Visual testing device for temporary plugging in seam and operation method of visual testing device

Abstract

The invention discloses an in-seam temporary plugging visual testing device and an operation method thereof, and belongs to the technical field of petroleum drilling and completion, and the device comprises a gas pressurization system, a process manifold system, a visual detection system and a data metering, collecting and processing system. Meanwhile, the invention further discloses an operation method of the in-seam temporary plugging visual testing device. According to the technical scheme, the designed main body model is mainly achieved through a visual model structure, systematic and accurate testing and evaluation on in-crack plugging and turning fracturing are achieved, the reliability of the testing and evaluation result is improved, the temporary plugging agent particle size distribution, the turning effect, the effective degradation rate and the like can be effectively evaluated, and therefore the temporary plugging agent can be effectively evaluated. The direct observation of the process of plugging the stratum crack by the temporary plugging agent is realized, and the plugging effect is tested.

Description

Technical Field

[0001] The invention belongs to the technical field of petroleum drilling and completion, and relates to a visualization test device for temporary plugging in a fracture and an operation method thereof. Background Art

[0002] With the growing demand for oil and gas resources in the international community and the development of exploration technology, more advanced oil exploration and development technologies have been developed and utilized, and more and more low-permeability oil fields have been discovered. Temporary plugging agents are commonly used as plugging materials in the process of fracturing transformation. They are mostly used for the diversion effect in the process of repeated fracturing downholes. The temporary plugging agents are used to temporarily plug the original blastholes or cracks, and a new crack is pressed in a direction different from the original crack, connecting unused reservoirs or oil layers with low utilization, increasing the oil leakage area and improving production capacity.

[0003] Temporary plugging agents in fractures can block the pressure transmission from the fluid pressure in the fracture to the fracture tip, increase the net pressure in the fracture, and force the fracture to make multiple turns, so as to activate and communicate more micro-cracks. The existing test and evaluation of temporary plugging agents in fractures uses drilling fluid plugging experimental equipment, without a dedicated evaluation system, and cannot effectively evaluate the particle size distribution, diversion effect, effective degradation rate, etc. of temporary plugging agents. There is a large gap between the field application effect and the indoor evaluation results. It is urgent to develop a set of evaluation system for temporary plugging in fractures. Summary of the invention

[0004] The purpose of the present invention is to overcome the defects in the prior art and provide a visual testing device for temporary plugging in fractures and its operation method, which can effectively evaluate the particle size distribution, diversion effect, effective degradation rate, etc. of the temporary plugging agent, realize direct observation of the temporary plugging agent plugging formation fracture process, and test the plugging effect. The embodiment of the present invention is implemented as follows:

[0005] On the one hand, an embodiment of the present invention provides a visual testing device for temporary plugging in cracks, which mainly consists of a gas pressurization system, a process manifold system, a visual inspection system, a data metering and acquisition processing system, etc. The gas pressurization system includes a gas cylinder, an air compressor, a booster pump, a gas storage tank, etc., which can store high-pressure gas, and instantly squeeze the mixed liquid on the upper part of the piston container after release, driving the fluid to flow into the detection system; the process manifold system includes a piston container, a valve, a pressure sensor, a pipeline, etc., which can control the flow of the mixed liquid; the visual inspection system includes a main body model, a heating sleeve, a temperature control instrument, etc., which can observe the flow of the mixed liquid in the gap, the plugging of the cracks by the temporary plugging agent particles, etc.; the data metering and acquisition processing system piston container and supporting equipment can collect the mixed liquid flowing out of the visual inspection system, and dry, screen, weigh, and analyze the influence of the particle size and composition of the temporary plugging agent on the temporary plugging effect.

