Device and method for quantitatively evaluating cementing capacity of well cementation second interface

Abstract

The invention provides a device and method for quantitatively evaluating the cementing capacity of a well cementation second interface, and the device comprises a plurality of rock core holders which are internally provided with rock cores and cement simulation layers and are used for holding the rock cores and the cement simulation layers; the formation parameter simulation systems are connected with the rock core holders and control formation parameters of the rock core holders; and the acoustic detection module is arranged on the rock core holder and comprises a sound source signal transmitter and a sound wave velocity measurement system. Wherein the rock core and the cement simulation layer are arranged in the rock core clamping device, experimental stratum parameters are set through the stratum parameter simulation device to enter a maintenance experiment, and after the maintenance period is reached, detection data are obtained through the acoustic detection system, and the sealing capacity of the second interface is calculated.

Description

Technical Field

[0001] The invention relates to a device and a method for quantitatively evaluating the bonding ability of a second interface of cementing, and belongs to the field of petroleum exploration. Background Art

[0002] In cementing technology, the bonding interface between the cement sheath and the wellbore is defined as the second cementing interface. Affected by various geological conditions such as complex lithology, high-pressure oil, gas and water layers, large-scale hydraulic fracturing, and drilling fluid mud cake, the sealing of the second cementing interface is more difficult and has a greater risk of failure. As the exploration and development process moves deeper into deep-earth and unconventional oil and gas resources, higher requirements are placed on the evaluation method and testing technology of the second cementing interface.

[0003] At present, a variety of interface test models and methods have been established for the research on experimental evaluation methods of cementing second interface, including interface bonding strength tester, cement ring interface crossflow tester, interface sealing ability test device that can simulate wellbore cyclic stress and fracturing, interface test device that can simulate perforation, interface strain detection device, cementing quality calibration model well group that can simulate 4 cement bonding states, etc. Based on the above devices, the macroscopic performance of the second interface shear strength, stress strain and overall sealing ability under conditions of high temperature and high pressure, oil-water gas crossflow, wellbore alternating load, fracturing and perforation can be analyzed, and remarkable results have been achieved.

[0004] However, current research mainly focuses on the evaluation and analysis of the macroscopic mechanical properties of the interface. The lack of precise quantitative testing makes it difficult to accurately guide the development of durable sealing cement slurry systems and the optimization of cementing processes. There is an urgent need to develop a more accurate quantitative evaluation device for the bonding ability of the second cementing interface. Summary of the invention

[0005] In view of the above-mentioned technical problems existing in the prior art, the present invention proposes a device and method for quantitatively evaluating the bonding ability of the second interface of cementing. The transmission acoustic wave method is used to accurately measure the evolution process of the sealing ability of the second interface of cementing, providing reference and guidance for the development of cement slurry system and optimization of cementing process.

[0006] The present invention proposes a device for quantitatively evaluating the bonding ability of the second interface of cementing, comprising:

[0007] A plurality of core holders, in which cores and cement simulation layers are arranged, are used to support the cores and cement simulation layers;

[0008] A plurality of formation parameter simulation systems connected to the core holder and controlling the formation parameters of the core holder; and

[0009] The acoustic detection module is arranged on the core holder shown, and comprises a sound source signal transmitter and a sound wave velocity measurement system.

[0010] The core and cement simulation layer are arranged in the core clamp shown, and the formation parameters of the experiment are set by the formation parameter simulation device to carry out the maintenance experiment. After reaching the maintenance period, the detection data is obtained by the acoustic detection system and the second interface sealing capacity is calculated.

[0011] A further improvement of the present invention is that the formation parameter simulation system comprises a formation fluid injection module, and the formation fluid injection module is connected to the core holder and injects fluid into the core holder.

[0012] A further improvement of the present invention is that the formation parameter simulation system further comprises a gas injection module, the gas injection module is connected to the core holder and injects gas into the core holder.

[0013] A further improvement of the present invention is that the formation parameter simulation system further includes a formation temperature control module, and the formation temperature control module controls the temperature in the core holder.

