A device and method for testing water solubility of heavy oil under reservoir conditions

Abstract

The application discloses a kind of heavy oil dissolving water testing device and method under reservoir condition, including reaction kettle, piston assembly, liquid supply mechanism and pressurizing mechanism;Reaction kettle is equipped with stirring equipment and heating equipment, and the detachable connection of reaction kettle is in cavity;Piston assembly is slidably connected on the inner wall of cylinder;Piston assembly separates the inner cavity of cylinder into upper chamber and lower chamber;Liquid supply mechanism includes second displacement pump, water storage component and oil storage component;Water storage component, oil storage component are communicated with upper chamber respectively, and water storage component, oil storage component are connected with second displacement pump;Pressurizing mechanism is communicated with lower chamber, for into hydraulic oil in lower chamber.This application can directly measure the miscibility of heavy oil and water under high pressure and high temperature, effectively simulate the condition of reservoir condition, provide convenience for determining the heavy oil dissolving water capacity under reservoir condition, improve the reliability and accuracy of test data;Simple operation, the determination result is intuitive, accurate and reliable, easy to implement.

Description

Technical Field

[0001] This invention relates to the field of oil and gas field development technology, and in particular to a device and method for testing the water solubility of heavy oil under reservoir conditions. Background Technology

[0002] Global demand for crude oil is increasing year by year, while conventional oil reservoirs are becoming increasingly difficult to extract, leading to a gradual increase in the proportion of heavy oil production in total output. Heavy oil reservoirs generally have relatively low temperatures and pressures, but they contain high levels of heavy components with higher activity than conventional crude oil, resulting in strong water solubility. The presence of water significantly alters the viscosity and density of crude oil.

[0003] In existing technologies, methods for evaluating water content in heavy oil are mainly for degassed heavy oil, and the conditions under which the test are at atmospheric pressure, which cannot effectively simulate reservoir conditions.

[0004] Therefore, a device and method for testing the water solubility of heavy oil under reservoir conditions are proposed. Summary of the Invention

[0005] The purpose of this invention is to provide a device and method for testing the water solubility of heavy oil under reservoir conditions, aiming to solve or improve at least one of the above-mentioned technical problems.

[0006] To achieve the above objectives, the present invention provides the following solution: The present invention provides a heavy oil water dissolution testing device under reservoir conditions, comprising:

[0007] A reaction vessel, on which a stirring device and a heating device are installed, and a cylinder is detachably connected inside the reaction vessel;

[0008] A piston assembly slidably connected to the inner wall of the cylinder; the piston assembly divides the inner cavity of the cylinder into an upper chamber and a lower chamber;

[0009] The liquid supply mechanism includes a second displacement pump, a water storage component, and an oil storage component; the water storage component and the oil storage component are respectively connected to the upper chamber, and both the water storage component and the oil storage component are connected to the second displacement pump;

[0010] A pressurizing mechanism, which is connected to the lower chamber, is used to introduce hydraulic oil into the lower chamber.

[0011] According to the present invention, a heavy oil water dissolution testing device under reservoir conditions is provided, wherein the reaction vessel comprises:

[0012] The vessel body has an outer shell, and the cylindrical body is installed inside the outer shell, with a gap between the outer shell and the outer wall of the cylindrical body;

[0013] End cap, which is detachably connected to the top of the vessel body shell;

[0014] An inner cavity base is detachably connected to the bottom of the inner cavity of the outer shell of the vessel; the inner cavity base has a through hole, and the inner cavity of the cylinder communicates with the spacer through the through hole;

[0015] A transparent viewing window is mounted on the side wall of the vessel shell by several fixing bolts, and the transparent viewing window is provided with scale.

[0016] The top and bottom of the cylinder are both open, the top of the cylinder is in contact with the end cap, and the bottom of the cylinder is in contact with the inner cavity base; the stirring device is installed on the end cap, and the heating device includes a high-temperature oven, which is covered by the outer shell of the vessel body.

