Method and device for determining dynamic and static mechanical parameter conversion relation of target rock core

Abstract

The invention relates to the technical field of petroleum engineering, in particular to a method and device for determining the dynamic and static mechanical parameter conversion relation of a target rock core. A target rock core is arranged in the dynamic and static mechanical parameter testing device, and the dynamic and static mechanical parameter testing device comprises a platform, a fixing mechanism, a scribing mechanism and an ultrasonic detection mechanism. The target rock core is fixed on the platform by the fixing mechanism; the method for determining the dynamic and static mechanical parameter conversion relation of the target rock core comprises the following steps: controlling a scribing mechanism to continuously scratch the target rock core so as to obtain a static mechanical parameter value of the target rock core; controlling the ultrasonic detection mechanism to perform wave velocity test on the target rock core so as to calculate a dynamic mechanical parameter value of the target rock core; and according to the dynamic mechanical parameter value and the static mechanical parameter value of the target rock core, determining a dynamic and static mechanical parameter conversion relationship of the target rock core. According to the embodiment of the invention, the dynamic and static mechanical parameter values of the target rock core can be simply and quickly obtained, and the dynamic and static mechanical parameter conversion relation of the target rock core is determined.

Description

Technical Field

[0001] The embodiments of this specification relate to the field of petroleum engineering technology, and specifically to a method and device for determining a conversion relationship between dynamic and static mechanical parameters of a target rock core. Background Art

[0002] In the field of petroleum engineering, the understanding of rock deformation characteristics is the basis for applying correct mathematical expressions to describe rock deformation, which is very important for engineering applications. Although there are many observation results on the dynamic and static elastic parameters of rocks and related theories of rock mechanics and rock physics, in the dynamic and static mechanical parameter conversion test of reservoir rocks, due to the strong heterogeneity of natural rocks, the relationship between dynamic parameters and static parameters is unstable, which is not conducive to studying the influence of mineral composition and pore structure on dynamic and static parameters.

[0003] At present, the conversion methods of full-diameter core mechanical parameters mainly include dynamic acquisition method and static acquisition method. Full-diameter core refers to the core taken out from the oil field on-site by coring technology. It is not cut or split, and the whole section is used for laboratory analysis and determination of relevant parameters. The dynamic acquisition method uses logging data and logging interpretation models to obtain the dynamic mechanical parameters of rocks. The static acquisition method mainly uses experimental measurements to obtain the static mechanical parameters of rocks, such as the uniaxial compression test to determine the uniaxial compressive strength, elastic modulus, and Poisson's ratio, and the three-point bending test to determine the fracture toughness. The parameters used in actual drilling and fracturing are calculated from the static mechanical parameters of rocks. However, the commonly used indoor experiments for determining static mechanical parameters are destructive tests, which cannot guarantee the integrity of the full-diameter core specimen structure. The test time is long and the test steps are complicated.

[0004] Therefore, how to overcome the problems of long testing time and complicated testing steps in the current conversion method of full-diameter core mechanical parameters, and propose a method and device for determining the dynamic and static mechanical parameter conversion relationship of the target core with short testing time, simple testing steps and high efficiency is a key issue that needs to be solved urgently. Summary of the invention

[0005] The purpose of the embodiments of this specification is to provide a method and device for determining the conversion relationship of the dynamic and static mechanical parameters of a target core, so as to overcome the problems of long testing time and complicated testing steps in the current conversion method of the mechanical parameters of the full-diameter core, shorten the testing time in the conversion process of the mechanical parameters of the full-diameter core, simplify the testing steps, and provide efficient testing results.

[0006] On the one hand, an embodiment of the present specification proposes a method for determining the conversion relationship between the dynamic and static mechanical parameters of a target rock core, and the method for determining the conversion relationship between the dynamic and static mechanical parameters of the target rock core includes: controlling the scratching mechanism to continuously scratch the target rock core to obtain the static mechanical parameter value of the target rock core; controlling the ultrasonic detection mechanism to perform a wave velocity test on the target rock core to calculate the dynamic mechanical parameter value of the target rock core; and determining the conversion relationship between the dynamic and static mechanical parameters of the target rock core according to the dynamic mechanical parameter value and the static mechanical parameter value of the target rock core.

[0007] On the other hand, a device for determining the conversion relationship between dynamic and static mechanical parameters of a target core is provided, the device comprising: an acquisition module for controlling a scratching mechanism to continuously scratch the target core to obtain the static mechanical parameter value of the target core; a calculation module for controlling an ultrasonic detection mechanism to perform a wave velocity test on the target core to calculate the dynamic mechanical parameter value of the target core; and a determination module for determining the conversion relationship between dynamic and static mechanical parameters of the target core based on the dynamic mechanical parameter value and static mechanical parameter value of the target core.

[0008] On the other hand, a dynamic and static mechanical parameters testing device is provided, which includes a platform, a fixing mechanism, a scratching mechanism, an ultrasonic detection mechanism and a controller; the target core is fixed on the platform by the fixing mechanism; and the controller is used to execute the method for determining the dynamic and static mechanical parameters conversion relationship of the above-mentioned target core.

