CN116577266A - Pipe corrosion fatigue limit testing device and method under corrosion and alternating load - Google Patents
Pipe corrosion fatigue limit testing device and method under corrosion and alternating load Download PDFInfo
- Publication number
- CN116577266A CN116577266A CN202310763097.0A CN202310763097A CN116577266A CN 116577266 A CN116577266 A CN 116577266A CN 202310763097 A CN202310763097 A CN 202310763097A CN 116577266 A CN116577266 A CN 116577266A
- Authority
- CN
- China
- Prior art keywords
- corrosion fatigue
- pressure
- corrosion
- kettle
- data processor
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 230000007797 corrosion Effects 0.000 title claims abstract description 215
- 238000005260 corrosion Methods 0.000 title claims abstract description 215
- 238000012360 testing method Methods 0.000 title claims abstract description 57
- 238000000034 method Methods 0.000 title claims abstract description 37
- 238000005452 bending Methods 0.000 claims abstract description 66
- 239000003381 stabilizer Substances 0.000 claims abstract description 53
- 238000007789 sealing Methods 0.000 claims abstract description 41
- 238000007906 compression Methods 0.000 claims abstract description 24
- 230000006835 compression Effects 0.000 claims abstract description 24
- 230000005540 biological transmission Effects 0.000 claims abstract description 18
- 238000010438 heat treatment Methods 0.000 claims abstract description 13
- 238000004321 preservation Methods 0.000 claims abstract description 5
- 238000002156 mixing Methods 0.000 claims description 67
- 238000009661 fatigue test Methods 0.000 claims description 56
- 238000002474 experimental method Methods 0.000 claims description 45
- 238000012544 monitoring process Methods 0.000 claims description 27
- 238000004088 simulation Methods 0.000 claims description 20
- 239000007788 liquid Substances 0.000 claims description 18
- 239000007787 solid Substances 0.000 claims description 9
- 230000008569 process Effects 0.000 claims description 8
- 239000007791 liquid phase Substances 0.000 claims description 6
- 238000012545 processing Methods 0.000 claims description 6
- 239000007790 solid phase Substances 0.000 claims description 6
- 238000004364 calculation method Methods 0.000 claims description 5
- 238000002360 preparation method Methods 0.000 claims description 5
- 238000003825 pressing Methods 0.000 claims description 5
- 230000006911 nucleation Effects 0.000 claims description 4
- 238000010899 nucleation Methods 0.000 claims description 4
- 238000009864 tensile test Methods 0.000 claims description 4
- 229910000831 Steel Inorganic materials 0.000 claims description 3
- 238000001816 cooling Methods 0.000 claims description 3
- 238000005336 cracking Methods 0.000 claims description 3
- 238000013001 point bending Methods 0.000 claims description 3
- 238000005086 pumping Methods 0.000 claims description 3
- 239000010959 steel Substances 0.000 claims description 3
- 238000013461 design Methods 0.000 abstract description 6
- 238000007689 inspection Methods 0.000 abstract description 3
- 150000002500 ions Chemical class 0.000 description 6
- 230000007547 defect Effects 0.000 description 3
- 238000005516 engineering process Methods 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- 238000010998 test method Methods 0.000 description 3
- 230000001808 coupling effect Effects 0.000 description 2
- 238000011161 development Methods 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000011156 evaluation Methods 0.000 description 2
- 238000009434 installation Methods 0.000 description 2
- 230000007704 transition Effects 0.000 description 2
- 241001391944 Commicarpus scandens Species 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 230000007812 deficiency Effects 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 239000007769 metal material Substances 0.000 description 1
- 238000005065 mining Methods 0.000 description 1
- 239000003129 oil well Substances 0.000 description 1
- 238000010008 shearing Methods 0.000 description 1
- 230000005476 size effect Effects 0.000 description 1
- 230000000087 stabilizing effect Effects 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N17/00—Investigating resistance of materials to the weather, to corrosion, or to light
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N3/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N3/32—Investigating strength properties of solid materials by application of mechanical stress by applying repeated or pulsating forces
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N3/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N3/56—Investigating resistance to wear or abrasion
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N2203/0058—Kind of property studied
- G01N2203/0069—Fatigue, creep, strain-stress relations or elastic constants
- G01N2203/0073—Fatigue
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N2203/02—Details not specific for a particular testing method
- G01N2203/022—Environment of the test
- G01N2203/0236—Other environments
- G01N2203/024—Corrosive
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E30/00—Energy generation of nuclear origin
- Y02E30/30—Nuclear fission reactors
Landscapes
- Life Sciences & Earth Sciences (AREA)
- Biochemistry (AREA)
- Analytical Chemistry (AREA)
- Pathology (AREA)
- Immunology (AREA)
- Physics & Mathematics (AREA)
- Health & Medical Sciences (AREA)
- Chemical & Material Sciences (AREA)
- General Physics & Mathematics (AREA)
- General Health & Medical Sciences (AREA)
- Biodiversity & Conservation Biology (AREA)
- Ecology (AREA)
- Environmental Sciences (AREA)
- Environmental & Geological Engineering (AREA)
- Investigating Strength Of Materials By Application Of Mechanical Stress (AREA)
Abstract
The invention provides a device and a method for testing the corrosion fatigue limit of a pipe under corrosion and alternating load, comprising a high-temperature high-pressure kettle; the high-temperature high-pressure kettle comprises a kettle body and a kettle cover; a heating sleeve and a heat preservation layer are arranged outside the kettle body; the kettle body is provided with a gas inlet and a gas outlet; the gas inlet and outlet of the kettle body are connected with a booster pump of a booster system; the bottom of the kettle body is provided with a kettle body stabilizer shell, and a wedge, an annular fixer and a kettle body rotary stabilizer are arranged in the kettle body stabilizer shell; the kettle body and the kettle cover are connected through a sealing bolt and a sealing nut; the kettle cover is provided with a combined sealing ring; the kettle cover is provided with a torque transmission shaft through a kettle cover sealing combination and a main shaft splicing cap; the torque transmission shaft is sequentially connected with the torque application shaft and the axial and radial loading assembly. The invention finely simulates high temperature, high pressure and H content 2 S‑CO 2 Corrosion environment and accurate test pipe bearingThe ultimate stress of corrosion fatigue fracture under complex alternating load states such as stretching, compression, bending and torsion provides technical support for quality inspection and optimal design of the pipe.
Description
Technical Field
The invention provides a device and a method for testing corrosion fatigue limit of a high-temperature high-pressure multiphase flow and complex alternating load working condition pipe, which belong to the technical field of mining exploitation and are used for evaluating H content of a metal pipe at high temperature, high pressure and high pressure 2 S-CO 2 And (3) under the corrosive environment and in a complex alternating load state of tension, compression, bending and torsion, the ultimate stress test of corrosion fatigue fracture does not occur in a specific service period or for a long time.
Background
During the service period of the oil and gas well pipe, the oil and gas well pipe is exposed to high temperature and high pressure and high H content 2 S-CO 2 The corrosion medium bears the tension, compression, bending and torsion hybrid load during the underground production operation, and the pipe is extremely easy to break in a stress state lower than the yield strength due to the corrosion and fatigue coupling effect in the long-time service process.
Patent 201410008876.0 proposes a corrosion fatigue life prediction method based on damage evolution, which only considers tensile load and cannot simulate complex load states such as pulling, pressing, bending, torsion and the like born by an oil and gas well pipe column in service, corrosion fatigue data obtained by test have a certain gap from field working conditions, and the accuracy of a prediction result does not meet engineering requirements.
Patent 2015143278. X provides a testing device for simulating rotary bending corrosion fatigue of an oil well pipe under the actual working condition of an oil field, and the technology does not consider the complex load states of pulling, pressing, bending, torsion and the like born by an oil and gas well pipe column during service.
201911150010.6, a method for predicting fatigue strength of a metal material by a tensile test is proposed, which cannot simulate complex load states such as pulling, pressing, bending, torsion and the like born by an oil and gas well tubular string during service; meanwhile, the size effect of the small-size sample is obvious, and the obtained result has weak reference to engineering practice.
