In-situ microemulsion oil displacement efficiency testing device

Abstract

The utility model relates to an in-situ micro-emulsion oil displacement efficiency testing device which comprises an in-situ nano micro-emulsion generator and a displacement testing device which are connected with each other and are both arranged in a temperature control device, rock cores and pressure sensors with the same permeability are arranged in the in-situ nanometer microemulsion generator and the displacement testing device; the in-situ nanometer microemulsion generator is connected with a liquid input system, and the outlet end of the displacement testing device is connected with a liquid collecting system; the system further comprises a data acquisition system, and the pressure sensors are all connected with the data acquisition system. The in-situ nanometer micro-emulsion production device further comprises a pressurization system, and the pressurization system is connected with the in-situ nanometer micro-emulsion generator. The temperature control device and the pressurization system simulate the high-temperature and high-pressure conditions of an oil reservoir, the in-situ generation process of the microemulsion is simulated under the high-temperature and high-pressure conditions of the oil reservoir, and the oil displacement efficiency is evaluated by comparing the pressure changes of the in-situ nanometer microemulsion generator and the displacement testing device.

Description

TECHNICAL FIELD

[0001] The utility model relates to oil and gas field development improves the oil recovery research field especially a kind of in situ microemulsion improves recovery ratio oil displacement experimental device. BACKGROUND

[0002] Microemulsion is a kind of mixed system with transparency, optical isotropy, thermodynamic stability, which is compounded by water, oil, surfactant and auxiliary agent. Compared with conventional emulsion, microemulsion has small droplet size (usually between 10-100 nm), ultra-low interfacial tension (<20 mN / m) and bidirectional wetting, and strong oil solubilization capacity. When nano materials are added into microemulsion, they can play a synergistic effect with microemulsion when driving oil into core pore, improving oil washing efficiency. Microemulsion flooding can reduce pressure and increase injection in low-permeability reservoirs, and improve imbibition oil displacement effect, which provides a new idea for efficient exploitation of low-permeability reservoirs.

[0003] However, a certain amount of crude oil has been solubilized in the micelles of ground microemulsion, and the oil phase solubilization window becomes narrow after injection into reservoir, which will affect the solubilization and oil displacement effect of microemulsion. Injection of surfactant-strengthened water into reservoir for in-situ emulsification can improve the solubilization window of microemulsion, and the viscosity of surfactant-strengthened water is lower than that of microemulsion, so it has better injection property in low-permeability reservoirs. In recent years, with the in-depth study of microemulsion mechanism by Chinese scholars, a series of microemulsions have been developed for improving the recovery of various reservoirs.

[0004] However, the complex interfacial properties and polydispersity characteristics of microemulsion / microemulsion+nanoparticle make the flow rule and the influence on improving recovery rate extremely complex, and there are still a large number of problems to be solved. At present, there are few studies on in-situ generation of nanomicroemulsion and its influence on oil displacement efficiency, and no evaluation device for in-situ generation of nanomicroemulsion flooding has been reported. Traditional micro-visualization model has simple structure, and relatively few simulation conditions can be realized, so it is difficult to realize in-situ microemulsion generation and oil displacement efficiency test under complex reservoir conditions. SUMMARY

[0005] The utility model aims at the above-mentioned problem, and proposes an in-situ microemulsion oil displacement efficiency test device.

[0006] The technical scheme of the utility model is:

[0007] An in-situ microemulsion oil displacement efficiency testing device, characterized in that: comprising a connected in-situ nano microemulsion generator and displacement testing device, which are placed in a temperature control device; the in-situ nano microemulsion generator and the displacement testing device are both internally provided with cores with the same permeability and pressure sensors; the in-situ nano microemulsion generator is connected with a liquid input system, and the outlet end of the displacement testing device is connected with a liquid collection system; further comprising a data acquisition system, the pressure sensors are all connected with the data acquisition system; further comprising a pressurizing system, the pressurizing system is connected with the in-situ nano microemulsion generator.

[0008] The in-situ nano microemulsion generator is internally provided with a first pressure sensor, and the displacement testing device is internally provided with a second pressure sensor, and the first pressure sensor and the second pressure sensor are both connected with the data acquisition system.

[0009] The in-situ nano microemulsion generator is further internally provided with a temperature sensor, and the temperature sensor is connected with the data acquisition system.

[0010] Further comprising a microemulsion property testing system; the microemulsion property testing system is connected to the liquid outlet of the in-situ nano microemulsion generator; the microemulsion testing system comprises a dynamic light scattering instrument / nano particle size analyzer, a small-angle X-ray scattering instrument / small-angle neutron scattering instrument, an interfacial tension instrument, a rheometer, a Zeta potential analyzer, a transmission electron microscope and a scanning electron microscope.

[0011] The in-situ nano microemulsion generator and the displacement testing device are connected through a liquid outlet pipeline; a sampling valve is arranged on the liquid outlet pipeline, and the microemulsion property testing system is connected with the sampling valve.

