Rock core experiment device for simulating oil reservoir environment

Abstract

The utility model discloses a rock core experiment device for simulating oil reservoir environment, which comprises an oil reservoir simulation device, the oil reservoir simulation device comprises a rock core cabin body, a rock core cabin opening is arranged on the top wall of the rock core cabin body, the rock core cabin body is connected with a pressure regulating device, and a rock core base is arranged on the bottom wall in the rock core cabin body. And the core base is in the projection of the core cabin opening. The oil reservoir simulation device can provide temperature, pressure and formation fluid, simulate the real consolidation condition and performance characteristics of the artificial rock core in the formation environment, truly reflect the characteristics of the artificial rock core in the formation environment, provide more real experimental data for sand prevention design, preferably select better products, and improve the production efficiency. The sand prevention effect of chemical sand prevention is improved, and the sand prevention validity period is prolonged.

Description

Technical Field

[0001] This utility model relates to the field of oil well simulation equipment technology, specifically a core experimental device for simulating oil reservoir environment. Background Technology

[0002] Loose sandstone reservoirs hold a vital position in my country's oil and gas resources, and their rational and efficient development is crucial for maintaining and increasing the country's oil and gas production. However, loose sandstone reservoirs have weak cementation strength, making them highly susceptible to sand production during production, which can cause significant damage and economic losses to normal oilfield operations. Chemical sand control is a commonly used method. To better design chemical sand control schemes and ensure their effectiveness, it is necessary to conduct adaptability evaluation experiments on sand-fixing systems, including sand-fixing agents and coated sands. The evaluation of sand-fixing systems begins with preparing rock samples, followed by evaluation of compressive strength and permeability.

[0003] The current conventional method for preparing rock samples involves adding rock sample preparation material into a glass tube of a certain size, manually compacting it, heating it to solidify for a period of time, and then breaking the glass tube to remove the solidified rock sample. This method has certain drawbacks: (1) it cannot simulate the solidification conditions of sand-fixing agents in the reservoir environment; (2) the experiment is subject to significant human factors, resulting in poor repeatability; and (3) the removal of the glass tube can easily lead to a low yield of rock cores and poses safety hazards. In order to solve the above problems, relevant technical personnel have also conducted relevant research.

[0004] The conventional method for evaluating the compressive strength of rock cores under high temperature and pressure involves placing the prepared rock core in an aging tank (filled with liquid), then placing the aging tank in a heating device for a certain period of time. After cooling to room temperature, the aging tank is opened, and the rock core is removed for compressive strength testing. This method simulates and evaluates the effects of high temperature and pressure in the formation and fluids on the compressive strength of the rock core; however, the pressure cannot accurately simulate the pressure of the oil reservoir.

[0005] Publication No. CN115728100A discloses a core preparation device and method. The device includes a fastening device and a clamping device connected to each other; it also includes a recovery device. The recovery device is connected to the bottom of the clamping device, and the inner cavity of the recovery device is in communication with the inner cavity of the clamping device. The recovery device includes a liquid guide tube and a recovery chamber. The liquid guide tube is threadedly connected to the bottom of the clamping cylinder of the clamping device; the recovery chamber is threadedly connected to the bottom of the liquid guide tube; the clamping cylinder, liquid guide tube, and recovery chamber of the clamping device are connected sequentially from top to bottom.

[0006] The existing technology cannot simulate the reservoir environment to test core consolidation and core compressive strength.

[0007] Publication No. CN114993847A discloses a cementing interface sealing capacity evaluation system and method. The evaluation system includes a mud cake forming device, a mud cake flushing device, an interface forming and curing mold, and an interface sealing capacity testing device. The mud cake forming device includes a first cylinder, a first pressure regulating unit, and a first temperature regulating unit. The mud cake flushing device includes a flushing vessel, a second pressure regulating unit, a second temperature regulating unit, a clamping unit, an outer cylinder, a rotating unit, and a circulation unit. The interface forming and curing mold provides a static fluid curing environment. The interface sealing capacity testing device is capable of testing the interface sealing capacity.

[0008] The existing technology cannot simulate the reservoir environment to test core consolidation and core compressive strength.

[0009] Publication No.: CN117662063A discloses a device and method for simulating high-temperature and high-pressure cement slurry plugging of oil and gas wells, including an outer cylinder, an inner cylinder A, and an inner cylinder B; the outer cylinder has a vertical inner cavity, the top can be opened and the bottom is sealed, the top has a liquid-air inlet and the bottom has a liquid-air outlet; the inner cylinder A contains a columnar core specimen, and the gap between the columnar core specimen and the inner cylinder A is sealed with resin to form a sealing structure, and the sealing structure is sealed in the lower part of the vertical inner cavity; the inner cylinder B is located in the upper part of the vertical inner cavity and is sealed and connected to the inner cylinder A.