202210835317.1 a test device for achieving a corrosive environment-bending fatigue coupling effect is proposed, which cannot simulate the complex load states of pulling, pressing, bending, torsion and the like born during the service of an oil and gas well tubular string.
In summary, the related testing device and method can not meet the requirements of on-site high temperature, high pressure and high H content 2 S-CO 2 The test requirement of the corrosion fatigue fracture limit stress of the pipe in the corrosion environment and in the complex alternating load state of tension, compression, bending and torsion greatly limits the test means for manufacturing the high corrosion fatigue limit of pipe manufacturers and greatly restricts the evaluation method for optimally designing the pipe in the oil-gas field.
Disclosure of Invention
The invention establishes a device for testing the corrosion fatigue limit of the pipe under corrosion and alternating load, and simultaneously forms a test method for evaluating the corrosion fatigue fracture limit stress of the pipe by using the device. Aims at finely simulating high temperature, high pressure and high H content 2 S-CO 2 The corrosion environment is used for accurately testing the ultimate stress of corrosion fatigue fracture of the pipe under the complex alternating load states of stretching, compression, bending, torsion and the like, and providing technical support for quality inspection and optimal design of the pipe.
The device solves the problems that:
1. provides a set of high-temperature high-pressure H-containing components 2 S-CO 2 The device for testing the corrosion fatigue limit stress of the pipe in the room under the working condition and the complex load condition;
2. extreme conditions can be simulated: the temperature is between room temperature and 350 ℃, the pressure is between normal pressure and 150MPa, and H is contained 2 S/CO 2 A gas-liquid-solid multiphase flow corrosive environment of a corrosive medium;
3. the method can simulate the tensile, compression, shearing and torsion complex alternating load states born by the pipe during service.
The specific technical scheme is that the pipe corrosion fatigue limit testing device under corrosion and alternating load comprises a high-temperature high-pressure kettle;
the high-temperature high-pressure kettle comprises a kettle body and a kettle cover; a heating sleeve and a heat preservation layer are arranged outside the kettle body;
the kettle body is provided with a gas inlet and a gas outlet; the gas inlet and outlet of the kettle body are connected with a booster pump of a booster system;
the bottom of the kettle body is provided with a kettle body stabilizer shell, and a wedge, an annular fixer and a kettle body rotary stabilizer are arranged in the kettle body stabilizer shell;
the kettle body and the kettle cover are connected through a sealing bolt and a sealing nut; the kettle cover is provided with a combined sealing ring; the kettle cover is provided with a torque transmission shaft through a kettle cover sealing combination and a main shaft splicing cap;
The torque transmission shaft is sequentially connected with the torque application shaft and the axial and radial loading assembly.
The axial and radial loading assembly comprises an axial loading assembly and a radial loading assembly;
the axial loading assembly comprises an upper stabilizer, an upper fixer, an upper sample joint, a radial loading upper cantilever, a corrosion fatigue sample, a radial loading lower cantilever, a lower sample joint, a lower fixer and a lower stabilizer which are sequentially connected from top to bottom. The loading and unloading of the axial tensile stress and the compressive stress of the corrosion fatigue test sample can be realized.
The radial loading assembly comprises an upper cantilever stabilizer and a lower cantilever stabilizer; the upper cantilever stabilizer and the lower cantilever stabilizer are respectively connected with the upper end and the lower end of the corrosion fatigue test sample;
the upper cantilever stabilizer is connected with the upper cantilever adapter through an upper cantilever adapter pin;
the lower cantilever stabilizer is connected with the lower cantilever adapter through a lower cantilever adapter pin;
the upper cantilever adapter and the lower cantilever adapter are connected with a bending stress loading shaft, and a bending stress loading nut is arranged on the bending stress loading shaft;
a high-temperature high-pressure kettle temperature and pressure sensor is arranged in the kettle body;
the torque transmission shaft is provided with a load sensor, a first strain sensor, a second strain sensor and a rotary power device, the first strain sensor and the second strain sensor are respectively arranged on a strain sensor fixing plate through a first strain sensor upper fixing flange and a second strain sensor upper fixing flange, and the strain sensor fixing plate is arranged on a kettle cover sealing flange through a strain sensor base and a strain sensor base fixing flange.
The high-temperature high-pressure kettle temperature and pressure sensor, the load sensor, the first strain sensor and the second strain sensor are respectively connected with the high-temperature high-pressure kettle temperature and pressure data processor, the load data processor, the first strain data processor and the second strain data processor;
the pressurizing system comprises a gas mixing device and a pressurizing pump, the gas mixing device comprises a gas mixing cylinder and a hydraulic cylinder, and a blending piston is arranged between the gas mixing cylinder and the hydraulic cylinder;
the booster pump is connected with the gas mixing cylinder; the gas mixing cylinders are also respectively connected with H 2 S gas cylinder, CO 2 Gas cylinder, N 2 Gas cylinder (312), CH 4 A gas cylinder;
the hydraulic cylinder is connected with the liquid filling tank, the liquid tank and the hydraulic pump;
the gas mixing device is arranged on the base of the gas mixing device;
a hydraulic pump pressure sensor is arranged on the hydraulic pump; a booster pump pressure sensor is arranged on the booster pump; a hydraulic cylinder pressure sensor is arranged in the hydraulic cylinder; a gas mixing cylinder pressure sensor is arranged in the gas mixing cylinder;
the hydraulic pump pressure sensor, the booster pump pressure sensor, the hydraulic cylinder pressure sensor and the gas mixing cylinder pressure sensor are respectively connected with the hydraulic pump pressure data processor, the booster pump pressure data processor, the hydraulic cylinder pressure data processor and the gas mixing cylinder pressure data processor;
The high-temperature high-pressure kettle temperature and pressure data processor, the load data processor, the first strain data processor and the second strain data processor, the hydraulic pump pressure data processor, the booster pump pressure data processor, the hydraulic cylinder pressure data processor and the gas mixing cylinder pressure data processor are respectively connected with the computer controller, and are used for dynamically monitoring and controlling corrosion fatigue experiment parameters such as the temperature, the pressure, the load, the strain and the like in the whole experiment process, recording data and drawing curves.
The device overcomes the defects that:
1. the problem of the field is solved that the device is required to test the pipe corrosion fatigue limit under the condition of complex load for indoor simulation test of extreme working conditions of a shaft;
2. the method overcomes the defects that the simulation test of the corrosion fatigue strength of the pipe is far away from the field working condition, and the extreme working conditions of deep wells, ultra-deep wells and deep wells of ten thousand meters cannot be simulated finely, the complex load and the dynamic multiphase flow working conditions;
3. the structural design deficiency of the current testing method and device is overcome, only the tensile load and the rotation load are considered, and the tensile load, the compression load, the bending load and the torsion load are obviously different from the tensile load, the compression load, the bending load and the torsion load of the pipe under the actual field working condition.
The method solves the problems that:
1. forming a test method for corrosion fatigue strength of the pipe under the condition of extreme working conditions and complex load;
2. Establishing high-temperature high-pressure high-content H in oil-gas well 2 S-CO 2 The limit stress determining method for the pipe without corrosion fatigue fracture in a specific period or for a long time under the complex alternating load state of corrosion environment and tension, compression, bending and torsion provides a checking means for manufacturing the pipe with high corrosion fatigue limit.
3. The applied load, sample deformation and corrosion fatigue fracture data are dynamically monitored, and the development of the optimal design technology of deep well ultra-deep well and ten-thousand-meter deep well pipes is effectively supported.
The specific technical scheme is as follows:
the method for testing the corrosion fatigue limit of the pipe under the corrosion and alternating load can be divided into six aspects of experiment preparation, sample loading, parameter setting, data monitoring, post-experiment treatment and corrosion fatigue limit calculation.