[0006] The gas cylinder and the air compressor are respectively connected to the gas booster pump with high-pressure metal pipelines; the generated high-pressure gas is stored in the gas storage tank, and the gas booster pump and the gas storage tank are connected with a high-pressure metal pipeline; the gas pressure reducing valve plays a role in regulating the gas pressure in the gas storage tank, and it is connected to the gas storage tank with a metal pipeline; each pressure gauge and air pressure valve is connected to the high-pressure metal pipeline with a thread; the gas storage tank is connected to the piston container with a high-pressure metal pipeline, and the air inlet is below the piston container; the heating sleeve is wrapped on the outer surface of the piston container, and plays a role in heating the medium in the piston container; the temperature control instrument is connected to the piston container with a thread, and is connected to the inside of the piston container, and plays a role in detecting the temperature of the internal medium; the upper part of the piston container is connected to the main model of the visual inspection system with a high-pressure metal pipeline, and the pressure sensor is connected to the high-pressure metal pipeline with a thread; the heating sleeve is wrapped on the outer surface of the main model, and plays a role in heating the medium in the main model; the temperature control instrument is connected to the main model with a thread, and is connected to the inside of the main model, and plays a role in detecting the temperature of the internal medium; the other end of the main model is connected to the piston container with a high-pressure metal pipeline, and the pressure sensor is connected to the high-pressure metal pipeline with a thread.

[0007] Furthermore, the gas pressurizing system is mainly composed of a gas cylinder, an air compressor, a gas booster pump, a gas storage tank, a left piston container, various valves, and a two-phase mixture of fracturing fluid and temporary plugging agent.

[0008] Furthermore, the visual inspection system is mainly composed of a main body model, and the main body model structure is composed of an upper flange, a Valqua pressure pad, an O-ring, a cavity, a lower flange, fastening bolts, nuts, gaskets, simulated cracks, 3D printed components, sapphire glass, a left fluid inlet and outlet, a visual window, and a right fluid inlet and outlet. The 3D printed component includes a 3D printed pad and a 3D printed pressure pad; the upper flange, the cavity, and the lower flange are connected by fastening bolts, and the fastening bolts are pre-tightened by gaskets and nuts; a Valqua pressure pad is installed between the upper flange, the lower flange, and the sapphire glass; the O-ring is installed between the 3D printed pad and the 3D printed pressure pad; the simulated crack size is 30×5mm; the visual window visible area is 300×30mm.

[0009] On the other hand, an embodiment of the present invention provides an operating method for a visualization test device for temporary plugging in fractures, by pressurizing the gas to drive the two-phase mixture of fracturing fluid and temporary plugging agent in the upper chamber of the piston container into the main model. The plugging process and plugging effect of the mixture in the simulated fracture can be visually seen through the sapphire glass visual window. The piston container and the main model of the present invention are equipped with a heating jacket, which is connected to a temperature control instrument and can monitor the heating temperature in real time. The heating temperature range of the heating jacket is from room temperature to 180°C, simulating the high temperature and complex environment underground. Pressure sensors are respectively installed at the inlet and outlet of the main model of the present invention to measure the pressure difference between the inlet and outlet of the main model, simulate the high-pressure environment underground, and evaluate the pressure resistance effect of temporary plugging in fractures.

[0010] During the flow of temporary plugging agents (fibers of different concentrations, particles of different concentrations, particles of different sizes) in the cracks, the plugging of the cracks begins with the adsorption of temporary plugging agent fibers or fine particles on the crack wall. The adsorbed fibers or fine particles continue to gather to form a dispersed plugging zone. After the plugging zone expands to a certain size, it begins to capture the flowing particles and fill them into the gaps between the fibers. The plugging zone begins to become dense, thereby changing the distribution of net pressure in the cracks, reducing the stress intensity factor at the crack tip, and accelerating the plugging process. Finally, a comprehensive plugging is formed to allow new cracks to be formed subsequently, multiple turns to occur, and more microcracks to be activated and communicated.

