A full bore plugging tester and a test method thereof

Abstract

The present application belongs to the technical field of drilling fluid performance testing in the oil and gas industry, and particularly relates to a full wellbore plugging tester and a testing method thereof. The full wellbore plugging tester comprises a simulation wellbore outer tube, an artificial well wall, a cylindrical filter screen, a simulation wellbore inner tube, an inner tube support, an inner tube support lifting ring, a stirring motor, a simulation nozzle, a base, a support rod, a wellbore inclination adjustment rod, a liquid storage tank, a pressurizing mechanism, a heating mechanism and a filtrate collection mechanism. The present application can simulate the plugging performance of drilling fluid under the conditions of circulation, pressurization, heating and wellbore inclination in a real wellbore, and can simulate the real conditions in the drilling wellbore to a high degree, so that the experimental data can better guide the field production. The present application has high simulation degree, simple structure, low manufacturing cost, simple operation, safety and reliability, and is conducive to popularization and application to scientific research and production units.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of drilling fluid performance testing in the oil and gas industry, and particularly relates to a full wellbore plugging tester and a testing method thereof. BACKGROUND

[0002] The plugging property of a drilling fluid is an important index for judging the performance of the drilling fluid. The plugging particles in the drilling fluid with good plugging property can plug the micro-pores and micro-cracks in the near-wellbore formation, and the free water in the drilling fluid is not easy to enter the formation through the micro-pores and micro-cracks, thereby reducing the hydration dispersion degree of clay in the formation, reducing the hydraulic wedge effect, and enhancing the wellbore stability. To improve the plugging property of the drilling fluid, the nanometer and micrometer plugging materials in the drilling fluid need to be matched with the micro-pores and micro-cracks in the formation to form effective plugging, inhibit the free water in the drilling fluid from entering the formation, and thereby improve the anti-sloughing performance of the drilling fluid.

[0003] At present, there is no ideal drilling fluid plugging property measuring instrument. Generally, the plugging property is evaluated by the filtration loss, and a small amount of plugging property measuring instruments measure the plugging property of static drilling fluid, which has a large difference from the plugging effect of the flowing drilling fluid in the wellbore, and the experimental data cannot well guide the field construction. SUMMARY

[0004] The application provides a full wellbore plugging tester and a testing method thereof, and one of the purposes is to provide a device and method that can simulate the real conditions in the drilling wellbore to a higher degree, so as to better guide the field production with the experimental data.

[0005] To achieve the above-mentioned purposes, the technical scheme adopted by the application is:

[0006] The application discloses a full wellbore plugging tester, which comprises a simulation wellbore outer cylinder, an artificial well wall, a cylindrical filter screen, a simulation wellbore inner cylinder, an inner cylinder support, an inner cylinder support lifting ring, a stirring motor, a simulation nozzle, a base, a support rod, a wellbore inclination adjusting rod, a liquid storage tank, a pressurizing mechanism, a heating mechanism and a filtrate collecting mechanism; the support rod and the wellbore inclination adjusting rod are vertically fixed on the two sides of the base respectively; the two ends of the simulation wellbore outer cylinder are horizontally fixed on the base through the support rod and the wellbore inclination adjusting rod; the front end and the rear end of the simulation wellbore outer cylinder are respectively sealingly connected with an outer cylinder top cover plate and an outer cylinder bottom cover plate; the simulation wellbore outer cylinder is internally provided with the artificial well wall, the inner side wall of the artificial well wall is provided with the cylindrical filter screen, and the two ends of the artificial well wall and the cylindrical filter screen are fixed on the outer cylinder top cover plate and the outer cylinder bottom cover plate respectively; there is a gap between the simulation wellbore outer cylinder and the artificial well wall; a plurality of inner cylinder supports which are vertically arranged and have the same length are connected to the inner side wall of the upper part of the simulation wellbore outer cylinder, the bottom end of each inner cylinder support is connected with an inner cylinder support lifting ring, and the simulation wellbore inner cylinder is fixed in the simulation wellbore outer cylinder through the plurality of inner cylinder support lifting rings; the outer cylinder top cover plate is connected with a shaft coupling, a liquid inlet pipe and a liquid outlet pipe, the outer end of the shaft coupling is connected with the stirring motor arranged outside the simulation wellbore outer cylinder, the inner end of the shaft coupling is connected with one end of the simulation wellbore inner cylinder, the inner end pipe opening of the liquid inlet pipe extends to the inside of the simulation wellbore inner cylinder, the inner end pipe opening of the liquid outlet pipe extends to the annular space between the simulation wellbore outer cylinder and the simulation wellbore inner cylinder, and the outer end pipe openings of the liquid inlet pipe and the liquid outlet pipe are connected with the liquid storage tank respectively; the outer cylinder bottom cover plate is connected with the heating mechanism and the pressurizing mechanism; the rear end of the simulation wellbore inner cylinder is connected with the simulation nozzle; and the filtrate collecting mechanism is connected to the bottom of the simulation wellbore outer cylinder.