S1, experimental preparation:
s1.1, determining experimental conditions for carrying out corrosion fatigue limit indoor simulation test. The corrosion parameters are determined according to the on-site working conditions, such as temperature, pressure, gas components and partial pressure, liquid phase and solid phase components and ion content, the brand of the pipe used in the experiment, the grade of steel, the type of load applied during service and the magnitude of the tension-compression-bending-torsion load;
s1.2, processing a corrosion fatigue limit indoor simulation test sample. Processing the tube used in the experiment into a rod-shaped tensile sample, wherein the length of a parallel section, the chamfer angle of a transition section, the outer diameter of the sample, the length and other dimensions all need to meet the installation requirement of an indoor simulation test device with corrosion fatigue limit;
S1.3, preparing corrosive gas with corresponding gas content. Pumping the gas mixing cylinder to vacuum; connecting the gas and H required by the experiment 2 S gas cylinder, CO 2 Gas cylinder, N 2 Gas cylinder, CH 4 A gas cylinder; according to the content required by the experiment, H is sequentially opened 2 S/CO 2 /N 2 /CH 4 The gas cylinder valve enables the gas to enter the gas mixing cylinder to prepare mixed gas with corresponding gas component proportion.
S1.4, preparing a corrosive liquid medium with corresponding liquid-solid content and ion proportion. According to the contents of liquid phase and solid phase components and ions, preparing corrosive liquid medium with corresponding liquid-solid components and contents, and continuously introducing corresponding gas components until saturation.
And S1.5, monitoring the pressure of the hydraulic cylinder by using a hydraulic cylinder pressure sensor, and monitoring the pressure of the gas mixing cylinder by using a gas mixing cylinder pressure sensor.
S2, loading a sample:
s2.1, installing a radial loading assembly. Assembling an upper cantilever stabilizer in the radial loading upper cantilever, sleeving the upper clamping end of the corrosion fatigue test sample to a position close to the parallel section, and fixing; assembling a lower cantilever stabilizer in the radial loading upper cantilever, sleeving the lower clamping end of the corrosion fatigue test sample to a position close to the parallel section, and fixing; the upper cantilever adapter, the lower cantilever adapter and the bending stress loading shaft are respectively connected;
S2.2, installing an axial loading assembly. Assembling a lower sample joint at the lower end of the corrosion fatigue test sample; the lower fixing device is arranged on the torque applying shaft and connected with the lower sample joint, and the whole body is put into the radial loading assembly and fixed by using the lower stabilizing device; assembling an upper sample joint at the upper end of the corrosion fatigue test sample; mounting an upper retainer on the torque applying shaft and connecting with the upper sample joint, integrally securing it to the radial loading assembly using an upper stabilizer;
s2.3, applying axial stretching or compression load. By adjusting the upper and lower anchors to apply a tensile or compressive load to the corrosion fatigue test specimen, the calculated relationship between applied load and deflection can be used directly with σ=e·ε, where σ is the tensile/compressive stress, E is the tensile elastic modulus or the compressive elastic modulus, and ε is the tensile/compressive strain.
S2.4, applying radial bending load. The deflection of the parallel section of the corrosion fatigue test sample is increased by tightening the bending stress loading nut, the radial bending load is applied to the corrosion fatigue test sample, and the relation between the applied load and the deflection can be corrected by adopting a four-point bending standard calculation formula or adopting an trial experiment.
S3, parameter setting:
s3.1, setting simulated corrosion environment parameters. Adding the prepared corrosive liquid medium into the kettle body, immersing a radial loading assembly on the liquid level, and sealing the kettle cover and the kettle body by using a sealing bolt and a sealing nut; the strain sensor base is fixed on the kettle cover sealing combination by using a strain sensor base fixing flange; fixing a strain sensor fixing plate on a torque transmission shaft by using a strain sensor upper fixing flange and a strain sensor upper fixing flange, and installing a first strain sensor and a second strain sensor on the strain sensor fixing plate; the load sensor and the rotary power device are sequentially connected with the torque transmission shaft.
S3.2, heating and pressurizing the kettle body. Setting a medium-temperature pressure data processor in a computer controller as experimental corresponding temperature pressure, and controlling a heating sleeve to heat a kettle body through a high-temperature high-pressure kettle temperature pressure sensor until the experimental set temperature is reached; through high temperature autoclave temperature pressure sensing) to control the booster pump to boost the pressure of the autoclave body until the experimental set pressure is reached.
S4, data monitoring:
s4.1, connecting a first strain data processor and a second strain data processor with a first strain sensor and a second strain sensor respectively, and monitoring the axial deformation of a corrosion fatigue sample during an experiment;
S4.2, connecting the high-temperature high-pressure kettle temperature and pressure data processor with a high-temperature high-pressure kettle temperature and pressure sensor, and monitoring the numerical variation of the internal temperature and pressure of the kettle body during the experiment;
s4.3, connecting a load data processor with a load sensor, and monitoring the axial tensile load and the torque variation of the corrosion fatigue test sample during the experiment;
and S4.4, connecting the hydraulic pump pressure data processor and the booster pump pressure data processor with the hydraulic pump pressure sensor and the booster pump pressure sensor respectively, monitoring the pump pressure of the hydraulic pump and the booster pump, connecting the hydraulic cylinder pressure data processor and the gas mixing cylinder pressure data processor with the hydraulic cylinder pressure sensor and the gas mixing cylinder pressure sensor respectively, and monitoring the internal pressure of the hydraulic cylinder and the gas mixing cylinder so as to ensure experimental safety.
S5, experimental post-treatment:
s5.1, taking out a corrosion fatigue test sample. And after the preset period of the experiment is reached, cooling, pressure relief, opening the corrosion fatigue limit testing device, and taking out the corrosion fatigue test sample.
S5.2, observing corrosion cracking characteristics. Analyzing and observing the morphology, the components and the protection characteristics of a corrosion product film on the surface of the corrosion fatigue test sample by using a macroscopic and microscopic means; and (5) observing and judging the nucleation, the expansion characteristics and the crack size of the parallel section cracks of the corrosion fatigue test sample.
S5.3, analyzing the fatigue strength of the sample. If the corrosion fatigue test sample breaks, continuing to carry out a corrosion fatigue limit test experiment under the stress condition; if the corrosion fatigue test sample is not broken, carrying out a room temperature tensile test, determining the residual strength of the pipe after the corrosion fatigue limit test, and simultaneously continuously carrying out the corrosion fatigue limit test under the condition that the stress is larger than that of the pipe;
s6, evaluating corrosion fatigue limit:
s6.1, a corrosion fatigue limit assessment method when bending stress is unchanged and tensile/compressive stress is changed.
And (3) maintaining the applied radial bending load unchanged, respectively designing corrosion fatigue limit indoor simulation experiments of series groups under different tensile/compressive stress states, measuring corrosion fatigue S-N curves, and evaluating the corrosion fatigue limit stress when the pipe is subjected to tensile/compressive stress under the bending stress.
S6.2, a corrosion fatigue limit assessment method when tensile/compressive stress is unchanged and bending stress is changed.
And (3) maintaining the applied axial stretching/compression load unchanged, respectively designing corrosion fatigue limit indoor simulation experiments of series groups under different bending stress states, measuring corrosion fatigue S-N curves, and evaluating the corrosion fatigue limit stress when the pipe is subjected to bending stress under the stretching/compression stress.
S6.3, evaluating the corrosion fatigue limit in the tensile/compression/bending/torsion alternating state.
And respectively designing corrosion fatigue limit indoor simulation experiments of series groups under different stretching, compression, bending and torque states by adopting a factor molecular method or an orthogonal experiment method, measuring a corrosion fatigue S-N curve, and evaluating the corrosion fatigue limit stress of the pipe in the corrosion environment.
The method overcomes the defects that:
1. it is clear that the high temperature, high pressure and high H content 2 S-CO 2 In a corrosion environment, the pipe is not subjected to corrosion fatigue fracture in a specific period or for a long time.