[0009] It can be seen from the technical solutions provided in the above embodiments of this specification that the method for determining the dynamic and static mechanical parameter conversion relationship of the target core provided in the embodiments of this specification can control the scratching mechanism to continuously scratch the target core to obtain the static mechanical parameter value of the target core; control the ultrasonic detection mechanism to perform wave velocity test on the target core to calculate the dynamic mechanical parameter value of the target core; and determine the dynamic and static mechanical parameter conversion relationship of the target core according to the dynamic mechanical parameter value and static mechanical parameter value of the target core. Compared with the existing methods, the dynamic and static mechanical parameter values ​​of the target core can be obtained simply and quickly through the scratching mechanism and the ultrasonic detection mechanism, and then the dynamic and static mechanical parameter conversion relationship of the target core can be determined. In addition, controlling the scratching mechanism to apply continuous scratches to the target core will not damage the structure of the target core, and the target core can be used for repeated testing of dynamic and static mechanical parameters or other types of testing. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] In order to more clearly illustrate the technical solutions in the embodiments of this specification or the prior art, the drawings required for use in the embodiments or the prior art description are briefly introduced below.

[0011] Figure 1It is a structural diagram of a dynamic and static mechanical parameter testing device provided in an embodiment of this specification;

[0012] Figure 2 It is a partial structural diagram of a dynamic and static mechanical parameter testing device provided in an embodiment of this specification;

[0013] Figure 3 It is a flow chart of a method for determining the conversion relationship of dynamic and static mechanical parameters of a target core provided in an embodiment of this specification;

[0014] Figure 4 It is a schematic diagram of the structural composition of a device for determining the dynamic and static mechanical parameter conversion relationship of a target rock core provided in an embodiment of this specification.

[0015] Reference numerals of the above drawings:

[0016] 1. Cutter head; 2. Cutter head baffle; 3. Three-dimensional force sensor; 4. Fixing mechanism; 5. Target core; 6. First motor; 7. Rotating wheel; 8. Steel column; 9. Second motor; 10. Ultrasonic detection mechanism; 11. 3D scanning sensor. DETAILED DESCRIPTION

[0017] The following will be combined with the drawings in the embodiments of this specification to clearly and completely describe the technical solutions in the embodiments of this specification. Obviously, the described embodiments are only part of the embodiments of this specification, not all of the embodiments. Based on the embodiments in this specification, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of this specification.

[0018] Figure 1 This is a structural diagram of a dynamic and static mechanical parameter testing device provided in an embodiment of this specification.

[0019] In some embodiments, the target core is placed in a dynamic and static mechanical parameter testing device, which includes a platform, a fixing mechanism, a scratching mechanism and an ultrasonic detection mechanism; the target core is fixed on the platform by the fixing mechanism.

[0020] By placing the target rock core in a dynamic and static mechanical parameter testing device, the dynamic and static mechanical parameter testing of the target rock core can be performed directly and quickly, and then the dynamic and static mechanical parameter conversion relationship of the target rock core can be determined.

[0021] Reference Figure 1 As shown, the dynamic and static mechanical parameter testing device includes a platform, a fixing mechanism 4, a scribing mechanism and an ultrasonic detection mechanism 10. The target core 5 is fixed on the platform of the dynamic and static mechanical parameter testing device by the fixing mechanism 4. Figure 2As shown, the scratching mechanism includes a cutter head base, a cutter head 1, a cutter head baffle 2, a second motor 9 and a rotating wheel 7. The cutter head baffle 2 can be used to fix the cutter head 1 on the cutter head base at a preset angle. The second motor 9 can be used to control the platform to move forward at a preset rate so that the cutter head 1 continuously scratches the target core 5 on the platform. The rotating wheel 7 can be used to control the height of the platform so that the depth of the continuous scratches on the surface of the target core 5 meets the preset depth. The ultrasonic detection mechanism 10 includes an ultrasonic pulse transmitter, a transmitting probe, a receiving probe and an oscilloscope. The transmitting probe is connected to the ultrasonic pulse transmitter, and the receiving probe is connected to the oscilloscope. The transmitting probe is located on the upper surface of the target core 5, and the receiving probe is located on the lower surface of the target core 5 directly opposite to the transmitting probe. The transmitting probe and the receiving probe are located opposite to each other and can move with the platform, and the shear wave velocity and longitudinal wave velocity of the target core 5 can be obtained by changing the probe type. The ultrasonic detection mechanism 10 can be used to perform non-destructive wave velocity testing on the target core 5. It can detect the shear wave velocity and longitudinal wave velocity of the target core through the principle of interaction between ultrasonic waves and the internal material of the target core 5. The ultrasonic pulse transmitter can be used to generate high-frequency electrical pulses, which are then converted into ultrasonic waves. The ultrasonic pulse transmitter generates electrical signals of specific frequency and waveform through an internal electronic oscillator or signal generator. After power amplification, these signals drive the transmitting probe to generate ultrasonic waves. The transmitting probe can convert the electrical pulse signal into mechanical vibration (ultrasonic wave) and transmit it to the target core 5. The receiving probe can be used to receive the ultrasonic wave reflected from the target core 5 and convert it back into an electrical signal. The oscilloscope can be used to display and analyze the received ultrasonic signal. The oscilloscope can capture and display the waveform of the electrical signal. By observing the characteristics of the waveform (such as amplitude, frequency, phase, etc.), the shear wave velocity and longitudinal wave velocity of the target core 5 can be calculated.

[0022] In some embodiments, the dynamic and static mechanical parameter testing device further includes a grinding mechanism; the grinding mechanism includes a grinding wheel and a first motor; the first motor is used to drive the grinding wheel.