[0007] The pressure resistance range of the simulation wellbore outer cylinder and the simulation wellbore inner cylinder is 0-10 MPa, and the temperature range is room temperature-150 DEG C; the simulation wellbore outer cylinder is a hollow cylinder with open two ends; the inner diameter is 117 mm-311 mm, and the length is 0.5-50 m.

[0008] The artificial well wall is a hollow annular structure with a porosity of 0.05-200 mu m, which is made of one or more of high polymer elastic materials, nano materials, metal materials, ceramic and sand.

[0009] The simulation wellbore inner cylinder comprises a plurality of cylinder bodies and a plurality of inner cylinder couplings; the adjacent cylinder bodies are connected through the inner cylinder couplings; each cylinder body is a hollow cylinder, the outer diameter is 89 mm-152 mm; the outer diameter of the inner cylinder coupling is 100-300% of the outer diameter of the simulation wellbore inner cylinder; and the total length of the simulation wellbore inner cylinder is 0.3-49 m.

[0010] The filtrate collection mechanism comprises a filtrate drainage filter screen, a filtrate drainage pipe and a filtrate collection box; the filtrate drainage filter screen is connected to the lower inner side wall of the simulation well shaft outer cylinder, and the filtrate collection box is fixedly connected to the outer side wall of the lower part of the simulation well shaft outer cylinder; the filtrate drainage filter screen and the filtrate collection box are communicated through the filtrate drainage pipe; a valve is arranged on the filtrate drainage pipe of the simulation well shaft outer cylinder.

[0011] The liquid storage tank comprises a tank body, a liquid supply pump and a liquid supply pump controller; the liquid supply pump is arranged in the interior of the tank body; the outer end of the liquid inlet pipe is connected with the liquid supply pump; the outer end of the liquid outlet pipe is communicated with the interior of the tank body; the liquid supply pump controller is connected to the tank body and electrically connected with the liquid supply pump.

[0012] The pressurizing mechanism comprises an air source pressure reducer and an air inlet valve rod; one end of the air inlet valve rod is communicated with the interior of the simulation well shaft outer cylinder through the outer cylinder bottom surface cover plate, and the other end of the air inlet valve rod is connected with the air source pressure reducer.

[0013] The heating mechanism adopts an electric heating rod; the electric heating rod is connected to the outer cylinder bottom surface cover plate; the front end of the electric heating rod extends into the annular space between the simulation well shaft outer cylinder and the simulation well shaft inner cylinder; the liquid supply pump is an adjustable displacement pump, and the displacement range is 0-15 L / s.

[0014] A test method of a full well shaft plugging tester, comprising the following steps,

[0015] Step one: fix the cylindrical filter screen on the outer cylinder top surface cover plate, then install the artificial well wall outside the cylindrical filter screen and fix it on the outer cylinder top surface cover plate, then install the outer cylinder bottom surface cover plate on the artificial well shaft outer cylinder, at the same time, install the cylindrical filter screen and the artificial well wall into the clamping groove of the outer cylinder bottom surface cover plate, connect the heating mechanism and the pressurizing mechanism, and close the filtrate drainage pipe;

[0016] Step two: adjust the height of the well shaft inclination adjustment rod to adjust the simulation well shaft outer cylinder to the required inclination angle;

[0017] Step three: fill the drilling fluid to be tested in the liquid storage tank; first, use the 4-8 L / s small displacement of the liquid supply pump in the liquid storage tank to fill the drilling fluid to be tested into the simulation well shaft outer cylinder and the simulation well shaft inner cylinder until they are filled, and establish the circulation between the liquid storage tank and the simulation well shaft outer cylinder and the simulation well shaft inner cylinder;

[0018] Step four: start the stirring motor to make the rotation speed of the simulation well shaft inner cylinder reach the preset rotation speed required by the test;

[0019] Step five: when the temperature and pressure of the annular space between the simulation well shaft outer cylinder and the simulation well shaft inner cylinder reach the preset values of the test, adjust the displacement of the liquid supply pump in the liquid storage tank to the preset displacement of the test, and start timing;

[0020] Step five: after the end of the test time, the simulation wellbore outer tube is reset to the horizontal position, the filtrate flow guide pipe is opened, the filtrate flows into the filtrate collection box, and the filtrate volume is measured and recorded.

[0021] The simulation wellbore outer tube can be adjusted to a range of 30-90° by the wellbore inclination adjustment rod, and the inclination is the included angle between the axis of the simulation wellbore outer tube and the plumb line; the simulation wellbore inner tube rotates under the driving of the stirring motor and the shaft coupling, and the rotating speed ranges from 0 to 300 rpm.