2. The problem that a pipe corrosion fatigue limit stress test method suitable for extreme working conditions, complex loads and dynamic multiphase flow conditions of deep wells and ultra-deep wells of ten thousand meters is not available at present is solved;
3. the problems that the current corrosion fatigue fracture limit stress test data is insufficient and the design technology of deep well ultra-deep well and ten-thousand-meter deep well pipes is difficult to support are effectively solved.
The invention achieves the effects and advantages that:
1. the corrosion fatigue indoor experimental device has the development temperature of between room temperature and 350 ℃, the normal pressure of between normal pressure and 150MPa and contains H 2 S/CO 2 Pipe bearing in gas-liquid-solid multiphase flow corrosive environment of corrosive mediumAnd (3) performing indoor simulation experiments on corrosion fatigue under the combined action of tensile stress, shear stress, tensile stress, torque or tensile stress, shear stress and torque load.
2. The temperature and pressure in the corrosion fatigue test process can be dynamically monitored, and the load, the sample deformation and the corrosion fatigue fracture data are applied.
3. Can test the temperature of 350 ℃, 150MPa and H content 2 S/CO 2 In multiphase flow corrosion environment, the crack nucleation and expansion characteristics of the pipe are born under the complex alternating load states of tension, compression, bending and torsion.
4. Can test the temperature of 350 ℃, 150MPa and H content 2 S/CO 2 In multiphase flow corrosion environment, the pipe bears corrosion fatigue limit stress under tension-compression-bending-torsion complex alternating load state.
5. The ultimate stress value of the pipe, which does not generate corrosion fatigue fracture in a specific period or for a long time in a service environment, is measured, a quality inspection means is provided for pipe manufacturers to develop the pipe with high corrosion fatigue limit, and an experimental device and a reliable evaluation method are provided for the optimal design of the pipe in the oil-gas field.
Drawings
FIG. 1 is one of the structural schematic diagrams of the present invention;
FIG. 2 is a second schematic diagram of the structure of the present invention
FIG. 3 is a top view of the corrosion fatigue limit testing system of the present invention;
FIG. 4 is a schematic view of the axial and radial loading assembly of the present invention.
Detailed Description
The specific technical scheme of the invention is described by combining the embodiments.
As shown in FIG. 1, the pipe corrosion fatigue limit testing device under corrosion and alternating load comprises a control system 1, a corrosion fatigue limit testing system 2 and a pressurizing system 3.
As shown in fig. 1, the control system 1 is composed of a computer controller 101, a high-temperature high-pressure kettle temperature pressure data processor 1A, a load data processor 1B, a first strain data processor 1C-1 and a second strain data processor 1C-2, and a hydraulic pump pressure data processor 1D, a booster pump pressure data processor 1E, a hydraulic cylinder pressure data processor 1F and a gas mixing cylinder pressure data processor 1G. The monitoring control of corrosion fatigue experiment parameters such as the temperature, pressure, load, strain and the like in the whole experimental process can be dynamically monitored, data are recorded, and a curve is drawn;
as shown in fig. 2 and 3, the corrosion fatigue limit test system 2 is composed of a control assembly, a high-temperature autoclave, an auxiliary assembly, an axial loading assembly and a radial loading assembly.
The control assembly consists of a high-temperature high-pressure kettle temperature pressure sensor 2A, a load sensor 2B, a first strain sensor 2C-1, a second strain sensor 2C-2, a rotary power device 210, a strain sensor upper fixing flange 211, a strain sensor upper fixing flange 212, a strain sensor fixing plate 213, a strain sensor base 214, a strain sensor base fixing flange 215 and a kettle cover sealing flange 216. Parameters such as temperature, pressure, load, strain and the like in the whole process of the corrosion fatigue experiment can be tested in real time, and data are transmitted to a control system.
The high-temperature high-pressure kettle consists of a sealing bolt 220, a sealing nut 221, a kettle cover 222, a kettle body 223, a heating sleeve 224, a heat preservation layer 225, a kettle cover sealing combination 226, a torque transmission shaft 227, a combined sealing ring 228, a main shaft splicing cap 229 and an axial radial loading assembly 240. Can realize the conditions of room temperature to 350 ℃, normal pressure to 150MPa and H content 2 S/CO 2 And (3) simulating the gas-liquid-solid multiphase flow corrosion environment of the corrosive gas.
The auxiliary components consist of a torque applying shaft 230, a gas inlet and outlet 231, a tank body stabilizer housing 232, a wedge 233, an annular retainer 234, and a tank body rotary stabilizer 235. The high-temperature high-pressure kettle and the loading component are matched to assist in realizing safe and stable performance of corrosion fatigue experiments.
The axial loading assembly consists of an upper stabilizer 241, an upper anchor 242, an upper sample joint 243, a radially loaded upper cantilever 244, a corrosion fatigue test specimen 245, a radially loaded lower cantilever 246, a lower sample joint 247, a lower anchor 248, and a lower stabilizer 249. The loading and unloading of the axial tensile stress and the compressive stress of the corrosion fatigue test sample can be realized.
The radial loading assembly consists of an upper cantilever stabilizer 250, an upper cantilever adapter 251, an upper cantilever adapter pin 252, a bending stress loading nut 253, a bending stress loading shaft 254, a lower cantilever adapter pin 255, a lower cantilever adapter 256, and a lower cantilever stabilizer 257. The loading and unloading of the bending stress of the corrosion fatigue test sample can be realized.
FIG. 3 is a top view of the corrosion fatigue limit testing system 2 showing the corrosion fatigue limit testing system high temperature autoclave top view characteristics. The method comprises the following steps:
the first strain sensor 2C-1 and the second strain sensor 2C-2 can measure the strain quantity of the sample in the corrosion fatigue test process; the rotary power device 210 can be externally connected with a multi-stage deceleration control system, so that torque meeting the conditions is provided for the experiment in corrosion fatigue; the strain sensor fixing plate 213 is used for fixing the first strain sensor 2C-1 and the second strain sensor 2C-2, so as to ensure accurate measurement of the strain; the kettle cover sealing flange 216, the sealing bolt 220, the sealing nut 221, the kettle cover 222 and the kettle cover sealing combination 226 are used for ensuring the ultrahigh temperature and ultrahigh pressure sealing effect of the high-temperature high-pressure kettle; the heating jacket 224 and the insulating layer 225 are used for heating and insulating, respectively.
As shown in FIG. 4, an enlarged view of the axial and radial loading assembly 240 is shown enlarged to illustrate the mounting of the components of the axial and radial loading assembly. Wherein:
the axial loading assembly consists of an upper stabilizer 241, an upper anchor 242, an upper sample joint 243, a radially loaded upper cantilever 244, a corrosion fatigue test specimen 245, a radially loaded lower cantilever 246, a lower sample joint 247, a lower anchor 248, and a lower stabilizer 249. The loading and unloading of the axial tensile stress and the compressive stress of the corrosion fatigue test sample can be realized.
The radial loading assembly consists of an upper cantilever stabilizer 250, an upper cantilever adapter 251, an upper cantilever adapter pin 252, a bending stress loading nut 253, a bending stress loading shaft 254, a lower cantilever adapter pin 255, a lower cantilever adapter 256, and a lower cantilever stabilizer 257. The loading and unloading of the bending stress of the corrosion fatigue test sample can be realized.
A pressurizing system 3, which is formed by a hydraulic pump pressure sensor 3D, a pressurizing pump pressure sensor 3E, a hydraulic cylinder pressure sensor 3F and a gas mixing cylinder pressure sensorDevices 3G, H 2 S gas cylinder 310, CO 2 Gas cylinder 311, N 2 Gas cylinder 312, CH 4 The device comprises a gas cylinder 313, a booster pump 314, a gas mixing cylinder 320, a blending piston 321, a hydraulic cylinder 322, a gas mixing device base 323, a liquid filling tank 324, a liquid tank 325 and a hydraulic pump 326. Can realize H 2 S/CO 2 /N 2 /CH 4 And mixing and preparing the equal gas components, pressurizing, and dynamically adjusting the internal pressure of the high-temperature high-pressure kettle according to the pressure required by the corrosion fatigue experiment.
