CN116242559A - In-situ leaching uranium mining cementing cement sheath sealing performance testing device - Google Patents

Abstract

The invention provides a device for detecting sealing performance of a cementing surface of an in-situ leaching uranium mining well cementation cement sheath, which relates to the technical field of in-situ leaching uranium mining, and comprises a surrounding rock simulation structure, a sheath body, a top cover and a bottom cover, wherein the top cover is in sealing connection with an upper port of the sheath body, and the bottom cover is in sealing connection with a lower port of the sheath body; the well cementation simulation structure comprises a cement collar, a PVC (polyvinyl chloride) shaft and a packer, wherein a detection module comprises a pressurizing unit and a control center, the pressurizing unit comprises a pressurizing pipeline, a first valve and a first pressure gauge, one end of the pressurizing pipeline is communicated with the liquid injection pipe, the first valve and the first pressure gauge are arranged on the pressurizing pipeline, the other end of the pressurizing pipeline is connected with a liquid pumping unit, and the control center is connected with the first pressure gauge. The invention realizes the measurement of the pressure and the cross flow range of the cross flow of the PVC shaft-cement sheath when the fracturing fluid is fractured, and better realizes the well cementation and micro-fracturing processes when the indoor reduced uranium ore is fractured, thereby being used for guiding the development of compact sandstone uranium ore.

Description

In-situ leaching uranium mining cementing cement sheath sealing performance testing device

technical field

The invention relates to the technical field of in-situ leaching uranium mining, in particular to a device for testing the sealing performance of a cement sheath cemented surface in in-situ leaching uranium mining.

Background technique

With the in-situ leaching development of conventional sandstone uranium deposits with good physical properties in my country, the existing and newly explored uranium resources are gradually developing from shallow to deep, and from high permeability to low permeability. question. Micro-fracturing can form micro-fractures around the wellbore through high-pressure fluids, transform the deep low-permeability uranium deposits with poor physical properties, and finally use dense fracture networks to connect injection and production wells, effectively improving the in-situ leaching development of tight uranium sandstone Effect.

Casings for in-situ leaching uranium production are mostly PVC wellbores. During micro-fracturing, due to the difference in wettability and compressibility between PVC wellbore and cement, the strength of the first cemented surface after cementing is poor, and it is easy to be exposed to high-pressure fluid Channeling flow is generated, which leads to the failure of uranium ore micro-fracturing. Therefore, a device for testing the sealing performance of the first cemented surface between the PVC wellbore and cement is needed indoors. The existing test device can only simulate the cementing conditions of the steel casing and the process of cement sheath formation, and cannot test the fracturing fluid. The pressure and flow range of PVC wellbore-cement sheath channeling are measured during fracturing. In addition, the perforation and fracturing process of PVC wellbore-cement sheath cannot be simulated.

Contents of the invention

The object of the present invention is to provide a test device for the sealing performance of the cement sheath cemented surface in uranium leaching well cementing, so as to improve the above problems. In order to achieve the above object, the technical scheme that the present invention takes is as follows:

This application provides a device for testing the sealing performance of the cement sheath cemented surface in in-situ leaching uranium mining cementing, including:

The surrounding rock simulation structure includes a casing, a top cover and a bottom cover, the top cover is sealingly connected with the upper port of the casing, and the bottom cover is sealingly connected with the lower port of the casing;

The cementing simulation structure includes a cement sheath, a PVC wellbore and a packer. The cement sheath is an annular structure formed on the outer surface of the PVC wellbore. The PVC wellbore, cement sheath and casing are nested sequentially from the inside to the outside. The packer includes a packer body and a liquid injection pipe connected to the packer body, and the packer body is nested in the hollow cavity of the PVC wellbore;

The detection module includes a pressurization unit and a control center, the pressurization unit includes a pressurization pipeline, a first valve and a first pressure gauge, one end of the pressurization pipeline communicates with the liquid injection pipe, and the first A valve and the first pressure gauge are arranged on the pressurized pipeline, the other end of the pressurized pipeline is connected with the pumping unit, and the control center is connected with the first pressure gauge.

Further, the bottom end of the PVC wellbore is a closed end, the lower section of the hollow cavity is a perforation section where perforations are arranged, and the detection module also includes a first pressure relief unit and a second pressure relief unit, wherein :

The first pressure relief unit includes a first pressure relief pipeline, a second valve and a second pressure gauge, one end of the first pressure relief pipeline communicates with the top of the casing, and the other end of the first pressure relief pipeline communicated with the outside atmosphere, the second valve and the second pressure gauge are arranged on the first pressure relief pipeline;

The second pressure relief pipeline includes a second pressure relief pipeline, a third valve and a third pressure gauge, one end of the second pressure relief pipeline communicates with the bottom of the casing, and the other end of the second pressure relief pipeline One end communicates with the outside atmosphere, and the third valve and the third pressure gauge are arranged on the second pressure relief pipeline;

The second pressure gauge and the third pressure gauge are respectively connected with the control center.

Further, the other end of the first pressure relief pipeline is connected with a first waste liquid tank, and the other end of the second pressure relief pipeline is connected with a second waste liquid tank.

Further, a pressure relief branch extends from the side of the pressurization pipeline to join the other end of the first pressure relief pipeline, and a fourth valve is arranged on the pressure relief branch.

Further, the perforation section is provided with a plurality of perforation opening areas, and the perforation opening area includes several perforations, and electrode sheets are arranged on the outer surface of each of the perforation opening areas. group, the bottom surface of the inner wall of the hollow cavity is provided with a common electrode, the electrode sheet group and the common electrode are respectively connected to the positive and negative poles of the power supply, the electrode sheet group is connected to a conductivity detection unit, and the conductivity detection unit The unit and the power supply are respectively connected with the control center.