[0014] A further improvement of the present invention is that the formation fluid injection module comprises a liquid source, the liquid source is connected to the core holder via a plurality of pipelines, and a liquid injection pump is arranged on the pipelines;

[0015] The gas injection module comprises a gas source, the gas source is connected to the core holder through a plurality of pipelines, and a gas flow controller is arranged on the pipelines.

[0016] A further improvement of the present invention is that the core holder comprises a cylinder, a first end cap and a second end cap are provided at both ends of the cylinder, the first end cap is provided with the first core plug, the first core plug is provided with a sound source signal transmitter, the second end cap is provided with the second core plug, and the second lithology is provided with the sound wave velocity measurement system;

[0017] A first flange is arranged on the outer side of the first end cap, a second flange is arranged on the outer side of the second end cap, and an adjusting nut is arranged on the second flange;

[0018] The cement simulation layer is arranged on the inner side of the first end cap, and the rock core is arranged on the inner side of the second end cap.

[0019] A further improvement of the present invention is that a rubber tube is arranged on the inner side of the cylinder body, the cement simulation layer and the rock core are arranged inside the rubber tube; and a rubber sleeve protective sleeve is arranged outside the rubber tube.

[0020] A further improvement of the present invention is that an annular cavity is formed between the rubber sleeve protective sleeve and the cylinder body, and a pressurizing port connected to the cavity is provided on the cylinder body, and the pressurizing port is connected to a confining pressure loading pump.

[0021] A further improvement of the present invention is that a plurality of second interface detection measuring points are arranged in the middle of the cylinder, and the second interface detection measuring points are aligned with the connection surface between the core and the cement simulation layer.

[0022] A further improvement of the present invention is that both the first flange and the second flange are connected to the cylinder through pressure-bearing screws.

[0023] According to another aspect of the present invention, a method for evaluating the bonding ability of the second interface of cementing is also highlighted by using the device for quantitatively evaluating the bonding ability of the second interface of cementing, comprising:

[0024] Obtain cement slurry parameters, target lithology parameters and formation parameters for cementing construction;

[0025] The device for quantitatively evaluating the bonding ability of the second interface of cementing is used, and experimental conditions are set according to cementing slurry parameters, target lithology parameters and formation parameters for cementing construction to conduct maintenance experiments;

[0026] After reaching the curing age, the acoustic detection module is turned on to test the attenuation of the sound amplitude when the sound wave passes through the sample interface, analyze the waveform changes, and obtain the macroscopic acoustic response data of the sample interface; by calculating the proportion of the first wave envelope value of the sound wave at different curing ages to the total sound amplitude signal, the quantitative evaluation of the bonding capacity of the second interface of cementing is achieved.

[0027] A further improvement of the present invention is to obtain the interface transmission sound amplitude, the total sound wave energy emitted by the instrument, and the measured total reflected sound wave energy ratio, calculate the transmission first wave signal amplitude ratio by the following formula, and quantitatively evaluate the sealing ability of the second interface of cementing at different curing ages.

[0028]

[0029] Where, u is the amplitude ratio of the transmitted first wave signal, %; A E is the amplitude of the interface transmitted sound, mV; A EITC is the total energy of sound waves emitted by the instrument, mV; U is the proportion of the total energy of reflected sound waves measured, %.

[0030] Compared with the prior art, the advantages of the present invention are:

[0031] The device and method for quantitatively evaluating the bonding ability of the second interface of cementing described in the present invention adopt the transmission acoustic wave method to accurately measure the evolution process of the sealing ability of the second interface of cementing, providing reference and guidance for the research and development of cement slurry systems and the optimization of cementing processes. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, in which:

[0033] Figure 1It is a schematic structural diagram of a device for quantitatively evaluating the bonding ability of the second interface of cementing according to one embodiment of the present invention;

[0034] Figure 2 The figure shows a schematic structural diagram of a core holder according to an embodiment of the present invention;