The connection relation between the parts is as follows:
the high-temperature high-pressure kettle comprises a kettle body 223 and a kettle cover 222; a heating jacket 224 and a heat preservation layer 225 are arranged outside the kettle body 223;
the kettle body 223 is provided with a gas inlet 231;
a kettle body stabilizer shell 232 is arranged at the inner bottom of the kettle body 223, and a wedge 233, an annular fixer 234 and a kettle body rotary stabilizer 235 are arranged in the kettle body;
The kettle body 223 and the kettle cover 222 are connected through a sealing bolt 220 and a sealing nut 221; the kettle cover 222 is provided with a combined sealing ring 228; the kettle cover 222 is provided with a torque transmission shaft 227 through a kettle cover sealing combination 226 and a main shaft splicing cap 229;
the torque transmission shaft 227 is sequentially connected with a torque application shaft 230 and an axial radial loading assembly 240;
the axial and radial loading assembly 240 includes an axial loading assembly and a radial loading assembly;
the axial loading assembly comprises, in order from top to bottom, an upper stabilizer 241, an upper anchor 242, an upper sample joint 243, a radially loaded upper cantilever 244, a corrosion fatigue test 245, a radially loaded lower cantilever 246, a lower sample joint 247, a lower anchor 248, and a lower stabilizer 249. The loading and unloading of the axial tensile stress and the compressive stress of the corrosion fatigue test sample can be realized.
A radial loading assembly comprising an upper cantilever stabilizer 250, a lower cantilever stabilizer 257; the upper cantilever stabilizer 250 and the lower cantilever stabilizer 257 are respectively connected to the upper end and the lower end of the corrosion fatigue test specimen 245;
the upper cantilever stabilizer 250 is connected to an upper cantilever adapter 251 by an upper cantilever adapter pin 252;
lower cantilever stabilizer 257 is coupled to lower cantilever adapter 256 by lower cantilever adapter pin 255;
The upper cantilever adapter 251 and the lower cantilever adapter 256 are connected with a bending stress loading shaft 254, and a bending stress loading nut 253 is arranged on the bending stress loading shaft 254;
a high-temperature high-pressure kettle temperature and pressure sensor 2A is arranged in the kettle body 223;
the torque transmission shaft 227 is provided with a load sensor 2B, a first strain sensor 2C-1, a second strain sensor 2C-2 and a rotary power device 210, wherein the first strain sensor 2C-1 and the second strain sensor 2C-2 are respectively arranged on a strain sensor fixing plate 213 through a first strain sensor upper fixing flange 211 and a second strain sensor upper fixing flange 212, and the strain sensor fixing plate 213 is arranged on a kettle cover sealing flange 216 through a strain sensor base 214 and a strain sensor base fixing flange 215.
The high-temperature high-pressure kettle temperature and pressure sensor 2A, the load sensor 2B, the first strain sensor 2C-1 and the second strain sensor 2C-2 are respectively connected with the high-temperature high-pressure kettle temperature and pressure data processor 1A, the load data processor 1B, the first strain data processor 1C-1 and the second strain data processor 1C-2;
the gas inlet 231 of the tank 223 is connected with a booster pump 314 of the booster system.
The pressurizing system comprises a gas mixing device and a pressurizing pump 314, the gas mixing device comprises a gas mixing cylinder 320 and a hydraulic cylinder 322, and a deployment piston 321 is arranged between the gas mixing cylinder 320 and the hydraulic cylinder 322;
The booster pump 314 is connected with the gas mixing cylinder 320; the gas mixing cylinders 320 are also respectively connected with H 2 S gas cylinder 310, CO 2 Gas cylinder 311, N 2 Gas cylinder 312, CH 4 A gas cylinder 313;
hydraulic cylinder 322 is connected to charge tank 324, tank 325, and hydraulic pump 326;
the gas mixing device is mounted on a gas mixing device base 323;
the hydraulic pump 326 is provided with a hydraulic pump pressure sensor 3D; the booster pump 314 is provided with a booster pump pressure sensor 3E; a hydraulic cylinder pressure sensor 3F is arranged in the hydraulic cylinder 322; a gas mixing cylinder pressure sensor 3G is arranged in the gas mixing cylinder 320;
the hydraulic pump pressure sensor 3D, the booster pump pressure sensor 3E, the hydraulic cylinder pressure sensor 3F and the gas mixing cylinder pressure sensor 3G are respectively connected with the hydraulic pump pressure data processor 1D, the booster pump pressure data processor 1E, the hydraulic cylinder pressure data processor 1F and the gas mixing cylinder pressure data processor 1G;
the high-temperature high-pressure kettle temperature pressure data processor 1A, the load data processor 1B, the first stress data processor 1C-1, the second stress data processor 1C-2, the hydraulic pump pressure data processor 1D, the booster pump pressure data processor 1E, the hydraulic cylinder pressure data processor 1F and the gas mixing cylinder pressure data processor 1G are respectively connected with the computer controller 101, and are used for dynamically monitoring and controlling corrosion fatigue experiment parameters such as the whole process temperature, pressure, load, stress and the like, recording data and drawing curves.
The method for testing the corrosion fatigue limit of the pipe under the extreme corrosion and alternating load working conditions can be divided into six aspects of experiment preparation, sample loading, parameter setting, data monitoring, experiment post-treatment and corrosion fatigue limit calculation.
S1, experimental preparation:
s1.1, determining experimental conditions for carrying out corrosion fatigue limit indoor simulation test. The corrosion parameters are determined according to the on-site working conditions, such as temperature, pressure, gas components and partial pressure, liquid phase and solid phase components and ion content, the brand of the pipe used in the experiment, the grade of steel, the type of load applied during service and the magnitude of the tension-compression-bending-torsion load;
s1.2, processing a corrosion fatigue limit indoor simulation test sample. Processing the tube used in the experiment into a rod-shaped tensile sample, wherein the length of a parallel section, the chamfer angle of a transition section, the outer diameter of the sample, the length and other dimensions all need to meet the installation requirement of an indoor simulation test device with corrosion fatigue limit;
s1.3, preparing corrosive gas with corresponding gas content. Pumping the gas mixing cylinder 320 to vacuum; connecting the gas and H required by the experiment 2 S gas cylinder 310, CO 2 Gas cylinder 311, N 2 Gas cylinder 312, CH 4 A gas cylinder 313; according to the content required by the experiment, H is sequentially opened 2 S/CO 2 /N 2 /CH 4 The gas cylinder valve allows gas to enter the gas mixing cylinder 320 to prepare a mixed gas with corresponding gas component proportions.
S1.4, preparing a corrosive liquid medium with corresponding liquid-solid content and ion proportion. According to the contents of liquid phase and solid phase components and ions, preparing corrosive liquid medium with corresponding liquid-solid components and contents, and continuously introducing corresponding gas components until saturation.
And S1.5, monitoring the hydraulic cylinder pressure by using a hydraulic cylinder pressure sensor 3F, and monitoring the gas mixing cylinder pressure by using a gas mixing cylinder pressure sensor 3G.
S2, loading a sample:
s2.1, installing a radial loading assembly. The upper cantilever stabilizer 250 is assembled inside the radial loading upper cantilever 244, sleeved to a position close to the parallel section by the upper clamping end of the corrosion fatigue test specimen 245 and fixed; assembling a lower cantilever stabilizer 257 inside the radial loading upper cantilever 244, sleeving the lower clamping end of the corrosion fatigue test specimen 245 to a position close to the parallel section and fixing; an upper cantilever adapter 251, a lower cantilever adapter 256, and a bending stress loading shaft 254 are connected respectively;
s2.2, installing an axial loading assembly. Assembling the lower sample joint 247 to the lower end of the corrosion fatigue test specimen 245; a lower retainer 248 is mounted on the torque application shaft 230 and connected to a lower sample joint 247, and the whole is placed into the radial loading assembly 240 and secured using a lower stabilizer 249; assembling an upper sample joint 243 on the upper end of the corrosion fatigue test specimen 245; an upper holder 241 is mounted on the torque application shaft 230 and connected to an upper sample joint 243, which is integrally secured to the radial load assembly 240 using the upper holder 241;
S2.3, applying axial stretching or compression load. By adjusting the upper and lower anchors 241, 248 to apply a tensile or compressive load to the corrosion fatigue specimen 245, the calculated relationship between applied load and deflection can be directly used with σ=e·ε, where σ is the tensile/compressive stress, E is the tensile elastic modulus or the compressive elastic modulus, and ε is the tensile/compressive strain.