Further, the electrode sheet group includes electrode sheet clusters arranged circle by circle from inside to outside on the outer surface of a circle of the perforation opening area, and each circle of electrode piece clusters includes electrode pieces arranged at intervals in the circumferential direction. The performance detection unit includes a sampling resistor, an operational amplifier and a wireless transmission module, each of the electrode sheets is connected with a sampling resistor, each of the sampling resistors is connected with an operational amplifier, and the wireless transmission module is provided with several signal input Each of the operational amplifiers is connected to a corresponding signal input port in the wireless transmission module, and the wireless transmission module is connected to the control center for signals.

Further, the liquid pump unit includes a first pump body, an intermediate tank and a third waste liquid tank, the first pump body communicates with the bottom of the intermediate tank through a pump liquid pipe, and the top of the intermediate tank communicates with the pressurization pipe The road is connected through the liquid inlet pipe, and the bottom of the third waste liquid tank is connected with the middle tank through the liquid outlet pipe. The pump liquid pipe, the liquid inlet pipe and the liquid outlet pipe are all equipped with valves, and the first pump body Connect with the control center.

Further, it also includes a temperature control module, the temperature control module includes a first temperature control unit, the first temperature control unit includes a first temperature regulator, a first heating couple and a first temperature gauge, the first The temperature regulator and the first temperature gauge are respectively connected to the control center, and the first heating couple is wrapped outside the pressurized tube.

Further, it also includes a confining pressure simulation unit, the sleeve body includes an outer sleeve body and an inner rubber sleeve nested in the outer sleeve body, the confining pressure simulation unit includes a confining pressure pipeline and a fourth pressure gauge, the enclosure One end of the pressure pipeline communicates with the space between the outer sleeve body and the inner rubber sleeve, the other end of the confining pressure pipeline is externally connected to the second pump body, and the fourth pressure gauge is connected to the space between the outer sleeve body and the inner rubber sleeve. The space is connected, and the fourth pressure gauge and the second pumping unit are respectively connected with the control center.

Further, the temperature control module also includes a second temperature control unit, the second temperature control unit includes a second temperature regulator, a second heating couple and a second temperature gauge, the second temperature regulator and the second temperature gauge The two thermometers are respectively connected to the control center, and the second heating couple is wrapped outside the casing.

Further, an external thread section is provided on the outer wall of the packer body, and an internal thread section matching the external thread section is provided on the inner wall of the hollow cavity.

The beneficial effects of the present invention are:

The present invention simulates the surrounding rock structure of the formation through the surrounding rock simulation structure, and simulates the cement sheath, PVC wellbore and packer of the in-ground leaching and mining uranium cementing structure through the cementing simulation structure, and through the pressurization unit and the control center in the detection module, realize On the basis of testing the sealing performance of the first cemented surface between the PVC wellbore and the cement sheath, measure the pressure of the PVC wellbore-cement sheath channeling when the fracturing fluid is fracturing, so as to better restore the uranium mine pressure indoors Fracture-time cementing and micro-fracturing processes are used to guide the development of dense sandstone uranium deposits.

Additional features and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.

Description of drawings

In order to illustrate the technical solutions of the embodiments of the present invention more clearly, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention, and thus It should be regarded as a limitation on the scope, and those skilled in the art can also obtain other related drawings based on these drawings without creative work.

Fig. 1 is a schematic structural view of the test device for the sealing performance of cement sheath cemented surface in uranium leaching well cementing of the present invention.

Fig. 2 is a schematic diagram of a cement sheath forming device in a specific embodiment.

Fig. 3 is a schematic structural view of a PVC shaft in the present invention.

Fig. 4 is a structural schematic diagram of the packer in the present invention.

Fig. 5 is a schematic diagram of the assembly structure of the surrounding rock simulation structure and the cementing simulation structure in the present invention.

Fig. 6 is a schematic diagram of the pressure change of the first pressure gauge in one of the perforation and fracturing simulation experiment results.

Fig. 7 is a schematic diagram of the pressure change of the second pressure gauge in one of the perforation and fracturing simulation experiment results.

Fig. 8 is a schematic diagram of the pressure change of the third pressure gauge in one of the perforation and fracturing simulation experiment results.

Fig. 9 is a schematic diagram of the pressure change of the first pressure gauge in the second result of the perforation and fracturing simulation experiment.

Fig. 10 is a schematic diagram of the pressure change of the second pressure gauge in the second perforation and fracturing simulation experiment result.

Fig. 11 is a schematic diagram of the pressure change of the third pressure gauge in the second result of the perforation and fracturing simulation experiment.

Fig. 12 is a structural schematic diagram of the first arrangement of the perforation opening area in the present invention.

Fig. 13 is one of the cross-flow area diagrams of fracturing fluid around the perforation opening area in the present invention.

Fig. 14 is the second diagram of the channeling area of fracturing fluid around the perforation opening area in the present invention.

Fig. 15 is the third diagram of the channeling area of fracturing fluid around the perforation opening area in the present invention.

Fig. 16 is a schematic diagram of the structure and principle of the current monitoring unit in the present invention.

Fig. 17 is a schematic diagram of the connection structure between the current monitoring unit and the microcontroller in the present invention.