[0035] Figure 3 It is a schematic diagram showing the acoustic wave response of a well-bonded interface according to an embodiment of the present invention;

[0036] Figure 4 It is a schematic diagram showing the acoustic wave response of a poorly bonded interface according to an embodiment of the present invention;

[0037] Figure 5 The table shows a comparison of the first wave acoustic amplitude and equivalent permeability of the shale-clean slurry interface at different curing ages according to an embodiment of the present invention;

[0038] Figure 6 Shown is a schematic diagram of a curve showing a change in the first wave signal amplitude ratio with the curing age according to an embodiment of the present invention.

[0039] The drawings are not drawn to scale.

[0040] The meanings of the reference numerals in the accompanying drawings are as follows:

[0041] 100. Core holder; 200. Acoustic detection module; 300. Formation fluid injection module; 400. Gas injection module; 500. Confining pressure loading pump; 600. Computer acquisition system; 1. Pressure screw; 2. First flange; 3. Sealing ring; 4. First core plug; 5. Sealing ring; 6. First head; 8. Cement simulation layer; 9. Rubber sleeve protective sleeve; 10. Measuring point for second interface detection; 11. Core; 12. Cylinder; 13. Second head; 14. Second flange; 15. Adjusting nut; 16. Second core plug; 17. Rubber cylinder. DETAILED DESCRIPTION

[0042] In order to make the technical solutions and advantages of the present invention more clearly understood, the exemplary embodiments of the present invention are further described in detail below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than an exhaustive list of all the embodiments. In addition, the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

[0043] When oil and gas wells are being mined underground, they often encounter situations where the underground fluid pressure and flow rate increase due to some reason. When encountering the above situation, it is necessary to close the fluid channel in time to avoid causing major safety accidents.

[0044] Downhole safety valve is a downhole tool that prevents blowouts and ensures production safety. There are many ways to classify downhole safety valves. According to the driving method, they can be divided into hydraulic control drive, electric control magnetic coupling drive, etc. However, as the depth of the traditional hydraulic control safety valve gradually increases, a greater hydraulic pressure is required to drive the valve plate, which puts a greater test on the material of the control pipeline and the internal seal of the safety valve. The downhole safety valve driven by magnetic coupling can make up for this defect.

[0045] The magnetic coupling drive structure can realize linear reciprocating motion. It is a transmission machine without dynamic seal and completely leakage-free. It has the characteristics of reliable high-pressure sealing, no leakage, long service life, low vibration, low noise, etc. It has broad application prospects in the fields of petroleum, chemical industry, food, pharmaceuticals, etc. Compared with mechanical transmission, when the magnetic drive transmits force or torque, the driven shaft is not connected to the outside world, the dynamic sealing device is cancelled, and the variable seal is changed to a static seal, which fundamentally eliminates the leakage of the shaft seal. Therefore, it is widely used in environments with special requirements for sealing.

[0046] In order to solve the above problems, the present invention proposes the axially magnetized annular permanent magnet coupling driven magnetic force measuring device, which has reasonable design, high measurement accuracy and is safe and reliable.

[0047] In accordance with Figure 1 In the illustrated embodiment, the device for quantitatively evaluating the bonding ability of the second interface of cementing comprises: a plurality of core holders 100, in which cores and cement simulation layers 8 are arranged, for supporting the cores and cement simulation layers 8;

[0048] A plurality of formation parameter simulation devices connected to the core holder 100 and controlling the formation parameters of the core holder 100, such as temperature, confining pressure, fluid pressure, etc.;

[0049] The acoustic detection module 200 is disposed on the core holder 100, and includes a sound source signal transmitter and a sound wave velocity measurement system.

[0050] The core and cement simulation layer 8 are arranged in the core holder 100 shown, and the formation parameters of the experiment are set by the formation parameter simulation device to carry out the maintenance experiment. After reaching the maintenance period, the detection data is obtained by the acoustic detection system and the second interface sealing capacity is calculated.