[0010] The existing technology cannot simulate the reservoir environment to test core consolidation and core compressive strength.

[0011] In summary, the technical solutions, technical problems to be solved, and beneficial effects of the above-disclosed technologies are all different from those of this utility model. For more technical features, technical problems to be solved, and beneficial effects of this utility model, the above-disclosed technical documents do not provide any technical inspiration. Utility Model Content

[0012] In view of the above-mentioned defects in the existing technology, the purpose of this utility model is to provide a core experimental device for simulating the reservoir environment.

[0013] To achieve the above objectives, the present invention adopts the following technical solution:

[0014] A core experimental device for simulating an oil reservoir environment includes an oil reservoir simulation device. The oil reservoir simulation device includes a core chamber, a core chamber hatch is provided on the top wall of the core chamber, a pressure regulating device is connected to the core chamber, and a core base is provided on the bottom wall inside the core chamber, with the core base within the projection of the core chamber hatch.

[0015] Furthermore, the core chamber can be filled with experimental liquid, and a drain port is provided on the bottom wall of the core chamber.

[0016] Furthermore, the experimental solution is formation water, simulated water, acid, or alkali.

[0017] Furthermore, the pressure regulating device includes a pressure regulating valve and a connecting cover;

[0018] Specifically, the connecting cover can be sealed to the core chamber hatch, and the pressure regulating valve is connected to the connecting cover.

[0019] Furthermore, the heating device is an electric heating coil wound around the outside of the side wall of the core chamber, and a temperature sensor is installed on the bottom wall inside the core chamber.

[0020] Furthermore, the core chamber is cylindrical.

[0021] Furthermore, the core chamber hatch is a cylindrical structure, the core base is a cylindrical structure, the core base is concentric with the core chamber hatch, and the inner wall of the core base is provided with steps to form an inner small diameter and an inner large diameter.

[0022] Furthermore, it also includes a core preparation device, which includes a sand filling pipe, a plunger rod, and a plug, wherein the plunger rod can be inserted from the upper end of the sand filling pipe;

[0023] Specifically, a plug is connected to the lower end of the sand-filling pipe, the plug is provided with a seepage hole, and a screen is provided between the plug and the sand-filling pipe.

[0024] Furthermore, a lower connector is provided at the lower end of the sand-filling pipe, and the plug is connected to the outer wall of the lower connector; the plug can fit into the inner large diameter of the core base, so that the plug sits on the step.

[0025] Furthermore, it also includes a pressurizing device, which is a pressure testing machine;

[0026] Specifically, the pressure head of the pressure testing machine is an extended pressure head;

[0027] Specifically, the extended pressure head includes a connecting plate, which is connected to the pressure rod of the pressure testing machine. An extension rod is provided at the center of the lower end of the connecting plate, and a pressure plate is provided at the lower end of the extension rod. The pressure plate is cylindrical, and the outer diameter of the pressure plate is smaller than the inner diameter of the core chamber hatch.

[0028] Compared with the prior art, the present invention has the following advantages:

[0029] 1. In the production of artificial rock cores, this utility model can utilize the constant pressure function of the pressurization device to achieve quantitative pressurization, which can better simulate the real situation of the rock core in the strata.

[0030] 2. The artificial core consolidation of this utility model is carried out in a reservoir simulation device, which can simulate the actual environment of the core in the formation, including temperature, pressure and formation fluids, and can truly reflect the consolidation of the artificial core under formation conditions.

[0031] 3. The evaluation of the compressive strength of the artificial core of this utility model can be carried out by using a reservoir simulation device to simulate the compressive strength of the core under formation conditions, providing real and powerful data support for the subsequent selection of artificial core materials.

[0032] 4. The reservoir simulation device of this utility model can provide temperature, pressure, and formation fluid to simulate the real consolidation and performance characteristics of artificial rock cores under formation conditions. It can truly reflect the characteristics of artificial rock cores under formation conditions, provide more realistic experimental data for sand control design, select better products, improve the sand control effect of chemical sand control, and extend the sand control validity period. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the core-making device in this utility model;

[0034] Figure 2 This is a schematic diagram of the reservoir simulation device in this utility model;

[0035] Figure 3 This is a schematic diagram of the extended pressure head in this utility model.

