the method or device may also contain other steps or elements. An element qualified by the phrase "comprising a ..." does not preclude the presence of additional identical elements in the process, method, article, or device that includes the element.

Among them, in the description of the embodiments of this application, unless otherwise specified, "/" means or means, for example, A/B can mean A or B; "and/or" in this article is only a description of associated objects The association relationship of indicates that there may be three kinds of relationships, for example, A and/or B may indicate: A exists alone, A and B exist simultaneously, and B exists independently. In addition, in the description of the embodiments of the present application, "plurality" refers to two or more than two.

In the description of this application, unless otherwise clearly defined, words such as setting, installation, and connection should be understood in a broad sense, and those skilled in the art can reasonably determine the specific meanings of the above words in this application in combination with the specific content of the technical solution.

Each embodiment in this specification is described in a progressive manner, each embodiment focuses on the difference from other embodiments, and the same and similar parts of each embodiment can be referred to each other.

In this paper, specific examples are used to illustrate the principle and implementation of the present invention, and the descriptions of the above embodiments are only used to help understand the method and core idea of the present invention. It should be pointed out that for those skilled in the art, without departing from the principle of the present invention, some improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims (10)

1. A coalbed methane well mining evaluation system, characterized in that it comprises: a model device, a gas injection device, a liquid injection device, a confining pressure control device, a drainage device, a gas-liquid-solid separation device and a data acquisition and processing device; The model device is used for simulating well bores and formations under different sand control completion methods; The gas injection device is used to inject the gas contained in the simulated formation into the model device; The liquid injection device is used to inject the liquid contained in the simulated formation into the model device; The extraction device is used to extract the mixed medium in the model device; The confining pressure control device is used to simulate and provide the formation stress suffered by the model device underground; The gas-liquid-solid separation device is used to separate the mixed medium extracted by the extraction device; The data acquisition and processing device is used to measure and collect data of the simulation device, the gas injection device, the liquid injection device and the gas-liquid-solid separation device. 2. The coalbed methane well production evaluation system according to claim 1, wherein the model device comprises a core chamber, a spacer, a rock sample wrapped with a core sleeve and a wellbore which are sequentially set from outside to inside, and the core chamber A first cavity is set between the pad and the pad, and through holes are set on the core casing, the pad and the wellbore, and the outlet ends of the gas injection device and the liquid injection device pass through the The core chamber communicates with the cushion block and the second cavity formed between the cushion block and the rock sample, and the output end of the confining pressure control device is arranged in the first cavity and is used to supply the pad One end of the wellbore is inserted into the interior of the rock sample, and the other end of the wellbore is exposed outside the model device and connected to the extraction device and the gas-liquid-solid separation device. 3. The coalbed methane well production evaluation system according to claim 2, characterized in that, the model device further comprises a rotating support, and the rotating support can rotate the connected core chamber. 4. The coalbed methane well production evaluation system according to claim 1, wherein the gas injection device comprises a gas cylinder connected in sequence, a first valve, a gas booster pump, a first buffer tank, and a first one-way valve and a first back pressure valve, the gas cylinder is used to contain the gas contained in the simulated formation, and the outlet port of the first back pressure valve communicates with the air inlet of the model device. 5. The coalbed methane well production evaluation system according to claim 4, wherein the liquid injection device comprises a liquid tank, a first injection pump, a second valve, a piston container, a second one-way valve, and a second one-way valve connected in sequence. Two back pressure valves, the liquid tank is used to store the liquid contained in the simulated formation, and the outlet port of the second back pressure valve communicates with the liquid inlet of the model device. 6. The coalbed methane well production evaluation system according to claim 5, further comprising a pressure control device for controlling the valve opening of the first back pressure valve and the second back pressure valve, the The pressure control device includes a second injection pump, a second buffer tank, a third valve and a fourth valve, the second injection pump is connected to the inlet of the second buffer tank, and the outlet of the second buffer tank is respectively connected to the The inlets of the third valve and the fourth valve are connected, and the outlets of the third valve and the fourth valve are respectively communicated with the set pressure chambers of the first back pressure valve and the second back pressure valve. 7. The coalbed methane well production evaluation system according to claim 1, wherein the gas-liquid-solid separation device includes a gas-liquid separator, a desiccant bottle, a second flow meter, a gas collection tank, a liquid storage tank, and an electronic scale, the wellbore outlet of the model device is communicated with the inlet of the gas-liquid separator, and the gas outlet of the gas-liquid separator is communicated with the gas collection tank through the desiccant bottle and the second flowmeter, The liquid outlet of the gas-liquid separator communicates with the liquid storage tank, and the electronic scale is used for weighing the liquid storage tank. 8. The coalbed methane well production evaluation system according to claim 1, further comprising a vacuum device for vacuuming the inside of the model device; And/or, the confining pressure control device includes a confining pressure pump, the output end of the confining pressure pump is a piston, and the piston is used to provide formation stress to the model device. 9. The coalbed methane well production evaluation system according to claim 1, wherein the extraction device is an oil pumping unit, or an electric submersible pump, or a jet pump, or a screw pump. 10. A coalbed methane well mining evaluation method, characterized in that the application of the coalbed methane well mining evaluation system according to claim 2 comprises the following steps: S1. Clean and assemble the model device, fill the model device with corresponding rock samples according to the formation to be simulated and the completion method, and arrange the wellbore according to the completion method; S2. Install the model device, the gas injection device, the liquid injection device, the confining pressure control device, the extraction device, the gas-liquid-solid separation device, and the data acquisition and processing device, and check Airtightness, and vacuumize the model device, and then load the confining pressure; S3. Turn on the gas injection device, the liquid injection device, the extraction device, the gas-liquid-solid separation device, and the data collection and processing device; the gas injection device and the liquid injection device send to the The model device injects formation gas and formation liquid respectively, and maintains the required injection pressure, temperature and flow rate during the test. The data acquisition and processing device monitors the outlet of the gas injection device and the pressure in the wellbore of the model device. difference, and the pressure difference between the outlet of the liquid injection device and the wellbore of the model device, the flow rate and total amount of the injection medium at the gas inlet and the liquid inlet, and the weight of the gas separated by the gas-liquid-solid separation device and flow rate, and the weight of solid particles and liquid separated by the gas-liquid-solid separation device, the data acquisition and processing device records the temperature, pressure, and flow dynamic parameters in the test process, and each item in the coalbed methane well development evaluation system The parameters were analyzed and compared.