[0051] According to the device for quantitatively evaluating the bonding ability of the second interface of cementing described in this embodiment, the core holder 100 is set to simulate the second interface of cementing between cement and the well wall, wherein the core can be an artificial core or a natural core. The ground parameter simulation device can simulate the formation parameters to ensure that the test conditions are the same as those of the real formation. The acoustic detection module 200 uses the transmission sound wave method to accurately measure the evolution process of the sealing ability of the second interface of cementing, providing reference and guidance for the development of cement slurry system and the optimization of cementing process.

[0052] In one embodiment, the formation parameter simulation device includes a formation fluid injection module 300, which is connected to the core holder 100 and injects fluid into the core holder 100 to provide a displacement medium for the experiment.

[0053] Preferably, the formation fluid injection module 300 includes a liquid source, and the liquid source is connected to the core clamp 100 through a plurality of pipelines, and a liquid injection pump is arranged on the pipeline. In the present embodiment, the liquid injection pump adopts a HAS-200HSB type double-cylinder constant speed and constant pressure pump, which is used for quantitative injection of the displacement medium and provides a power source for the test. A double-cylinder pump with continuous pulse-free circulation and constant speed and constant pressure operation is selected. The liquid injection pump has accurate metering and high precision, a maximum working pressure of 40MPa, a flow rate of 0.001-25mL / min, pressure protection and upper and lower limit protection of the position, a pump head material of 316L, and has suction, discharge, and pre-pressurization functions, and a reversing valve adopts an electromagnetically controlled pneumatic valve, a small pump chamber volume, and a short static time. The pump is equipped with a communication port and can be operated by a computer or manually.

[0054] In one embodiment, the formation parameter simulation system further includes a gas injection module 400 , which is connected to the core holder 100 and injects gas into the core holder 100 .

[0055] Preferably, the gas injection module 400 comprises a gas source, the gas source is connected to the core holder 100 via a plurality of pipelines, and a gas flow controller is disposed on the pipelines.

[0056] The pipeline is also provided with a pressure regulating valve, an air inlet valve and a one-way valve for adjusting pressure, flow rate, etc., and a pressure gauge is also provided on the pipeline for displaying the pressure in the pipeline.

[0057] In one embodiment, the formation parameter simulation system further includes a formation temperature control module, and the formation temperature control module controls the temperature inside the core holder 100 .

[0058] The main device of the formation temperature control module is a high-precision constant temperature box: it can simulate the formation temperature conditions through an air bath, with a maximum working temperature of 150°C and a temperature control accuracy of ±1°C. The instrument has PID adjustment and can perform programmed temperature rise. At the same time, it can automatically coordinate changes in the temperature program according to pressure rise and fall.

[0059] In one embodiment, the core clamp 100 includes a cylinder 12, and a first head 6 and a second head 13 are provided at both ends of the cylinder 12. The first head 6 is provided with the first core plug 4, and the first core plug 4 is provided with a sound source signal transmitter. The second head 13 is provided with the second core plug 16, and the second rock type is provided with the sound wave velocity measurement system.

[0060] A first flange 2 is provided on the outer side of the first end cap 6 , and the cylinder 12 is connected via the first flange 2 ; a second flange 14 is provided on the outer side of the second end cap 13 , and the cylinder 12 is connected via the second flange 14 .

[0061] The cement simulation layer 8 is disposed inside the first end cap 6 , and the rock core is disposed inside the second end cap 13 .

[0062] Preferably, the main body of the first core plug is a cylindrical structure, one end of which extends out of the first flange 2 and is connected to the acoustic wave generator or the formation fluid injection module 300. The second core plug has a similar structure to the first core plug. An adjusting nut 15 is provided on the second flange 14. The adjusting nut 15 is a circular ring structure, connected to the second flange 14 on the outside and connected to the second core plug on the inside. The depth of the second core plug can be adjusted by rotating the adjusting nut 15.