[0022] Beneficial effects:

[0023] (1) The present application can simulate the plugging performance of the drilling fluid under the conditions of circulation, pressurization, heating and wellbore inclination in the real wellbore, and can imitate the real conditions in the drilling wellbore to a higher degree, so that the experimental data can better guide the field production.

[0024] (2) The present application is simple and safe to operate.

[0025] (3) The present application has high simulation degree, simple structure and low manufacturing cost, and is conducive to popularization to scientific research and production units.

[0026] The above description is only a summary of the technical scheme of the present application, in order to more clearly understand the technical means of the present application, and can be implemented according to the content of the specification, as follows. BRIEF DESCRIPTION OF DRAWINGS

[0027] In order to more clearly illustrate the technical scheme in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creating laborious work.

[0028] Figure 1 The present application is a structural schematic diagram.

[0029] In the figure: 1, simulation wellbore outer tube; 2, artificial well wall; 3, cylindrical filter screen; 4, simulation wellbore inner tube; 5, inner tube coupling; 6, simulation nozzle; 7, outer tube bottom cover plate; 8, outer tube top cover plate; 9, shaft coupling; 10, stirring motor; 11, electric heating rod; 12, gas source pressure reducer; 13, filtrate drainage filter screen; 14, filtrate flow guide pipe; 15, filtrate collection box; 16, base; 17, support rod; 18, wellbore inclination adjustment rod; 19, liquid inlet pipe; 20, liquid outlet pipe; 21, liquid storage tank; 22, liquid supply pump; 23, liquid supply pump controller; 24, inner tube support; 25, inner tube support lifting ring; 26, tank body; 27, air inlet valve rod. DETAILED DESCRIPTION

[0030] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of the present application.

[0031] Embodiment one:

[0032] According to Figure 1 As shown in a full wellbore plugging tester, comprising a simulation wellbore outer cylinder 1, an artificial well wall 2, a cylindrical filter screen 3, a simulation wellbore inner cylinder 4, an inner cylinder support 24, an inner cylinder support lifting ring 25, a stirring motor 10, a simulation nozzle 6, a base 16, a support rod 17, a wellbore inclination adjusting rod 18, a liquid storage tank 21, a pressurizing mechanism, a heating mechanism and a filtrate collecting mechanism; the support rod 17 and the wellbore inclination adjusting rod 18 are respectively vertically fixed on both sides of the base 16; the two ends of the simulation wellbore outer cylinder 1 are horizontally fixed on the base 16 through the support rod 17 and the wellbore inclination adjusting rod 18; the front and rear ends of the simulation wellbore outer cylinder 1 are respectively sealingly connected with an outer cylinder top cover plate 8 and an outer cylinder bottom cover plate 7; the simulation wellbore outer cylinder 1 is provided with the artificial well wall 2, the inner side wall of the artificial well wall 2 is provided with the cylindrical filter screen 3, and the two ends of the artificial well wall 2 and the cylindrical filter screen 3 are respectively fixed on the outer cylinder top cover plate 8 and the outer cylinder bottom cover plate 7; there is a gap between the simulation wellbore outer cylinder 1 and the artificial well wall 2; a plurality of vertically arranged inner cylinder supports 24 with the same length are connected to the inner side wall of the upper part of the simulation wellbore outer cylinder 1, the bottom end of each inner cylinder support 24 is connected with an inner cylinder support lifting ring 25, and the simulation wellbore inner cylinder 4 is fixed in the inside of the simulation wellbore outer cylinder 1 through the plurality of inner cylinder support lifting rings 25; the outer cylinder top cover plate 8 is connected with a shaft coupling 9, a liquid inlet pipe 19 and a liquid outlet pipe 20, the outer end of the shaft coupling 9 is connected with the stirring motor 10 placed outside the simulation wellbore outer cylinder 1, the inner end of the shaft coupling 9 is connected with one end of the simulation wellbore inner cylinder 4, the inner end pipe opening of the liquid inlet pipe 19 extends to the inside of the simulation wellbore inner cylinder 4, the inner end pipe opening of the liquid outlet pipe 20 extends to the annulus between the simulation wellbore outer cylinder 1 and the simulation wellbore inner cylinder 4, and the outer end pipe openings of the liquid inlet pipe 19 and the liquid outlet pipe 20 are respectively connected with the liquid storage tank 21; the outer cylinder bottom cover plate 7 is connected with the heating mechanism and the pressurizing mechanism; the rear end of the simulation wellbore inner cylinder 4 is connected with the simulation nozzle 6; and the filtrate collecting mechanism is connected to the bottom of the simulation wellbore outer cylinder 1.