[0036] In the figure: core preparation device 1, sand filling pipe 101, plug 102, screen 103, plunger rod 104;

[0037] Reservoir simulation device 2, core chamber body 201, core chamber hatch 202, core base 203, drain port 204, pressure regulating device 205, heating device 206;

[0038] Extended pressure head 3, connecting plate 301, extension rod 302, pressure plate 303. Detailed Implementation

[0039] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0040] Example 1:

[0041] Please see Figure 2This embodiment provides a core experiment apparatus for simulating an oil reservoir environment, including an oil reservoir simulation device 2. The oil reservoir simulation device 2 includes a core chamber 201, a heating device 206 installed on the side wall of the core chamber 201, a core chamber hatch 202 installed on the top wall of the core chamber 201, a pressure regulating device 205 connected to the core chamber 201, and a core base 203 installed on the bottom wall inside the core chamber 201, the core base being within the projection of the core chamber hatch. The oil reservoir simulation device 2 can be used for core consolidation and core compressive strength experiments.

[0042] Specifically, the core preparation device 1 is placed into the core base 203 through the core chamber hatch 202, and then experimental liquid is added through the core chamber hatch 202 to simulate the humidity of the target stratum. The core chamber hatch 202 is then sealed, and the pressure of the target stratum is simulated by the pressure regulating device 205. The temperature of the target stratum is simulated by the heating device 206.

[0043] Furthermore, the bottom wall of the core chamber 201 is provided with a drain port 204 for quickly discharging the experimental liquid. The drain port 204 is sealed by a sealing cap, and its pressure resistance meets the experimental requirements.

[0044] Specifically, the core chamber 201 is made of heat-resistant, pressure-resistant, and corrosion-resistant materials. The core chamber 201 is cylindrical, which allows the heating device 206 to heat the core chamber 201 quickly and evenly. A temperature sensor is installed on the bottom wall inside the core chamber 201, which can accurately obtain the temperature of the experimental liquid and is easy to set.

[0045] Specifically, the core chamber hatch 202 is a cylindrical structure, which facilitates the connection of a sealing cover or other equipment. The core chamber hatch 202 is located on the top wall of the core chamber body 201, which allows other objects to enter the core chamber through the hatch on the core chamber.

[0046] Specifically, the core base 203 is a cylindrical structure, the core base 203 is concentric with the core chamber hatch 202, and the inner wall of the core base 203 is provided with steps to form an inner small diameter and an inner large diameter.

[0047] Specifically, the core base 203 enables the core production device 1 to be fixed inside the core chamber 201 and will not be displaced by external forces.

[0048] Specifically, the pressure regulating device 205 includes a pressure regulating valve and a connecting cover. The connecting cover can be connected to the core chamber hatch 202 via threads and gaskets, providing a sealed and pressure-resistant seal. The pressure regulating valve is connected to the connecting cover. First, a constant pressure value is set for the pressure regulating valve. Then, by connecting the pressurization pipeline to the pressure regulating valve, pressure is applied to the core chamber 201 via an automatic or manual pressurization device. After the pressure reaches the constant pressure value, the pressure regulating valve maintains a constant pressure inside the core chamber 201. The pressure adjustment range of the pressure regulating valve can meet the experimental requirements.

[0049] Specifically, the heating device 206 is an electric heating coil wound around the outside of the side wall of the core chamber 201. The heating device 206 can uniformly and quickly heat the core chamber 201 to reach the experimental formation temperature.

[0050] Specifically, the experimental solution is formation water or other water or acid required for experiments.

[0051] Example 2:

[0052] Based on Example 1, please refer to Figure 1 A core testing apparatus simulating an oil reservoir environment also includes a core preparation device 1, comprising a sand-filling pipe 101, the lower end of which is connected to a plug 102, the plug 102 being provided with seepage holes, a screen 103 being provided between the plug 102 and the sand-filling pipe 101, and a plunger rod 104, which can be inserted from the upper end of the sand-filling pipe 101. Core preparation material is placed into the sand-filling pipe 101, and the core preparation material is compacted into a core by the plunger rod 104 and a pressurizing device. The required length of core is obtained by repeatedly adding core preparation material and compaction operations, during which liquid in the material is discharged through the seepage holes of the screen 103 and the plug 102.

[0053] Specifically, the sand-filling pipe 101 is made of stainless steel 304, with a length of 20cm and an inner diameter of 2.54cm, and the inner wall is uniformly coated with an organosilicon release agent.

[0054] Specifically, the plug 102 is made of stainless steel 304, and a lower connector is provided at the lower end of the sand filling pipe 101. The plug 102 is connected to the outer wall of the lower connector by threads. The outer diameter of the plug 102 is the same as the inner diameter of the core base 203, and they can be fitted together so that the plug 102 sits on the step.

[0055] Specifically, the screen 103 is a stainless steel screen.