Marks in the figure: 1. PVC shaft; 2. Internal thread section; 3. Perforation section; 4. Solid base; 5. Quick connector; 6. First sealing bolt; 7. Rotary card slot; 8. First sealing plug ;9. Packer body; 10. External thread section; 11. Liquid injection pipe; 12. Cement sheath; 13. Outer sleeve of cement annulus; 14. Oily paper outside screen; 15. Oily paper inside sleeve; 16 , fixed base; 17, top cover; 18, cement; 19, casing; 20, bottom cover; 21, second sealing plug and second sealing bolt; 22, second pressure relief port; 23, first pressure relief port ;24, liquid injection port; 25, the third sealing plug and the third sealing bolt; 26, the quick joint that is successfully connected; 27, the fourth sealing plug and the fourth sealing bolt; 28, the first pressure gauge; 29, the second Pressure gauge; 30, the third pressure gauge; 31, the fourth pressure gauge; 32, the first thermometer; 33, the second thermometer; 34, the first heating couple; 35, the second heating couple; 36, the first 1. Pressure relief pipeline; 37. Second pressure relief pipeline; 38. Pressure relief branch; 39. Perforation; 40. Electrode sheet cluster; 41. Monitoring module; 42. First wire; 43. Second wire; 44. Charging port; 45. Third wire; 46. Fourth wire; 47. Electrode sheet; 48. Sampling resistor; 49. Common electrode; 50. Power supply; 51. Operational amplifier; 52. Microcontroller; 101. The first 1. Waste liquid tank; 102. Holder; 103. Second temperature regulator; 104. Second pump body; 105. Second waste liquid tank; 191. External casing; 192. Internal rubber sleeve; 201. First Temperature regulator; 202, pressurized pipeline; 203, intermediate tank; 204, first pump body; 205, third waste liquid tank; 301, control center.

Detailed ways

In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments It is a part of embodiments of the present invention, but not all embodiments. The components of the embodiments of the invention generally described and illustrated in the figures herein may be arranged and designed in a variety of different configurations. Accordingly, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative efforts fall within the protection scope of the present invention.

It should be noted that like numerals and letters denote similar items in the following figures, therefore, once an item is defined in one figure, it does not require further definition and explanation in subsequent figures. Meanwhile, in the description of the present invention, the terms "first", "second", etc. are only used to distinguish descriptions, and cannot be understood as indicating or implying relative importance. In the present invention, the term "perforation density" refers to the number of perforations per meter length, and the unit is hole/m. The term "phase angle" refers to the difference between the perforation charges in two adjacent perforation areas. The included angle is called the phase angle.

In this specific embodiment, the manufacturing method of the cementing simulation structure is as follows:

First, determine the water-cement ratio of the cement slurry used in the experiment, the parameters of the PVC wellbore and the parameters of the cementing simulation device. 145mm, the height of the internal thread section 2 is preferably 24cm, the height of the perforation section 3 is preferably 2cm, the perforation aperture is preferably 5mm, the perforations are evenly arranged on the perforation section 3, and the number of perforations is 60 in total , the bottom end of the PVC shaft 1 is a closed end, the bottom end of the PVC is a solid base 4, the solid base 4 and the internal thread section 2 are preferably equal in height to 24cm, and the total height of the PVC shaft 1 is preferably 50cm; Parameters of the cementing simulation device: the inner diameter of the outer sleeve 13 of the cement sheath is preferably 150 mm, the outer diameter is preferably 155 mm, and the inner diameter of the fixed base 16 is preferably 156 mm.

Afterwards, place the PVC wellbore 1 vertically on the center of the fixed base 16 of the cementing simulation device as shown in Figure 2, and place the cement sheath outer sleeve 13 vertically on the fixed base 16; 15 and the oily paper 14 outside the screen tube are completely and tightly attached to the inner side of the outer sleeve 13 of the cement sheath and the outer side of the perforation section 3 to prevent the cement slurry from leaking from the screen tube into the pressurized cavity, and to avoid the cement slurry after solidification. To solve the problem that it is difficult to take out the sample when cemented to the outer sleeve 13 of the cement sheath, the packer body 9 is screwed into the PVC wellbore 1, and the first sealing plug 8 and the first sealing bolt 6 are reinforced after tightening, and the cement slurry is injected into the cementing simulation In the annulus of the device, the sample is completely taken out from the cementing simulation device after being cured and cemented. The sample is the cementing simulation structure, and the cementing simulation structure includes the cement sheath 12, the PVC wellbore 1 and the packer. The cement sheath 12 is an annular structure formed on the outer surface of the PVC wellbore 1, the PVC wellbore 1, the cement sheath 12 and the casing 19 are nested sequentially from inside to outside, and the packer includes a packer body 9 and A liquid injection pipe 11 connected to the packer body 9 nested in the hollow cavity of the PVC wellbore 1 .

Wherein, the PVC wellbore 1, as shown in Figure 3, includes a solid base 4, a perforation section 3, and an internal thread section 2, and the internal thread section 2 is adapted to the external thread section 10 on the packer body 9, The internal thread section 2 for screwing the packer body 9 into the PVC wellbore 1 forms a pressurized cavity with the solid base 4. The height of the packer body 9 is 5 cm, and the material is PVC. The perforation section 3 is used to simulate the fracturing hydraulic fracturing after the fracturing perforation, the length of the perforation section 3 is designed according to the actual length of the perforation section, the aperture is between 1 mm and 1 cm, and the solid base 4 is PVC material, the solid base 4 is connected to the perforation section 3, and the perforation section 3 is connected to the internal thread section 2, the total height of the PVC wellbore is 40cm-80cm, and the height of the screen section is 1mm Between ~10cm, the solid base 4 is at the same height as the threaded section.

