A method for conducting injection tests into rock bodies with dynamic fractures, which involves measuring the permeability in real time through synchronization.

Abstract

We provide a sampling fracture rock body injection test device that measures seepage rate in real time and with synchronization. [Solution] The pressurizing device includes a base 13 located within the pressurizing device, the base 13 having a chamber for containing a sample, and the chamber includes an intake section located at the bottom, the intake section being used to supply high-pressure gas into the chamber in communication with a gas source, and an exhaust section located at the top of the chamber, the intake end of the exhaust section being in contact with the top of the sample, the exhaust section being located within a piston 2, the piston 2 being slidably installed within the chamber, the exhaust end of the exhaust section being located outside the piston 2, the top of the piston 2 being attached to the pressurizing end of the pressurizing device, and an injection section enclosing the side wall of the sample, the outlet end of the injection section being in communication with the chamber, used to inject slurry into the chamber, and a displacement sensor used to detect the distance between the pressurizing end of the pressurizing device and the top of the chamber.

Claims

[Claim 1] A method for testing injection into a rock body with a sampling fracture to measure permeability, A base (13) placed inside a pressurizing device, the base (13) having a chamber for containing a sample, An intake section provided at the bottom of the chamber, wherein the exhaust end of the intake section is in contact with the bottom of the sample, the intake end of the intake section is located outside the base (13), and the intake section is in communication with a gas source and used to inject high-pressure gas into the chamber, An exhaust section is provided at the top of the chamber, the intake end of the exhaust section is in contact with the top of the sample, the exhaust section is provided inside a piston (2), the piston (2) is slidably installed inside the chamber, the exhaust end of the exhaust section is located outside the piston (2), and the top of the piston (2) is attached to the pressurizing end of the pressurizing device. An injection section that encloses the side wall of the sample, the bottom of the injection section is fixedly connected to the base (13), the outlet end of the injection section communicates with the chamber, and the injection section is used to inject slurry into the chamber. A displacement sensor is used to detect the height of the piston (2) above the top of the chamber and to obtain the height of the sample, This is performed using a sampling fracture rock body injection test device that measures permeability including, A step of filling the chamber with the sample and controlling the piston (2) to come into contact with the sample, The process involves driving the pressurizing end of the pressurizing device to move the piston (2) and push down the sample, adjusting the porosity of the sample, and detecting the amount of displacement of the pressurizing end of the pressurizing device using a displacement sensor. The process involves, after reaching the target initial porosity, releasing the pressure to a stable value, maintaining a constant load pressure at the pressurizing end of the pressurizing device, activating the gas source and injection mechanism to inject grout into the chamber, and starting the infiltration injection test. The process involves controlling the injection unit to inject slurry into the injection mechanism, thereby injecting the slurry into the chamber. A step of connecting a gas source to the intake section and controlling the gas source to inject high-pressure gas into the chamber through the intake section, A step of connecting the gas collection device to the exhaust section, A step of acquiring intake pressure data based on the intake volume of the intake section, A step of acquiring exhaust pressure data based on the exhaust volume of the exhaust section, A step of acquiring injection pressure data of the injection section, The process includes obtaining permeability and nonlinear permeability coefficient based on the intake volume, intake pressure data, exhaust volume, exhaust pressure data, and injection pressure data. The formula for calculating the corrected penetration rate is as follows: [Math 1] Here, p ｉｎ is the gas pressure at the intake port, p ｏｕｔ ρ is the gas pressure at the exhaust port. ω is fluid density, m ｓ ρ is the mass of the rock sample. ｓ The mass density of the rock sample, [Math 2] r is the gas pipeline flow rate at the intake port, r is the bottom radius of the inner injection cylinder, h is the gas pipeline flow rate at the intake port r is the bottom radius of the inner injection cylinder, and h is the gas pipeline flow rate at the intake port. ｍ This is the height of the rock sample after axial pressure was applied. [Math 3] is T ｉ Cumulative flow rate of the slurry pipeline at time, μ is the fluid kinematic viscosity coefficient. The corrected nonlinear penetration coefficient is as follows: [Math 4] Here, ρ ω is the fluid density, m ｓ is the mass of the rock sample, ρ ｓ is the mass density of the rock sample, [Math 5] r is the gas pipeline flow rate at the intake port, r is the bottom radius of the inner injection cylinder, h is the gas pipeline flow rate at the intake port r is the bottom radius of the inner injection cylinder, and h is the gas pipeline flow rate at the intake port. ｍ This is the height of the rock sample after axial pressure was applied. [Math 6] is T ｉ A sampling fracture rock body injection test method for measuring permeability, characterized by the cumulative flow rate of the slurry pipeline at a given time, where μ is the fluid kinematic viscosity coefficient. [Claim 2] The injection section is The system includes an internal injection cylinder (8), the bottom of which is bearing-supported on the base (13), the chamber is installed inside the internal injection cylinder (8), and a plurality of injection holes are uniformly drilled in the side wall of the internal injection cylinder (8) for communication with the chamber. The inner injection cylinder (8) includes an outer cylinder (7) installed coaxially on the outside, the bottom of the outer cylinder (7) being fixedly connected to the top of the base (13), and the top of the outer cylinder (7) being fixedly connected to the top of the inner injection cylinder (8), The inner wall of the outer cylinder (7) and the outer wall of the inner injection cylinder (8) are formed surrounding a slurry temporary storage cavity, and the slurry temporary storage cavity is in communication with the liquid supply ends of the plurality of injection holes. The sampling fracture rock injection test method for measuring permeability according to claim 1, characterized in that the slurry temporary storage cavity is in communication with an injection port (10), and the injection port (10) is drilled in the outer cylinder (7). [Claim 3] The intake section is, The chamber includes a first honeycomb-shaped porous air cavity (9) installed at the bottom of the chamber, the intake end of the first honeycomb-shaped porous air cavity (9) is in communication with the exhaust end of the intake line, the intake line is embedded in the base (13), the intake port (12) of the intake line is installed on the side wall of the base (13), and the intake port (12) is used to connect to a gas source. A sampling fracture rock body injection test method for measuring permeability according to claim 1, characterized in that a thin, breathable gauze (14) is laid between the exhaust end of the first honeycomb porous air cavity (9) and the sample. [Claim 4] The aforementioned exhaust section is A sampling crack rock injection test method for measuring permeability according to claim 1, comprising a second honeycomb-shaped porous air cavity (6) slidably installed in the chamber, wherein the second honeycomb-shaped porous air cavity (6) is fixedly connected to the bottom of the piston (2), the intake end of the second honeycomb-shaped porous air cavity (6) is in contact with and in communication with the top of the sample, the exhaust end of the second honeycomb-shaped porous air cavity (6) is in communication with the intake end of the exhaust pipe, the exhaust pipe is embedded in the piston (2), and the exhaust port (3) of the exhaust pipe is drilled in the side wall of the piston (2). [Claim 5] The displacement sensor is A sampling fracture rock injection test method for measuring permeability according to claim 2, comprising a linear variable differential transformer (4), wherein the fixed end of the linear variable differential transformer (4) is fixedly connected to the top of the internal injection cylinder (8), and the movable end of the linear variable differential transformer (4) is fixedly connected to the pressurized end of the pressurizing device. [Claim 6] The pressurizing device is The system includes an axial displacement control device (1), the base (13) is located within the axial displacement control device (1), and the movable end of the axial displacement control device (1) is fixedly connected to the top of the piston (2). The sampling fracture rock injection test method for measuring permeability according to claim 5, characterized in that the movable end of the linear variable differential transformer (4) is fixedly connected to the movable end of the axial displacement control device (1).

Images