Glue injection manufacturing device and method for casting body sheet under formation pressure condition

Abstract

The invention belongs to the technical field of petroleum geological exploration, and discloses a glue injection manufacturing device and method for a casting body sheet under the formation pressure condition. The device comprises a clamp holder, a confining pressure pump, an end plug, a pressurizing pipeline and a vacuumizing pipeline, the two ends of the clamp holder are externally connected with a pressurizing pipeline for applying pore pressure and a vacuumizing pipeline for vacuumizing; a confining pressure pump is connected beside the clamp holder; a rock sample is placed in the clamp holder, and overlying formation pressure is applied to the rock sample through a confining pressure pump; end plugs are respectively arranged on the end surfaces, tightly attached to the two ends of the rock sample, in the clamp holder; one end of the end plug is provided with a central round hole, and the other end is provided with a conical cavity; the tip end of the conical cavity is communicated with the central round hole; the central round hole is communicated with the pressurizing pipeline; an end plug slim hole axially penetrating through the end plug is formed in the edge of the end plug, and the end plug slim hole is communicated with a vacuumizing pipeline. The casting body sheet manufactured by the method can effectively reflect the pore structure characteristics of the rock core under the real formation pressure condition, and the device and the method are easy to operate.

Description

Technical Field

[0001] The invention belongs to the technical field of petroleum geological exploration, and in particular relates to a glue injection manufacturing device and method for a cast thin slice under formation pressure conditions. Background Art

[0002] Cast thin sections are made by injecting colored liquid glue into the rock pore space under vacuum pressure and solidifying it, then grinding it into thin rock slices. After the rock pores are filled with colored glue, they are very eye-catching under a microscope and easy to observe, providing an effective way to study the size, distribution, pore type, connectivity, combination characteristics and geometric morphology of rock pores.

[0003] At present, the common method for making cast thin sections in the laboratory is as follows: first, put a 3-5mm thick rock slice into a glass test tube, add colored epoxy resin glue to submerge the core slice; second, immerse the test tube in white oil, apply one-dimensional hydrostatic pressure (generally limited by experimental conditions, only about 30MPa can be applied) to press the epoxy resin colloid into the rock slice; finally, after the colloid solidifies, it is polished into a cast thin section. The glue injection process of this method has the following defects: the pressure of glue injection is inconsistent with the actual pressure conditions underground, that is, the rock slice does not bear the overlying stratum pressure and the pore pressure is not the real stratum pressure. Therefore, the cast thin section produced cannot reflect the actual pore structure characteristics of the core underground.

[0004] The existing patent CN115704750A discloses a rock chip casting tube and method, including a die-casting tube, a clamping bin and a tube plug; one end of the die-casting tube is sealed, and the tube plug is sealed and connected to the other end of the die-casting tube, and a glue injection tube and a vacuum tube are passed through the tube plug, and the ends of the glue injection tube and the vacuum tube are located inside the die-casting tube; a plurality of clamping bins are arranged inside the die-casting tube, and the clamping bins include a bin body and a bin cover, and the bin cover is detachably connected to the bin body, and through holes are arranged on the top of the bin cover, the side and bottom of the bin body. The rock cuttings casting method includes the following processes: putting rock cuttings in each clamping bin, putting the clamping bin with rock cuttings into a die-casting tube, and sealing the die-casting tube with a tube plug; first evacuating the inside of the die-casting tube through a vacuum tube, and then injecting die-casting glue into the die-casting tube through a glue injection tube; after the glue injection is completed, taking out the tube plug, and putting the die-casting tube into a casting instrument for rock cuttings casting; the device and method of this patent can solve the problems of small individual pieces of rock cuttings, poor molding, and difficulty in distinguishing, but the glue injection process of this patent is carried out in a vacuum and pressureless environment, and the die-casting tube is placed in a casting instrument for rock cuttings casting, which can only apply a certain pore pressure, and cannot apply the overlying formation pressure and pore pressure at the same time. Therefore, it has the defect of not being able to restore the real underground pressure conditions of the sample, and the produced casting slices cannot reflect the real pore structure characteristics of the core underground. Summary of the invention

[0005] The present invention aims to address the technical problems existing in the background technology and provide a device and method for injecting glue to produce cast thin slices under formation pressure conditions. When the overlying formation pressure and pore pressure under real pressure conditions are applied to the rock thin slices, colored die-casting glue is injected, so that the produced cast thin slices can reflect the pore structure characteristics of the core under the real formation pressure conditions, and the operation is simple and easy to implement.