As shown in FIG. 4 , the simulated packer includes a quick joint 5 , a first sealing bolt 6 , a first sealing plug 8 , an external thread section 10 , a swivel slot 7 , and a liquid injection pipe 11 .

As shown in Figure 1, this embodiment provides a device for detecting the sealing performance of the cement sheath cemented surface in in-situ leaching mining uranium well cementing, including:

The above-mentioned surrounding rock simulation structure equipped with a cementing simulation structure;

A detection module, the detection module comprising:

A pressurization unit and a control center 301, the pressurization unit includes a pressurization pipeline 202, a first valve and a first pressure gauge 28, one end of the pressurization pipeline 202 communicates with the liquid injection pipe 11, the The first valve and the first pressure gauge 28 are arranged on the pressure pipeline 202, the other end of the pressure pipeline 202 is connected to the pumping unit, and the control center 301 is connected to the first pressure gauge 28;

A first pressure relief unit and a second pressure relief unit, the first pressure relief unit includes a first pressure relief pipeline 36, a second valve and a second pressure gauge 29, one end of the first pressure relief pipeline 36 is connected to The top of the casing 19 communicates, the other end of the first pressure relief pipeline 36 communicates with the outside atmosphere, the second valve and the second pressure gauge 29 are arranged on the first pressure relief pipeline 36; The second pressure relief pipeline 37 includes a second pressure relief pipeline 37, a third valve and a third pressure gauge 30. One end of the second pressure relief pipeline 37 communicates with the bottom of the casing 19, and the second pressure relief pipeline The other end of the road 37 communicates with the outside atmosphere. The third valve and the third pressure gauge 30 are arranged on the second pressure relief pipeline 37. The second pressure gauge 29 and the third pressure gauge 30 are respectively connected with the control The center 301 is connected, the other end of the first pressure relief pipeline 36 is connected with the first waste liquid tank 101, the other end of the second pressure relief pipeline 37 is connected with the second waste liquid tank 105, the pressurized A pressure relief branch 38 extends from the side of the pipeline 202 and merges with the other end of the first pressure relief pipeline 36. The pressure relief branch 38 is provided with a fourth valve, and the pumping unit includes a first pump body 204 , an intermediate tank 203 and a third waste liquid tank 205, the first pump body 204 communicates with the bottom of the intermediate tank 203 through a pump liquid pipe, and the top of the intermediate tank 203 communicates with the pressurization pipeline 202 through a liquid inlet pipe, The third waste liquid tank 205 communicates with the bottom of the intermediate tank 203 through a liquid outlet pipe. The pump liquid pipe, liquid inlet pipe and liquid outlet pipe are all provided with valves. The first pump body 204 is connected to the control center 301 connection, wherein, the sleeve 19 includes an outer sleeve 191 and an inner rubber sleeve 192 nested in the outer sleeve 191 .

A temperature control module, the temperature control module includes a first temperature control unit and a second temperature control unit, the first temperature control unit includes a first temperature regulator 201, a first heating couple 34 and a first temperature gauge 32, The first temperature regulator 201 and the first temperature gauge 32 are respectively connected to the control center 301, the first heating couple 34 is wrapped outside the pressurized tube, and the second temperature control unit includes a second temperature control unit. The regulator 103, the second heating couple 35 and the second temperature gauge 33, the second temperature regulator 103 and the second temperature gauge 33 are respectively connected with the control center 301, and the second heating couple 35 is wrapped in the the outside of the casing 19;

A confining pressure simulation unit, the confining pressure simulation unit includes a confining pressure pipeline and a fourth pressure gauge 31, one end of the confining pressure pipeline communicates with the space between the outer casing 191 and the inner rubber sleeve 192, the confining pressure The other end of the pressure pipeline is externally connected to the second pump body 104, the fourth pressure gauge 31 communicates with the space between the outer sleeve body 191 and the inner rubber sleeve 192, and the fourth pressure gauge 31 and the second pump liquid unit are respectively Connect with the control center 301.

Wherein, the top cover 17 is provided with a liquid injection port 24 and a first pressure relief port 23, and the bottom cover 20 is provided with a second pressure relief port 22, and the quick connector 5 is connected with the liquid injection port 24 to form a The quick connector 26 that is successfully connected is screwed into the top cover 17 and the bottom cover 20, the first pressure relief port 23 and the second pressure relief port 22 are respectively connected to the bottom cover 20 and the top cover 17 through pipelines, and the second sealing plug is tightened and the second sealing bolt 21, the third sealing plug and the third sealing bolt 25, the fourth sealing plug and the fourth sealing bolt 27, close all valves, wherein the first pressure relief port 23 and the first pressure relief pipeline 36 , the second pressure relief port 22 is in communication with the second pressure relief pipeline 37 , and the liquid injection port 24 is in communication with the pressurization pipeline 202 .

As shown in Figure 5, put the sample taken out into the sleeve body 19 inside the holder 102, the holder 102 is the surrounding rock simulation structure, and the surrounding rock simulation structure includes a sleeve body 19, a top cover 17 And the bottom cover 20, the top cover 17 is in sealing connection with the upper port of the sleeve body 19, and the bottom cover 20 is in sealing connection with the lower port of the sleeve body 19. Use the quick connector 5 to connect the pressurizing pipeline 202 with the liquid injection pipe 11, inject liquid and pressurize into the pressurized cavity, and the first sealing bolt 6 and the first sealing plug 8 maintain the The packer is in a sealed state under high pressure (above 30MPa), and the pressure of the pressurized cavity is maintained. The external threaded section 10 fits and coincides with the thread of the internal threaded section 2 of the PVC wellbore 1, and the packing The liquid injection pipe 11 of the packer can work normally under the pressure above 30MPa, and the said rotating clamping groove 7 is used for tightening said packer and said PVC wellbore 1.