[0023] Based on the grinding mechanism, the target core can be ground, and then the roughness of the ground target core can be guaranteed to meet the requirements of dynamic and static mechanical parameter testing.

[0024] Reference Figure 1 As shown, the dynamic and static mechanical parameter testing device also includes a grinding mechanism. The grinding mechanism may include a grinding wheel and a first motor 6. The grinding wheel is detachable. The grinding wheel can be used to grind the target core 5. Before grinding the target core 5, the grinding wheel can be installed in the grinding mechanism, and after grinding the target core 5, the grinding wheel can be removed from the grinding mechanism. The first motor 6 can be used to drive the grinding wheel to grind the target core 5 so that the surface roughness of the ground target core meets the requirements of the dynamic and static mechanical parameter testing.

[0025] In some embodiments, the dynamic and static mechanical parameter testing device also includes a 3D scanning sensor.

[0026] Based on the 3D scanning sensor, on the one hand, it can be determined whether the surface roughness of the target rock core after being polished by the polishing mechanism meets the requirements of the dynamic and static mechanical parameter tests; on the other hand, it can also be determined whether the roughness of the continuous scratches on the surface of the target rock core 5 after being scratched by the scratching mechanism meets the preset scratch roughness, and then the scratching mechanism can be adjusted according to the deviation from the preset scratch depth.

[0027] Reference Figure 1 As shown, the dynamic and static mechanical parameter testing device also includes a 3D scanning sensor 11. The 3D scanning sensor 11 can have two uses. After the surface of the target core 5 is polished using the polishing mechanism, the 3D scanning sensor 11 can be used to determine whether the surface roughness of the polished target core 5 meets the requirements of the dynamic and static mechanical parameter test. After the surface of the target core 5 is continuously scratched using the scratching mechanism, the rock debris on the surface of the continuous scratches can be cleaned and the 3D scanning sensor 11 can be used to determine whether the roughness of the continuous scratches on the surface of the target core 5 after scratching meets the preset scratch roughness. If not, the surface of the target core 5 can be polished using the polishing mechanism until it meets the requirements of the dynamic and static mechanical parameter test, and then the scratching mechanism can be adjusted to continuously scratch the surface of the target core 5 again.

[0028] In some embodiments, the dynamic and static mechanical parameter testing device also includes a three-dimensional force sensor; the three-dimensional force sensor is connected to the tool head base of the scribing mechanism.

[0029] Based on the three-dimensional force sensor and the connection relationship between the three-dimensional force sensor and the cutter head base in the scratching mechanism, the static mechanical parameter values ​​in the process of continuously scratching the target core using the scratching mechanism can be obtained.

[0030] Reference Figure 1 and Figure 2 As shown, the dynamic and static mechanical parameter testing device also includes a three-dimensional force sensor 3. The three-dimensional force sensor 3 is connected to the cutter head base in the scratching mechanism. When the cutter head 1 in the scratching mechanism is used to continuously scratch the surface of the target core 5, the three-dimensional force sensor 3 can obtain the stress-strain curve during the continuous scratching process through the cutter head base, and then determine the static elastic modulus and static Poisson's ratio of the target core according to the stress-strain curve of the continuous scratches of the target core. When the cutter head 1 in the scratching mechanism is used to continuously scratch the surface of the target core 5, the force on the cutter head is transmitted to the three-dimensional force sensor 3 through the cutter head base between the cutter head 1 and the three-dimensional force sensor 3, and real-time monitoring of the tangential force and normal force of the cutting surface of the cutter head can also be achieved.

[0031] In some embodiments, the dynamic and static mechanical parameter testing device further includes four steel columns.

[0032] Based on the four steel columns, it can be ensured that the platform of the dynamic and static mechanical parameter testing device remains horizontal, thereby ensuring that it remains stable during the process of using the cutter head in the scratching mechanism to continuously scratch the target rock core.

[0033] Reference Figure 1 As shown, the dynamic and static mechanical parameter testing device further comprises four steel columns 8. The four steel columns 8 can ensure that the platform of the dynamic and static mechanical parameter testing device remains horizontal, so that the cutter head 1 can perform stable and continuous scratches on the target core 5 when using the scratching mechanism.

[0034] Corresponds to Figure 1 The dynamic and static mechanical parameter testing device in this specification also provides a method for determining the conversion relationship of the dynamic and static mechanical parameters of a target core. Figure 3 A flow chart of a method for determining the conversion relationship between dynamic and static mechanical parameters of a target core provided in an embodiment of this specification.

[0035] In specific implementation, the method for determining the conversion relationship of the dynamic and static mechanical parameters of the target core includes the following steps:

[0036] S301: Control the scribing mechanism to continuously scratch the target core to obtain static mechanical parameter values ​​of the target core.

[0037] In some embodiments, the dynamic and static mechanical parameter testing device may further include a grinding mechanism; the grinding mechanism may include a grinding wheel and a first motor; the first motor may be used to drive the grinding wheel; the first motor may be controlled to drive the grinding wheel to grind the target core, and the grinding is used to make the roughness of the target core meet a preset roughness threshold.

[0038] By controlling the first motor to drive the grinding wheel to grind the target rock core, it can be ensured that the roughness of the target rock core after grinding meets the requirements of dynamic and static mechanical parameter testing.