[0017] According to the present invention, a heavy oil water dissolution testing device under reservoir conditions is provided, wherein the piston assembly includes a shaped piston slidably connected to the inner wall of the cylinder, and the shaped piston divides the inner cavity of the cylinder into an upper chamber and a lower chamber;

[0018] The outer wall of the irregularly shaped piston is equipped with a double-layer sealing ring, which abuts against the inner wall of the cylinder; a conical groove is provided on the top of the irregularly shaped piston.

[0019] According to the present invention, a heavy oil water dissolution testing device under reservoir conditions is provided, wherein the water storage component includes a first intermediate container, the oil storage component includes a second intermediate container, the first intermediate container is connected to a first main pipe through a first branch pipe, and the second intermediate container is connected to the first main pipe through a second branch pipe; the first main pipe passes through the end cap and is connected to the upper chamber; a second valve is installed on the first branch pipe, and a third valve is installed on the second branch pipe;

[0020] The first intermediate container and the second intermediate container are respectively connected to the output pipe of the second displacement pump through a third branch pipe, and a fourth valve is installed on the output pipe of the second displacement pump.

[0021] According to the present invention, a heavy oil water dissolution testing device under reservoir conditions is provided, wherein the pressurization mechanism includes a first displacement pump, a second main pipe is installed at the output end of the first displacement pump, the second main pipe passes through the end cap and extends into the interval, and a first valve is installed on the second main pipe.

[0022] According to the present invention, a heavy oil water dissolution test device under reservoir conditions is provided, wherein a triangular rotating support is detachably connected to the bottom of the vessel shell.

[0023] According to the present invention, a heavy oil water dissolution testing device under reservoir conditions is provided, wherein a sealing ring is installed between the end cap and the cylinder, and a sealing gasket is installed between the bottom of the cylinder and the inner cavity base.

[0024] According to the present invention, a heavy oil water solubility testing device under reservoir conditions is provided, wherein the inner diameter of the cylinder is 3cm to 5cm, the outer diameter of the cylinder is 5cm to 8cm, and the height of the cylinder is 15cm to 20cm.

[0025] This invention also provides a method for testing the water solubility of heavy oil under reservoir conditions, comprising the following steps:

[0026] Step 1: Retrieve degassed oil, formation water, and associated gas from the oilfield. Dehydrate the degassed oil and prepare heavy oil for the reservoir. Transfer the prepared heavy oil to the oil storage unit and transfer the formation water to the water storage unit.

[0027] Step 2: Pump formation water into the upper chamber; introduce hydraulic oil into the lower chamber through the pressurization mechanism and push the piston assembly to move, pressurizing the formation water in the upper chamber to the reservoir pressure; continuously inject hydraulic oil during the formation water pressurization process, so that the hydraulic oil pressure is higher than the formation water pressure in the upper chamber;

[0028] Step 3: Start the heating equipment to heat the temperature inside the reactor to the reservoir temperature;

[0029] Step 4: After the temperature stabilizes, pump the heavy oil into the upper chamber, while simultaneously retracting the pressurizing mechanism to maintain a constant pressure;

[0030] Step 5: Turn on the mixing equipment. After the heavy oil and formation water in the upper chamber are mixed and dissolved, let it stand.

[0031] Step 6: Pump formation water into the upper chamber again until a water layer appears in the lower part of the upper chamber;

[0032] Step 7: Change the heating temperature and the output pressure of the pressurizing mechanism, repeat step 6, and record the amount of water dissolved in the heavy oil.

[0033] According to the present invention, a method for testing the water solubility of heavy oil under reservoir conditions is provided. In step three, the temperature inside the reaction vessel is heated to the reservoir temperature and stabilized for five hours. In step five, the heavy oil in the upper chamber is mixed and dissolved with the formation water and then left to stand for five hours.