The perforation section 3 is provided with a plurality of perforation opening areas, and the perforation opening area includes several perforations 39, and an electrode sheet group is arranged on the outer surface of each of the perforation opening areas in the circumferential direction. , the bottom surface of the inner wall of the hollow cavity is provided with a common electrode, the electrode sheet group and the common electrode 49 are respectively connected to the positive and negative electrodes of the power supply 50, the electrode sheet group is connected to a conductivity detection unit, and the conductivity The detection unit and the power supply 50 are respectively connected to the control center 301 .

The electrode sheet group includes electrode sheet clusters 40 arranged circle by circle from inside to outside on the outer surface of the perforation opening area, and each circle of electrode piece clusters 40 includes electrode sheets 47 arranged at intervals in the circumferential direction. The performance detection unit comprises a sampling resistor 48, an operational amplifier 51 and a wireless transmission module, each of the electrode sheets 47 is connected with a sampling resistor 48, each of the sampling resistors 48 is connected with an operational amplifier 51, and the wireless transmission module Several signal input ports are provided, and each operational amplifier is connected to a corresponding signal input port in the wireless transmission module, and the wireless transmission module is connected to the control center 301 for signals.

The wireless transmission module can directly transmit the information on whether there is channeling to the control center 301 for centralized data processing to describe the channeling range of the first cemented surface.

Wherein, the multiple perforation opening areas include at least two perforation opening areas with different perforation densities, and among the two perforation opening areas with different perforation densities, the perforation in one of the perforation opening areas The density is 1.3-2.6 times the perforation density of another perforation area. The plurality of perforation opening areas include at least two perforation opening areas with different perforation densities, so that different permeability and porosity can exist in formations corresponding to simulated in-situ leaching mining of uranium.

Wherein, the electrode sheets on two adjacent circles of electrode sheet clusters 40 are arranged in a misalignment with each other.

The present invention will be further described by several different ways of laying out electrode sheets on the perforation opening area below:

Layout method one:

As shown in Figure 12, it is a schematic diagram of the expansion of the perforation section 3. There are two perforation opening areas on the perforation section 3, and the phase angle of the two perforation opening areas is 180°. One of the perforation opening areas includes Four perforations 39 are arranged at intervals in the vertical direction, and six rings of electrode clusters 40 in total, A, B, C, D, E, and F, are arranged on the outer surface of the circumference of the perforation area from inside to outside. Circle A is provided with electrode sheets A1, A2..., Circle B is provided with electrode sheets B1, B2... at intervals, Circle C is provided with electrode sheets C1, C2... at intervals, and Circle D is provided with electrode sheets D1, Electrodes D1, D2..., and F1, F2... are arranged at intervals in circles D2 and E; the other perforation opening area includes 6 perforations arranged at intervals in the vertical direction 39. A total of six electrode clusters 40, A', B', C', D', E', and F', are arranged on the outer surface of the circumference of the perforation area from the inside to the outside. The electrode sheets A'1, A'2... are arranged at intervals in sequence, the electrode sheets B'1, B'2... are arranged at intervals in the circle B', and the electrode sheets C'1, C'2... are arranged in intervals in the circle C' , the D' circle is successively provided with electrode sheets D'1, D'2..., the E' circle is sequentially provided with electrode sheets E'1, E'2..., and the F' circle is sequentially provided with electrode sheets F'1, F'2..., an electrode sheet group is arranged on the outer surface of the circumference of each perforation opening area, and a common electrode is arranged on the bottom surface of the inner wall of the hollow cavity, and the electrode sheet group and the common electrode 49 They are respectively connected to the positive and negative poles of the power supply 50, and the electrode sheet group includes electrode sheet clusters 40 that are arranged circle by circle from inside to outside on the outer surface of a circle of the perforation opening area, and each circle of electrode piece clusters 40 includes circumferential The electrode sheets 47 , which are arranged at intervals, the electrode sheets on the electrode sheet clusters 40 of two adjacent circles are arranged in a misalignment with each other.

As shown in Figure 16, each of the electrode sheets 47 is connected with a sampling resistor 48, and each of the sampling resistors 48 is connected with an operational amplifier 51, and each of the operational amplifiers 51 is connected to the corresponding signal input in the wireless transmission module. The ports are connected, the electrode sheet 47, the common electrode 49, the sampling resistor 48, the operational amplifier 51 and the power supply 50 together form a current monitoring unit, and all the current monitoring units share the power supply 50 and the common electrode 49.

As shown in Figure 17, described wireless transmission module is connected with control center 301 signal, and described wireless transmission module is built-in microcontroller 52 of Zigbee integrated circuit, is provided with the signal corresponding to each electric current monitoring unit on microcontroller 52 input port.

After injecting fracturing fluid into the hollow cavity of the PVC wellbore 1, the control center 301 controls to turn on the power supply, the common electrode first contacts the fracturing fluid, and the fracturing fluid is gradually injected into the hollow cavity. Channeling occurs around, and a current loop will be formed between the electrode sheet 47 arranged around the corresponding perforation opening area and the common electrode 49. The current flows through the resistance to form a pressure difference, which is amplified by the operational amplifier 51 and then outputs a monitoring signal. Each current monitoring The unit output voltage enters different signal input ports of the micro-controller 52, and the micro-controller 52 corresponds to the setting position of each electrode sheet 47 according to different input ports, and the position information of the electrode sheet 47 with the current signal is converted into The wireless signal is transmitted to the control center 301, and the control center 301 will receive the position information of the electrode piece 47 with the current signal and use the received position information to map the fracturing fluid channeling range around the perforation 39 as shown in Figure 13-15 Show.