[0056] In this embodiment, the core material is sand, and the screen 103 is a 40-mesh stainless steel screen.

[0057] Specifically, the plunger rod 104 is clearance-fitted with the sand-filling pipe 101.

[0058] After the core compaction is completed by the core preparation device 1, the plunger 104 is removed and the core preparation device 1 is placed into the core chamber 201. The outer wall of the plug 102 fits into the inner large diameter of the core base 203, so that the plug 102 sits on the step. The size of the core chamber 201 is such that the sand filling pipe 101 can be completely placed inside it.

[0059] Example 3:

[0060] Based on Example 2, please refer to Figure 3 A core testing apparatus simulating an oil reservoir environment also includes a pressurization device, which is a pressure testing machine. The pressure head of the pressure testing machine is replaced by an extended pressure head 3. The extended pressure head 3 includes a connecting plate 301, which is connected to the pressure rod of the pressure testing machine by bolts. An extension rod 302 is provided at the center of the lower end of the connecting plate 301. A pressure plate 303 is provided at the lower end of the extension rod 302. The pressure plate 303 is cylindrical, and the outer diameter of the pressure plate 303 is smaller than the inner diameter of the core chamber hatch 202.

[0061] Specifically, the design of the core base 203 does not affect the test of the core compressive strength. The inner minor diameter of the core base 203 is larger than the outer diameter of the standard core to prevent the core base 203 from contacting the core and generating stress. The core base 203 ensures that the core will not detach from the core base 203 during transportation. The core base 203 will not contact the pressure plate 303 during the core compressive strength test.

[0062] Specifically, the pressure testing machine is existing technology, which has the function of setting constant pressure and displaying pressure peak value. Those skilled in the art are aware of this. In this embodiment, its pressure head is replaced with an extended pressure head 3, and the outer diameter of the pressure plate 303 is smaller than the core chamber hatch 202, so that the pressure plate 303 can extend into the core chamber 201 to conduct a pressure test on the core.

[0063] Specifically, when the pressure testing machine is used to prepare rock cores, a constant pressure is set as required, and the plunger rod 104 is pressurized at a constant pressure for a certain period of time. When the pressure testing machine is used to measure the compressive strength of the rock core, the pressure plate 303 enters the rock core chamber 201 and continuously pressurizes until the rock core breaks. The pressure testing machine automatically records the peak pressure and obtains the compressive strength of the rock core.

[0064] Specifically, the pressure testing machine can be the YAW-2000 microcomputer-controlled fully automatic pressure testing machine.

[0065] Example 4:

[0066] Based on Example 3, this example provides a method for using a core experimental apparatus to simulate an oil reservoir environment:

[0067] S1. Preparation of artificial rock cores:

[0068] Set the pressure testing machine to a constant pressure output of 4.0 MPa. Place a screen 103 inside the sand filling tube 101 and connect a plug 102. Then add the core preparation material (coated sand and curing agent of 0.425 cm-0.850 cm) in batches. After each addition of the core preparation material, place the plunger 104 into the sand filling tube and pressurize the plunger 104 with the pressure testing machine. When the pressure reaches 4.0 MPa, maintain this pressure for 5 minutes, then stop pressurizing, remove the plunger 104, add the core preparation material, and repeat the above operation until the core length meets the experimental requirements.

[0069] S2. Simulated consolidation of sand-stabilizing agents in reservoir environment:

[0070] Clean the reservoir simulation device 2, check each component to ensure that each component is in normal working order, connect each component, and check the overall sealing of the device;

[0071] After inspection, place the sand-filled pipe 101 containing the artificial core onto the core base 203 inside the core chamber 201, close the drain port 204, add formation water into the core chamber 201, seal the connection cap of the pressure regulating device 205 to the core chamber hatch 202, set the pressure regulating valve of the pressure regulating device 205 to maintain a pressure of 8 MPa, connect the heating device 206, set the temperature target to 60°C, and start pressurization and heating. When the pressure reaches 8 MPa and the temperature reaches 60°C, start timing. Consolidate at this temperature and pressure for 72 hours, then close the heating device 206. When the temperature drops to room temperature, open the pressure regulating valve to slowly release the pressure, then open the core chamber hatch 202, remove the sand-filled pipe 101, and take out the consolidated artificial core for later use. Open the drain port 204 of the core chamber to drain the experimental liquid, and rinse the core chamber with clean water.