S2.4, applying radial bending load. The bending stress loading nut 253 is screwed to increase the deflection of the parallel section of the corrosion fatigue test specimen 245, the radial bending load is applied to the corrosion fatigue test specimen 245, and the relation between the applied load and the deflection can be corrected by adopting a four-point bending standard calculation formula or adopting an trial experiment.
S3, parameter setting:
s3.1, setting simulated corrosion environment parameters. Adding the prepared corrosive liquid medium into the kettle body 223, immersing a radial loading assembly 240 in the liquid level, and sealing the kettle cover 222 and the kettle body 223 by using a sealing bolt 220 and a sealing nut 221; the strain sensor base 214 is fixed on the kettle cover sealing combination 226 by using a strain sensor base fixing flange 215; fixing the strain sensor fixing plate 213 to the torque transmission shaft 227 using the strain sensor upper fixing flange 211 and the strain sensor upper fixing flange 212, and mounting the first and second strain sensors 2C-1 and 2C-2 to the strain sensor fixing plate 213; the load sensor 2B and the rotary power unit 210 are connected to the torque transmission shaft 227 in this order.
S3.2, heating and pressurizing the kettle body. Setting a medium-temperature and pressure data processor 1A of the computer controller 101 as experimental corresponding temperature and pressure, and controlling a heating sleeve 224 to heat a kettle body 223 by a high-temperature high-pressure kettle temperature and pressure sensor 2A until the experimental set temperature is reached; the booster pump 314 is controlled by the high-temperature high-pressure kettle temperature and pressure sensor 2A to boost the pressure of the kettle body 223 until the experimental set pressure is reached.
S4, data monitoring:
s4.1, connecting a first strain data processor 1C-1 and a second strain data processor 1C-2 with a first strain sensor 2C-1 and a second strain sensor 2C-2 respectively, and monitoring the axial deformation of the corrosion fatigue test sample 245 during an experiment;
s4.2, connecting the high-temperature high-pressure kettle temperature and pressure data processor 1A with the high-temperature high-pressure kettle temperature and pressure sensor 2A, and monitoring the numerical variation of the temperature and pressure inside the kettle body 223 during the experiment;
s4.3, connecting the load data processor 1B with the load sensor 2B, and monitoring the change amount of the axial tensile load and the torque of the corrosion fatigue test specimen 245 during the experiment;
s4.4, the hydraulic pump pressure data processor 1D and the booster pump pressure data processor 1E are respectively connected with the hydraulic pump pressure sensor 3D and the booster pump pressure sensor 3E, the pump pressure of the hydraulic pump 326 and the booster pump 314 is monitored, the hydraulic cylinder pressure data processor 1F and the gas mixing cylinder pressure data processor 1G are respectively connected with the hydraulic cylinder pressure sensor 3F and the gas mixing cylinder pressure sensor 3G, and the internal pressure of the hydraulic cylinder 322 and the gas mixing cylinder 320 is monitored so as to ensure experimental safety.
S5, experimental post-treatment:
s5.1, taking out a corrosion fatigue test sample. And after the preset period of the experiment is reached, cooling, pressure relief, opening the corrosion fatigue limit testing device, and taking out the corrosion fatigue test sample 245.
S5.2, observing corrosion cracking characteristics. Analyzing and observing the morphology, the components and the protection characteristics of the corrosion product film on the surface of the corrosion fatigue test sample 245 by using macroscopic and microscopic means; and (5) observing and judging the nucleation, the expansion characteristics and the crack size of the parallel section cracks of the corrosion fatigue test specimen 245.
S5.3, analyzing the fatigue strength of the sample. If the corrosion fatigue test specimen 245 breaks, continuing to carry out a corrosion fatigue limit test under the stress condition; if the corrosion fatigue test specimen 245 is not broken, carrying out a room temperature tensile test, determining the residual strength of the pipe after the corrosion fatigue limit test, and simultaneously continuously carrying out a corrosion fatigue limit test under the condition that the stress is greater than that of the pipe;
s6, evaluating corrosion fatigue limit:
s6.1, a corrosion fatigue limit assessment method when bending stress is unchanged and tensile/compressive stress is changed.
And (3) maintaining the applied radial bending load unchanged, respectively designing corrosion fatigue limit indoor simulation experiments of series groups under different tensile/compressive stress states, measuring corrosion fatigue S-N curves, and evaluating the corrosion fatigue limit stress when the pipe is subjected to tensile/compressive stress under the bending stress.
S6.2, a corrosion fatigue limit assessment method when tensile/compressive stress is unchanged and bending stress is changed.
And (3) maintaining the applied axial stretching/compression load unchanged, respectively designing corrosion fatigue limit indoor simulation experiments of series groups under different bending stress states, measuring corrosion fatigue S-N curves, and evaluating the corrosion fatigue limit stress when the pipe is subjected to bending stress under the stretching/compression stress.
S6.3, evaluating the corrosion fatigue limit in the tensile/compression/bending/torsion alternating state.
And respectively designing corrosion fatigue limit indoor simulation experiments of series groups under different stretching, compression, bending and torque states by adopting a factor molecular method or an orthogonal experiment method, measuring a corrosion fatigue S-N curve, and evaluating the corrosion fatigue limit stress of the pipe in the corrosion environment.
Claims (5)
1. The pipe corrosion fatigue limit testing device under corrosion and alternating load is characterized by comprising a high-temperature high-pressure kettle;
the high-temperature high-pressure kettle comprises a kettle body (223) and a kettle cover (222); a heating sleeve (224) and a heat preservation layer (225) are arranged outside the kettle body (223);
the kettle body (223) is provided with a gas inlet and a gas outlet (231); a gas inlet and outlet (231) of the kettle body (223) is connected with a booster pump (314) of the booster system;
a kettle body stabilizer shell (232) is arranged at the inner bottom of the kettle body (223), and a wedge (233), an annular fixer (234) and a kettle body rotary stabilizer (235) are arranged in the kettle body;
The kettle body (223) and the kettle cover (222) are connected through a sealing bolt (220) and a sealing nut (221); a combined sealing ring (228) is arranged on the kettle cover (222); a torque transmission shaft (227) is arranged on the kettle cover (222) through a kettle cover sealing combination (226) and a main shaft splicing cap (229);
the torque transmission shaft (227) is sequentially connected with a torque application shaft (230) and an axial radial loading assembly (240).
2. The pipe corrosion fatigue limit testing device under corrosion and alternating load according to claim 1, wherein the axial radial loading assembly (240) comprises an axial loading assembly and a radial loading assembly;
the axial loading assembly comprises an upper stabilizer (241), an upper fixer (242), an upper sample joint (243), a radial loading upper cantilever (244), a corrosion fatigue test sample (245), a radial loading lower cantilever (246), a lower sample joint (247), a lower fixer (248) and a lower stabilizer (249) which are sequentially connected from top to bottom; the loading and unloading of the axial tensile and compressive stress of the corrosion fatigue test sample can be realized;
the radial loading assembly comprises an upper cantilever stabilizer (250) and a lower cantilever stabilizer (257); the upper cantilever stabilizer (250) and the lower cantilever stabilizer (257) are respectively connected to the upper end and the lower end of the corrosion fatigue test sample (245);
The upper cantilever stabilizer (250) is connected with the upper cantilever adapter (251) through an upper cantilever adapter pin (252);
the lower cantilever stabilizer (257) is connected with the lower cantilever adapter (256) through a lower cantilever adapter pin (255);
the upper cantilever adapter (251) and the lower cantilever adapter (256) are connected with a bending stress loading shaft (254), and a bending stress loading nut (253) is arranged on the bending stress loading shaft (254).