[0033] In actual use, in order to facilitate the installation and fixation of the artificial well wall 2 and the cylindrical filter screen 3, a clamping groove is arranged on the inner side wall of the outer cylinder bottom cover plate 7.

[0034] In specific use, first, one end of the cylindrical filter screen 3 is fixed on the outer cylinder top cover plate 8, then the artificial well wall 2 is placed outside the cylindrical filter screen 3, and one end thereof is fixed on the outer cylinder top cover plate 8, after that, the outer cylinder bottom cover plate 7 is installed on the simulation well cylinder outer cylinder 1, at the same time, the cylindrical filter screen 3 and the artificial well wall 2 are installed in the clamping groove of the outer cylinder bottom cover plate 7, the heating mechanism and the pressurizing mechanism are connected, and the filtrate collecting mechanism is closed. Subsequently, the height of the well cylinder inclination adjusting rod 18 is adjusted, and the simulation well cylinder outer cylinder 1 is adjusted to the required inclination angle; after that, the drilling fluid to be tested is filled in the liquid storage tank 21, the liquid storage tank 21 is first filled with the drilling fluid to be tested at a small discharge of 4-8 L / s through the liquid inlet pipe 19 to the simulation well cylinder inner cylinder 4, and the drilling fluid to be tested enters the annulus between the simulation well cylinder inner cylinder 4 and the simulation well cylinder outer cylinder 1, until it is filled. After the circulation between the liquid storage tank 21 and the simulation well cylinder outer cylinder 1 and the simulation well cylinder inner cylinder 4 is established, the stirring motor 10 is started, under the driving of the stirring motor 10, the simulation well cylinder inner cylinder 4 rotates, and the rotation speed of the simulation well cylinder inner cylinder 4 reaches the preset value required by the test; when the temperature and pressure of the annulus between the simulation well cylinder outer cylinder 1 and the simulation well cylinder inner cylinder 4 reach the preset values required by the test, the discharge of the liquid storage tank 21 is adjusted to the preset discharge required by the test, and the timing is started; under the action of the pressure, the drilling fluid to be tested penetrates through the artificial well wall 2 to generate filtrate, and the filtrate flows into the annulus between the artificial well wall 2 and the simulation well cylinder outer cylinder 1. After the test time is over, the simulation well cylinder outer cylinder 1 is reset to the horizontal position, the filtrate collecting mechanism is opened, and the filtrate flowing into the annulus between the artificial well wall 2 and the simulation well cylinder outer cylinder 1 is collected and recorded, and the test is over. The smaller the volume of the collected filtrate is, the better.

[0035] The simulation well cylinder inner cylinder 4 after the embodiment can rotate under the driving of the stirring motor 10 and the shaft coupling 9, and the rotation speed range is 0-300 rpm.

[0036] In order to ensure that the simulation well cylinder inner cylinder 4 normally operates under the driving of the stirring motor 10, one rotary seal is connected to each end of the shaft coupling 9, one rotary seal is used for connection with the simulation well cylinder inner cylinder 4, and the other rotary seal is connected with the liquid inlet pipe 19, so that the drilling fluid enters the simulation well cylinder inner cylinder 4 under the rotation of the inner cylinder.

[0037] The support rod 17 in the embodiment has a fixed length and cannot be changed; the length of the well cylinder inclination adjusting rod 18 can be elongated or shortened, and the inclination angle of the simulation well cylinder outer cylinder 1 is changed by changing the length of the well cylinder inclination adjusting rod 18. In the initial state, the lengths of the well cylinder inclination adjusting rod 18 and the support rod 17 are equal.

[0038] The technical solution of this invention can simulate the sealing performance of drilling fluid under circulation, pressurization, and heating conditions in a real wellbore, closely mimicking the actual conditions inside the wellbore and enabling experimental data to better guide field production. This invention is simple to operate, safe and reliable, and features high simulation accuracy, simple structure, and low manufacturing cost, making it suitable for widespread application.

[0039] Example 2:

[0040] according to Figure 1 The full wellbore plugging test instrument shown differs from Embodiment 1 in that: the pressure resistance range of the simulated wellbore outer cylinder 1 and the simulated wellbore inner cylinder 4 is 0-10MPa and the temperature range is room temperature-150℃; the simulated wellbore outer cylinder 1 is a hollow cylinder with open ends; its inner diameter is 117mm-311mm and its length is 0.5-50m.

[0041] In practical use, the simulated well outer cylinder 1 and simulated well inner cylinder 4 adopt the above technical solution, which can meet the real pressure, temperature and fluid flow conditions inside the drilling well, so that the obtained test data can well guide the on-site construction.