[0034] The present invention discloses the following technical effects:

[0035] This invention uses a heating device to heat the formation water and heavy oil in the upper chamber, and a pressurizing mechanism to introduce hydraulic oil into the lower chamber, thereby pressurizing the upper chamber through a piston assembly, thus enabling experimental testing under high temperature and high pressure conditions; the stirring device can fully mix the formation water and heavy oil in the upper chamber, providing convenience for measuring water content;

[0036] This invention enables experiments to be conducted under high pressure and high temperature conditions, allowing for a direct measurement of the miscibility of heavy oil with water under these conditions. It effectively simulates reservoir conditions, providing convenience for determining the water solubility of heavy oil under reservoir conditions and improving the reliability and accuracy of test data. The operation is simple, the measurement results are intuitive, accurate and reliable, and easy to implement. It can objectively evaluate the miscibility of heavy oil and help improve the understanding of heavy oil reservoirs. Attached Figure Description

[0037] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0038] Figure 1 This is the front view of the present invention;

[0039] Figure 2 This is a schematic diagram of the structure of the present invention;

[0040] Among them, 1. First displacement pump; 2. Second displacement pump; 3. First intermediate container; 4. Second intermediate container; 5. First valve; 6. Second valve; 7. Third valve; 8. High-temperature oven; 9. Fixing bolt; 10. Reactor; 11. Transparent window; 12. Triangular rotating support; 13. Reactor shell; 14. Cylinder; 15. Irregular piston; 16. Magnetic stirrer; 17. First main pipe; 18. Second main pipe; 19. Hydraulic oil; 20. Sealing ring; 21. End cap; 22. Inner cavity base; 23. Sealing gasket; 24. Double-layer sealing ring. Detailed Implementation

[0041] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0042] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0043] Reference Figure 1-2 This invention provides a device for testing the water solubility of heavy oil under reservoir conditions, comprising:

[0044] The reactor 10 is equipped with a stirring device and a heating device, and a cylinder 14 is detachably connected inside the reactor 10.

[0045] The piston assembly is slidably connected to the inner wall of the cylinder 14; the piston assembly divides the inner cavity of the cylinder 14 into an upper chamber and a lower chamber.

[0046] The liquid supply mechanism includes a second displacement pump 2, a water storage component, and an oil storage component; the water storage component and the oil storage component are respectively connected to the upper chamber, and both the water storage component and the oil storage component are connected to the second displacement pump 2;

[0047] A pressurizing mechanism is connected to the lower chamber and is used to introduce hydraulic oil 19 into the lower chamber; in this embodiment, the hydraulic oil 19 is hydraulic silicone oil.

[0048] With this configuration, the present invention heats the formation water and heavy oil in the upper chamber using a heating device, introduces hydraulic oil into the lower chamber through a pressurizing mechanism, and then pressurizes the upper chamber through a piston assembly, thereby enabling experimental testing under high temperature and high pressure conditions; the stirring device can fully mix the formation water and heavy oil in the upper chamber, providing convenience for measuring water content;

[0049] This invention enables experiments to be conducted under high pressure and high temperature conditions, allowing for a direct measurement of the miscibility of heavy oil with water under these conditions. It effectively simulates reservoir conditions, providing convenience for determining the water solubility of heavy oil under reservoir conditions and improving the reliability and accuracy of test data. The operation is simple, the measurement results are intuitive, accurate and reliable, and easy to implement. It can objectively evaluate the miscibility of heavy oil and help improve the understanding of heavy oil reservoirs.

[0050] To further optimize the design, a magnetic stirrer 16 is adopted as the stirring equipment. Under the condition of internal sealing, the magnetic stirrer 16 achieves full stirring of the fluid by magnetically driving the rotor inside the reactor 10.

[0051] Further optimization of the design, reactor 10 includes:

[0052] The outer shell 13 of the vessel body and the cylindrical body 14 are installed inside the outer shell 13 of the vessel body, and there is a gap between the outer walls of the outer shell 13 of the vessel body and the outer walls of the cylindrical body 14;

[0053] End cap 21, which is detachably connected to the top of the vessel shell 13;

[0054] The inner cavity base 22 is detachably connected to the bottom of the inner cavity of the outer shell 13 of the vessel body; the inner cavity base 22 is provided with a through hole, and the inner cavity of the cylinder 14 is connected to the spacer through the through hole;

[0055] A transparent viewing window 11 is mounted on the side wall of the vessel shell 13 by several fixing bolts 9. The transparent viewing window 11 has a scale with an accuracy of 0.1mm. There are two transparent viewing windows 11, which are elongated and are respectively located on opposite side walls of the vessel shell 13. In this embodiment, there are 8 fixing bolts 9.