[0006] In order to achieve the above technical objectives, the present invention adopts the following technical solutions:

[0007] A glue injection manufacturing device for casting thin slices under formation pressure conditions, comprising a clamp, a confining pressure pump, an end plug, a pressurizing pipeline and a vacuum pipeline;

[0008] Both ends of the clamp are externally connected to a pressurized pipeline and a vacuum pipeline, the pressurized pipeline is used to apply pore pressure, and the vacuum pipeline is used to draw a vacuum; the clamp is connected to a confining pressure pump; the inside of the clamp is used to place the rock sample, and the overlying formation pressure is applied to the rock sample through the confining pressure pump;

[0009] An end plug is provided in the clamp, close to the end faces of the two ends of the rock sample; a central circular hole is opened at one end of the end plug, and a conical cavity is opened at the other end; the tip of the conical cavity is connected with the central circular hole; the central circular hole is connected with the pressurized pipeline; an end plug fine hole axially penetrating the end plug is opened at the edge of the end plug, and the end plug fine hole is connected with the vacuum pipeline.

[0010] Furthermore, the end plug is a stainless steel cylinder; the diameter of the end plug is equal to the diameter of the rock sample.

[0011] Furthermore, a vacuum pump is arranged on the vacuum pipeline, the vacuum pump is connected to the end plug holes at both ends of the rock sample through the pipeline, and a vacuum valve is arranged on the pipeline between the vacuum pump and the end plug holes.

[0012] Furthermore, a pore pressure high-pressure metering pump is provided on the pressurized pipeline to simulate the application of pore pressure to the end plugs at both ends of the rock sample for glue injection.

[0013] Furthermore, the clamp also includes a heating device and a temperature control device;

[0014] The heating device is used to heat the holder so that the colloid in the rock sample can be fully solidified;

[0015] The temperature control device is electrically connected to the heating device to control the heating temperature.

[0016] Furthermore, the heating device is a heating and heat-insulating layer sleeved on the periphery of the clamp, or a heating belt wrapped around the outer shell of the clamp.

[0017] At the same time, the present invention also provides a method for making a cast thin slice under formation pressure conditions by injection, using the above-mentioned device, and the method comprises the following steps:

[0018] Step S1: preparing a rock sample to be injected with glue;

[0019] Step S2: pre-load the colored die-casting glue into the end plug, place the end plug close to the end surfaces on both sides of the rock sample, and then load the end plug and the rock sample into the holder together;

[0020] Step S3: Turn on the confining pressure pump, apply the overlying formation pressure to the clamp through the pressurized medium, and then open the vacuum pipeline to vacuum the device;

[0021] Step S4: close the vacuum line to stop vacuuming, open the pressurized line to gradually apply pore pressure to the end plug and the rock sample, push the colored die-casting glue into the rock sample, and gradually increase the pore pressure to the formation hydrostatic pressure, and then keep the pore pressure constant;

[0022] Step S5: solidifying the colloid in the rock sample;

[0023] Step S6: After the solidification is completed, the overlying formation pressure and pore pressure are unloaded, and the rock sample and the end plug are taken out, thus completing the glue injection production of the cast thin slice under formation pressure conditions.

[0024] Furthermore, the step S1 specifically includes:

[0025] Step S101: Select a rock core and cut it into rock samples;

[0026] Step S102: Wash the rock sample to remove oil and salt, and then place it in a constant temperature and humidity oven for drying.

[0027] Furthermore, the size of the rock sample cut in step S101 is: diameter 25 mm×depth 5 mm, or diameter 38 mm×depth 5 mm.

[0028] Furthermore, in step S2, the colored die-casting adhesive is a colored epoxy resin die-casting adhesive.

[0029] Further, in step S3, the pressurized medium is white oil or castor oil.

[0030] Furthermore, the step S5 specifically includes:

[0031] Step S501: Keep the overburden pressure and pore pressure unchanged, heat the holder by a heating device, the initial temperature of the holder is 65-75°C, and control the temperature of the holder to rise by 10-15°C per hour by a temperature control device, and finally keep the temperature constant at 90-100°C; maintain the temperature and pressure of the holder for 9-12 hours after stabilization, and complete the die casting process;

[0032] Step S502: After die casting, cool for 1-3 hours to fully solidify the colloid in the rock sample.