[0072] S3. Compressive strength test of artificial cores under simulated reservoir conditions:

[0073] Check the sealing of the reservoir simulation device 2. Make the prepared artificial core into a standard specimen and place it into the inner small diameter of the core base 203 inside the core chamber 201. Close the drain port 204. Add formation water into the core chamber. Seal the connection cover of the pressure regulating device 205 to the core chamber hatch 202. Set the pressure regulating valve of the pressure regulating device 205 to 15MPa. Connect the heating device 206 and set the temperature target to 300℃. Start pressurization and heating. When the pressure reaches 15MPa and the temperature reaches 300℃, start timing. After 96 hours of experimentation at this temperature and pressure, turn off the heating device 206. When the temperature drops to room temperature, open the pressure regulating device 205 and slowly depressurize to atmospheric pressure. After completely draining the experimental liquid through the drain port 204, close the drain port 204.

[0074] Then, the reservoir simulation device 2 is placed on the platform of the pressure testing machine, the artificial core is moved to the center of the core base 203, the pressure plate 303 is aligned with the artificial core, the core chamber hatch 202 is sealed with a sealing cover, the heating device 206 is connected, the temperature target is set to 300℃, the switch is turned on, and the temperature is heated for 2 hours after reaching the set temperature. Then the core chamber hatch 202 is opened, the pressure testing machine is started to conduct a compressive strength test, the pressure plate 303 contacts the artificial core through the core chamber hatch 202, and the compressive strength of the artificial core under reservoir conditions is obtained after the artificial core is crushed.

[0075] Complete the experiment and clean all experimental equipment.

[0076] All components not discussed in detail in this application, as well as the connection methods of these components, are well-known technologies in this field. They can be directly applied and will not be elaborated further.

[0077] In this utility model, the term "multiple" refers to two or more unless otherwise explicitly defined. The terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; "linking" can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0078] In the description of this utility model, it should be understood that the terms "upper", "lower", "left", "right", "front", "rear", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or unit referred to must have a specific orientation or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0079] In the description of this specification, the terms "one embodiment," "some embodiments," "specific embodiment," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0080] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A core experimental apparatus for simulating an oil reservoir environment, characterized in that, The system includes a reservoir simulation device, which includes a core chamber. The top wall of the core chamber is provided with a core chamber hatch. The core chamber is connected to a pressure regulating device. The bottom wall inside the core chamber is provided with a core base, which is located within the projection of the core chamber hatch.

2. The core experimental apparatus for simulating reservoir environment according to claim 1, characterized in that, The core chamber can be filled with experimental liquid, and a drain port is provided on the bottom wall of the core chamber.

3. The core experimental apparatus for simulating reservoir environment according to claim 2, characterized in that, The experimental solution is formation water, simulated water, acid, or alkali.

4. The core experimental apparatus for simulating reservoir environment according to claim 1, characterized in that, The pressure regulating device includes a pressure regulating valve and a connecting cover; The connecting cover can be sealed to the core chamber hatch, and the pressure regulating valve is connected to the connecting cover.

5. The core experimental apparatus for simulating an oil reservoir environment according to claim 1, characterized in that, A heating device, which is an electric heating coil, is installed on the side wall of the core chamber. A temperature sensor is installed on the bottom wall inside the core chamber.

6. A core experimental apparatus for simulating a reservoir environment according to any one of claims 1-5, characterized in that, The core chamber is cylindrical.

7. The core experimental apparatus for simulating reservoir environment according to claim 6, characterized in that, The core chamber hatch is a cylindrical structure, the core base is a cylindrical structure, the core base is concentric with the core chamber hatch, and the inner wall of the core base is provided with steps to form an inner small diameter and an inner large diameter.

8. The core experimental apparatus for simulating an oil reservoir environment according to claim 7, characterized in that, It also includes a core preparation device, which includes a sand filling pipe, a plunger rod, and a plug, wherein the plunger rod can be inserted from the upper end of the sand filling pipe; The lower end of the sand-filling pipe is connected to a plug, the plug is provided with a seepage hole, and a screen is provided between the plug and the sand-filling pipe.

9. The core experimental apparatus for simulating reservoir environment according to claim 8, characterized in that, The lower end of the sand-filling pipe is provided with a lower connector, and the plug is connected to the outer wall of the lower connector; the plug can fit into the inner large diameter of the core base, so that the plug sits on the step.

10. The core experimental apparatus for simulating reservoir environment according to claim 8, characterized in that, It also includes a pressurizing device, which is a pressure testing machine; The pressure head of the pressure testing machine is an extended pressure head; The extended pressure head includes a connecting plate, which is connected to the pressure rod of the pressure testing machine. An extension rod is provided at the center of the lower end of the connecting plate, and a pressure plate is provided at the lower end of the extension rod. The pressure plate is cylindrical, and the outer diameter of the pressure plate is smaller than the inner diameter of the core chamber hatch.

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