An experimental device for simulating thin interbed cross fracturing

Abstract

This invention relates to the field of oil and gas well production enhancement, specifically to an experimental apparatus simulating cross-layer fracturing of thin interbedded layers. The apparatus includes a main body, a triaxial servo pressurization system, a liquid injection system, a heating control system, and a simulated formation module. The simulated formation module is located inside the main body, and the triaxial servo pressurization system is mounted on the main body, applying pressure to the simulated formation module from the X, Y, and Z directions. The main body has a simulated well injection port, which is connected to the liquid injection system via an injection pipeline. The heating control system is connected to the simulated formation module and is used to control its temperature. This invention utilizes the heating control system to control the temperature of the experimental artificial cement stone, employing temperature-controlled Young's modulus technology to conduct fracture propagation experiments on multilayer systems with different rock mechanical parameters of the same thickness. This method is low-cost and highly efficient.

Description

Technical Field

[0001] This utility model relates to the field of oil and gas well production enhancement technology, and in particular to an experimental device for simulating cross-layer fracturing of thin interlayers. Background Technology

[0002] A reservoir composed of multiple lithologies superimposed on each other is called a multi-thin interbedded reservoir. Its characteristics are that the sandstone reservoir containing oil and gas resources has a thin single layer and a large number of vertical layers, but is separated by mudstone, tuff and other layers that do not contain oil and gas resources.

[0003] Currently, physical simulation fracturing is commonly used to understand the complex fracture morphology of different thin interbedded reservoirs under various process conditions, guiding field construction and improving oilfield development and well completion technology. During fracturing, cross-layer fracturing is typically employed to create fractures of sufficient height vertically, allowing these fractures to penetrate multiple interbedded sandstone reservoirs, achieving multi-layered coordinated vertical exploitation and increasing single-well oil and gas production.

[0004] However, existing simulated fracturing test equipment generally only sets up fracturing experiments in one direction, and requires the configuration of several samples with different Young's modulus and Poisson's ratio to meet the requirements for simulating multi-layer reservoirs with different Young's modulus, which is costly and cumbersome to operate. Utility Model Content

[0005] In order to solve the problems existing in the prior art, this utility model provides an experimental device for simulating cross-layer fracturing of thin interlayers.

[0006] To achieve the purpose of this utility model, the technical solution adopted by this utility model is as follows: an experimental device for simulating cross-layer fracturing of thin interlayers, comprising a device body, a triaxial servo pressurization system, a liquid injection system, a heating control system, and a simulated formation module;

[0007] The simulated formation module is installed inside the device body, and the three-dimensional servo pressurization system is installed on the device body, applying pressure to the simulated formation module from the X, Y, and Z directions respectively.

[0008] The device body is provided with a simulated well injection hole, and the liquid injection system is connected to the simulated well injection hole through an injection pipeline;

[0009] The heating control system is connected to the simulated formation module and is used to control the temperature of the simulated formation module.

[0010] The present invention is further configured such that the three-directional servo pressurization system includes an X-direction servo pressurization system, a Y-direction servo pressurization system, and a Z-direction servo pressurization system;

[0011] The Z-direction servo pressurization system is located on the top of the device body and includes a first servo press and a first pressurization device. The output end of the first pressurization device extends into the device body and contacts the simulated formation module. The first servo press drives the first pressurization device.

[0012] The X-direction servo pressurization system is located on the left or right side of the device body, including a second servo press and a second pressurization device. The output end of the second pressurization device extends into the device body and contacts the simulated formation module. The second servo press drives the second pressurization device.

[0013] The Y-direction servo pressurization system is located on the front or rear side of the device body, including a third servo press and a third pressurization device. The output end of the third pressurization device extends into the device body and contacts the simulated formation module. The third servo press drives the third pressurization device.

[0014] The present invention is further configured such that the first pressurizing device, the second pressurizing device and the third pressurizing device are hydraulic pumps or mechanical telescopic structures.

[0015] The present invention is further configured such that the experimental apparatus for simulating thin interlayer cross-delamination fracturing also includes an acoustic emission system, which is disposed on the apparatus body.

[0016] Acoustic emission systems are based on the elastic wave signals released when materials fracture. By capturing, analyzing, and locating these signals, they are used to monitor the initiation, propagation, and evolution of cracks in real time.