[0012] The liquid input system comprises a liquid inlet pipeline, the inlet end of the liquid inlet pipeline is connected to a first pressurizing pump, and the outlet end is connected to the in-situ nano microemulsion generator, and a liquid piston container is arranged between the liquid inlet pipeline and the in-situ nano microemulsion generator.

[0013] A one-way valve is arranged on the liquid inlet pipeline between the liquid piston container and the in-situ nano microemulsion generator.

[0014] The pressurizing system is a second pressurizing pump; the temperature control device is a thermostat; and the liquid collection system is a measuring cylinder or a measuring cup.

[0015] The technical effect of the utility model lies in that:

[0016] The temperature control device and the pressurizing system of the utility model simulate high-temperature and high-pressure conditions of an oil reservoir, realize in-situ generation of microemulsions under the high-temperature and high-pressure conditions of the oil reservoir, and evaluate oil displacement efficiency by comparing pressure changes of the in-situ nano microemulsion generator and the displacement testing device. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1Is a structural schematic diagram of the utility model.

[0018] The figure mark: 1, first booster pump;2, liquid piston container;3, liquid inlet pipeline;4, check valve;5, in situ nano microemulsion generator;6, first pressure sensor;7, liquid outlet pipeline;8, sampling valve;9, displacement test device;10, thermostat;11, data acquisition system;12, microemulsion property test system;13, liquid collection system;14, temperature sensor;15, booster system;16, second pressure sensor. DETAILED DESCRIPTION

[0019] Example 1

[0020] A kind of in situ microemulsion oil displacement efficiency testing device, it is characterized by: including connected in situ nano microemulsion generator 5 and displacement test device 9, it is placed in a temperature control device;The in situ nano microemulsion generator 5 and displacement test device 9 are all built-in core with same permeability and pressure sensor;In situ nano microemulsion generator 5 is connected with liquid input system, and the outlet end of displacement test device 9 is connected with liquid collection system 13;Still include data acquisition system 11, and pressure sensor is connected with data acquisition system 11;Still include a booster system 15, the booster system 15 is connected with in situ nano microemulsion generator 5.

[0021] The specific implementation process of the utility model is:

[0022] (1) select the low-permeability core column placed in in situ nano microemulsion generator 5 and displacement test device 9, and its permeability is greater than 50 × 10-3 μm 2, and it is placed in in situ nano microemulsion generator 5 and displacement test device 9 respectively;

[0023] (2) by liquid input system, input crude oil and surfactant composite system to in situ nano microemulsion generator 5;

[0024] (3) by temperature control device and booster system 15 simulate high temperature and high pressure conditions of oil reservoir;Temperature control device adjusts temperature interval to be 30°C ~ 90°C (the stability of microemulsion is greatly influenced by temperature, too high temperature can lead to surfactant degradation or microemulsion phase change.Too low temperature can reduce the flowability of microemulsion, influence oil displacement effect), and booster system 15 adjusts pressure interval to be 5 MPa ~ 30 MPa;(microemulsion oil displacement needs certain pressure to inject microemulsion into oil reservoir and drive crude oil, too low pressure can lead to microemulsion unable to effectively displace crude oil, and too high pressure can damage oil reservoir structure or lead to microemulsion phase change);

[0025] (4) The crude oil and surfactant composite system is reacted in the in-situ nano microemulsion generator 5 for 10-50 min; the generated microemulsion is injected into the displacement test device 9, and the oil displacement efficiency is evaluated by comparing the pressure changes of the in-situ nano microemulsion generator 5 and the displacement test device 9.

[0026] Example 2

[0027] Based on the example 1, further comprising:

[0028] The in-situ nano microemulsion generator 5 is provided with a first pressure sensor 6, and the displacement test device 9 is provided with a second pressure sensor 16, and the first pressure sensor 6 and the second pressure sensor 16 are connected with a data acquisition system 11. The in-situ nano microemulsion generator 5 is further provided with a temperature sensor 14, and the temperature sensor 14 is connected with the data acquisition system 11.

[0029] Example 3

[0030] Based on the example 2, further comprising:

[0031] Further comprising a microemulsion property test system 12; the microemulsion property test system 12 is connected to the liquid outlet of the in-situ nano microemulsion generator 5; the microemulsion test system includes a dynamic light scattering instrument / nanoparticle size analyzer, a small-angle X-ray scattering instrument / small-angle neutron scattering instrument, an interfacial tension instrument, a rheometer, a Zeta potential analyzer, a transmission electron microscope and a scanning electron microscope. The in-situ nano microemulsion generator 5 and the displacement test device 9 are connected through a liquid outlet pipeline 7; the liquid outlet pipeline 7 is provided with a sampling valve 8, and the microemulsion property test system 12 is connected with the sampling valve 8.