[0042] Example 3:

[0043] according to Figure 1 The full wellbore plugging test instrument shown differs from Example 1 in that the artificial well wall 2 is a hollow ring-shaped structure with a porosity of 0.05μm-200μm, made of one or more of the following materials: polymer elastic material, nanomaterial, metal material, ceramic and sand.

[0044] In practical use, under pressure, the drilling fluid to be tested permeates through the artificial well wall 2 to produce filtrate, which flows into the annulus between the artificial well wall 2 and the simulated well outer cylinder 1. Therefore, this invention can obtain an artificial well wall 2 that meets the porosity requirements of a real well wall, making the test results closer to reality and providing guidance for on-site operations.

[0045] In practical applications, the following materials and processing methods can be used to make artificial well walls 2.

[0046] A. Artificial well walls with different porosities (0.05μm-200μm) are formed by compression molding or injection molding of high-temperature resistant plastics or rubber and by intelligent laser treatment.

[0047] B. It is made of plastic and rubber in a ratio of 6:4 to 4:6, and has a certain elasticity. It is formed by laser drilling to create artificial well walls with different porosities (0.05μm-200μm).

[0048] C. By pressing injection molding of clay under different pressures, firing, forming a porosity of 0.05 μm-200 μm artificial well wall.

[0049] D. By adding crosslinking agent in different particle size of quartz sand, pressure casting under different pressures, forming a porosity of 0.05 μm-200 μm artificial well wall.

[0050] In the prior art, as long as the material has a certain strength and can be made into a certain porosity.

[0051] Example four:

[0052] According to Figure 1 A full wellbore sealing test instrument is shown in FIG. 1, which is different from example one in that the simulation wellbore inner cylinder 4 includes multiple cylinder sections and multiple inner cylinder joints 5; adjacent cylinder sections are connected through the inner cylinder joints 5; each of the cylinder sections is a hollow cylinder with an outer diameter of 89 mm-152 mm; the outer diameter of the inner cylinder joint 5 is 100-300% of the outer diameter of the simulation wellbore inner cylinder 4; and the total length of the simulation wellbore inner cylinder 4 is 0.3-49 m.

[0053] In actual use, the cylinder section is a hollow cylinder, which can make the fluid flow inside it. The outer diameter of the inner cylinder joint 5 is 100-300% of the outer diameter of the simulation wellbore inner cylinder 4, which is to simulate the drill tool joint in the actual drilling process, so as to evaluate the influence of the joint on the flow pattern and flow rate of the drilling fluid in the wellbore, and the influence of the flow pattern and flow rate of the drilling fluid on the cuttings transport after the change.

[0054] Example five:

[0055] According to Figure 1 A full wellbore sealing test instrument is shown in FIG. 1, which is different from example one in that the simulation wellbore inner cylinder 4 includes multiple cylinder sections and multiple inner cylinder joints 5; adjacent cylinder sections are connected through the inner cylinder joints 5; each of the cylinder sections is a hollow cylinder with an outer diameter of 89 mm-152 mm; the outer diameter of the inner cylinder joint 5 is 100-300% of the outer diameter of the simulation wellbore inner cylinder 4; and the total length of the simulation wellbore inner cylinder 4 is 0.3-49 m.

[0056] In actual use, under the action of pressure, the drilling fluid to be tested penetrates through the artificial well wall 2 to generate filtrate, which flows to the annulus between the artificial well wall 2 and the simulation wellbore outer cylinder 1. After the test is completed, the filtrate flowing to the annulus between the artificial well wall 2 and the simulation wellbore outer cylinder 1 can be collected in the filtrate collection box 15 through the filtrate drainage filter screen 13 and the filtrate flow guide pipe 14. The amount of filtrate collected in the filtrate collection box 15 is used to evaluate the sealing performance of the drilling fluid. The smaller the volume of the filtrate, the better the sealing performance of the drilling fluid.

[0057] Example 6

[0058] According to Figure 1 The difference between the full wellbore plugging tester shown in FIG. 6 and example 1 is that the liquid storage tank 21 comprises a tank body 26, a liquid supply pump 22 and a liquid supply pump controller 23; the liquid supply pump 22 is arranged inside the tank body 26; the outer end of the liquid inlet pipe 19 is connected with the liquid supply pump 22; the outer end of the liquid outlet pipe 20 is in communication with the inside of the tank body 26; the liquid supply pump controller 23 is connected on the tank body 26, and the liquid supply pump controller 23 is electrically connected with the liquid supply pump 22.