[0033] Compared with the prior art, the beneficial effects of the present invention are:

[0034] (1) The present invention places a rock sample in a clamp, and places two end plugs on the end surfaces of both ends of the rock sample. The end plugs are pre-loaded with colored die-casting glue through a special structural design. By applying overlying formation pressure to the clamp, vacuum is drawn through the end plug pores through the end plugs, and pore pressure is applied to the end plugs in the clamp by a pressurized pipeline, so that the colored die-casting glue is injected when the overlying formation pressure and pore pressure under the real pressure conditions are applied to the rock slice, so that the manufactured cast slice can reflect the pore structure characteristics of the core under the real formation pressure conditions. The device is simple and easy to implement, the method is convenient to operate, and the practicability is strong;

[0035] (2) The device of the present invention optimizes the pipeline structure so that the two end plugs at both ends of the rock sample share a vacuum pump and a pore pressure high-pressure metering pump, which not only reduces equipment investment and equipment costs, but also ensures that the two end plugs at both ends of the rock sample are vacuumed or pressurized and injected synchronously, thereby improving the convenience and efficiency of operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 is a schematic structural diagram of an end plug according to an embodiment of the present invention;

[0037] Figure 2 A schematic diagram of the structure of an experimental device according to an embodiment of the present invention;

[0038] Figure 3 is a flow chart of a method according to an embodiment of the present invention;

[0039] Figure 4 This is a cast thin slice inspection observation diagram of an embodiment of the present invention;

[0040] Markings in the figure: 1-pore pressure high-pressure metering pump; 2-confining pressure pump; 3-end plug; 4-rock sample; 5-holder; 6-pressurization pipeline; 7-vacuum pump; 8-vacuum valve; 9-vacuum pipeline;

[0041] 301-central circular hole; 302-conical cavity; 303-end plug hole; 501-heating and thermal insulation layer. DETAILED DESCRIPTION

[0042] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0043] In the description of the present invention, it is necessary to understand that the terms "coaxial", "bottom", "one end", "top", "middle", "the other end", "upper", "one side", "top", "inside", "front", "center", "both ends" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0044] In the present invention, unless otherwise clearly stipulated and limited, the terms such as "installation", "setting", "connection", "fixation" and "screw-on" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be the internal connection of two elements or the interaction relationship between two elements. Unless otherwise clearly defined, ordinary technicians in this field can understand the specific meanings of the above terms in the present invention according to the specific circumstances.

[0045] Example 1

[0046] Combination Figure 1-2 As shown, an embodiment of the present invention provides a glue injection manufacturing device for cast thin slices under formation pressure conditions, including a clamp 5, a confining pressure pump 2, an end plug 3, a pressurizing pipeline 6 and a vacuum pipeline 9.

[0047] Both ends of the clamp 5 are externally connected to a pressurized pipeline 6 and a vacuum pipeline 9, wherein the pressurized pipeline 6 is used to apply pore pressure, and the vacuum pipeline 9 is used to draw a vacuum; the clamp 5 is connected to the confining pressure pump 2; the inside of the clamp 5 is used to place a rock sample 4, and the confining pressure pump 2 applies overlying formation pressure to the rock sample 4; the rock sample 4 is a rock slice with a diameter of 25 mm and a length of 5 mm.

[0048] An end plug 3 is provided in the holder 5, close to the end faces of the two ends of the rock sample 4, and the end plug 3 is a 304 stainless steel cylinder with a diameter of 25 mm and a length of 20 mm; a central circular hole 301 with a diameter of 3 mm and a length of 5 mm is opened at the center of one end of the end plug 3, and a conical cavity 302 with a bottom diameter of 15 mm and a height of 15 mm is opened at the center of the other end; the tip of the conical cavity 302 is connected to the central circular hole 301; the central circular hole 301 is connected to the pressure pipeline 6; an end plug fine hole 303 with a diameter of 0.5 mm and a length of 20 mm that axially penetrates the end plug is opened on the edge of the end plug 3, and the end plug fine hole 303 is connected to the vacuum pipeline 9.

[0049] In some embodiments, a vacuum pump 7 is provided on the vacuum pipeline 9, and the vacuum pump 7 is connected to the end plug holes 303 at both ends of the rock sample 4 through pipelines, and a vacuum valve 8 is provided on the pipeline between the vacuum pump 7 and the end plug holes 303.

[0050] Compared with connecting one vacuum pump 7 to each of the two end plug holes 303, the above arrangement not only saves one vacuum pump and reduces equipment investment, but also ensures that the two end plug holes 303 are vacuumed synchronously, thereby improving the convenience and efficiency of operation.

[0051] In some embodiments, a pore pressure high-pressure metering pump 1 is provided on the pressurized pipeline 6 to simulate applying pore pressure to the end plugs 3 at both ends of the rock sample 4 for glue injection.