[0039] Reference Figure 1 As shown, the dynamic and static mechanical parameter testing device also includes a grinding mechanism. The grinding mechanism may include a grinding wheel and a first motor 6. The grinding wheel may be used to grind the target core 5. The first motor 6 may be used to drive the grinding wheel to grind the target core 5 so that the surface roughness of the target core after grinding meets the requirements of the dynamic and static mechanical parameter testing. The first motor 6 may be controlled to drive the grinding wheel to grind the target core 5 so that the roughness of the target core 5 meets the preset roughness threshold, and then the target core 5 may be subjected to a continuous scratch test.

[0040] In some embodiments, the scoring mechanism may include a cutter head base, a cutter head, a cutter head baffle, a second motor and a rotating wheel; the second motor may be used to drive the platform to move at a preset speed; the rotating wheel may be controlled to adjust the platform to a preset height; the cutter head baffle may be controlled to fix the cutter head on the cutter head base at a preset angle; the second motor may be controlled to enable the cutter head to continuously scratch the target core on the platform.

[0041] By controlling the second motor to make the cutter head continuously scratch the target core on the platform, there is no need to use a discrete sampling point-based method to test the static mechanical parameters of the target core, which is simpler, faster and more accurate.

[0042] Reference Figure 1 and Figure 2 As shown, the scratching mechanism includes a cutter head base, a cutter head 1, a cutter head baffle 2, a second motor 9 and a rotating wheel 7. The cutter head baffle 2 can be used to fix the cutter head 1 on the cutter head base at a preset angle. The second motor 9 can be used to control the platform to move forward at a preset rate so that the cutter head 1 continuously scratches the target core 5 on the platform. The rotating wheel 7 can be used to control the height of the platform so that the depth of the continuous scratches on the surface of the target core 5 meets the preset depth. Before the static mechanical parameter test of the target core 5 is performed, the rotating wheel 7 can be controlled to adjust the platform to a preset height and the cutter head baffle 2 can be controlled to fix the cutter head 1 on the cutter head base at a preset angle. When the static mechanical parameter test of the target core 5 is performed, the second motor 9 can be controlled to make the cutter head 1 directly scratch the target core 5 on the platform continuously, without the need to perform static mechanical parameter tests on the target core at multiple discrete sampling points, which is simpler, faster and the static mechanical parameter test results are more accurate.

[0043] In some embodiments, the dynamic and static mechanical parameter testing device also includes a 3D scanning sensor; based on the 3D scanning sensor, the roughness of the continuous scratch surface of the target core is obtained; based on the roughness, the scratching mechanism is adjusted to continuously scratch the target core.

[0044] By obtaining the roughness of the continuous scratch surface of the target core through a 3D scanning sensor, the scratching mechanism can be adjusted to make more precise continuous scratches on the target core, thereby obtaining more accurate static mechanical test parameter values, which helps to establish a more accurate conversion relationship between dynamic and static mechanical parameters of the target core.

[0045] Reference Figure 1As shown, the dynamic and static mechanical parameter testing device also includes a 3D scanning sensor 11. After the surface of the target core 5 is continuously scratched using the scratching mechanism, the 3D scanning sensor 11 can be used to determine whether the roughness of the continuous scratches on the surface of the target core 5 after scratching meets the preset scratch roughness. If not, the surface of the target core 5 can be polished using a grinding mechanism until it meets the requirements of the dynamic and static mechanical parameter testing, and then the scratching mechanism can be adjusted to continuously scratch the surface of the target core 5 again.

[0046] In some embodiments, before the dynamic and static mechanical parameter tests are performed on the target core, the roughness of the surface of the target core can be obtained according to the 3D scanning sensor; and according to the roughness, the grinding mechanism is adjusted to grind the target core.

[0047] By using a 3D scanning sensor to obtain the roughness of the target core surface and then using a grinding mechanism to grind the target core, repeated dynamic and static mechanical parameter tests of the target core can be achieved.

[0048] Before any dynamic and static mechanical parameter test on the surface of the target core 5, the 3D scanning sensor 11 can be used to determine whether the surface roughness of the target core 5 meets the requirements of the dynamic and static mechanical parameter test. If it does not meet the requirements of the dynamic and static mechanical parameter test, the grinding mechanism can be used to grind the target core 5 again until the surface roughness of the target core 5 meets the requirements of the dynamic and static mechanical parameter test.

[0049] In some embodiments, the dynamic and static mechanical parameter testing device also includes a three-dimensional force sensor; the three-dimensional force sensor is connected to the cutter head base of the scratching mechanism; based on the three-dimensional force sensor, the stress-strain curve of the continuous scratches on the target core is obtained; based on the stress-strain curve of the continuous scratches on the target core, the static elastic modulus of the target core is determined.

[0050] By obtaining the stress-strain curve of the continuous scratches of the target core, the continuous static mechanical parameters of the target core are obtained, which helps to obtain a more accurate conversion relationship between dynamic and static mechanical parameters.

[0051] Reference Figure 1 and Figure 2As shown, the dynamic and static mechanical parameter testing device also includes a three-dimensional force sensor 3. The three-dimensional force sensor 3 is connected to the cutter head base in the scratching mechanism. When the cutter head 1 in the scratching mechanism is used to continuously scratch the surface of the target core 5, the three-dimensional force sensor 3 can obtain the stress-strain curve during the continuous scratching process through the cutter head base, and then the static elastic modulus of the target core can be determined according to the stress-strain curve of the continuous scratching of the target core. The static elastic modulus of the target core refers to the ratio of the positive stress to the corresponding positive strain of the target core during the elastic deformation stage.