As shown in Figure 12 and Figure 2, in the present invention, the power supply and the conductivity detection unit are integrated into a monitoring module 41, and the monitoring module 41 is pre-buried inside the solid base 4, the power supply is a charging power supply, and the solid base 4 The bottom is provided with the charging port 44 of the charging power supply, the signal connection between the conductivity detection unit and the control center 301, the switch of the power supply is a remote control switch, and the remote control switch of the power supply and the control center 301 are remote control switches. Control connection, during the preparation process of the PVC wellbore 1, the electrode sheet cluster 40 is embedded on the outer surface of the perforation section 3 on the PVC wellbore 1, the common electrode is embedded on the bottom surface of the inner wall of the hollow cavity, and the connecting electrode sheet The first wire 42 connecting the group and the power supply, the second wire 43 connecting the common electrode and the power supply, the third wire 45 connecting the charging power supply and the charging port 44, and the fourth wire 46 connecting the electrode sheet group and the conductivity detection unit are all Embedded in the inside of the PVC shaft 1.

Layout method two:

The difference from the first layout method is that the phase angle of the two perforation opening areas on the perforation section 3 is 90°.

Layout method three:

The difference from the first arrangement is that the phase angle of the two perforation areas on the perforation section 3 is 45°.

Layout method four:

The difference from the layout method 1 is that the phase angle of the two perforation opening areas on the perforation section 3 is 30°.

Layout method five:

The difference from the layout method 1 is that the perforation section 3 is provided with three perforation opening areas, the phase angle between two adjacent perforation opening areas is 120°, and the perforation density of the two perforation opening areas is The same, and the perforation density of these two perforation opening areas is greater than that of the remaining one perforation opening area, and the electrode sheet clusters 40 arranged circle by circle from inside to outside on the outer surface of the three perforation opening areas The method is the same as the layout method 1.

Layout method six:

The difference from the layout method 1 is that the perforation section 3 is provided with four perforation opening areas, and the phase angle between two adjacent perforation opening areas is 90° so that the four perforation opening areas are center-symmetrical in two groups The perforation area of the center symmetric perforation area, in which the perforation density of the two perforation areas in one group of centrosymmetric perforation areas is the same, and the perforation density of the two perforation areas in the other group of The perforation density is the same, and the perforation density of one group of center-symmetrical perforation areas is greater than that of the other group of center-symmetrical perforation areas.

The present invention will be further described by taking the specific experimental operation process of layout mode 1 as an example below:

Open the second pump body 104 to add confining pressure to the sample, the sample is a cementing simulation structure to simulate the confining pressure of the surrounding rock of the formation, and the confining pressure in this embodiment is set to 2MP;

Turn on the second temperature regulator 103 to heat the sample and maintain a constant temperature environment for the sample. In this embodiment, the temperature is set to 40°C, thereby simulating the formation temperature;

Turn on the first temperature regulator 201 to maintain the temperature of the liquid injected from the intermediate tank 203 into the cementing simulation structure. In this embodiment, the temperature is set to 40°C, thereby simulating the temperature of the fracturing fluid;

Open the top and bottom valves of the tundish 203 storing the fracturing fluid. The fracturing fluid in this embodiment is 0.1% slick water;

Open the valve between the first temperature regulator 201 and the liquid injection port 24, set the pump speed of the first pump body 204 to 10-30ml/min, and the pump speed of this embodiment is 20ml/min to start to set the temperature in the pressurized cavity. The fracturing fluid with a constant temperature of 40°C was injected in the way of flow rate.

Use the control center 301 to detect the temperature T2 of the surrounding rock simulation structure, the temperature T1 of the injection fluid, the pressure P2 of the first pressure relief port, the pressure P3 of the second pressure relief port, the confining pressure P4 of the cementing simulation structure, and the pressure P1 in the pressurized cavity , when the pressure in the pressurized cavity starts to increase, reduce the flow rate of the first pump body 204 to 1-10 ml/min, and the pump speed of the first pump body 204 in this embodiment is 3 ml/min.

The control center 301 continuously detects and records the value of P1 changing with time. If there is a sudden drop in pressure, record the pressure P' before the sudden drop. This pressure is the channeling flow of the cementing simulation structure when fracturing with fracturing fluid The pressure is the hydraulically measured cementation strength of the cement sheath cementation surface in the cementing simulation structure.

If the pressure of P1 increases slowly and does not decrease, it is necessary to record the values of the conductivity detection unit, P2 and P3 over time. If the conductivity detection unit shows that one or both of the two perforation positions have similar As shown in Figure 15, it shows that the fracturing fluid has channeled around the perforation and may have overflowed the wellbore. At this time, it is necessary to continue to detect the readings of P2 and P3. If the readings of P2 and P3 gradually increase with the injection of fracturing fluid, and gradually equalize with P1, it means that there is a problem in the sample preparation process, and the cement sheath is not completely cemented to the PVC wellbore. If there are cracks or connected pores on the surface, the sample needs to be re-prepared according to the above-mentioned sample preparation process, and the test should be carried out again.