[0052] Compared with connecting one pore pressure high-pressure metering pump 1 to each of the two end plugs 3, the above arrangement not only saves one pore pressure high-pressure metering pump 1 and reduces equipment investment, but also ensures that the two end plugs 3 are pressurized and injected synchronously, thereby improving the convenience and efficiency of operation.

[0053] In some embodiments, the holder 5 further comprises a heating device and a temperature control device. The heating device is a heating and heat-insulating layer 501 sleeved on the periphery of the holder 5, and is used to heat the holder 5 so that the colloid in the rock sample 4 is fully solidified; the temperature control device (not shown) is electrically connected to the heating device to control the heating temperature.

[0054] In some other embodiments, the heating device may also be a heating belt wound around the outer shell of the clamp 5 .

[0055] Example 2

[0056] An embodiment of the present invention provides a method for injecting glue to produce a cast thin slice under formation pressure conditions. The device described in Example 1 is used, and end plugs 3 pre-loaded with colored epoxy resin glue are placed at both ends of a rock sample 4. The rock sample 4 and the end plugs 3 are placed in a clamp 5, and then the overlying formation pressure is applied to the clamp 5. The pore pressure is applied to the end plug 3 through a pressurized oil such as white oil to push the colored epoxy resin glue in the end plug 3 into the rock sample, and the colored epoxy resin glue is heated under the conditions of overlying formation pressure and pore pressure to quickly solidify the colored epoxy resin glue.

[0057] like Figure 1 As shown, the method specifically comprises the following steps:

[0058] Step S1: preparing a rock sample to be injected with glue, specifically including:

[0059] Step S101: select a conglomerate rock sample at a depth of 2260.00 m, and cut the rock sample into rock slices with a diameter of 25 mm and a depth of 5 mm as rock sample 4;

[0060] Step S102: Wash the rock sample 4 to remove oil and salt, and then place it in a constant temperature and humidity oven for drying for 24 hours.

[0061] Step S2: pre-fill colored epoxy resin glue into the conical cavities 302 of the two end plugs 3, place the two end plugs 3 close to the end surfaces of the rock sample 4 on both sides, and then place the end plugs 3 and the rock sample 4 together into the holder 5.

[0062] Step S3: select white oil as the pressurized medium, turn on the confining pressure pump 2, apply an overlying formation pressure of 52 MPa to the clamp 5 through the pressurized medium, then turn on the vacuum pump to evacuate the device for 1 hour, so that the absolute pressure in the clamp 5 is lower than 13.3 Pa; in some other embodiments, the pressurized medium may also be castor oil.

[0063] Step S4: Close the vacuum pump 7 and the vacuum valve 8, and stop vacuuming; use the pore pressure high-pressure metering pump 1 to gradually apply a certain pore pressure at the central circular hole 301 of the end plug 3, push the colored epoxy resin glue into the rock sample 4, and gradually increase the pore pressure to the formation hydrostatic pressure of 22.6MPa, and then keep the pore pressure constant until the volume reading of the pore pressure high-pressure metering pump 1 no longer changes.

[0064] Step S5: heating the colloid in the die-cast rock sample and solidifying it after die-casting is completed; specifically comprising:

[0065] Step S501: Keep the overburden pressure and pore pressure unchanged, heat the holder 5 by the heating device, the initial temperature of the holder is 70°C, and control the temperature of the holder 5 to rise by 10°C per hour by the temperature control device, and finally keep the temperature at 100°C; the temperature and pressure of the holder 5 are kept stable for 10 hours, and the die casting process is completed;

[0066] Step S502: After the die casting is completed, the sample is cooled for 2 hours to fully solidify the colloid in the rock sample 4.

[0067] Step S6: After the solidification is completed, the overlying formation pressure and pore pressure are unloaded, and the rock sample 4 and the end plug 3 are taken out, thus completing the glue injection production of the cast thin slice under formation pressure conditions.

[0068] The casting thin slice inspection and observation diagram finally obtained in the embodiment of the present invention is as follows Figure 4 As shown, the area framed by the white curve in the figure is the die-casting glue.

[0069] The present invention places a rock sample in a clamp, places two end plugs in close contact with the end surfaces at both ends of the rock sample, the end plugs are pre-loaded with colored die-casting glue through a special structural design, and overlying formation pressure is applied to the clamp. After vacuum is drawn through the end plug fine holes through the end plugs, pore pressure is applied to the end plugs in the clamp by a pressurized pipeline, so that colored die-casting glue is injected when overlying formation pressure and pore pressure under real pressure conditions are applied to the rock slice, so that the manufactured cast slice can reflect the pore structure characteristics of the core under real formation pressure conditions. The device is simple and easy to implement, the method is convenient to operate, and the practicability is strong.