[0052] In some embodiments, based on the three-dimensional force sensor, the tangential force and normal force of the cutter head cutting surface of the target core continuous scratches can be obtained; based on the tangential force and normal force of the cutter head cutting surface, the uniaxial compressive strength and fracture toughness at the target core continuous scratches can be calculated.

[0053] By obtaining the tangential force and normal force on the cutting surface of the cutter head during the continuous scratch test, the uniaxial compressive strength and fracture toughness of the target core at the continuous scratch can be calculated. Without the need for additional testing, the material mechanical properties of the target core can be more comprehensively evaluated and understood.

[0054] Reference Figure 1 and Figure 2 As shown, when the cutter head 1 in the scratching mechanism continuously scratches the surface of the target core 5, the force of the cutter head 1 is transmitted to the three-dimensional force sensor 3 through the cutter head base between the cutter head 1 and the three-dimensional force sensor 3, and the real-time monitoring of the tangential force and normal force of the cutting surface of the cutter head 1 can also be achieved. According to the tangential force and normal force of the cutting surface of the cutter head, the uniaxial compressive strength and fracture toughness at the continuous scratches of the target core 5 can be calculated as follows:

[0055]

[0056] Where, UCS is the uniaxial compressive strength at the continuous scratch of the target core 5, unit: MPa; F T is the tangential force on the cutting surface of the cutter head 1, unit: N; w is the width of the continuous scratch of the cutter head 1, unit: m; d is the depth of the continuous scratch, unit: m; K IC is the fracture toughness of the target core 5 at the continuous scratch, unit: MPa·m 0.5 ; F Vis the normal force on the cutting surface of the cutter head 1, unit: N. The uniaxial compressive strength of the target core refers to the load that the target core can withstand per unit area when it is uniaxially compressed to failure. The fracture toughness of the target core refers to the ability of the target core to resist the unstable expansion of macro cracks. The tangential force and normal force on the cutting surface of the cutter head are obtained during the continuous scratch test. The uniaxial compressive strength and fracture toughness of the target core at the continuous scratch can be obtained through the above calculation, which can more comprehensively evaluate and understand the material mechanical properties of the target core without the need for additional testing.

[0057] S302: Control the ultrasonic detection mechanism to perform a wave velocity test on the target rock core to calculate a dynamic mechanical parameter value of the target rock core.

[0058] In some embodiments, the ultrasonic detection mechanism includes an ultrasonic pulse transmitter, a transmitting probe, a receiving probe and an oscilloscope; the transmitting probe is connected to the ultrasonic pulse transmitter; the receiving probe is connected to the oscilloscope; the transmitting probe is located on the upper surface of the target core; the receiving probe is located on the lower surface of the target core directly opposite to the transmitting probe; the ultrasonic pulse transmitter is controlled to generate an ultrasonic pulse signal to transmit the ultrasonic pulse signal to the receiving probe through the transmitting probe; according to the oscilloscope, the propagation time of the ultrasonic pulse signal in the target core is obtained; according to the propagation time, the longitudinal wave velocity and the transverse wave velocity of the target core are determined; according to the longitudinal wave velocity and the transverse wave velocity, the dynamic mechanical parameter value of the target core is calculated.

[0059] By using an ultrasonic detection mechanism to obtain the propagation time of the ultrasonic pulse signal in the target core, the longitudinal wave velocity and the transverse wave velocity of the target core can be determined, thereby realizing a rapid test of the dynamic mechanical parameters of the target core.

[0060] Reference Figure 1 and Figure 2As shown, the ultrasonic detection mechanism 10 includes an ultrasonic pulse transmitter, a transmitting probe, a receiving probe and an oscilloscope. The transmitting probe is connected to the ultrasonic pulse transmitter, and the receiving probe is connected to the oscilloscope. The transmitting probe is located on the upper surface of the target core 5, and the receiving probe is located on the lower surface of the target core 5 directly opposite to the transmitting probe. The transmitting probe and the receiving probe are directly opposite and can move with the platform, and the shear wave velocity and longitudinal wave velocity of the target core 5 can be obtained by changing the probe type. The ultrasonic detection mechanism 10 can be used to perform non-destructive wave velocity testing on the target core 5. It can detect the shear wave velocity and longitudinal wave velocity of the target core through the principle of interaction between ultrasonic waves and the internal material of the target core 5. Specifically, the ultrasonic pulse transmitter can be used to generate high-frequency electrical pulses, which are then converted into ultrasonic waves. The ultrasonic pulse transmitter generates electrical signals of specific frequency and waveform through an internal electronic oscillator or signal generator. After power amplification, these signals drive the transmitting probe to generate ultrasonic waves. The transmitting probe can convert the electrical pulse signal into mechanical vibration (ultrasonic wave) and transmit it into the target core 5. The receiving probe can be used to receive the ultrasonic wave reflected from the target core 5 and convert it back into an electrical signal. The oscilloscope can be used to display and analyze the received ultrasonic signal. The oscilloscope can capture and display the waveform of the electrical signal, obtain the propagation time of the ultrasonic pulse signal in the target core by observing the characteristics of the waveform (such as amplitude, frequency, phase, etc.), and then calculate the shear wave velocity and longitudinal wave velocity of the target core 5 according to the following formula:

[0061]

[0062] In the formula, υ p is the longitudinal wave velocity of the target core 5, unit: m / s; υ s is the shear wave velocity of the target core 5, unit: m / s; L is the vertical distance between the upper and lower surfaces of the target core 5 (the vertical distance between the transmitting probe and the receiving probe), unit: m; t p is the propagation time of the longitudinal wave in the target core 5, unit: s; t s is the propagation time of the shear wave in the target core 5, unit: s; t0 is the system zero delay of the ultrasonic detection mechanism, unit: s.