[0011] The beneficial effects of the embodiments of the present invention are:

[0012] The present invention provides a visual testing device for temporary plugging in a seam and an operating method thereof, and its beneficial effects are specifically embodied in the following aspects:

[0013] 1. The visual testing device and implementation method for temporary plugging in fractures provided by the present invention can systematically evaluate different ratios of fracturing fluid and temporary plugging agent, temporary plugging agent particle size, temporary plugging diversion fracturing effect, and temporary plugging agent effective degradation rate. A mixture of fracturing fluid and temporary plugging agent of different types and particle sizes is prepared in the upper chamber of the left piston container, wherein the temporary plugging agent type may include fibers of different concentrations and particles of different concentrations. The mixture is pushed into the simulated fracture of the main model by the gas compression piston in the lower chamber, and the plugging formation process of different temporary plugging agents in the fracture is observed through the visual window, and the pressure and flow rate in the fracture during the plugging process are recorded. At the same time, the pressure difference and temperature of the inlet and outlet of the main model can be set in advance, and the plugging effect, diversion fracturing effect, and effective degradation rate of plugging agent fibers and particles under different pressure and temperature conditions can be accurately simulated, so as to systematically and accurately test and evaluate the plugging in fractures and diversion fracturing.

[0014] 2. The test device provided by the present invention is equipped with heating sleeves on the left piston container and the main model, and pressure sensor detection devices are installed at the inlet and outlet of the main model to simulate the high temperature and high pressure environment of the well, so that the test evaluation results are more reliable. The heating temperature can be displayed by the temperature control instrument to achieve the temperature setting of room temperature to 180℃.

[0015] 3. The main body model designed by the present invention is mainly realized by the visual model structure, which is mainly composed of an upper flange, a Valqua pressure pad, an O-ring, a cavity, a lower flange, fastening bolts, nuts, gaskets, simulated cracks, 3D printing components, sapphire glass, a left fluid inlet and outlet, a visual window, and a right fluid inlet and outlet. The 3D printing component includes a 3D printing pad and a 3D printing pressure pad; the upper flange, the cavity, and the lower flange are connected by fastening bolts, and the fastening bolts are pre-tightened by gaskets and nuts; a Valqua pressure pad is installed between the upper flange, the lower flange and the sapphire glass; the O-ring is installed between the 3D printing pad and the 3D printing pressure pad; the simulated crack size is 30×5mm; the visual window visible area is 300×30mm. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0017] Figure 1 It is a flow chart of an operation method of a visual testing device for temporary plugging in a seam according to the present invention;

[0018] Figure 2 It is a cross-sectional view of the main body model of the present invention;

[0019] Figure 3 It is the main view of the model of the present invention. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0021] like Figure 1 , Figure 2 , Figure 3As shown, a visual testing device for temporary plugging in a seam and its implementation method are mainly composed of a gas pressurizing system, a process manifold system, a visual inspection system 11, a data metering, acquisition and processing system, etc. The overall process of the device is as follows: the gas cylinder 3 is connected to the gas booster pump 6, and a gas cylinder outlet valve is installed between the gas cylinder 3 and the gas booster pump for adjusting the outlet gas volume, and the gas cylinder outlet valve, a pressure gauge 2 and a gas booster pump inlet valve are installed between the gas cylinder and the gas booster pump in sequence; the air compressor 1 is connected to the gas booster pump, and a gas pressure reducing valve 4, a pressure gauge 2 and a valve are installed between the air compressor 1 and the gas booster pump in sequence; a valve is installed at the outlet of the gas booster pump; a pressure gauge 2 and a valve are installed at the outlet of the gas storage tank in sequence; the gas booster pump and the gas storage tank 5 are connected in sequence to the gas pressure reducing valve 4, the pressure gauge 2 and the left piston container 13, and the left piston container Valves are respectively set at the inlet and outlet of the device 13, a heating device 7 is installed on the outside of the left piston container 13, and the heating device 7 is connected to the temperature control instrument 8; the outlet valve of the left piston container is connected to the inlet of the main model 10, and an isolator 14 and a pressure sensor 9 are respectively installed on both sides of the inlet and outlet of the main model 10. The isolator 14 is mainly used to separate the liquid and solid particles in the mixed liquid. A heating device is also installed on the outside of the main model, and the heating device is connected to the temperature control instrument; the outlet of the main model is connected to the inlet valve of the right piston container 12, the inlet valve is connected to the upper cavity of the right piston container, and the lower cavity of the right piston container is connected to the external gas storage device.