[0017] The present invention is further configured such that the acoustic emission system is a 32-channel acoustic emission device.

[0018] The present invention is further configured such that the liquid injection system includes an input pump and a fracturing fluid storage tank; the input end of the input pump is connected to the fracturing fluid storage tank, and the output end of the input pump is connected to the injection hole of the simulated well through the injection pipeline.

[0019] The input pump delivers fracturing fluid from the fracturing fluid tank to the injection port of the simulated well.

[0020] The present invention is further configured such that the heating control system further includes a heating wire, which is electrically connected to the heating control system, and the heating wire is disposed on the output end of the first pressurizing device, the second pressurizing device and the third pressurizing device.

[0021] The present invention is further configured such that the simulated formation module includes a first cement stone, a second cement stone and a third cement stone stacked in sequence, and a simulated well is opened on the first cement stone, the second cement stone and the third cement stone, with the wellhead of the simulated well set on the first cement stone.

[0022] The first cement stone, the second cement stone, and the third cement stone are artificial cement stones of different thicknesses.

[0023] The experimental artificial cement stone is a novel temperature-controlled material. Its main components are resin, rock fragments, and cement mixed in different proportions, enabling the resin strength and Young's modulus to change with temperature. The resin is preferably a phenolic resin.

[0024] The present invention is further configured such that the position of the wellhead of the simulated well matches the position of the injection hole of the simulated well.

[0025] The present invention is further configured such that the experimental apparatus for simulating thin interlayer fracturing also includes a control module, which is signal-connected to the triaxial servo pressurization system, the liquid injection system, the heating control system and the acoustic emission system.

[0026] Compared with the prior art, the beneficial effects of this utility model are specifically reflected in:

[0027] (1) This utility model establishes an indoor experimental simulation device for the propagation of fractures in thin interbedded tight sandstone formations to study the influence of geological factors such as stress difference between reservoir layers, reservoir layer thickness, and rock mechanical properties, as well as engineering factors such as fracturing fluid viscosity and construction discharge on the propagation of hydraulic fracturing fractures in thin interbedded formations, thereby providing theoretical and technical support for on-site fracturing.

[0028] (2) The present invention provides an experimental device that can simulate the cross-layer propagation of fractures in thin interlayer hydraulic fracturing, which can simulate the hydraulic propagation of three to five thin layers.

[0029] (3) This utility model controls the temperature of the artificial cement stone used in the experiment through a heating control system. As the temperature changes, the strength of the artificial cement stone resin changes, which in turn changes its Young's modulus. By using the technology of temperature-controlled Young's modulus of cement stone, a crack propagation experiment of a multi-layer system with different rock mechanical parameters of the same thickness can be obtained. This method is low in cost and high in efficiency. Attached Figure Description

[0030] Figure 1 A simplified diagram of an experimental setup for simulating cross-layer fracturing of thin interlayers.

[0031] Figure 2 This is a schematic diagram of a simulated formation module.

[0032] The meanings of the reference numerals in the attached figures are as follows:

[0033] 1-1 First servo press; 1-2 Second servo press; 1-3 Third servo press; 1-4 First pressurizing device; 1-5 Second pressurizing device; 1-6 Third pressurizing device; 1-7 Acoustic emission device; 1-8 Liquid injection system; 1-9 Injection pipeline; 1-10 Simulated well injection hole; 1-11 Heating control system; 1-12 Heating wire;

[0034] 2-1-1, Simulated well; 2-1, First cement stone; 2-2, Second cement stone; 2-3, Third cement stone. Detailed Implementation

[0035] To make the objectives and technical solutions of this utility model clearer, the technical solutions of this utility model will be clearly and completely described below in conjunction with the embodiments.

[0036] Example 1

[0037] Combination Figure 1 As shown, this embodiment provides an experimental apparatus for simulating cross-layer fracturing of thin interlayers, including an apparatus body, a triaxial servo pressurization system, a liquid injection system 1-8, a heating control system 1-11, and a formation simulation module;

[0038] The simulated formation module is installed inside the device body, and the three-dimensional servo pressurization system is installed on the device body, applying pressure to the simulated formation module from the X, Y, and Z directions respectively.

[0039] The device body is provided with a simulated well injection hole 1-10, and the liquid injection system 1-8 is connected to the simulated well injection hole 1-10 through an injection pipeline 1-9.