[0056] The top and bottom of the cylinder 14 are both open, the top of the cylinder 14 is in contact with the end cover 21, and the bottom of the cylinder 14 is in contact with the inner cavity base 22; the stirring device is installed on the end cover 21, and the heating device includes a high temperature oven 8, which is covered outside the outer shell 13 of the vessel body;

[0057] With this setup, the mixing of heavy oil and water in the upper chamber under reservoir temperature and pressure can be directly observed through the transparent window 11. The scale on the transparent window 11 and the conical groove in the irregular piston 15 ensure that even a small amount of fluid can be observed in terms of volume, thereby allowing for an objective evaluation of its miscibility and helping to improve the understanding of heavy oil reservoirs.

[0058] A gap is provided between the outer shell 13 of the vessel body and the outer wall of the cylinder 14, so that when pressurized, the gap is filled with hydraulic silicone oil, which can ensure the pressure balance inside and outside the cylinder 14 and ensure that it can withstand high pressure.

[0059] The design was further optimized. The outer shell 13 of the vessel is made of high-pressure steel and can withstand a pressure of 25 MPa. The cylinder 14 is made of transparent high-temperature and high-pressure resistant glass. During the test, the pressure difference between the upper and lower parts of the irregularly shaped piston 15 inside the cylinder 14 is controlled to not exceed 2 MPa.

[0060] Further optimization of the design includes a piston assembly comprising a shaped piston 15 that is slidably connected to the inner wall of the cylinder 14, the shaped piston 15 dividing the inner cavity of the cylinder 14 into an upper chamber and a lower chamber;

[0061] A double-layer sealing ring 24 is installed on the outer wall of the irregular piston 15, and the double-layer sealing ring 24 abuts against the inner wall of the cylinder 14; a conical groove is opened on the top of the irregular piston 15; the depth of the conical groove is 1mm; the irregular piston 15 is cylindrical in shape, and the inner cavity of the cylinder 14 is cylindrical; the shape of the irregular piston 15 is adapted to the shape of the inner cavity of the cylinder 14; an irregular structure is formed by opening a conical groove on the top surface of the cylinder, and a volume scale is provided on the irregular piston 15 to facilitate the reading of experimental data.

[0062] The scheme is further optimized. The water storage component includes a first intermediate container 3, and the oil storage component includes a second intermediate container 4. The first intermediate container 3 is connected to a first main pipe 17 through a first branch pipe, and the second intermediate container 4 is connected to the first main pipe 17 through a second branch pipe. The first main pipe 17 passes through the end cap 21 and is connected to the upper chamber. A second valve 6 is installed on the first branch pipe, and a third valve 7 is installed on the second branch pipe.

[0063] The first intermediate container 3 and the second intermediate container 4 are respectively connected to the output pipe of the second displacement pump 2 through the third branch pipe, and the output pipe of the second displacement pump 2 is equipped with a fourth valve.

[0064] The scheme is further optimized. The pressurization mechanism includes a first displacement pump 1. The output end of the first displacement pump 1 is equipped with a second main pipe 18. The second main pipe 18 passes through the end cover 21 and extends into the interval. A first valve 5 is installed on the second main pipe 18.

[0065] The design is further optimized by detachably connecting a triangular rotating bracket 12 to the bottom of the vessel shell 13. The bracket is made of stainless steel and can be suspended at 180 degrees. The triangular rotating bracket 12 can be rotated 180 degrees, which facilitates the replacement of the cylinder 14, sealing ring 20, and sealing gasket 23.