[0063] In some embodiments, according to the longitudinal wave velocity and the shear wave velocity, the formula and formula Calculate the dynamic elastic modulus and dynamic Poisson's ratio of the target core; where E d represents the dynamic elastic modulus of the target core; μ d represents the dynamic Poisson's ratio of the target core; ρ represents the density of the target core; υ p represents the longitudinal wave velocity of the target core; υ srepresents the shear wave velocity of the target core.

[0064] By formula and formula The dynamic elastic modulus and dynamic Poisson's ratio of the target rock core can be obtained, realizing the rapid test of the dynamic mechanical parameters of the target rock core.

[0065] The density of the target core 5 can be obtained. According to the longitudinal wave velocity, transverse wave velocity and density of the target core 5, the dynamic elastic modulus and dynamic Poisson's ratio of the target core can be calculated using the following formula:

[0066]

[0067] In the formula, E d represents the dynamic elastic modulus of the target core; μ d represents the dynamic Poisson's ratio of the target rock core; ρ represents the density of the target rock core, unit: kg / m 3 ;υ p Indicates the longitudinal wave velocity of the target core, unit: m / s; υ s Indicates the shear wave velocity of the target core, unit: m / s. The dynamic elastic modulus of the target core refers to the ratio of the stress to the strain of the target core under the action of dynamic load. The dynamic Poisson's ratio of the target core refers to the ratio of the transverse strain to the longitudinal strain when subjected to dynamic load.

[0068] S303: Determine a dynamic and static mechanical parameter conversion relationship of the target core according to the dynamic mechanical parameter value and the static mechanical parameter value of the target core.

[0069] In some embodiments, based on the dynamic elastic modulus and static elastic modulus of the target core, the dynamic-static elastic modulus conversion relationship of the target core can be determined; the static Poisson's ratio of the target core can be obtained; based on the dynamic Poisson's ratio and static Poisson's ratio of the target core, the dynamic-static Poisson's ratio conversion relationship of the target core can be determined.

[0070] The dynamic / static elastic modulus and dynamic / static Poisson's ratio of the target core can be used to determine the conversion relationship between the dynamic and static elastic modulus and the dynamic and static Poisson's ratio of the target core, which helps to use dynamic parameters to make up for the shortcomings of static parameters in measurement and helps to understand the mechanical properties of the target core more comprehensively.

[0071] The static Poisson's ratio of the target core refers to the ratio of the lateral deformation to the longitudinal deformation of the target core under the action of static force. In some embodiments, the static Poisson's ratio of the target core can be obtained by a device for measuring rock deformation such as a press, a strain gauge, or a displacement meter. For example, the target core can be placed in a press and a compressive force perpendicular to the upper surface of the sample is applied. The lateral extrusion deformation (lateral strain) and longitudinal tensile deformation (axial strain) of the sample are measured using a strain measuring device, and the magnitude of the compressive force, the lateral extrusion deformation, and the longitudinal tensile deformation are recorded to calculate the static Poisson's ratio of the target core. These data will be used for subsequent calculations and analysis. I will not go into details here.

[0072] According to the dynamic elastic modulus, static elastic modulus, dynamic Poisson's ratio and static Poisson's ratio of the target core obtained by the test, the following dynamic and static elastic modulus conversion relationship and dynamic and static Poisson's ratio conversion relationship can be obtained by using the regression model fitting:

[0073] E s =α e E d +β e ;

[0074] μ s =α μ μ d +β μ ;

[0075] In the formula, E d represents the dynamic elastic modulus of the target core; μ d represents the dynamic Poisson's ratio of the target core; E s represents the static elastic modulus of the target core; μ s represents the static Poisson's ratio of the target core; α e , β e , α μ and β μIt is the conversion parameter obtained by fitting the regression model. The regression model can be linear regression, polynomial regression, nonlinear regression, etc. For example, a linear regression model can be used to fit the dynamic and static elastic modulus conversion relationship. Specifically, a linear regression model can be used to establish a linear regression equation based on the test values ​​of the dynamic elastic modulus and static elastic modulus of the target core. The form of the linear regression equation depends on the selected regression model. The regression coefficients in the regression equation can be solved by the least squares method or other optimization algorithms. These coefficients can be calculated specifically by the regression analysis function in statistical software or programming language, which will not be repeated here. After the regression coefficients are calculated, the fitted dynamic and static elastic modulus conversion relationship can be verified using a verification data set to evaluate the accuracy and reliability of the fitted dynamic and static elastic modulus conversion relationship. On the basis of verifying the accuracy of the fitted dynamic and static elastic modulus conversion relationship, the dynamic and static elastic modulus conversion relationship can be applied to the dynamic and static elastic modulus conversion of the target core. By inputting the value of the dynamic elastic modulus, the model can predict the corresponding value of the static elastic modulus.

[0076] Based on the above-mentioned method for determining the conversion relationship of the dynamic and static mechanical parameters of the target rock core, this specification also proposes an embodiment of a device for determining the conversion relationship of the dynamic and static mechanical parameters of the target rock core. Figure 4 As shown, the target core dynamic and static mechanical parameter conversion relationship determination device 400 may specifically include the following modules:

[0077] The acquisition module 401 may be used to control the scratching mechanism to continuously scratch the target core to obtain the static mechanical parameter value of the target core.