[0063] In one embodiment, a rubber tube is disposed inside the cylinder body 12, and the cement simulation layer 8 and the rock core are disposed inside the rubber tube; a rubber sleeve protective sleeve 9 is disposed outside the rubber tube.

[0064] The rubber tube is elastic and can provide pressure for the internal cement simulation layer 8 and the rock core.

[0065] In one embodiment, an annular cavity is formed between the rubber tube protective sleeve and the cylinder 12, and a pressurizing port connected to the cavity is provided on the cylinder 12, and the pressurizing port is connected to the confining pressure loading pump 500. The confining pressure loading pump 500 loads pressure into the cavity through the pressurizing port, thereby pushing the rubber tube to apply pressure inward.

[0066] In one embodiment, a plurality of second interface detection measuring points 10 are disposed in the middle of the cylinder 12 , and the second interface detection measuring points 10 are aligned with the connection surface between the core and the cement simulation layer 8 .

[0067] Preferably, the first flange 2 and the second flange 14 are both connected to the cylinder 12 via pressure-bearing screws 1 .

[0068] In one embodiment, the main devices of the acoustic test module are a sound source signal transmitter and a sound wave velocity measurement system: the sound source signal transmitter vibrates the excitation chip, emits sound waves that propagate in the test material, and then is received by a receiver, converting the sound energy into a weak electrical signal and sending it to the receiving system, where the waveform is displayed on the screen after the signal is amplified.

[0069] The amplitude and first arrival time (t) are read from the waveform. From the known distance (L) of the test material, the longitudinal wave velocity (Vp) of the ultrasonic wave propagating in the test material can be calculated, that is, Vp = L / t.

[0070] The acoustic wave velocity measurement system uses the acoustic pulse transmission method to measure the propagation time of longitudinal or transverse waves along the length of the sample, and calculates the longitudinal and transverse wave velocities of the sample and the acoustic wave attenuation amplitude. The "filtered" waveform is obtained by using waveform filtering, waveform screening degree, bandpass frequency selection (low / high), suppression band (dB) and conversion bandwidth (kHz) on the original data, which is very convenient for processing the "original" waveform. The ultrasonic velocity system can simulate the on-site shear conditions of the triaxial chamber and the true triaxial chamber, and can also be used for on-site testing.

[0071] According to another aspect of the present invention, a method for evaluating the bonding ability of the second interface of cementing is provided by using the device for quantitatively evaluating the bonding ability of the second interface of cementing according to the above embodiment, comprising the following steps:

[0072] Obtain cement slurry parameters, target lithology parameters and formation parameters for cementing construction;

[0073] The device for quantitatively evaluating the bonding ability of the second interface of cementing is used, and experimental conditions are set according to cementing slurry parameters, target lithology parameters and formation parameters for cementing construction to conduct maintenance experiments;

[0074] After reaching the curing age, the acoustic detection module 200 is turned on to test the attenuation of the sound amplitude when the sound wave passes through the sample interface, analyze the waveform change, and obtain the macroscopic acoustic response data of the sample interface; by calculating the ratio of the first wave envelope value of the sound wave at different curing ages to the total sound amplitude signal, the quantitative evaluation of the bonding ability of the second interface of the cementing is achieved.

[0075] Preferably, the interface transmission sound amplitude, the total sound wave energy emitted by the instrument, and the measured total reflected sound wave energy ratio are obtained, and the amplitude ratio of the transmitted first wave signal is calculated by the following formula to quantitatively evaluate the sealing ability of the second interface of cementing at different curing ages.

[0076]

[0077] Where, u is the amplitude ratio of the transmitted first wave signal, %; A E is the amplitude of the interface transmitted sound, mV; A EITCis the total energy of sound waves emitted by the instrument, mV; U is the proportion of the total energy of reflected sound waves measured, %.

[0078] In a specific embodiment, the method comprises the following steps:

[0079] Obtain cement slurry parameters (liquid silicon system, foam system, etc.) for cementing construction, including: cement slurry density, key admixtures, cement paste wave velocity, cement paste compressive strength, etc.