[0066] In a further optimized design, a sealing ring 20 is installed between the end cap 21 and the cylinder 14, and a sealing gasket 23 is installed between the bottom of the cylinder 14 and the inner cavity base 22.

[0067] Further optimization of the design: the inner diameter of the cylinder 14 is 3cm to 5cm; the outer diameter of the cylinder 14 is 5cm to 8cm; and the height of the cylinder 14 is 15cm to 20cm.

[0068] This invention also provides a method for testing the water solubility of heavy oil under reservoir conditions, comprising the following steps:

[0069] Step 1: Retrieve degassed oil, formation water, and associated gas from the oilfield. Dehydrate the degassed oil and prepare reservoir heavy oil. Transfer the prepared heavy oil to the oil storage unit and transfer the formation water to the water storage unit. Prepare the reservoir heavy oil in a sampler according to the production gas-oil ratio.

[0070] Step 2: Pump formation water into the upper chamber; introduce hydraulic oil (19 MPa to approximately 1 MPa) into the lower chamber through the pressurization mechanism, and push the piston assembly to move, pressurizing the formation water in the upper chamber to the reservoir pressure; continuously inject hydraulic oil (19) during the formation water pressurization process, injecting hydraulic oil (19) into the inter-chamber and the lower chamber, and making the pressure of hydraulic oil (19) about 1 MPa higher than the formation water pressure in the upper chamber;

[0071] Step 3: Start the heating equipment to heat the temperature inside the reactor 10 to the reservoir temperature;

[0072] Step 4: After the temperature stabilizes, pump 40ml of heavy oil into the upper chamber, while simultaneously retracting the pressurizing mechanism to maintain constant pressure.

[0073] Step 5: Turn on the mixing equipment. After the heavy oil and formation water in the upper chamber are mixed and dissolved, let it stand.

[0074] Step 6: Pump formation water into the upper chamber again until a water layer appears in the lower layer of the upper chamber; taking advantage of the density difference between oil and water, undissolved water will exist in the lower layer. Continuously pump formation water into the upper chamber and stabilize it until a residual water layer appears in the lower layer of the transparent window 11, indicating that the heavy oil is now fully saturated with aqueous solution.

[0075] Step 7: Change the heating temperature and the output pressure of the pressurizing mechanism, repeat step 6, and record the water solubility of the heavy oil. This will allow you to obtain the water solubility of the heavy oil under different conditions.

[0076] Further optimization of the scheme: In step three, the temperature inside the reactor 10 is heated to the reservoir temperature and stabilized for five hours; in step five, the heavy oil in the upper chamber is mixed and dissolved with the formation water and then left to stand for five hours.