[0078] The calculation module 402 may be used to control the ultrasonic detection mechanism to perform a wave velocity test on the target rock core to calculate the dynamic mechanical parameter value of the target rock core.

[0079] The determination module 403 may be used to determine the dynamic and static mechanical parameter conversion relationship of the target core according to the dynamic mechanical parameter value and the static mechanical parameter value of the target core.

[0080] In some embodiments, the acquisition module 401 can be specifically used to control the rotating wheel to adjust the platform to a preset height; control the cutter head baffle to fix the cutter head on the cutter head base at a preset angle; and control the second motor to enable the cutter head to continuously scratch the target core on the platform.

[0081] In some embodiments, the acquisition module 401 can also be used to control the rotating wheel to adjust the platform to a preset height; control the cutter head baffle to fix the cutter head on the cutter head base at a preset angle; and control the second motor to enable the cutter head to continuously scratch the target core on the platform.

[0082] In some embodiments, the acquisition module 401 may be specifically used to acquire the roughness of the continuously scratched surface of the target core according to the 3D scanning sensor; and adjust the scratching mechanism according to the roughness to continuously scratch the target core.

[0083] In some embodiments, the acquisition module 401 can also be used to obtain the stress-strain curve of the continuous scratches on the target core according to the three-dimensional force sensor; and determine the static elastic modulus of the target core according to the stress-strain curve of the continuous scratches on the target core.

[0084] In some embodiments, the above-mentioned calculation module 402 can be specifically used to control the ultrasonic pulse transmitter to generate an ultrasonic pulse signal, so as to transmit the ultrasonic pulse signal to the receiving probe through the transmitting probe; according to the oscilloscope, the propagation time of the ultrasonic pulse signal in the target core is obtained; according to the propagation time, the longitudinal wave velocity and the transverse wave velocity of the target core are determined; according to the longitudinal wave velocity and the transverse wave velocity, the dynamic mechanical parameter value of the target core is calculated.

[0085] In some embodiments, the calculation module 402 can also be used to calculate the velocity of the longitudinal wave and the velocity of the transverse wave using the formula: and formula Calculate the dynamic elastic modulus and dynamic Poisson's ratio of the target core; where E d represents the dynamic elastic modulus of the target core; μ d represents the dynamic Poisson's ratio of the target core; ρ represents the density of the target core; υ p represents the longitudinal wave velocity of the target core; υ s represents the shear wave velocity of the target core.

[0086] In some embodiments, the above-mentioned determination module 403 can specifically determine the dynamic-static elastic modulus conversion relationship of the target core according to the dynamic elastic modulus and static elastic modulus of the target core; obtain the static Poisson's ratio of the target core; and determine the dynamic-static Poisson's ratio conversion relationship of the target core according to the dynamic Poisson's ratio and static Poisson's ratio of the target core.

[0087] As can be seen from the above, based on the device for determining the conversion relationship of dynamic and static mechanical parameters of the target core provided in the embodiment of this specification, the scratching mechanism can be controlled to perform continuous scratches on the target core to obtain the static mechanical parameter values ​​of the target core; the ultrasonic detection mechanism can be controlled to perform wave velocity test on the target core to calculate the dynamic mechanical parameter values ​​of the target core; and the dynamic and static mechanical parameter conversion relationship of the target core can be determined according to the dynamic mechanical parameter values ​​and static mechanical parameter values ​​of the target core. Compared with the existing methods, the dynamic and static mechanical parameter values ​​of the target core can be obtained simply and quickly through the scratching mechanism and the ultrasonic detection mechanism, and then the dynamic and static mechanical parameter conversion relationship of the target core can be determined. In addition, controlling the scratching mechanism to apply continuous scratches to the target core will not damage the structure of the target core, and the target core can be used for repeated testing of dynamic and static mechanical parameters or other types of testing.

[0088] It should be noted that the units, devices or modules described in the above embodiments can be implemented by computer chips or entities, or by products with certain functions. For the convenience of description, the above devices are described separately by functions divided into various modules. Of course, when implementing this specification, the functions of each module can be implemented in the same or more software and / or hardware, or the modules that implement the same function can be implemented by a combination of multiple sub-modules or sub-units. The device embodiments described above are only schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0089] In order to complete the above instructions more accurately, refer to Figure 1 As shown, an embodiment of the present specification provides a specific dynamic and static mechanical parameter testing device, which includes a platform, a fixing mechanism, a scratching mechanism, an ultrasonic detection mechanism and a controller; the target core is fixed on the platform by the fixing mechanism; the controller is used to execute the above-mentioned method for determining the dynamic and static mechanical parameter conversion relationship of the target core.

[0090] The controller can be specifically used to control the scratching mechanism to continuously scratch the target rock core to obtain the static mechanical parameter value of the target rock core; control the ultrasonic detection mechanism to perform wave velocity test on the target rock core to calculate the dynamic mechanical parameter value of the target rock core; and determine the dynamic and static mechanical parameter conversion relationship of the target rock core according to the dynamic mechanical parameter value and static mechanical parameter value of the target rock core.