[0070] The above description is only an embodiment of the present invention and is not intended to limit the present invention. Any modification, equivalent replacement and improvement made within the application scope of the present invention shall be included in the protection scope of the present invention.

Claims

1. A glue injection manufacturing device for casting thin slices under formation pressure conditions, characterized in that: Includes a holder, a confining pressure pump, an end plug, a pressurizing pipeline, and a vacuuming pipeline; Both ends of the clamp are externally connected to a pressurized pipeline and a vacuum pipeline, the pressurized pipeline is used to apply pore pressure, and the vacuum pipeline is used to draw a vacuum; the clamp is connected to a confining pressure pump; the inside of the clamp is used to place the rock sample, and the overlying formation pressure is applied to the rock sample through the confining pressure pump; An end plug is provided in the clamp, close to the end faces of the two ends of the rock sample; a central circular hole is opened at one end of the end plug, and a conical cavity is opened at the other end; the tip of the conical cavity is connected with the central circular hole; the central circular hole is connected with the pressurized pipeline; an end plug fine hole axially penetrating the end plug is opened at the edge of the end plug, and the end plug fine hole is connected with the vacuum pipeline.

2. The device according to claim 1, characterized in that The end plug is a stainless steel cylinder; the diameter of the end plug is equal to the diameter of the rock sample.

3. The device according to claim 1 or 2, characterized in that: A vacuum pump is arranged on the vacuum pipeline, and the vacuum pump is connected to the end plug holes at both ends of the rock sample through the pipeline, and a vacuum valve is arranged on the pipeline between the vacuum pump and the end plug holes.

4. The device according to claim 3, characterized in that The pressurized pipeline is provided with a pore pressure high-pressure metering pump for simulating the application of pore pressure to the end plugs at both ends of the rock sample for glue injection.

5. The device according to claim 4, characterized in that The clamp also includes a heating device and a temperature control device; The heating device is used to heat the holder so that the colloid in the rock sample can be fully solidified; The temperature control device is electrically connected to the heating device to control the heating temperature.

6. The device according to claim 5, characterized in that The heating device is a heating and heat-insulating layer sleeved on the periphery of the clamp, or a heating belt wound on the outer shell of the clamp.

7. A method for making a thin cast sheet under formation pressure by injection, using the device as claimed in any one of claims 1 to 6, characterized in that: The method comprises the following steps: Step S1: preparing a rock sample to be injected with glue; Step S2: pre-load the colored die-casting glue into the end plug, place the end plug close to the end surfaces on both sides of the rock sample, and then load the end plug and the rock sample into the holder together; Step S3: Turn on the confining pressure pump, apply the overlying formation pressure to the clamp through the pressurized medium, and then open the vacuum pipeline to vacuum the device; Step S4: close the vacuum line to stop vacuuming, open the pressurized line to gradually apply pore pressure to the end plug and the rock sample, push the colored die-casting glue into the rock sample, and gradually increase the pore pressure to the formation hydrostatic pressure, and then keep the pore pressure constant; Step S5: heating the colloid in the die-cast rock sample and solidifying it after die-casting is completed; Step S6: After the solidification is completed, the overlying formation pressure and pore pressure are unloaded, and the rock sample and the end plug are taken out, thus completing the glue injection production of the cast thin slice under formation pressure conditions.

8. The method according to claim 7, characterized in that The step S1 specifically includes: Step S101: Select a rock core and cut it into rock samples; Step S102: Wash the rock sample to remove oil and salt, and then place it in a constant temperature and humidity oven for drying.

9. The method according to claim 8, characterized in that The size of the rock sample cut in step S101 is: diameter 25 mm×depth 5 mm, or diameter 38 mm×depth 5 mm.

10. The method according to claim 7, characterized in that In step S2, the colored die-casting adhesive is a colored epoxy resin die-casting adhesive.

11. The method according to claim 7, characterized in that In step S3, the pressurized medium is white oil or castor oil.

12. The method according to claim 7, characterized in that The step S5 specifically includes: Step S501: Keep the overburden pressure and pore pressure unchanged, heat the holder by a heating device, the initial temperature of the holder is 65-75°C, and control the temperature of the holder to rise by 10-15°C per hour by a temperature control device, and finally keep the temperature constant at 90-100°C; maintain the temperature and pressure of the holder for 9-12 hours after stabilization, and complete the die casting process; Step S502: After die casting, cool for 1-3 hours to fully solidify the colloid in the rock sample.

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