[0080] Obtain target lithology parameters (shale, sandstone, mudstone, etc.), including mineral composition, cementation strength, permeability and porosity, and prepare natural or artificial cores.

[0081] Obtain formation parameters, including: formation ambient temperature, high-pressure water layer pressure, formation water mineralization, in situ stress, etc.

[0082] The device for quantitatively evaluating the bonding ability of the second interface of cementing is assembled into a sample dynamic curing mold, the water inlet and outlet of the core clamp 100 are opened, the water inlet pressure is set according to the actual working conditions, and high-pressure water is introduced to prepare the "cement stone-core" interface sample under dynamic curing conditions. The curing pressure is 21MPa, the curing temperature is the target rock formation ambient temperature, and the curing age is 1 to 30 days. The curing age can be adjusted according to actual research needs.

[0083] After reaching the curing age, the water inlet and outlet are closed, the acoustic wave detection system is turned on, the acoustic amplitude attenuation of the acoustic wave passing through the sample interface is tested, the waveform changes are analyzed, and the macroscopic acoustic response data of the sample interface is obtained. The better the interface bonding performance, the smaller the interface longitudinal wave impedance, the smaller the energy loss when the longitudinal wave penetrates the interface, and the more complete the waveform received by the longitudinal wave acoustic receiver. When the interface bonding is poor, multiple groups of peaks appear in the longitudinal wave acoustic waveform, and the peak value is not obvious. As the wave time increases, the amplitude of the acoustic wave signal is relatively average. It can be seen that the first wave acoustic amplitude envelope value is closely related to the interface bonding ability. The larger the proportion of the first wave acoustic amplitude envelope value, the more obvious the peak, and the stronger the interface bonding ability; the smaller the proportion of the first wave acoustic amplitude envelope value, the multiple peaks appear in the longitudinal wave acoustic waveform, indicating that the interface begins to deteriorate, the permeability gradually increases, and the sealing ability weakens. Therefore, the quantitative evaluation of the bonding ability of the second interface of cementing can be achieved by calculating the proportion of the first wave envelope value of the acoustic wave at different curing ages to the total acoustic amplitude signal.

[0084] In one embodiment, outcrop shale and cement slurry (Jiahua G-grade cement + 44% water + 0.3% defoamer, density 1.88 g / cm 3 ) system to prepare 14 groups of interface test specimens, with a curing age of 1 to 14 days. The experiment showed that after the fourth day, the "shale-neat slurry" interface began to seep water and the interface sealing ability began to deteriorate.

[0085] After the curing is completed, based on the above method steps of the invention content, the acoustic wave characteristic analysis and the interface sealing ability quantitative analysis are performed on the samples.

[0086] By analyzing the acoustic wave response characteristics of the interface between the clean slurry system and shale at different curing ages, the first acoustic wave duration of the clean slurry-shale sample can be determined. The typical response curve is as follows: Figure 3 and Figure 4 shown. Figure 3 is the acoustic wave response curve when the bonding interface is good. Figure 4 This is the acoustic wave response curve after the bonding interface deteriorates.

[0087] As can be seen from the figure, the interface of the net slurry and shale with good cementation presents a single peak feature, and the tail wave amplitude decays rapidly, and the first wave of sound wave arrives at 56μs; when the cementation interface is poor, the sound wave response shows multiple peaks, and the signals are superimposed. In the later stage of the sound wave response, the signal amplitude does not show obvious attenuation, and the first wave of sound wave arrives at 58μs. However, no matter how the waveform changes, the duration of the first wave of sound wave is basically the same. A comprehensive analysis of the acoustic wave signals of the interfaces at different curing ages determined that the duration of the first wave of the longitudinal wave is between 56 and 250μs, and the total energy of the sound wave signal is 33700mv. Based on this, the proportion of the first wave of longitudinal wave amplitude at different ages to the total sound wave energy can be calculated based on the formula. The calculation results are shown in Figure 5 .