[0059] In actual use, the opening of the liquid supply pump 22 is controlled by the liquid supply pump controller 23. The drilling fluid to be tested in the liquid storage tank 21 enters the simulation wellbore inner cylinder 4 through the liquid inlet pipe 22 under the action of the liquid supply pump 22, and then enters the annulus between the simulation wellbore inner cylinder 4 and the simulation wellbore outer cylinder 1 through the simulation nozzle 6 connected at the rear end of the simulation wellbore inner cylinder 4. The drilling fluid in the annulus can also return to the tank body 26 through the liquid outlet pipe 20, thereby establishing circulation of the drilling fluid to be tested between the liquid storage tank 21, the simulation wellbore outer cylinder 1 and the simulation wellbore inner cylinder 4.

[0060] The liquid supply pump controller 23 in this example is a prior art device for controlling the opening, closing and displacement of the liquid supply pump 22.

[0061] Example 7

[0062] According to Figure 1 The difference between the full wellbore plugging tester shown in FIG. 7 and example 1 is that the pressurizing mechanism comprises a gas source pressure reducer 12 and an air inlet valve rod 27; one end of the air inlet valve rod 27 is in communication with the inside of the simulation wellbore outer cylinder 1 through the outer cylinder bottom surface cover plate 7, and the other end of the air inlet valve rod 27 is connected with the gas source pressure reducer 12.

[0063] In actual use, the external gas source is adjusted in pressure by the gas source pressure reducer 12, and then input into the annulus between the simulation wellbore outer cylinder 1 and the simulation wellbore inner cylinder 4 through the air inlet valve rod 27, thereby ensuring the supply and stability of the pressure in the annulus and ensuring that the test is closer to the actual downhole pressure, thereby providing support for subsequent tests.

[0064] Example 8

[0065] According to Figure 1 The difference between the full wellbore plugging tester shown in FIG. 8 and example 1 is that the heating mechanism adopts an electric heating rod 11; the electric heating rod 11 is connected on the outer cylinder bottom surface cover plate 7; the front end of the electric heating rod 11 extends into the annulus between the simulation wellbore outer cylinder 1 and the simulation wellbore inner cylinder 4; and the liquid supply pump 22 is an adjustable displacement pump with a displacement range of 0-15 L / s.

[0066] In actual use, the heating end of the electric heating rod 11, i.e., the front end, is located in the annulus between the outer cylinder 1 and the inner cylinder 4 of the simulated wellbore, so as to heat the drilling fluid in the annulus, and the rear end of the electric heating rod 11 is connected with the external power supply.

[0067] The technical scheme of heating by the electric heating rod 11 makes the heating operation more flexible and convenient, and the cost is relatively low.

[0068] The liquid supply pump 22 in the embodiment is an adjustable displacement pump, and the displacement range is 0-15 L / s. In this way, the flow rate required for the drilling fluid in the circulation in the test can be met, and the cost can be saved.

[0069] Embodiment Nine:

[0070] A test method of a full wellbore plugging tester, comprising the following steps,

[0071] Step one: fix the cylindrical filter screen 3 on the outer cylinder top cover plate 8, then install the artificial well wall 2 outside the cylindrical filter screen, fix the artificial well wall on the outer cylinder top cover plate, then install the outer cylinder bottom cover plate on the artificial wellbore outer cylinder, at the same time, install the cylindrical filter screen and the artificial well wall in the clamping groove of the outer cylinder bottom cover plate, connect the heating mechanism and the pressurizing mechanism, and close the filtrate flow guide pipe 14;

[0072] Step two: adjust the height of the wellbore inclination adjusting rod 18, and adjust the simulated wellbore outer cylinder 1 to the required inclination angle;

[0073] Step three: pour the drilling fluid to be tested in the liquid storage tank 21, and first use the 4-8 L / s small displacement of the liquid supply pump 22 in the liquid storage tank 21 to fill the drilling fluid to be tested into the simulated wellbore outer cylinder 1 and the simulated wellbore inner cylinder 4 until the simulated wellbore outer cylinder 1 and the simulated wellbore inner cylinder 4 are filled, and the circulation between the liquid storage tank 21 and the simulated wellbore outer cylinder 1 and the simulated wellbore inner cylinder 4 is established;

[0074] Step four: start the stirring motor 10, so that the rotating speed of the simulated wellbore inner cylinder 4 reaches the preset rotating speed required by the test;

[0075] Step five: when the temperature and pressure in the annulus between the simulated wellbore outer cylinder 1 and the simulated wellbore inner cylinder 4 reach the preset values of the test, adjust the displacement of the liquid supply pump 22 in the liquid storage tank 21 to the preset displacement of the test, and start timing;

[0076] Step five: after the test time is over, reset the simulated wellbore outer cylinder 1 to the horizontal position, open the filtrate flow guide pipe 14, so that the filtrate flows into the filtrate collection box 15, and measure and record the volume of the filtrate.