If the P1 pressure does not increase slowly and does not decrease, the normal experiment can be carried out, and the control center 301 can be used to continuously detect the pressure changes of P1, conductivity detection unit, P2, and P3 over time. When P' (that is, P1 sudden drop pressure) is detected, the first pump body 204 needs to be stopped immediately, the switch between the first temperature regulator 201 and the liquid injection port 24 should be closed, and the third waste liquid tank 205 should be opened to discharge Empty line pressure;

Open the switch of the first pressure relief port 23 and the second pressure relief port 22, open the switch between the liquid injection port 24 and the first waste liquid tank 101, and channel in the pressurized cavity and flow into the holder 102 The fracturing fluid is discharged into the first waste liquid tank 101 and the second waste liquid tank 105 .

After the test, the wellbore fluid measured cementation strength P' was recorded, and the information of the water level sensor was integrated to analyze the change of the channeling position according to the time step. After being processed by the control center 301, it can be determined that the conductivity detection unit detects the current change of the electrode sheet at different times, and the channeling area is mapped.

The control center 301 draws the channeling area map according to the method received as follows: first collect the data detected by the conductivity detection unit at different times, and set the position of each electrode piece corresponding to the data detected by the conductivity detection unit in the perforation Segment 3 is marked in the tiling diagram, and the final channeling area is shown in Figure 13 and Figure 14. Figure 13 shows that the water level sensor signals are: A9, A13, B13, B16, C16, C17, C118, and the channeling position is the area where the left perforation is opened. Figure 14 shows that the water level sensor signals are: A'2, A'3, A'4, A'5, B'3, B'4, B'5, B'6, C'4, C'5, C' 6. C'7, D'4, D'5, D'6, D'7, D'8, E'4, E'5, E'6, E'7, E'8, the channeling position is Right perforation opening area.

When it is necessary to quickly determine whether the perforation channeling is at the upper end or the lower end, it can be quickly judged directly according to the readings of the pressure gauges P1, P2 and P3. The judgment method is as follows:

One of the results of the perforation and fracturing simulation experiment is shown in Figure 6-8. The reading on the pressure gauge P1 decreases until time t2 and then increases gradually. The reading on the pressure gauge P2 also increases gradually at time t2, and the reading on the pressure gauge P3 In the case that the reading remains unchanged, it is the channeling flow at the upper end of the perforation section 3.

The second result of the perforation and fracturing simulation experiment is shown in Fig. 9-11. The reading on the pressure gauge P1 decreases until time t2 and then increases gradually. The reading on the pressure gauge P3 also increases gradually at time t2, and the reading on the pressure gauge P2 gradually increases. If the reading remains unchanged, it is channeling at the lower end of perforation section 3.

The present invention simulates the surrounding rock structure of the formation through the surrounding rock simulation structure, and simulates the cement sheath, PVC wellbore and packer of the in-ground leaching and mining uranium cementing structure through the cementing simulation structure, and through the pressurization unit and the control center in the detection module, realize On the basis of testing the sealing performance of the first cemented surface between the PVC wellbore and the cement sheath, the pressure of the PVC wellbore-cement sheath channeling when the fracturing fluid is fracturing is measured. In addition, the present invention also simulates the fracturing and perforation of the PVC wellbore-cement sheath through the above perforation section, and determines the specific position of the perforation through the first pressure relief unit and the second pressure relief unit, and also through the The above structure simulates formation pressure, formation temperature and fracturing fluid temperature. In addition, the present invention also determines the channeling range around the perforation through the above-mentioned electrode sheet group, monitoring module and common electrode. In this way, the well cementing and micro-fracturing processes during uranium ore fracturing can be better reduced indoors, so as to guide the development of dense sandstone uranium ore.

The specific operation principles of other layout methods are similar to that of layout method 1, and the specific operation process of other layout methods can be analogized according to the specific operation process of layout method 1.

It is worth noting that the perforation and fracturing simulation experiment in the present invention simulates the impact of the fracturing process of the fracturing fluid at the perforation on the cement sheath cemented surface after perforation, not the simulation of the perforation process itself.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

The above is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Anyone skilled in the art can easily think of changes or substitutions within the technical scope disclosed in the present invention. Should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims (10)