[0088] Depend on Figure 5 The calculation results can be used to draw a curve of the first wave signal amplitude ratio changing with the curing age, such as Figure 6 shown.

[0089] As can be seen from the figure, the interface began to seep water on the 4th day, and the corresponding first wave signal amplitude accounted for 54.00593%. As the maintenance age increases, the first wave signal amplitude ratio continues to decrease, and by the 14th day, it accounted for 36.35015%. It can be seen that for the geological conditions corresponding to the implementation group, the threshold value of the first wave signal amplitude ratio corresponding to the sealing ability of the "shale-clean slurry" interface is 54.00593%. In the later evaluation process, the acoustic variable density logging sound amplitude signal ratio is converted into the first wave signal amplitude ratio using formula 3, which can realize the quantitative evaluation of the "shale-clean slurry" interface cementation ability and predict the change of the interface sealing ability.

[0090] It should be understood that the embodiments disclosed in the present invention are not limited to the specific structures, processing steps or materials disclosed herein, but should be extended to equivalent substitutions of these features understood by ordinary technicians in the relevant field. It should also be understood that the terms used herein are only used for the purpose of describing specific embodiments and are not meant to be limiting.

[0091] In the description of the present invention, unless otherwise specified, "plurality" means two or more than two; the orientations or positional relationships indicated by the terms "upper", "lower", "left", "right", "inner", "outer", "front end", "rear end", "head", "tail", etc. are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", "third", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0092] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0093] Certain terms are used throughout this specification to refer to specific system components. As will be appreciated by those skilled in the art, different names may be used to refer to the same component, and thus this specification is not intended to distinguish between components that differ only in name and not in function. References to "one embodiment" or "an embodiment" in the specification mean that a particular feature, structure, or characteristic described in conjunction with the embodiment is included in at least one embodiment of the invention. Therefore, the phrases "one embodiment" or "an embodiment" appearing in various places throughout the specification do not necessarily all refer to the same embodiment.

[0094] The embodiments of the present invention are given for the purpose of illustration and description, and are not intended to be exhaustive or to limit the invention to the disclosed forms. Many modifications and variations will be apparent to those of ordinary skill in the art. The embodiments are selected and described in order to better illustrate the principles and practical applications of the present invention and to enable those of ordinary skill in the art to understand the present invention and thereby design various embodiments with various modifications suitable for specific uses.

[0095] Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they are aware of the basic creative concepts. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and / or modifications that fall within the scope of the present invention, and changes and / or modifications made according to the embodiments of the present invention should be included within the scope of protection of the present invention.

Claims

1. A device for quantitatively evaluating the bonding ability of the second interface of cementing, characterized in that: include: A plurality of core holders (100), wherein the core and the cement simulation layer (8) are arranged inside the core holders, and used for holding the core and the cement simulation layer (8); A plurality of formation parameter simulation systems connected to the core holder (100) and controlling the formation parameters of the core holder (100); as well as The acoustic detection module (200) is arranged on the core holder (100) shown, and comprises a sound source signal transmitter and a sound wave velocity measurement system. The core and cement simulation layer (8) are arranged in the core holder (100) shown, and the formation parameters of the experiment are set by the formation parameter simulation device to carry out the maintenance experiment. After reaching the maintenance period, the acoustic detection system is used to obtain the detection data and calculate the second interface sealing capacity.

2. The device for quantitatively evaluating the bonding ability of the second interface of cementing according to claim 1, characterized in that: The formation parameter simulation system comprises a formation fluid injection module (300), wherein the formation fluid injection module (300) is connected to the core holder (100) and injects fluid into the core holder (100).

3. The device for quantitatively evaluating the bonding ability of the second interface of cementing according to claim 2, characterized in that: The formation parameter simulation system further comprises a gas injection module (400), wherein the gas injection module (400) is connected to the core holder (100) and injects gas into the core holder (100).

4. The device for quantitatively evaluating the bonding ability of the second interface of cementing according to claim 3 is characterized in that: The formation parameter simulation system further comprises a formation temperature control module, and the formation temperature control module controls the temperature inside the core holder (100).

