A reservoir water invasion process visualization simulation device and method

Abstract

The present application relates to a kind of reservoir water invasion process visualization simulation device and method, it is related to energy underground reservoir development and porous medium seepage simulation technique, including visualization rock plate holder, valve, pressure sensor, back pressure valve, condensing device, gas flow meter, metering pump, throttle valve, gas cylinder, computer, image sensor;Visualization rock plate holder mainly includes holder steel shell, reinforced glass plate, glass adhesive layer, thin film pressure sensor matrix, inlet end connection fluid injection system, export end is connected back pressure and export metering system respectively, through reinforced glass plate to the rock plate in the center is clamped and is visually observed;By testing the fluorescence intensity distribution of simulated formation water added with fluorescent agent in rock plate, monitor water saturation field;Pressure field is monitored by thin film pressure sensor matrix.The present application can simulate water invasion behavior of water body in reservoir development process, monitor the water invasion form of experimental rock plate in water invasion process, pressure field and saturation field.

Description

Technical Field

[0001] This invention relates to the field of underground energy reservoir development and porous media seepage simulation technology, and particularly to an experimental device and method for visual simulation of gas-water two-phase transport processes in underground reservoirs. It is applicable to oil and gas reservoir development, geothermal resource development, carbon dioxide geological sequestration (CCUS), underground gas storage facilities, and other underground resource development processes involving multiphase fluid transport. Specifically, it is a device and method for visual simulation of reservoir water intrusion processes. Background Technology

[0002] Water intrusion refers to the phenomenon of natural water sources (such as bottom water or edge water) entering the reservoir during reservoir development. It typically occurs because a decrease in reservoir pressure during production allows surrounding water to infiltrate the reservoir along seepage channels. Water intrusion simulation experiments can simulate and monitor this phenomenon during reservoir development, clarify its characteristics, optimize development strategies, and effectively reduce its adverse effects on reservoir development, thereby improving the final recovery rate.

[0003] Currently, indoor physical simulation experiments on water intrusion processes mainly employ the placement of electrodes and resistivity sensors at different locations within a cylindrical core holder. By monitoring the resistivity changes at various core positions during displacement in real time, the dynamics of water intrusion can be characterized. However, this method still suffers from limitations such as limited monitoring resolution, difficulties in installing and sealing the outer electrodes under high temperature and pressure conditions, and insufficient reservoir representativeness due to the small scale of cylindrical cores. Furthermore, this experimental method struggles to realistically reproduce the spatial distribution and dynamic evolution of fluid water intrusion under complex fracture networks, thus imposing certain limitations on subsequent optimization of mine production systems and formulation of water injection development plans.

[0004] Therefore, improving the safety level of experimental equipment, monitoring accuracy, and visualization during the experimental process is of great significance for developing dynamic analysis and optimizing production and construction systems. Summary of the Invention

[0005] To address the aforementioned problems, this invention aims to provide a visualization simulation device and method for reservoir water intrusion processes. This device and method can simulate and visualize the water intrusion behavior during reservoir development, while simultaneously quantitatively monitoring the water intrusion morphology, pressure field, and saturation field of the experimental rock slab during the intrusion process. The device includes a visualization rock slab holder, valves, pressure sensors, a backpressure valve, a condensation device, a gas flow meter, a metering pump, a throttle valve, a gas cylinder, a computer, and an image sensor. The visualization rock slab holder mainly comprises a steel shell, a reinforced glass plate, a glass adhesive layer, and a thin-film pressure sensor matrix. Its inlet end is connected to a fluid injection system, and its outlet end is connected to both a backpressure system and an outlet metering system. During the experiment, the rock slab held in the center can be visualized through the reinforced glass plate; the water saturation field is indirectly monitored by monitoring the fluorescence intensity distribution of simulated formation water with added fluorescent agent in the experimental rock slab; and the pressure field is monitored through the thin-film pressure sensor matrix. This device and method can simulate the water intrusion behavior of water bodies during reservoir development and can be visualized and observed. At the same time, it can quantitatively monitor the water intrusion morphology, pressure field and saturation field of the experimental rock slab during the water intrusion process, providing experimental reference for the efficient development of underground reservoir energy.

[0006] The visualized rock slab holder has a multi-layered internal structure, with an outer steel shell containing a reinforced glass plate. Pipeline interfaces are reserved on all four sides of the steel shell. The interior of the visualized rock slab holder consists of, in sequence, a reinforced glass plate, a first glass adhesive layer, an experimental rock slab, a second glass adhesive layer, a thin-film pressure sensor matrix, and a third glass adhesive layer.