[0022] like Figure 2 As shown, the main body model is mainly composed of an upper flange 16, a Valka pressure pad 17, an O-ring 18, a cavity 19, a lower flange 20, fastening bolts 21, nuts 22, gaskets 23, 3D printed pressure pads 24, simulated cracks 25, 3D printed pads 26, sapphire glass 27, a left fluid inlet and outlet 28, a visual window 29, a right fluid inlet and outlet 30, etc. The upper flange 16, the cavity 19, and the lower flange 20 are connected by fastening bolts 21, and the fastening bolts 21 are pre-tightened by gaskets 23 and nuts 22; the Valka pressure pad 17 is installed between the upper flange 16, the lower flange 20 and the sapphire glass 27; the O-ring 18 is installed between the 3D printed pad 26 and the 3D printed pressure pad 24; the size of the simulated crack 25 is 30×5mm; the area size of the visible window 29 formed by the sapphire glass 27 is 300×30mm, and the compressive strength of the sapphire glass 27 is 20MPa. The mixture enters the simulated crack 25 in the main model through the left fluid inlet and outlet 28, and the plugging process and plugging effect of the mixture in the simulated crack can be intuitively seen through the sapphire glass 27.

[0023] The working temperature of the above heating device is room temperature to 180°C.

[0024] It should be understood that the above specific embodiments of the present invention are only used to illustrate or explain the principles of the present invention, and do not constitute a limitation of the present invention. Therefore, any modifications, equivalent substitutions, improvements, etc. made without departing from the spirit and scope of the present invention should be included in the protection scope of the present invention. In addition, the appended claims of the present invention are intended to cover all changes and modifications that fall within the scope and boundaries of the appended claims, or the equivalent forms of such scope and boundaries.

Claims

1. A visual testing device for temporary plugging in a seam, characterized in that: Including gas pressurization system, process manifold system, visual inspection system, data measurement collection and processing system; The gas pressurization system includes gas cylinders, air compressors, booster pumps, and gas storage tanks, which are used to store high-pressure gas. After release, the gas instantly squeezes the mixed liquid on the top of the piston container and drives the fluid to flow into the detection system. The process manifold system includes piston containers, valves, pressure sensors, and pipelines to control the flow of the mixed liquid. The visual inspection system includes a main model, a heating jacket, and a temperature control instrument to observe the flow of the mixed liquid in the gap and the sealing of the cracks by the temporary plugging agent particles. The piston container and supporting equipment of the data measurement collection and processing system are used to collect the mixed liquid flowing out of the visual inspection system, and then dry, screen and weigh it, and analyze the influence of the particle size and composition of the temporary plugging agent on the temporary plugging effect; The gas cylinder and the air compressor are respectively connected to the gas booster pump with high-pressure metal pipelines; the generated high-pressure gas is stored in the gas storage tank, and the gas booster pump and the gas storage tank are connected with a high-pressure metal pipeline; the gas pressure reducing valve plays a role in regulating the gas pressure in the gas storage tank, and it is connected to the gas storage tank with a metal pipeline; each pressure gauge and air pressure valve is connected to the high-pressure metal pipeline with a thread; the gas storage tank is connected to the piston container with a high-pressure metal pipeline, and the air inlet is below the piston container; the heating sleeve is wrapped on the outer surface of the piston container, and plays a role in heating the medium in the piston container; the temperature control instrument is connected to the piston container with a thread, and is connected to the inside of the piston container, and plays a role in detecting the temperature of the internal medium; the upper part of the piston container is connected to the main model of the visual inspection system with a high-pressure metal pipeline, and the pressure sensor is connected to the high-pressure metal pipeline with a thread; the heating sleeve is wrapped on the outer surface of the main model, and plays a role in heating the medium in the main model; the temperature control instrument is connected to the main model with a thread, and is connected to the inside of the main model, and plays a role in detecting the temperature of the internal medium; the other end of the main model is connected to the piston container with a high-pressure metal pipeline, and the pressure sensor is connected to the high-pressure metal pipeline with a thread.