5. The device for quantitatively evaluating the bonding ability of the second interface of cementing according to claim 2 or 3, characterized in that: The formation fluid injection module (300) comprises a liquid source, the liquid source is connected to the core holder (100) via a plurality of pipelines, and a liquid injection pump is arranged on the pipelines; The gas injection module (400) comprises a gas source, the gas source is connected to the core holder (100) via a plurality of pipelines, and a gas flow controller is arranged on the pipelines.

6. The device for quantitatively evaluating the bonding ability of the second interface of cementing according to any one of claims 1 to 5, characterized in that: The core holder (100) comprises a cylinder (12), a first end cap (6) and a second end cap (13) are arranged at both ends of the cylinder (12), the first end cap (6) is provided with the first core plug (4), the first core plug (4) is provided with a sound source signal transmitter, the second end cap (13) is provided with the second core plug (16), and the second lithology is provided with the sound wave velocity measurement system; A first flange (2) is arranged on the outer side of the first end cap (6), a second flange (14) is arranged on the outer side of the second end cap (13), and an adjusting nut (15) is arranged on the second flange (14); The cement simulation layer (8) is arranged on the inner side of the first sealing head (6), and the rock core is arranged on the inner side of the second sealing head (13).

7. The device for quantitatively evaluating the bonding ability of the second interface of cementing according to claim 6, characterized in that: A rubber tube is arranged inside the cylinder (12), and the cement simulation layer (8) and the rock core are arranged inside the rubber tube; a rubber sleeve protective sleeve (9) is arranged outside the rubber tube.

8. The device for quantitatively evaluating the bonding ability of the second interface of cementing according to claim 7, characterized in that: An annular cavity is formed between the rubber cylinder protective sleeve and the cylinder body (12), and a pressurizing port communicating with the cavity is provided on the cylinder body (12), and the pressurizing port is connected to a confining pressure loading pump (500).

9. The device for quantitatively evaluating the bonding ability of the second interface of cementing according to claim 8, characterized in that: A plurality of second interface detection measuring points (10) are arranged in the middle of the cylinder (12), and the second interface detection measuring points (10) are aligned with the connection surface between the rock core and the cement simulation layer (8).

10. The device for quantitatively evaluating the bonding ability of the second interface of cementing according to claim 9, characterized in that: The first flange (2) and the second flange (14) are both connected to the cylinder (12) via pressure-bearing screws (1).

11. A method for evaluating the bonding ability of the second interface of cementing by using the device for quantitatively evaluating the bonding ability of the second interface of cementing according to any one of claims 1 to 10, characterized in that: include: Obtain cement slurry parameters, target lithology parameters and formation parameters for cementing construction; The device for quantitatively evaluating the bonding ability of the second interface of cementing is used, and experimental conditions are set according to cementing slurry parameters, target lithology parameters and formation parameters for cementing construction to conduct maintenance experiments; After the curing age is reached, the acoustic detection module (200) is turned on to test the attenuation of the acoustic amplitude when the acoustic wave passes through the sample interface, analyze the waveform change, and obtain the macroscopic acoustic response data of the sample interface; by calculating the ratio of the first wave envelope value of the acoustic wave at different curing ages to the total acoustic amplitude signal, the quantitative evaluation of the cementing ability of the second interface of the cementing is achieved.

12. The method according to claim 11, characterized in that The amplitude of interface transmission sound, the total energy of sound waves emitted by the instrument, and the proportion of the total energy of reflected sound waves measured were obtained. The proportion of the amplitude of the first transmission wave signal was calculated by the following formula to quantitatively evaluate the sealing ability of the second interface of cementing at different curing ages. Where, u is the amplitude ratio of the transmitted first wave signal, %; A E is the amplitude of the interface transmitted sound, mV; A EITC is the total energy of sound waves emitted by the instrument, mV; U is the proportion of the total energy of reflected sound waves measured, %.

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