[0007] To achieve the above technical objectives, the present invention provides the following experimental technical solution, which specifically includes the following steps: Step 1: Before the experiment, thoroughly wash the rock slabs used in the experiment with oil and salt, and dry them (110 ℃, 24 h). Measure the length of the core. L ,Width W ,high H The porosity was obtained by measuring the porosity of a standard core sample (2.5 cm in diameter and 5 cm in length) taken from the corresponding reservoir using a porosimeter. With penetration rate ; Step 2: Select small-sized fractured rock slabs of the same type and thickness as the experimental rock slabs, wash them thoroughly with oil and salt, and dry them (110 ℃, 24 h); use the vacuum positive pressure saturation method to fully saturate the rock slabs with simulated formation water containing fluorescent agents. Step 3: After removing the rock slab from the simulated formation water, quickly place it in the visualization rock slab holder 1, and use image sensor 15 to acquire signals and record the fluorescence intensity of the matrix portion under fully saturated water conditions. Fluorescence intensity of the crack portion Open the visual slab holder 1 and remove the small-sized slab; Step 4: At the start of the experiment, all valves in the device are closed by default; open the visual rock slab holder 1, insert the experimental rock slab after the joint has been made and the glass glue has been applied, press the glass slab firmly so that the first glass glue layer 17 and the second glass glue layer 20 are tightly attached to the wide surface of the rock slab, close the visual rock slab holder 1; connect the inlet and outlet pipelines to the corresponding interfaces. Step 5: Open gas cylinder 12 and throttle valve 11, and load the second metering pump 10 to the initial pressure. Turn on computer 14 and image sensor 15; open third valve 9, monitor the pressure signal received by the thin-film pressure sensor matrix 21 from computer 14, and wait until the pressure at all measuring points reaches the initial pressure. Then, close the third valve 9; Step 6: Apply back pressure to the first metering pump 7. Pre-inject formation water with added fluorescent agent into the cylinder of the third metering pump 13; load the third metering pump 13 to the inlet pressure. Open the first valve 2 and the second valve 8 to begin simulating the water intrusion process; Step 7: The water phase and gas phase flow rate at the outlet are recorded in real time by the condenser 5 and the gas phase flow meter 6; the saturation signal transmitted by the image sensor 15 and the pressure signal transmitted by the thin film pressure sensor matrix 21 are recorded in real time by the computer 14. Step 8: After the saturation field and pressure field of the experimental rock plate no longer change, and there is no flow in the outlet gas flow meter 6, organize the experimental data and calculate the dynamic water intrusion damage index. The experiment is now over.

[0008] Dynamic water intrusion damage index The calculation is performed using the following formula: ; ; in, The average water saturation of the experimental rock slab, % Let t be the volume of the water phase in the experimental rock slab, in mL; The volume of the rock slab pores is mL. The coordinates of the experimental rock slab at time t are: The area at point d A The water saturation of the infinitesimal element, % The area of ​​the wide side of the experimental rock slab is in cm². 3 ; Let be the outlet gas flow rate at time t, in mL / s; The initial outlet gas flow rate is expressed in mL / s. Let t be the outlet aqueous phase flow rate at time t, in mL / s.

[0009] According to the dynamic water intrusion damage index The size of the reservoir water intrusion damage can be classified into different levels: Table 1 Evaluation Table of Dynamic Water Intrusion Damage Index Compared with existing core water intrusion monitoring devices and methods, the advantages of this invention are: (1) The visual rock plate holder designed in this invention can more intuitively observe the water invasion process of water bodies during reservoir development than the traditional cylindrical rock core holder; (2) This invention can not only indirectly monitor the water saturation field by monitoring the fluorescence intensity distribution of simulated formation water with added fluorescent agent in the experimental rock plate, but also monitor the pressure field through a thin-film pressure sensor matrix. Attached Figure Description

[0010] Figure 1 This is a schematic diagram of the reservoir water intrusion process visualization simulation device in this invention; In the diagram: 1-Visual rock slab holder, 2-First valve, 3-Pressure sensor, 4-Back pressure valve, 5-Condensation device, 6-Gas flow meter, 7-First metering pump, 8-Second valve, 9-Third valve, 10-Second metering pump, 11-Throttle valve, 12-Gas cylinder, 13-Third metering pump, 14-Computer, 15-Image sensor; Figures 2(a), 2(b), 2(c), 2(d), and 2(e) are all schematic diagrams of the visualized rock slab clamp structure in this invention; In Figure 2(a): 16 - tempered glass plate, 17 - first glass adhesive layer; In Figure 2(b): 18 - experimental rock slab, 19 - pipeline interface; In Figure 2(c): 20 - second glass adhesive layer, 21 - thin-film pressure sensor matrix, 22 - third glass adhesive layer; In Figure 2(d): 21 - Matrix of thin-film pressure sensors; In Figure 2(e): 16-reinforced glass plate, 17-first glass adhesive layer, 18-experimental rock plate, 19-pipeline interface, 20-second glass adhesive layer, 21-thin film pressure sensor matrix, 22-third glass adhesive layer, 23-clamp steel shell. Detailed Implementation

[0011] The present invention will be described below with reference to the accompanying drawings. The description herein is for illustration and explanation only, and its scope of protection is not limited to what is described below.

[0012] like Figure 1The reservoir water intrusion process visualization simulation device shown mainly includes: 1-visual rock plate holder, 2-first valve, 3-pressure sensor, 4-back pressure valve, 5-condensation device, 6-gas flow meter, 7-first metering pump, 8-second valve, 9-third valve, 10-second metering pump, 11-throttle valve, 12-gas cylinder, 13-third metering pump, 14-computer, and 15-image sensor.

[0013] The visualized rock slab holder has a multi-layer structure. The outer part is a steel shell with a reinforced glass plate embedded on it. Pipeline interfaces are reserved on the four sides of the steel shell. The inside of the holder consists of a reinforced glass plate, a first glass adhesive layer, an experimental rock slab, a second glass adhesive layer, a thin-film pressure sensor matrix, and a third glass adhesive layer.

[0014] In one specific embodiment, the experimental steps are as follows: Step 1: A rock slab sample taken from a tight gas reservoir in a certain block of the Tarim Basin was thoroughly washed for oil and salt, and then dried (110 ℃, 24 h). The length of the experimental rock slab was measured. L =50 cm, width W =50 cm, height H =3 cm; The porosity was determined by measuring the standard core (2.5 cm in diameter and 5 cm in length) taken from the corresponding reservoir of the rock slab using a porosimeter to obtain representative porosity. =5.56% and penetration rate = 0.01568 mD; Step 2: Select small-sized fractured rock slabs of the same type and thickness as the experimental rock slabs, wash them thoroughly with oil and salt, and dry them (110 ℃, 24 h); use the vacuum positive pressure saturation method to fully saturate the rock slabs with simulated formation water containing fluorescent agents. Step 3: After removing the rock slab from the simulated formation water, quickly place it in the visualization rock slab holder 1, and use image sensor 15 to acquire signals and record the fluorescence intensity of the matrix portion under fully saturated water conditions. = 1698, fluorescence intensity of the crack portion =3458; Open the visual slab holder 1 and remove the small-sized slab; Step 4: At the start of the experiment, all valves in the device are closed by default; open the visual rock slab holder 1, insert the experimental rock slab after the joint has been made and the glass glue has been applied, press the glass slab firmly so that the first glass glue layer 17 and the second glass glue layer 20 are tightly attached to the wide surface of the rock slab, close the visual rock slab holder 1; connect the inlet and outlet pipelines to the corresponding interfaces. Step 5: Open gas cylinder 12 and throttle valve 11, and load the second metering pump 10 to the initial pressure. = 0.5 MPa; turn on computer 14 and image sensor 15; open the third valve 9, monitor the pressure signal received by the thin-film pressure sensor matrix 21 from computer 14, and wait until the pressure at all measuring points is the initial pressure. After the pressure reaches 0.5 MPa, close the third valve 9. Step 6: Apply back pressure to the first metering pump 7. = 0.5 MPa; inject the formation water with added fluorescent agent into the cylinder of the third metering pump 13 in advance; load the third metering pump 13 to the inlet pressure. = 0.7 MPa; Open the first valve 2 and the second valve 8 to start the simulated water intrusion process; Step 7: The water phase and gas phase flow rate at the outlet are recorded in real time by the condenser 5 and the gas phase flow meter 6 to obtain the change curve of the gas and water phase flow rates over time; the saturation signal transmitted by the image sensor 15 and the pressure signal transmitted by the thin film pressure sensor matrix 21 are recorded in real time by the computer 14. Step 8: After the saturation field and pressure field of the experimental rock plate no longer change, and there is no flow in the outlet gas flow meter 6, organize the experimental data and calculate the dynamic water intrusion damage index. The experiment is now over.

[0015] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any person skilled in the art can make some modifications or alterations to the disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Therefore, any modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A visualization simulation device for reservoir water intrusion processes, characterized in that, The visualized rock slab holder includes a steel shell, a reinforced glass plate, a first glass adhesive layer, a second glass adhesive layer, a thin-film pressure sensor matrix, and a third glass adhesive layer.

2. A visualization simulation device for reservoir water intrusion process, characterized in that, In the visualized rock slab holder, the experimental rock slab should be held between the first and second glass glue layers; the pipeline interface can be sealed by screwing screws into the non-connection ports according to connection requirements; the size of the visualized rock slab holder can be designed and customized according to the size of the target experimental rock slab; to consider the experimental effect, the height (shortest side) of the experimental rock slab should not exceed 3 cm; based on full-diameter core observation, imaging logging and seismic data, the width, length and connectivity of the cracks in the experimental rock slab are determined, and cracks are created by wire cutting method.

3. A visualization simulation device for reservoir water intrusion process, characterized in that, To ensure the airtightness of the device, before the experimental rock slab is installed into the device, glass glue should be evenly applied to the contact surfaces between the rock slab and the first and second glass glue layers; the glass glue layers should be as thin as possible while ensuring airtightness.

4. A visualization simulation device for reservoir water intrusion process, characterized in that, To ensure experimental safety and device sealing, the maximum load on the reinforced glass plate in the visualization rock plate holder is 2.0 MPa, and the maximum pore pressure should not exceed 1.6 MPa.

5. A method for visualizing and simulating reservoir water intrusion processes, characterized in that, The saturation field of the experimental rock slab was calibrated using the following steps: Step 1: Select small-sized fractured rock slabs of the same type and thickness as the experimental rock slabs, wash them thoroughly with oil and salt, and dry them (110 ℃, 24 h); use the vacuum positive pressure saturation method to fully saturate the rock slabs with simulated formation water containing fluorescent agents. Step 2: After being removed from the simulated formation water, the rock slab is quickly placed in the visualization rock slab holder 1. The image sensor 15 is used to acquire signals and record the fluorescence intensity of the matrix portion under fully saturated water conditions. Fluorescence intensity of the crack portion Then the fluorescence intensity , The water saturation of the matrix and the crack portion are respectively , .

6. A method for visualizing and simulating reservoir water intrusion processes, characterized in that the steps include... include: Step 1: Before the experiment, thoroughly wash the rock slabs used in the experiment with oil and salt, and dry them (110 ℃, 24 h). Measure the length of the experimental rock slabs. L ,Width W ,high H The porosity was obtained by measuring the porosity of a standard core sample (2.5 cm in diameter and 5 cm in length) taken from the corresponding reservoir using a porosimeter. With penetration rate ; Step 2: At the start of the experiment, all valves in the device are closed by default; open the visual rock slab holder 1, insert the experimental rock slab after the joint has been made and the glass glue has been applied, press the glass slab firmly so that the first glass glue layer 17 and the second glass glue layer 20 are tightly attached to the wide surface of the rock slab, close the visual rock slab holder 1; connect the inlet and outlet pipelines to the corresponding interfaces. Step 3: Open gas cylinder 12 and throttle valve 11, and load the second metering pump 10 to the initial pressure. Turn on computer 14 and image sensor 15; open third valve 9, monitor the pressure signal received by the thin-film pressure sensor matrix 21 from computer 14, and wait until the pressure at all measuring points reaches the initial pressure. Then, close the third valve 9; Step 4, apply back pressure to the first metering pump 7. Pre-inject formation water with added fluorescent agent into the cylinder of the third metering pump 13; load the third metering pump 13 to the inlet pressure. Open the first valve 2 and the second valve 8 to begin simulating the water intrusion process; Step 5: The water phase and gas phase flow rate at the outlet are recorded in real time by the condenser 5 and the gas phase flow meter 6; the saturation (fluorescence intensity) signal transmitted by the image sensor 15 and the pressure signal transmitted by the thin film pressure sensor matrix 21 are recorded in real time by the computer 14. Step 6: After the saturation field and pressure field of the experimental rock plate no longer change, and there is no flow in the outlet gas flow meter 6, the experiment ends.

7. A method for visualizing and simulating reservoir water intrusion processes, characterized in that, Based on the experimental results, a dynamic water intrusion damage index is defined. And it is calculated using the following formula: ； ； in, The average water saturation of the experimental rock slab, % Let t be the volume of the water phase in the experimental rock slab, in mL; The volume of the rock slab pores is mL. The coordinates of the experimental rock slab at time t are: The area at is The water saturation of the infinitesimal element, % The area of ​​the wide side of the experimental rock slab is in cm². 3 ; Let be the outlet gas flow rate at time t, in mL / s; The initial outlet gas flow rate is expressed in mL / s. Let be the outlet aqueous phase flow rate at time t, in mL / s; according to The size of the reservoir water intrusion can be used to classify the degree of reservoir water invasion into different stages; when When ≤0.05, the degree of water intrusion is no water intrusion; when 0.05 < When the water level is ≤0.3, the degree of water intrusion is weak; when 0.3 < When the water level is ≤0.5, the degree of water intrusion is moderate to weak; when 0.5 < When the water level is ≤0.7, the degree of water intrusion is moderate to strong; when the degree of water intrusion is <0.7 When the value is ≤0.9, the degree of water intrusion is considered strong water intrusion; when When the value is greater than 0.9, the degree of water intrusion is considered extremely severe.

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