[0091] Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0092] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0093] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0094] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0095] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for determining the conversion relationship between dynamic and static mechanical parameters of a target core, characterized in that: The target rock core is placed in a dynamic and static mechanical parameter testing device, which includes a platform, a fixing mechanism, a scribing mechanism and an ultrasonic detection mechanism; the target rock core is fixed on the platform by the fixing mechanism; The method for determining the conversion relationship of dynamic and static mechanical parameters of the target core includes: Controlling the scratching mechanism to continuously scratch the target rock core to obtain static mechanical parameter values ​​of the target rock core; Controlling the ultrasonic detection mechanism to perform a wave velocity test on the target rock core to calculate a dynamic mechanical parameter value of the target rock core; According to the dynamic mechanical parameter value and the static mechanical parameter value of the target rock core, the dynamic and static mechanical parameter conversion relationship of the target rock core is determined.

2. The method according to claim 1, characterized in that: The dynamic and static mechanical parameter testing device further includes a grinding mechanism; the grinding mechanism includes a grinding wheel and a first motor; the first motor is used to drive the grinding wheel; The method further comprises: The first motor is controlled to drive a grinding wheel to grind the target rock core, wherein the grinding is used to make the roughness of the target rock core meet a preset roughness threshold.

3. The method according to claim 1, characterized in that: The scribing mechanism comprises a cutter head base, a cutter head, a cutter head baffle, a second motor and a rotating wheel; the second motor is used to drive the platform to move at a preset speed; The step of controlling the scratching mechanism to continuously scratch the target core includes: Controlling the rotating wheel to adjust the platform to a preset height; Controlling the cutter head baffle to fix the cutter head on the cutter head base at a preset angle; The second motor is controlled to enable the cutter head to continuously scratch the target core on the platform.

4. The method according to claim 1, characterized in that: The dynamic and static mechanical parameters testing device also includes a 3D scanning sensor; The method further comprises: According to the 3D scanning sensor, the roughness of the continuous scratch surface of the target core is obtained; According to the roughness, the scoring mechanism is adjusted to continuously score the target core.

5. The method according to claim 1, characterized in that: The dynamic and static mechanical parameter testing device also includes a three-dimensional force sensor; the three-dimensional force sensor is connected to the cutter head base of the scribing mechanism; The step of obtaining the static mechanical parameter value of the target core comprises: According to the three-dimensional force sensor, a stress-strain curve of continuous scratches on the target core is obtained; The static elastic modulus of the target core is determined according to the stress-strain curve of the continuous scratches of the target core.

6. The method according to claim 1, characterized in that: The ultrasonic detection mechanism comprises an ultrasonic pulse transmitter, a transmitting probe, a receiving probe and an oscilloscope; the transmitting probe is connected to the ultrasonic pulse transmitter; the receiving probe is connected to the oscilloscope; the transmitting probe is located on the upper surface of the target rock core; the receiving probe is located on the lower surface of the target rock core directly facing the transmitting probe; The controlling the ultrasonic detection mechanism to perform a wave velocity test on the target rock core to calculate a dynamic mechanical parameter value of the target rock core includes: Controlling the ultrasonic pulse transmitter to generate an ultrasonic pulse signal, so as to transmit the ultrasonic pulse signal to a receiving probe through a transmitting probe; According to the oscilloscope, obtaining the propagation time of the ultrasonic pulse signal in the target core; Determining the longitudinal wave velocity and the shear wave velocity of the target core according to the propagation time; The dynamic mechanical parameter values ​​of the target core are calculated according to the longitudinal wave velocity and the shear wave velocity.

7. The method according to claim 6, characterized in that: The step of calculating the dynamic mechanical parameters of the target core according to the longitudinal wave velocity and the shear wave velocity comprises: According to the longitudinal wave velocity and the shear wave velocity, the dynamic elastic modulus and the dynamic Poisson's ratio of the target core are calculated using the following formula: In the formula, E d represents the dynamic elastic modulus of the target core; μ d represents the dynamic Poisson's ratio of the target core; ρ represents the density of the target core; υ p represents the longitudinal wave velocity of the target core; υ s represents the shear wave velocity of the target core.

8. The method according to claim 1, characterized in that: Determining the dynamic and static mechanical parameter conversion relationship of the target core according to the dynamic mechanical parameter value and the static mechanical parameter value of the target core includes: Determining a dynamic-static elastic modulus conversion relationship of the target rock core according to the dynamic elastic modulus and the static elastic modulus of the target rock core; Obtain the static Poisson's ratio of the target core; According to the dynamic Poisson's ratio and the static Poisson's ratio of the target rock core, a conversion relationship between the dynamic and static Poisson's ratios of the target rock core is determined.

9. A device for determining the conversion relationship between dynamic and static mechanical parameters of a target rock core, characterized in that: The device comprises: An acquisition module, used for controlling a scratching mechanism to continuously scratch the target rock core to obtain a static mechanical parameter value of the target rock core; A calculation module, used for controlling the ultrasonic detection mechanism to perform a wave velocity test on the target rock core to calculate a dynamic mechanical parameter value of the target rock core; The determination module is used to determine the dynamic and static mechanical parameter conversion relationship of the target rock core according to the dynamic mechanical parameter value and the static mechanical parameter value of the target rock core.

10. A dynamic and static mechanical parameter testing device, characterized in that: The dynamic and static mechanical parameter testing device includes a platform, a fixing mechanism, a scratching mechanism, an ultrasonic detection mechanism and a controller; the target core is fixed on the platform by the fixing mechanism; and the controller is used to execute the method described in any one of claims 1-8.

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