[0077] Further, the simulation wellbore outer tube 1 can be adjusted to a range of 30-90 degrees by the wellbore inclination adjusting rod 18, the inclination being the angle between the axis of the simulation wellbore outer tube 1 and the plumb line; the simulation wellbore inner tube 4 is rotated under the driving of the stirring motor 10 and the shaft coupling 9, and the rotating speed ranges from 0 to 300 rpm.

[0078] The present application can simulate the sealing performance of drilling fluid in a real wellbore under the conditions of circulation, pressurization, heating and wellbore inclination, and can simulate the real conditions in the drilling wellbore to a higher degree, so that the experimental data can better guide the field production.

[0079] In the case of no conflict, the skilled in the art can combine the technical features related in the above examples according to the actual situation to achieve the corresponding technical effects, and the specific combinations are not described one by one here.

[0080] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present application are only used to explain the relative positional relationship, movement condition, etc. between the components in a certain specific posture (as shown in the drawings), and if the specific posture changes, the directional indications will also change accordingly.

[0081] In addition, the description of "first", "second" and the like in the present application is only for the purpose of description, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first", "second" can explicitly or implicitly include at least one of the features.

[0082] The above is only the preferred embodiment of the present application, and the present application will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein. Any simple modification, equivalent change and modification of the above embodiments according to the technical essence of the present application are still within the scope of the technical scheme of the present application.

Claims

1. A full-wellbore plugging test apparatus, characterized in that: The system includes a simulated well outer cylinder (1), an artificial well wall (2), a cylindrical filter screen (3), a simulated well inner cylinder (4), an inner cylinder support (24), an inner cylinder support lifting ring (25), a stirring motor (10), a simulated nozzle (6), a base (16), a support rod (17), a well inclination adjustment rod (18), a storage tank (21), a pressurizing mechanism, a heating mechanism, and a filtrate collection mechanism; the support rod (17) and the well inclination adjustment rod (18) are respectively vertically fixed on both sides of the base (16); the two ends of the simulated well outer cylinder (1) are connected by the support rod (17). The wellbore slope adjustment rod (18) is horizontally fixed on the base (16); the front and rear ends of the simulated wellbore outer cylinder (1) are respectively sealed with the top cover plate (8) and the bottom cover plate (7); an artificial well wall (2) is provided inside the simulated wellbore outer cylinder (1), and a cylindrical filter screen (3) is provided on the inner side wall of the artificial well wall (2). The two ends of the artificial well wall (2) and the cylindrical filter screen (3) are respectively fixed on the top cover plate (8) and the bottom cover plate (7) of the outer cylinder; there is a gap between the simulated wellbore outer cylinder (1) and the artificial well wall (2); the simulated wellbore outer cylinder (1) and the artificial well wall (2) are respectively fixed on the top cover plate (8) and the bottom cover plate (7) of the outer cylinder; Multiple vertically arranged inner cylinder supports (24) of the same length are connected to the upper inner wall of the cylinder (1). The bottom end of each inner cylinder support (24) is connected to an inner cylinder support lifting ring (25). The simulated well cylinder inner cylinder (4) is fixed inside the simulated well cylinder outer cylinder (1) by multiple inner cylinder support lifting rings (25). A coupling (9), an inlet pipe (19), and an outlet pipe (20) are connected to the top cover plate (8) of the outer cylinder. The outer end of the coupling (9) is connected to the stirring motor (10) placed outside the simulated well cylinder outer cylinder (1), and the inner end of the coupling (9) is connected to the stirring motor (10) placed outside the simulated well cylinder outer cylinder (1). One end of the simulated well inner cylinder (4) is connected to the inner end of the inlet pipe (19) which extends into the interior of the simulated well inner cylinder (4), and the inner end of the outlet pipe (20) which extends into the annulus between the simulated well outer cylinder (1) and the simulated well inner cylinder (4). The outer ends of the inlet pipe (19) and the outlet pipe (20) are respectively connected to the storage tank (21). A heating mechanism and a pressurizing mechanism are connected to the bottom cover plate (7) of the outer cylinder. A simulated nozzle (6) is connected to the rear end of the simulated well inner cylinder (4). The filtrate collection mechanism is connected to the bottom of the simulated well outer cylinder (1).

2. The full wellbore plugging test apparatus as described in claim 1, characterized in that: The simulated well outer cylinder (1) and simulated well inner cylinder (4) have a pressure resistance range of 0-10MPa and a temperature range of room temperature-150℃. The simulated well outer cylinder (1) is a hollow cylinder with open ends. Its inner diameter is 117mm-311mm and its length is 0.5-50m.

3. The full wellbore plugging test apparatus as described in claim 1, characterized in that: The artificial well wall (2) is a hollow ring-shaped structure with a porosity of 0.05μm-200μm, made of one or more of the following materials: polymer elastic material, nanomaterial, metal material, ceramic and sand.

4. The full wellbore plugging test apparatus as described in claim 1, characterized in that: The simulated wellbore inner cylinder (4) includes multiple cylinder sections and multiple inner cylinder couplings (5); adjacent cylinder sections are connected by inner cylinder couplings (5); each cylinder section is a hollow cylinder with an outer diameter of 89mm-152mm; the outer diameter of the inner cylinder coupling (5) is 100-300% of the outer diameter of the simulated wellbore inner cylinder (4); the total length of the simulated wellbore inner cylinder (4) is 0.3-49m.

5. The full wellbore plugging test apparatus as described in claim 1, characterized in that: The filtrate collection mechanism includes a filtrate diversion filter (13), a filtrate guide pipe (14), and a filtrate collection box (15). The filtrate diversion filter (13) is connected to the lower inner wall of the outer cylinder (1) of the simulated well, and the filtrate collection box (15) is fixedly connected to the lower outer wall of the outer cylinder (1) of the simulated well. The filtrate diversion filter (13) and the filtrate collection box (15) are connected by the filtrate guide pipe (14). A valve is provided on the filtrate guide pipe (14) located on the outer cylinder (1) of the simulated well.

6. The full wellbore plugging test apparatus as described in claim 1, characterized in that: The liquid storage tank (21) includes a tank body (26), a liquid supply pump (22), and a liquid supply pump controller (23); the liquid supply pump (22) is located inside the tank body (26); the outer end of the liquid inlet pipe (19) is connected to the liquid supply pump (22); the outer end of the liquid outlet pipe (20) is connected to the inside of the tank body (26); the liquid supply pump controller (23) is connected to the tank body (26), and the liquid supply pump controller (23) is electrically connected to the liquid supply pump (22).

7. The full wellbore plugging test apparatus as described in claim 1, characterized in that: The pressurization mechanism includes a gas source pressure divider (12) and an air intake valve rod (27); one end of the air intake valve rod (27) is connected to the interior of the simulated well outer cylinder (1) through the outer cylinder bottom cover plate (7), and the other end of the air intake valve rod (27) is connected to the gas source pressure divider (12).

8. The full wellbore plugging test apparatus as described in claim 6, characterized in that: The heating mechanism is an electric heating rod (11); the electric heating rod (11) is connected to the bottom cover plate (7) of the outer cylinder; the front end of the electric heating rod (11) extends into the annulus between the outer cylinder (1) and the inner cylinder (4) of the simulated well; the liquid supply pump (22) is an adjustable displacement pump with a displacement range of 0-15L / s.

9. The test method of a full wellbore plugging test apparatus as described in any one of claims 1-8, characterized in that: Includes the following steps, Step 1: Fix the cylindrical filter screen (3) to the top cover plate (8) of the outer cylinder, then install the artificial well wall (2) on the outside of the cylindrical filter screen and fix it to the top cover plate of the outer cylinder. Then install the bottom cover plate of the outer cylinder onto the outer cylinder of the artificial well. At the same time, install the cylindrical filter screen and the artificial well wall into the slot of the bottom cover plate of the outer cylinder, connect the heating mechanism and the pressurizing mechanism, and close the filtrate guide pipe (14). Step 2: Adjust the height of the wellbore inclination adjustment rod (18) to adjust the simulated wellbore outer cylinder (1) to the required inclination angle; Step 3: Fill the storage tank (21) with the drilling fluid to be tested. The pump (22) in the storage tank (21) first uses a small pumping speed of 4-8L / s to fill the simulated well outer cylinder (1) and simulated well inner cylinder (4) with the drilling fluid to be tested until they are full, and establish the circulation between the storage tank (21) and the simulated well outer cylinder (1) and simulated well inner cylinder (4); Step 4: Start the stirring motor (10) to make the rotation speed of the simulated well inner cylinder (4) reach the preset speed required for the test; Step 5: When the temperature and pressure of the annulus of the simulated well outer cylinder (1) and the simulated well inner cylinder (4) reach the preset test values, adjust the discharge rate of the liquid supply pump (22) in the storage tank (21) to the preset test discharge rate and start timing; Step 6: After the test time is over, reset the outer cylinder (1) of the simulated well to the horizontal position, open the filtrate guide pipe (14) to let the filtrate flow into the filtrate collection box (15), and measure and record the filtrate volume.

10. The test method of the full wellbore plugging test apparatus as described in claim 9, characterized in that: The simulated well outer cylinder (1) can be adjusted in an inclination range of 30-90° by the well inclination adjustment rod (18). The inclination is the angle between the axis of the simulated well outer cylinder (1) and the vertical line. The simulated well inner cylinder (4) rotates under the drive of the stirring motor (10) and the coupling (9), with a rotation speed range of 0-300 rpm.

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