1. In-situ leaching mining uranium cementing cement sheath cementing surface sealing performance detection device, characterized in that it includes: The surrounding rock simulation structure includes a casing (19), a top cover (17) and a bottom cover (20), the top cover (17) is sealed with the upper port of the casing (19), and the bottom cover (20) It is sealingly connected with the lower port of the casing (19); The cementing simulation structure includes a cement sheath (12), a PVC wellbore (1) and a packer, the cement sheath (12) is an annular structure formed on the outer surface of the PVC wellbore (1), and the PVC wellbore ( 1), the cement sheath (12) and casing (19) are nested sequentially from inside to outside, and the packer includes a packer body (9) and a liquid injection pipe (11) connected to the packer body (9). ), the PVC wellbore (1) is provided with a hollow cavity, and the packer body (9) is nested in the hollow cavity of the PVC wellbore (1); The detection module includes a pressurization unit and a control center (301), the pressurization unit includes a pressurization pipeline (202), a first valve and a first pressure gauge (28), and the pressurization pipeline (202) One end communicates with the injection pipe (11), the first valve and the first pressure gauge (28) are arranged on the pressurized pipeline (202), and the other end of the pressurized pipeline (202) is connected to the pump liquid unit, the control center (301) is connected to the first pressure gauge (28). 2. The device for detecting the sealing performance of cement sheath cemented surface in ground leaching mining uranium well cementing according to claim 1, characterized in that: the bottom end of the PVC wellbore (1) is a closed end, and the lower section of the hollow cavity is The perforation section (3) with perforation (39) is arranged, and the detection module also includes a first pressure relief unit and a second pressure relief unit, wherein: The first pressure relief unit includes a first pressure relief pipeline (36), a second valve and a second pressure gauge (29), and one end of the first pressure relief pipeline (36) communicates with the top of the casing (19) , the other end of the first pressure relief pipeline (36) communicates with the outside atmosphere, and the second valve and the second pressure gauge (29) are arranged on the first pressure relief pipeline (36); The second pressure relief pipeline (37) includes a second pressure relief pipeline (37), a third valve and a third pressure gauge (30), and one end of the second pressure relief pipeline (37) is connected to the casing ( 19) The bottom is connected, the other end of the second pressure relief pipeline (37) communicates with the outside atmosphere, the third valve and the third pressure gauge (30) are arranged on the second pressure relief pipeline (37) superior; The second pressure gauge (29) and the third pressure gauge (30) are respectively connected with the control center (301). 3. The device for detecting the sealing performance of cement sheath cemented surface in ground leaching mining uranium well cementing according to claim 2, characterized in that: the other end of the first pressure relief pipeline (36) is connected with a first waste liquid tank ( 101), the other end of the second pressure relief pipeline (37) is connected with a second waste liquid tank (105). 4. The device for detecting the sealing performance of the cement sheath cemented surface of in-situ leaching uranium production well cementing according to claim 3, characterized in that: the pressure relief branch (38) and the first pressurization pipeline (202) extend sideways The other end of a pressure relief pipeline (36) joins together, and a fourth valve is arranged on the pressure relief branch (38). 5. The device for detecting the sealing performance of cement sheath cemented surface in ground leaching mining uranium well cementing according to claim 2, characterized in that: said perforation section (3) is provided with a plurality of perforation opening areas, and said perforation The opening area includes several perforations (39), and an electrode sheet group is arranged on the outer surface of each circumference of the opening area of the perforation, and a common electrode is arranged on the bottom surface of the inner wall of the hollow cavity, and the electrodes The sheet group and the common electrode (49) are respectively connected to the positive and negative poles of the power supply (50), and the electrode sheet group is connected with a conductivity detection unit, and the conductivity detection unit and the power supply (50) are respectively connected to the control center (301) connect. 6. The device for detecting the sealing performance of cement sheath cemented surface in ground leaching mining uranium well cementing according to claim 5, characterized in that: the electrode sheet group includes a circle from inside to outside on the outer surface of the circumference of the perforation opening area. Electrode sheet clusters (40) arranged circle by circle, each circle of electrode sheet clusters (40) includes electrode sheets (47) arranged at intervals in the circumferential direction, and the conductivity detection unit includes sampling resistors (48), operational amplifiers (51) and A wireless transmission module, each of the electrode sheets (47) is connected with a sampling resistor (48), each of the sampling resistors (48) is connected with an operational amplifier (51), and the wireless transmission module is provided with several A signal input port, each of the operational amplifiers (51) is connected to a corresponding signal input port in the wireless transmission module, and the wireless transmission module is connected to the control center (301) for signals. 7. The device for detecting the sealing performance of cement sheath cemented surface in ground leaching mining uranium well cementing according to claim 1, characterized in that: the pump liquid unit includes a first pump body (204), a tundish (203) and a third A waste liquid tank (205), the first pump body (204) communicates with the bottom of the intermediate tank (203) through a pump liquid pipe, and the top of the intermediate tank (203) communicates with the pressurization pipeline (202) through a liquid inlet The third waste liquid tank (205) communicates with the bottom of the intermediate tank (203) through a liquid outlet pipe, and valves are provided on the pump liquid pipe, liquid inlet pipe and liquid outlet pipe, and the first The pump body (204) is connected with the control center (301). 8. The device for detecting the sealing performance of cement sheath cemented surface in ground leaching mining uranium well cementing according to claim 1, characterized in that: it also includes a temperature control module, and the temperature control module includes a first temperature control unit, and the first The temperature control unit comprises a first temperature regulator (201), a first heating couple (34) and a first temperature gauge (32), and the first temperature regulator (201) and the first temperature gauge (32) are respectively connected with The control center (301) is connected, and the first heating couple (34) is wrapped around the outside of the pressurized tube. 9. The device for detecting the sealing performance of cement sheath cemented surface in ground leaching mining uranium well cementing according to claim 8, characterized in that: it also includes a confining pressure simulation unit, and the casing (19) includes an outer casing (191) and The inner rubber sleeve (192) nested in the outer casing (191), the confining pressure simulation unit includes a confining pressure pipeline and a fourth pressure gauge (31), and one end of the confining pressure pipeline is connected to the outer casing ( 191) communicates with the space between the inner rubber sleeve (192), the other end of the confining pressure pipeline is externally connected to the second pump body (104), and the fourth pressure gauge (31) is connected to the outer sleeve body (191) and The spaces between the inner rubber sleeves (192) are communicated, and the fourth pressure gauge (31) and the second pumping unit are respectively connected to the control center (301). 10. The device for detecting the sealing performance of the cement sheath cemented surface of in-situ leaching mining uranium well cementing according to claim 9, characterized in that: the temperature control module further includes a second temperature control unit, and the second temperature control unit includes a first temperature control unit. Two temperature regulators (103), the second heating couple (35) and the second temperature gauge (33), the second temperature regulator (103) and the second temperature gauge (33) are respectively connected with the control center (301) connected, the second heating couple (35) is wrapped on the outside of the sleeve (19).

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