[0077] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0078] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A method for testing water solubility of heavy oil under reservoir conditions, using a device for testing water solubility of heavy oil under reservoir conditions, characterized in that: the device for testing water solubility of heavy oil under reservoir conditions comprises: a reaction kettle (10) provided with stirring equipment and heating equipment, and a cylinder (14) detachably connected in the reaction kettle (10); a piston assembly slidingly connected to the inner wall of the cylinder (14), which separates the inner cavity of the cylinder (14) into an upper chamber and a lower chamber, and comprises a special-shaped piston (15) slidingly connected to the inner wall of the cylinder (14), and a tapered groove is formed in the top of the special-shaped piston (15); a liquid supply mechanism comprising a second displacement pump (2), a water storage assembly and an oil storage assembly, wherein the water storage assembly and the oil storage assembly are respectively in communication with the upper chamber, and are both connected to the second displacement pump (2); the water storage assembly comprises a first intermediate container (3), and the oil storage assembly comprises a second intermediate container (4), and the first intermediate container (3) and the second intermediate container (4) are respectively in communication with the output pipe of the second displacement pump (2) through a third branch pipe; a pressurizing mechanism in communication with the lower chamber for introducing hydraulic oil (19) into the lower chamber; the reaction kettle (10) comprises: a kettle shell (13), wherein the cylinder (14) is installed in the kettle shell (13), and a space is provided between the kettle shell (13) and the outer wall of the cylinder (14); an end cover (21) detachably connected to the top of the kettle shell (13); an inner cavity base (22) detachably connected to the bottom of the inner cavity of the kettle shell (13), wherein a through hole is formed in the inner cavity base (22), and the inner cavity of the cylinder (14) is in communication with the space through the through hole; and a transparent window (11) installed on the side wall of the kettle shell (13) through a plurality of fixing bolts (9), and provided with a scale; wherein the top and bottom of the cylinder (14) are both open, the top of the cylinder (14) is in contact with the end cover (21), and the bottom of the cylinder (14) is in contact with the inner cavity base (22); the stirring equipment is installed on the end cover (21), and the heating equipment comprises a high-temperature oven (8) covering the outside of the kettle shell (13); and the method for testing water solubility of heavy oil under reservoir conditions comprises the following steps: Step 1: recovering degassed oil, formation water and associated gas from an oilfield site, preparing reservoir heavy oil by dehydrating the degassed oil, and transferring the prepared heavy oil to the oil storage assembly and the formation water to the water storage assembly; ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Step two, pumping formation water into the upper chamber; through the pressurizing mechanism to the lower chamber into hydraulic oil (19), and push the piston assembly to move, the formation water in the upper chamber to the reservoir pressure; formation water pressure process continues to inject hydraulic oil (19), so that the hydraulic oil (19) pressure is higher than the formation water pressure in the upper chamber; Step three, start heating equipment, heating the temperature in the reactor (10) to reservoir temperature; Step four, after the temperature stabilizes, pump the heavy oil into the upper chamber, and back off the pressure mechanism to keep the pressure constant; Step five, open the stirring device, and after the heavy oil in the upper chamber is mixed and mutually soluble with the formation water, stand still; Step six, pump formation water into the upper chamber again until water layer appears in the lower layer of the upper chamber; Step seven, change the heating temperature and the output pressure of the pressure mechanism, repeat step six, and record the water solubility of the heavy oil.

2. The method for testing water solubility of heavy oil under reservoir conditions according to claim 1, characterized in that: The special-shaped piston (15) separates the inner cavity of the barrel (14) into the upper chamber and the lower chamber; A double-layer sealing rubber ring (24) is installed on the outer side wall of the special-shaped piston (15), and the double-layer sealing rubber ring (24) abuts against the inner wall of the barrel (14).

3. The method according to claim 1, wherein: The first intermediate container (3) is connected with a first main pipe (17) through a first branch pipe, the second intermediate container (4) is communicated with the first main pipe (17) through a second branch pipe; the first main pipe (17) penetrates the end cover (21) and is communicated with the upper chamber; a second valve (6) is installed on the first branch pipe, and a third valve (7) is installed on the second branch pipe; A fourth valve is installed on the output pipe of the second displacement pump (2).

4. The method for testing water solubility of heavy oil under reservoir conditions according to claim 1, characterized in that: The pressurizing mechanism includes a first displacement pump (1), and a second main pipe (18) is installed at the output end of the first displacement pump (1), the second main pipe (18) penetrates the end cover (21) and extends into the interval, and a first valve (5) is installed on the second main pipe (18).

5. The method of claim 1, wherein: A triangular rotating support (12) is detachably connected to the bottom of the kettle body shell (13).

6. The method of claim 1, wherein: A sealing ring (20) is installed between the end cover (21) and the barrel (14), and a sealing gasket (23) is installed between the bottom of the barrel (14) and the inner cavity base (22).

7. The method according to claim 1, wherein: The inner diameter of the barrel (14) is 3cm-5cm; the outer diameter of the barrel (14) is 5cm-8cm, and the height of the barrel (14) is 15cm-20cm.

8. The method of claim 1, wherein: In step three, after the temperature in the reactor (10) is heated to the reservoir temperature, it is stabilized for five hours; in step five, after the heavy oil in the upper chamber is mixed and mutually soluble with the formation water, it is stood still for five hours.

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