[0032] Example 4

[0033] Based on the example 3, further comprising:

[0034] The liquid input system includes a liquid inlet pipeline 3, the inlet end of the liquid inlet pipeline 3 is connected to the first booster pump 1, and the outlet end is connected to the in-situ nano microemulsion generator 5, and a liquid piston container 2 is arranged therebetween. The booster pump is used to inject the crude oil and surfactant composite system into the in-situ nano microemulsion generator 5, and the liquid piston container 2 is used to store and pressurize the crude oil and surfactant composite system. A one-way valve 4 is arranged on the liquid inlet pipeline 3 between the liquid piston container 2 and the in-situ nano microemulsion generator 5, so as to ensure the one-way flow of the crude oil and surfactant composite system and prevent backflow. The booster system 15 is a second booster pump. The temperature control device is a thermostat 10. The liquid collection system 13 is a measuring cylinder or a measuring cup.

[0035] Specific application cases

[0036] (1) Two low permeability core columns with length of 10 cm and permeability of 80x10⁻³ μm² were selected and placed in the in-situ nano-microemulsion generator 5 and the displacement testing device 9 respectively;

[0037] (2) The crude oil and surfactant composite system was pressurized and transported into the in-situ nano-microemulsion generator 5 by the first booster pump 1 and the liquid piston container 2, and the oil-water ratio of the crude oil and surfactant composite system was 3:7;

[0038] (3) The high temperature and high pressure conditions of the oil reservoir were simulated by the temperature control device and the second booster pump; the temperature control device adjusted the temperature to 47℃, and the second booster pump adjusted the pressure to 12 MPa;

[0039] (4) After the crude oil and surfactant composite system reacted in the in-situ nano-microemulsion generator 5 for 30 min, the generated microemulsion was injected into the displacement testing device 9, and the oil displacement efficiency was evaluated by comparing the pressure changes of the in-situ nano-microemulsion generator 5 and the displacement testing device 9;

[0040] (5) The microemulsion generated by the in-situ nano-microemulsion generator 5 was sampled through the sampling valve 8, and the particle size and its distribution, rheological properties, microstructure and phase behavior of the microemulsion were tested by the microemulsion property testing system 12.

Claims

1. An in-situ microemulsion oil displacement efficiency testing device characterized by: The in-situ nano-microemulsion generator (5) and the displacement test device (9) are placed in a temperature control device; the in-situ nano-microemulsion generator (5) and the displacement test device (9) are both provided with cores with the same permeability and pressure sensors; the in-situ nano-microemulsion generator (5) is connected with a liquid input system, and the outlet end of the displacement test device (9) is connected with a liquid collection system (13); a data acquisition system (11) is further included, and the pressure sensors are connected with the data acquisition system (11); a pressurizing system (15) is further included, and the pressurizing system (15) is connected with the in-situ nano-microemulsion generator (5).

2. The in-situ microemulsion oil displacement efficiency testing device according to claim 1, characterized in that: The in-situ nano-microemulsion generator (5) is provided with a first pressure sensor (6), and the displacement test device (9) is provided with a second pressure sensor (16), and the first pressure sensor (6) and the second pressure sensor (16) are connected with the data acquisition system (11).

3. The in-situ microemulsion oil displacement efficiency testing device according to claim 2, characterized in that: The in-situ nano-microemulsion generator (5) is further provided with a temperature sensor (14), and the temperature sensor (14) is connected with the data acquisition system (11).

4. The in-situ microemulsion oil displacement efficiency testing device according to claim 3, characterized in that: A microemulsion property test system (12) is further included; the microemulsion property test system (12) is connected to the liquid outlet of the in-situ nano-microemulsion generator (5); and the microemulsion test system includes a dynamic light scattering instrument / nanoparticle size analyzer, a small-angle X-ray scattering instrument / small-angle neutron scattering instrument, an interfacial tension instrument, a rheometer, a Zeta potential analyzer, a transmission electron microscope and a scanning electron microscope.

5. The in-situ microemulsion oil displacement efficiency testing device according to claim 4, characterized in that: The in-situ nano-microemulsion generator (5) and the displacement test device (9) are connected through a liquid outlet pipeline (7); a sampling valve (8) is arranged on the liquid outlet pipeline (7), and the microemulsion property test system (12) is connected with the sampling valve (8).

6. The in-situ microemulsion oil displacement efficiency testing device according to claim 1, characterized in that: The liquid input system includes a liquid inlet pipeline (3), the inlet end of the liquid inlet pipeline (3) is connected to a first pressurizing pump (1), and the outlet end is connected to the in-situ nano-microemulsion generator (5), and a liquid piston container (2) is arranged therebetween.

7. The in-situ microemulsion oil displacement efficiency testing device according to claim 5, characterized in that: A one-way valve (4) is arranged on the liquid inlet pipeline (3) between the liquid piston container (2) and the in-situ nano-microemulsion generator (5).

8. The in-situ microemulsion oil displacement efficiency testing device according to claim 1, characterized in that: The pressurizing system (15) is a second pressurizing pump.

9. The in-situ microemulsion oil displacement efficiency testing device according to claim 1, characterized in that: The temperature control device is a thermostat (10).

10. The in-situ microemulsion oil displacement efficiency testing device of claim 1, wherein: The liquid collection system (13) is a measuring cylinder or a measuring cup. The temperature control device is a thermostat (10). The liquid collection system (13) is a measuring cylinder or a measuring cup.

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