2. The visual testing device for temporary plugging in seams according to claim 1 is characterized in that: The gas pressurizing system is mainly composed of a gas cylinder, an air compressor, a gas booster pump, a gas storage tank, a left piston container, various valves, and a two-phase mixture of fracturing fluid and temporary plugging agent.

3. The visual testing device for temporary plugging in seams according to claim 1, characterized in that: The visual inspection system is composed of a main model, and the main model structure is composed of an upper flange, a Valka pressure pad, an O-ring, a cavity, a lower flange, fastening bolts, nuts, gaskets, simulated cracks, 3D printed components, sapphire glass, a left fluid inlet and outlet, a visual window, and a right fluid inlet and outlet.

4. The visual testing device for temporary plugging in seams according to claim 3 is characterized in that: The 3D printing assembly includes a 3D printing pad and a 3D printing pressure pad.

5. The visual testing device for temporary plugging in seams according to claim 3 is characterized in that: The upper flange, the cavity and the lower flange are connected by fastening bolts, and the fastening bolts are pre-tightened by gaskets and nuts.

6. The visual testing device for temporary plugging in seams according to claim 3, characterized in that: A Valqua pressure pad is installed between the upper flange, the lower flange and the sapphire glass.

7. The visual testing device for temporary plugging in seams according to claim 3, characterized in that: The O-ring is installed between the 3D printing pad and the 3D printing pressure pad.

8. The visual testing device for temporary plugging in seams according to claim 3, characterized in that: The simulated crack size is 30×5 mm; the visible area of ​​the visible window is 300×30 mm.

9. An operating method of the temporary plugging visualization testing device for seam according to any one of claims 1 to 8, characterized in that: The following steps are involved: Step 1, controlling the flow rate and inflow volume of the mixture of fracturing fluid and temporary plugging agent by controlling the gas pressure at the inlet of the lower part of the piston container, simulating different temporary plugging processes; Step 2: Visually observe the plugging process and plugging effect of the mixture in the simulated crack through the sapphire glass viewing window; Step 3: Install a heating jacket on the piston container and the main model, connect the heating jacket to a temperature control instrument, monitor the heating temperature in real time, and simulate the high temperature and complex environment underground; Step 4: The pressure sensors at the inlet and outlet of the main model measure the pressure difference between the inlet and outlet of the main model, simulate the downhole high-pressure environment, and evaluate the temporary plugging and pressure resistance effect in the fracture; Step 5: Collect the mixture flowing out of the outlet of the main model, dry, sieve and weigh it, and analyze the influence of the particle size and composition of the temporary plugging agent on the temporary plugging effect.

10. The operating method of the temporary plugging visualization testing device for seam according to claim 9, characterized in that: In step 2, during the flow of the temporary plugging agent in the crack, the plugging of the crack begins with the adsorption of the temporary plugging agent fibers or fine particles on the crack wall. The adsorbed fibers or fine particles continue to gather to form a dispersed plugging zone. After the plugging zone expands to a certain size, it begins to capture the flowing particles and fill them into the gaps between the fibers. The plugging zone begins to become dense, thereby changing the distribution of the net pressure in the crack, reducing the stress intensity factor at the crack tip, and accelerating the plugging process. Finally, a comprehensive plugging is formed to allow new cracks to be formed subsequently, multiple turns to occur, and more microcracks to be activated and communicated.

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