3. The pipe corrosion fatigue limit testing device under corrosion and alternating load according to claim 1, wherein the pressurizing system comprises a gas mixing device and a pressurizing pump (314), the gas mixing device comprises a gas mixing cylinder (320) and a hydraulic cylinder (322), and a deployment piston (321) is arranged between the gas mixing cylinder (320) and the hydraulic cylinder (322);
the booster pump (314) is connected with the gas mixing cylinder (320); the gas mixing cylinders (320) are also respectively connected with H 2 S gas cylinder (310), CO 2 Gas cylinder (311), N 2 Gas cylinder (312), CH 4 A gas cylinder (313);
the hydraulic cylinder (322) is connected with a liquid filling tank (324), a liquid tank (325) and a hydraulic pump (326);
the gas mixing device is mounted on a gas mixing device base (323).
4. A pipe corrosion fatigue limit testing device under corrosion and alternating load according to claim 3, wherein the kettle body (223) is internally provided with a high-temperature high-pressure kettle temperature pressure sensor (2A);
The torque transmission shaft (227) is provided with a load sensor (2B), a first strain sensor (2C-1), a second strain sensor (2C-2) and a rotary power device (210), the first strain sensor (2C-1) and the second strain sensor (2C-2) are respectively arranged on a strain sensor fixing plate (213) through a first strain sensor upper fixing flange (211) and a second strain sensor upper fixing flange (212), and the strain sensor fixing plate (213) is arranged on a kettle cover sealing flange (216) through a strain sensor base (214) and a strain sensor base fixing flange (215);
the high-temperature high-pressure kettle temperature and pressure sensor (2A), the load sensor (2B), the first strain sensor (2C-1) and the second strain sensor (2C-2) are respectively connected with the high-temperature high-pressure kettle temperature and pressure data processor (1A), the load data processor (1B), the first strain data processor (1C-1) and the second strain data processor (1C-2);
a hydraulic pump pressure sensor (3D) is arranged on the hydraulic pump (326); a booster pump pressure sensor (3E) is arranged on the booster pump (314); a hydraulic cylinder pressure sensor (3F) is arranged in the hydraulic cylinder (322); a gas mixing cylinder pressure sensor (3G) is arranged in the gas mixing cylinder (320);
the hydraulic pump pressure sensor (3D), the booster pump pressure sensor (3E), the hydraulic cylinder pressure sensor (3F) and the gas mixing cylinder pressure sensor (3G) are respectively connected with the hydraulic pump pressure data processor (1D), the booster pump pressure data processor (1E), the hydraulic cylinder pressure data processor (1F) and the gas mixing cylinder pressure data processor (1G);
The high-temperature high-pressure kettle temperature pressure data processor (1A), the load data processor (1B), the first stress data processor (1C-1) and the second stress data processor (1C-2), the hydraulic pump pressure data processor (1D), the booster pump pressure data processor (1E), the hydraulic cylinder pressure data processor (1F) and the gas mixing cylinder pressure data processor (1G) are respectively connected with the computer controller (101), dynamically monitor and control corrosion fatigue experiment parameters in the whole experiment process, record data and draw curves.
5. A method for testing the corrosion fatigue limit of a pipe under corrosion and alternating load, which adopts the device for testing the corrosion fatigue limit of the pipe under corrosion and alternating load according to any one of claims 1 to 4, and comprises the following steps:
s1, experimental preparation:
s1.1, determining experimental conditions for carrying out corrosion fatigue limit indoor simulation test; the corrosion parameters are determined according to the on-site working conditions, such as temperature, pressure, gas components and partial pressure, liquid phase and solid phase components and ion content, the brand of the pipe used in the experiment, the grade of steel, the type of load applied during service and the magnitude of the tension-compression-bending-torsion load;
s1.2, processing a corrosion fatigue limit indoor simulation test sample; processing the pipe used in the experiment into a rod-shaped tensile sample;
S1.3, preparing corrosive gas with corresponding gas content; pumping the gas mixing cylinder (320) to vacuum; connecting the gas and H required by the experiment 2 S gas cylinder (310), CO 2 Gas cylinder (311), N 2 Gas cylinder (312), CH 4 A gas cylinder (313); according to the content required by the experiment, H is sequentially opened 2 S/CO 2 /N 2 /CH 4 The gas cylinder valve enables the gas to enter a gas mixing cylinder (320) to prepare mixed gas with corresponding gas component proportions;
s1.4, preparing a corrosive liquid medium with corresponding liquid-solid content and ion proportion; preparing corrosive liquid medium with corresponding liquid-solid components and contents according to the liquid phase and solid phase components and the ion contents, and continuously introducing corresponding gas components until saturation;
s1.5, monitoring the pressure of a hydraulic cylinder by using a hydraulic cylinder pressure sensor (3F), and monitoring the pressure of a gas mixing cylinder by using a gas mixing cylinder pressure sensor (3G);
s2, loading a sample:
s2.1, installing a radial loading assembly; assembling an upper cantilever stabilizer (250) inside the radial loading upper cantilever (244), sleeving the upper clamping end of the corrosion fatigue test sample (245) to a position close to the parallel section, and fixing; assembling a lower cantilever stabilizer (257) inside the radial loading upper cantilever (244), sleeving the lower clamping end of the corrosion fatigue test sample (245) to a position close to the parallel section, and fixing; the upper cantilever adapter (251), the lower cantilever adapter (256) and the bending stress loading shaft (254) are respectively connected;
S2.2, installing an axial loading assembly; assembling a lower sample joint (247) at the lower end of the corrosion fatigue test sample (245); mounting a lower holder (248) on the torque application shaft (230) and connecting with the lower sample joint (247), integrally placing the radial loading assembly (240) and securing with a lower stabilizer (249); assembling an upper sample joint (243) at the upper end of the corrosion fatigue test sample (245); mounting an upper holder (241) on the torque application shaft (230) and connecting with the upper sample joint (243), the upper holder (241) being used to integrally secure it to the radial load assembly (240);
s2.3, applying an axial stretching or compression load; by adjusting the upper and lower holders (241, 248) to apply a tensile or compressive load to the corrosion fatigue specimen (245), the calculated relationship between applied load and deflection can be directly used σ = E · epsilon, where σ is the tensile/compressive stress, E is the tensile elastic modulus or the compressive elastic modulus, epsilon is the tensile/compressive strain;
s2.4, applying radial bending load; the bending stress loading nut (253) is screwed down to increase the deflection of the parallel section of the corrosion fatigue test specimen (245), radial bending load is applied to the corrosion fatigue test specimen (245), and the relation between the applied load and the deflection can be corrected by adopting a four-point bending standard calculation formula or adopting an trial experiment;
S3, parameter setting:
s3.1, setting simulated corrosion environment parameters; adding the prepared corrosive liquid medium into a kettle body (223), immersing a radial loading assembly (240) on the liquid level, and sealing a kettle cover (222) and the kettle body (223) by using a sealing bolt (220) and a sealing nut (221); a strain sensor base (214) is fixed on a kettle cover sealing combination (226) by using a strain sensor base fixing flange (215); fixing a strain sensor fixing plate (213) on a torque transmission shaft (227) by using a strain sensor upper fixing flange (211) and a strain sensor upper fixing flange (212), and mounting a first strain sensor (2C-1) and a second strain sensor (2C-2) on the strain sensor fixing plate (213); sequentially connecting a load sensor (2B) and a rotary power device (210) with a torque transmission shaft (227);
s3.2, heating and pressurizing the kettle body; setting a temperature and pressure data processor (1A) in a computer controller (101) as experimental corresponding temperature and pressure, and controlling a heating sleeve (224) to heat a kettle body (223) through a high-temperature high-pressure kettle temperature and pressure sensor (2A) until the experimental set temperature is reached; a booster pump (314) is controlled by a high-temperature high-pressure kettle temperature and pressure sensor (2A) to boost the kettle body (223) until the experimental set pressure is reached;