[0040] The heating control system 1-11 is connected to the simulated formation module and is used to control the temperature of the simulated formation module.

[0041] The tri-directional servo pressurization system includes an X-direction servo pressurization system, a Y-direction servo pressurization system, and a Z-direction servo pressurization system;

[0042] The Z-direction servo pressurization system is located on the top of the device body and includes a first servo press 1-1 and a first pressurization device 1-4. The output end of the first pressurization device 1-4 extends into the device body and contacts the simulated formation module. The first servo press 1-1 drives the first pressurization device 1-4.

[0043] The X-direction servo pressurization system is located on the left or right side of the device body, including a second servo press 1-2 and a second pressurization device 1-5. The output end of the second pressurization device 1-5 extends into the device body and contacts the simulated formation module. The second servo press 1-2 drives the second pressurization device 1-5.

[0044] The Y-direction servo pressurization system is located on the front or rear side of the device body, including a third servo press 1-3 and a third pressurization device 1-6. The output end of the third pressurization device 1-6 extends into the device body and contacts the simulated formation module. The third servo press 1-3 drives the third pressurization device 1-6.

[0045] The first pressurizing device 1-4, the second pressurizing device 1-5 and the third pressurizing device 1-6 adopt hydraulic pumps or mechanical telescopic structures.

[0046] The experimental apparatus for simulating thin interlayer cross-delaminar fracturing also includes acoustic emission systems 1-7, which are mounted on the apparatus body. The acoustic emission systems are 32-channel acoustic emission devices.

[0047] Acoustic emission systems 1-7 are based on the elastic wave signals released when materials fracture. By capturing, analyzing and locating these signals, they are used to monitor the initiation, propagation and evolution of cracks in real time.

[0048] The fluid injection system 1-8 includes an input pump and a fracturing fluid storage tank; the input end of the input pump is connected to the fracturing fluid storage tank, and the output end of the input pump is connected to the simulated well injection port 1-10 through the injection pipeline 1-9. The input pump delivers the fracturing fluid in the fracturing fluid storage tank to the simulated well injection port 1-10.

[0049] The heating control system 1-11 also includes a heating wire 1-12, which is electrically connected to the heating control system 1-11. The heating wire 1-12 is disposed on the output end of the first pressurizing device 1-4, the second pressurizing device 1-5 and the third pressurizing device 1-6.

[0050] The simulated formation module includes a first cement stone 2-1, a second cement stone 2-2, and a third cement stone 2-3 stacked sequentially. A simulated well 2-1-1 is opened on the first cement stone 2-1, the second cement stone 2-2, and the third cement stone 2-3. The wellhead of the simulated well 2-1-1 is located on the first cement stone 2-1. The position of the wellhead of the simulated well 2-1-1 corresponds to the position of the simulated well injection hole 1-10.

[0051] The first cement stone 2-1, the second cement stone 2-2, and the third cement stone 2-3 are artificial cement stones of different thicknesses. Artificial cement stones are made by mixing phenolic resin, rock fragments, and cement in different proportions, allowing the resin strength and Young's modulus to change with temperature.

[0052] The experimental apparatus for simulating thin interlayer fracturing also includes a control module, which is connected to the triaxial servo pressurization system, liquid injection system 1-8, heating control system 1-11 and acoustic emission system 1-7.

[0053] In actual operation, the entire experimental procedure includes:

[0054] 1. Sample preparation: Based on the simulated thin interlayer parameters, determine the thickness of different layers, and prepare large artificial cement stone pieces with dimensions of 300mm*300mm*different thicknesses and small cylindrical artificial cement stone pieces with diameters of 25mm*50mm with different formulation ratios. Allow them to set and cure at room temperature.

[0055] 2. Sample loading: Measure the Young's modulus and Poisson's ratio of small artificial cement stone pieces with different formulation ratios when heated to different temperatures, and prepare a sample coverage table; determine the formulation ratio and required experimental temperature for the corresponding coverage range based on the Young's modulus and Poisson's ratio of the thin interlayer to be simulated.

[0056] A forklift was used to load large samples of the artificial cement stone according to the formula ratio and place them in the main body of the device.

[0057] 3. Install acoustic emission system 1-7: Install a 32-channel acoustic emission device on the main body of the device to monitor the crack propagation.

[0058] 4. Perform heating operation: Use the heating control system 1-11 to raise the temperature to the experimental temperature confirmed in step 2.

[0059] 5. Perform triaxial stress loading operation: Use a triaxial servo pressurization system to apply triaxial stress.

[0060] 6. Conduct fracturing simulation experiments: simulate cross-layer fracturing by pumping fracturing fluid into the input pump and obtain relevant fracture propagation data.

[0061] 7. Experiment completed.

[0062] In this embodiment, the length and width of the artificial cement stone are 300mm and 300mm respectively, and the thickness is adjustable within the range of 0-800mm.

[0063] This invention can conduct simulation experiments on reservoirs with multiple layers and different Young's moduli. It can also use the technology of temperature-controlled cement stone Young's moduli to obtain the propagation morphology of hydraulic fracturing fractures under different rock mechanical parameters of the same thickness, and has a wide range of applications.

[0064] The above are merely embodiments of this utility model, described in a relatively specific and detailed manner, but they should not be construed as limiting the scope of this utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model.

Claims

1. An experimental apparatus for simulating a cross-fracturing of thin interbeds, characterized in that, It includes the device body, a three-dimensional servo pressurization system, a liquid injection system, a heating control system, and a simulated formation module; The simulated formation module is installed inside the device body, and the three-dimensional servo pressurization system is installed on the device body, applying pressure to the simulated formation module from the X, Y, and Z directions respectively. The device body is provided with a simulated well injection hole, and the liquid injection system is connected to the simulated well injection hole through an injection pipeline; The heating control system is connected to the simulated formation module and is used to control the temperature of the simulated formation module.

2. The experimental setup of claim 1, wherein, The tri-directional servo pressurization system includes an X-direction servo pressurization system, a Y-direction servo pressurization system, and a Z-direction servo pressurization system; The Z-direction servo pressurization system is located on the top of the device body and includes a first servo press and a first pressurization device. The output end of the first pressurization device extends into the device body and contacts the simulated formation module. The first servo press drives the first pressurization device. The X-direction servo pressurization system is located on the left or right side of the device body, including a second servo press and a second pressurization device. The output end of the second pressurization device extends into the device body and contacts the simulated formation module. The second servo press drives the second pressurization device. The Y-direction servo pressurization system is located on the front or rear side of the device body, including a third servo press and a third pressurization device. The output end of the third pressurization device extends into the device body and contacts the simulated formation module. The third servo press drives the third pressurization device.

3. The experimental apparatus according to claim 2, characterized in that, The first pressurizing device, the second pressurizing device, and the third pressurizing device are equipped with hydraulic pumps or mechanical telescopic structures.

4. The experimental apparatus according to claim 3, characterized in that, The experimental apparatus for simulating thin interlayer cross-delaminar fracturing also includes an acoustic emission system, which is mounted on the apparatus body.

5. The experimental apparatus according to claim 4, characterized in that, The acoustic emission system is a 32-channel acoustic emission device.

6. The experimental apparatus according to claim 5, characterized in that, The liquid injection system includes an input pump and a fracturing fluid tank; the input end of the input pump is connected to the fracturing fluid tank, and the output end of the input pump is connected to the injection port of the simulated well through the injection pipeline.

7. The experimental apparatus according to claim 6, characterized in that, The heating control system also includes a heating wire, which is electrically connected to the heating control system. The heating wire is disposed at the output ends of the first pressurizing device, the second pressurizing device, and the third pressurizing device.

8. The experimental apparatus according to claim 1, characterized in that, The simulated formation module includes a first cement stone, a second cement stone, and a third cement stone stacked in sequence. A simulated well is opened on the first cement stone, the second cement stone, and the third cement stone, and the wellhead of the simulated well is set on the first cement stone. The first cement stone, the second cement stone, and the third cement stone are artificial cement stones of different thicknesses.

9. The experimental apparatus according to claim 8, characterized in that, The location of the simulated wellhead is matched with the location of the simulated well injection hole.

10. The experimental apparatus according to claim 4, characterized in that, The experimental apparatus for simulating thin interlayer cross-layer fracturing also includes a control module, which is connected to the triaxial servo pressurization system, liquid injection system, heating control system and acoustic emission system.

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