S4, data monitoring:
s4.1, connecting a first strain data processor (1C-1) and a second strain data processor (1C-2) with a first strain sensor (2C-1) and a second strain sensor (2C-2) respectively, and monitoring the axial deformation of a corrosion fatigue specimen (245) during an experiment;
s4.2, connecting the high-temperature high-pressure kettle temperature and pressure data processor (1A) with the high-temperature high-pressure kettle temperature and pressure sensor (2A), and monitoring the numerical variation of the internal temperature and pressure of the kettle body (223) during the experiment;
s4.3, connecting a load data processor (1B) with a load sensor (2B), and monitoring the axial tensile load and the torque variation of the corrosion fatigue test sample (245) during the experiment;
s4.4, respectively connecting a hydraulic pump pressure data processor (1D) and a booster pump pressure data processor (1E) with a hydraulic pump pressure sensor (3D) and a booster pump pressure sensor (3E), monitoring the pump pressure of a hydraulic pump (326) and a booster pump (314), respectively connecting a hydraulic cylinder pressure data processor (1F) and a gas mixing cylinder pressure data processor (1G) with a hydraulic cylinder pressure sensor (3F) and a gas mixing cylinder pressure sensor (3G), and monitoring the internal pressures of a hydraulic cylinder (322) and a gas mixing cylinder (320) so as to ensure experimental safety;
s5, experimental post-treatment:
s5.1, taking out a corrosion fatigue test sample; after reaching the experiment preset period, cooling, decompressing, opening a corrosion fatigue limit testing device, and taking out a corrosion fatigue sample (245);
S5.2, observing corrosion cracking characteristics; analyzing and observing the morphology, the components and the protection characteristics of a corrosion product film on the surface of a corrosion fatigue test sample (245) by using macroscopic and microscopic means; observing and judging the nucleation and the expansion characteristics and the crack size of the parallel section cracks of the corrosion fatigue test sample (245);
s5.3, analyzing the fatigue strength of the sample; if the corrosion fatigue test specimen (245) breaks, continuing to carry out a corrosion fatigue limit test under the stress condition; if the corrosion fatigue test sample (245) is not broken, carrying out a room temperature tensile test, determining the residual strength of the pipe after the corrosion fatigue limit test, and simultaneously continuously carrying out a corrosion fatigue limit test under the stress condition;
s6, evaluating corrosion fatigue limit:
s6.1, a corrosion fatigue limit assessment method when bending stress is unchanged and tensile/compressive stress is changed;
the applied radial bending load is kept unchanged, corrosion fatigue S-N curves are measured by designing corrosion fatigue limit indoor simulation experiments of series groups under different tensile/compressive stress states, and corrosion fatigue limit stress when the pipe is subjected to tensile/compressive stress is evaluated under the bending stress;
s6.2, a corrosion fatigue limit assessment method when tensile/compressive stress is unchanged and bending stress is changed;
The applied axial stretching/compression load is kept unchanged, corrosion fatigue limit indoor simulation experiments of series groups are designed under different bending stress states respectively, corrosion fatigue S-N curves are measured, and the corrosion fatigue limit stress when the pipe is subjected to bending stress under the stretching/compression stress is evaluated;
s6.3, a corrosion fatigue limit assessment method in a pulling/pressing/bending/torsion alternating state;
and respectively designing corrosion fatigue limit indoor simulation experiments of series groups under different stretching, compression, bending and torque states by adopting a factor molecular method or an orthogonal experiment method, measuring a corrosion fatigue S-N curve, and evaluating the corrosion fatigue limit stress of the pipe in the corrosion environment.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310763097.0A CN116577266A (en) | 2023-06-27 | 2023-06-27 | Pipe corrosion fatigue limit testing device and method under corrosion and alternating load |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310763097.0A CN116577266A (en) | 2023-06-27 | 2023-06-27 | Pipe corrosion fatigue limit testing device and method under corrosion and alternating load |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN116577266A true CN116577266A (en) | 2023-08-11 |
Family
ID=87543349
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202310763097.0A Pending CN116577266A (en) | 2023-06-27 | 2023-06-27 | Pipe corrosion fatigue limit testing device and method under corrosion and alternating load |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN116577266A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117606923A (en) * | 2023-11-07 | 2024-02-27 | 中煤科工开采研究院有限公司 | Anchor rod stress corrosion test method and device in corrosion environment and application |
| CN118190657A (en) * | 2024-05-17 | 2024-06-14 | 西南石油大学 | Tensile test device in high-temperature high-pressure kettle |
-
2023
- 2023-06-27 CN CN202310763097.0A patent/CN116577266A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117606923A (en) * | 2023-11-07 | 2024-02-27 | 中煤科工开采研究院有限公司 | Anchor rod stress corrosion test method and device in corrosion environment and application |
| CN118190657A (en) * | 2024-05-17 | 2024-06-14 | 西南石油大学 | Tensile test device in high-temperature high-pressure kettle |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN101387598B (en) | Rock porosity real-time test device under action of Chemosmosis and creep coupling | |
| US5869750A (en) | Method, system and device for testing two-phase compressible compositions having gas under pressure | |
| CN110082214B (en) | Sandstone oil and gas well casing string simulation test device and evaluation method thereof | |
| CN106442136B (en) | Device for testing stress corrosion behavior of metal material under high pressure of fluid | |
| CN116577266A (en) | Pipe corrosion fatigue limit testing device and method under corrosion and alternating load | |
| CN108106945A (en) | A kind of non-homogeneous outer crowded load testing machine of casing and casing deformation computational methods | |
| US20120227467A1 (en) | Device for testing pressure resistance of vessel and method for testing pressure resistance of vessel by using the device | |
| CN111521493B (en) | High-temperature triaxial rock creep testing machine capable of simultaneously loading in multiple stages and using method | |
| CN103674679B (en) | Fracture-cavity type carbonate reservoir environment mechanical property test device and test method | |
| CN111735716A (en) | Rock temperature-stress coupling creep test device and test method under water environment | |
| CN109163978B (en) | Full-scale test method for pressure-bearing capacity and ductile-brittle transition behavior of low-temperature gas transmission steel pipe | |
| CN105571991A (en) | Cement slurry performance test system and a method thereof | |
| CN112268854A (en) | Pipe corrosion resistance evaluation device, installation method and evaluation method in corrosive environment | |
| CN211740920U (en) | Deep high-stress high-permeability environment simulation experiment system | |
| US20220196530A1 (en) | Precision High-Temperature Hydrogen Attack Apparatus | |
| CN112393970B (en) | Method and device for evaluating stress corrosion cracking sensitivity of pipe | |
| US7942064B2 (en) | Method and apparatus for measurement of mechanical characteristics of a cement sample | |
| CN111289377A (en) | Deep high-stress high-permeability environment simulation experiment system and experiment method thereof | |
| Han et al. | Assessment of stress distribution in premium connections with ultrasonic phased array and metal magnetic memory | |
| CN114778307A (en) | Experimental device and method for simulating tubular column mechanical test | |
| Tandon et al. | Evaluation of existing fracture mechanics models for burst pressure predictions, theoretical and experimental aspects | |
| EP3591375A1 (en) | Apparatus, sample and method for tensile tests, especially under hydrogen | |
| CN109916731B (en) | Reliability testing device and method for rubber cylinder under corrosion and stress effects | |
| CN108871931B (en) | Liquid-filled jointed rock mass sample liquid application device and method for flange type SHPB (split-type Rockwell) | |
| CN116642776B (en) | Material hydrogen induced cracking testing device and method for high-pressure hydrogen environment |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |