CN114993820B - Method for obtaining rock compressive strength using drilling cuttings - Google Patents
Method for obtaining rock compressive strength using drilling cuttings Download PDFInfo
- Publication number
- CN114993820B CN114993820B CN202210557691.XA CN202210557691A CN114993820B CN 114993820 B CN114993820 B CN 114993820B CN 202210557691 A CN202210557691 A CN 202210557691A CN 114993820 B CN114993820 B CN 114993820B
- Authority
- CN
- China
- Prior art keywords
- rock
- cuttings
- compressive strength
- sample
- indentation
- 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.)
- Active
Links
- 239000011435 rock Substances 0.000 title claims abstract description 288
- 238000005520 cutting process Methods 0.000 title claims abstract description 86
- 238000000034 method Methods 0.000 title claims abstract description 35
- 238000005553 drilling Methods 0.000 title abstract description 20
- 238000007373 indentation Methods 0.000 claims abstract description 89
- 238000002474 experimental method Methods 0.000 claims abstract description 44
- 238000013178 mathematical model Methods 0.000 claims abstract description 15
- 238000007906 compression Methods 0.000 claims abstract description 10
- 230000006835 compression Effects 0.000 claims abstract description 10
- 239000003822 epoxy resin Substances 0.000 claims abstract description 10
- 229920000647 polyepoxide Polymers 0.000 claims abstract description 10
- 239000003292 glue Substances 0.000 claims abstract description 9
- 239000012634 fragment Substances 0.000 claims description 37
- 238000012360 testing method Methods 0.000 claims description 34
- 238000005498 polishing Methods 0.000 claims description 12
- 239000000463 material Substances 0.000 claims description 8
- 239000004568 cement Substances 0.000 claims description 6
- 238000000611 regression analysis Methods 0.000 claims description 6
- 238000004364 calculation method Methods 0.000 claims description 5
- 238000000227 grinding Methods 0.000 claims description 5
- 238000010438 heat treatment Methods 0.000 claims description 4
- 238000005266 casting Methods 0.000 claims description 3
- 230000001419 dependent effect Effects 0.000 claims description 3
- 239000011521 glass Substances 0.000 claims description 3
- 239000007788 liquid Substances 0.000 claims description 3
- 238000007789 sealing Methods 0.000 claims description 3
- 239000004593 Epoxy Substances 0.000 claims description 2
- 230000015572 biosynthetic process Effects 0.000 claims description 2
- 238000011160 research Methods 0.000 abstract description 7
- 238000003672 processing method Methods 0.000 abstract description 3
- 238000007544 microindentation test Methods 0.000 description 8
- 235000019580 granularity Nutrition 0.000 description 7
- 238000009826 distribution Methods 0.000 description 6
- 238000004458 analytical method Methods 0.000 description 5
- 238000012669 compression test Methods 0.000 description 5
- 238000006073 displacement reaction Methods 0.000 description 5
- 230000000694 effects Effects 0.000 description 4
- 239000002245 particle Substances 0.000 description 4
- 239000011148 porous material Substances 0.000 description 4
- 238000005516 engineering process Methods 0.000 description 2
- 238000009472 formulation Methods 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 238000005457 optimization Methods 0.000 description 2
- 238000002360 preparation method Methods 0.000 description 2
- 238000012545 processing Methods 0.000 description 2
- 239000004576 sand Substances 0.000 description 2
- 239000004575 stone Substances 0.000 description 2
- 230000002159 abnormal effect Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 239000004927 clay Substances 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 238000002425 crystallisation Methods 0.000 description 1
- 230000008025 crystallization Effects 0.000 description 1
- 238000000556 factor analysis Methods 0.000 description 1
- 229910052500 inorganic mineral Inorganic materials 0.000 description 1
- 230000002452 interceptive effect Effects 0.000 description 1
- 238000007620 mathematical function Methods 0.000 description 1
- 239000011159 matrix material Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 239000011707 mineral Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000004806 packaging method and process Methods 0.000 description 1
- 239000003208 petroleum Substances 0.000 description 1
- 238000012216 screening Methods 0.000 description 1
- 230000005476 size effect Effects 0.000 description 1
- 239000000758 substrate Substances 0.000 description 1
Classifications
-
- 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
- G01N3/08—Investigating strength properties of solid materials by application of mechanical stress by applying steady tensile or compressive forces
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N1/00—Sampling; Preparing specimens for investigation
- G01N1/28—Preparing specimens for investigation including physical details of (bio-)chemical methods covered elsewhere, e.g. G01N33/50, C12Q
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N1/00—Sampling; Preparing specimens for investigation
- G01N1/28—Preparing specimens for investigation including physical details of (bio-)chemical methods covered elsewhere, e.g. G01N33/50, C12Q
- G01N1/36—Embedding or analogous mounting of samples
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N1/00—Sampling; Preparing specimens for investigation
- G01N1/28—Preparing specimens for investigation including physical details of (bio-)chemical methods covered elsewhere, e.g. G01N33/50, C12Q
- G01N1/44—Sample treatment involving radiation, e.g. heat
-
- 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
- G01N3/02—Details
- G01N3/06—Special adaptations of indicating or recording means
-
- 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
- G01N3/40—Investigating hardness or rebound hardness
- G01N3/42—Investigating hardness or rebound hardness by performing impressions under a steady load by indentors, e.g. sphere, pyramid
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F17/00—Digital computing or data processing equipment or methods, specially adapted for specific functions
- G06F17/10—Complex mathematical operations
- G06F17/18—Complex mathematical operations for evaluating statistical data, e.g. average values, frequency distributions, probability functions, regression analysis
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N1/00—Sampling; Preparing specimens for investigation
- G01N1/28—Preparing specimens for investigation including physical details of (bio-)chemical methods covered elsewhere, e.g. G01N33/50, C12Q
- G01N1/36—Embedding or analogous mounting of samples
- G01N2001/364—Embedding or analogous mounting of samples using resins, epoxy
-
- 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
- G01N2203/0001—Type of application of the stress
- G01N2203/0003—Steady
-
- 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
- G01N2203/0014—Type of force applied
- G01N2203/0016—Tensile or compressive
- G01N2203/0019—Compressive
-
- 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
- G01N2203/0075—Strain-stress relations or elastic constants
-
- 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
- G01N2203/06—Indicating or recording means; Sensing means
- G01N2203/067—Parameter measured for estimating the property
- G01N2203/0676—Force, weight, load, energy, speed or acceleration
-
- 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
- G01N2203/06—Indicating or recording means; Sensing means
- G01N2203/067—Parameter measured for estimating the property
- G01N2203/0682—Spatial dimension, e.g. length, area, angle
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Life Sciences & Earth Sciences (AREA)
- Immunology (AREA)
- Biochemistry (AREA)
- Health & Medical Sciences (AREA)
- Pathology (AREA)
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- General Health & Medical Sciences (AREA)
- Engineering & Computer Science (AREA)
- Data Mining & Analysis (AREA)
- Mathematical Optimization (AREA)
- Pure & Applied Mathematics (AREA)
- Theoretical Computer Science (AREA)
- Mathematical Physics (AREA)
- Mathematical Analysis (AREA)
- Computational Mathematics (AREA)
- Evolutionary Biology (AREA)
- General Engineering & Computer Science (AREA)
- Software Systems (AREA)
- Databases & Information Systems (AREA)
- Algebra (AREA)
- Probability & Statistics with Applications (AREA)
- Operations Research (AREA)
- Bioinformatics & Computational Biology (AREA)
- Bioinformatics & Cheminformatics (AREA)
- Investigation Of Foundation Soil And Reinforcement Of Foundation Soil By Compacting Or Drainage (AREA)
- Investigating Strength Of Materials By Application Of Mechanical Stress (AREA)
Abstract
The invention provides a method for obtaining rock compressive strength by using drilling cuttings, which comprises the steps of obtaining the non-confining pressure compressive strength of a rock core through an indoor uniaxial compression experiment, obtaining the cuttings with preset sizes from the rock corresponding to a rock core sample, preparing a plurality of rock cuttings and rock samples by using the cuttings and epoxy resin glue, obtaining the indentation elastic modulus of the rock cuttings sample through a rock cuttings micron indentation experiment, establishing a rock and rock cuttings compressive strength relation prediction model according to the non-confining pressure compressive strength of the rock core and the indentation elastic modulus of the rock cuttings sample, and selecting different types of rock cores in different strata for experiments to verify the universality of the compressive strength relation prediction model. The invention simulates the rock breaking process of the stratum drill bit to prepare corresponding rock scraps, discusses the mathematical relationship between the rock core and the related mechanical parameters of the rock scraps by utilizing the related mathematical model and the data processing method, establishes the mathematical relationship model between the rock scraps and the mechanical parameters of the rock, and improves the accuracy of the research on the microscopic mechanical properties of the rock.
Description
Technical Field
The invention belongs to the technical field of drilling, and particularly relates to a method for obtaining rock compressive strength by using drilling cuttings.
Background
Based on the important role played by the mechanical properties of stratum rock in the petroleum drilling field, more and more expert students aim at developing and taking in the research of the mechanical properties of stratum rock, continuously develop the research and experiment on the mechanical properties of rock, perfects a research result system and is applied to the on-site drilling process. In the absence of drill cores or logging data, the mechanical properties of formation rock are evaluated using well-formed, readily available, well-sourced drill cuttings. The technology or instrument for directly acquiring or measuring the micromechanics of the rock debris is not mature and accurate in consideration of the current research situation at home and abroad.
Disclosure of Invention
The invention mainly aims to provide a method for acquiring compressive strength of rock by using drill cuttings, and aims to solve the technical problem that the accuracy of directly acquiring or measuring compressive strength of the cuttings is not high in the prior art.
In order to achieve the above object, the present invention provides a method for obtaining compressive strength of rock by using drill cuttings, comprising the steps of:
acquiring the confining pressure-free compressive strength of the core through an indoor uniaxial compression experiment;
obtaining rock scraps with preset sizes from rock corresponding to the core sample, and preparing a plurality of rock scraps and rock samples by using the rock scraps and the epoxy resin glue;
obtaining the indentation elastic modulus of a rock debris sample through a rock debris micron indentation experiment;
Establishing a compressive strength relation prediction model of the rock and the rock chips according to the confining pressure-free compressive strength of the rock core and the indentation elastic modulus of the rock chip sample;
And selecting different types of rock cores in different stratum to perform experiments so as to verify universality of the compressive strength relation prediction model.
In an embodiment of the present invention, the step of obtaining the confining pressure-free compressive strength of the core through an indoor uniaxial compression experiment includes:
selecting a core sample with a preset size from stratum rock, and heating and sealing the core sample by adopting a heat-shrinkable sleeve;
Placing the core sample in a confining pressure chamber and loading the core sample in the axial direction until the core sample is damaged;
Recording the stress suffered by the core sample in the loading process in real time, and drawing a stress-strain curve;
and obtaining the compressive strength of the core sample according to the stress-strain curve.
In an embodiment of the present invention, the step of obtaining rock chips with a preset size from the rock corresponding to the core sample, and preparing a plurality of rock chip rock samples by using the rock chips and the epoxy resin glue includes:
crushing rock corresponding to the core sample by using a hammer and selecting a plurality of rock fragments with preset granularity from the rock fragments, wherein the range of the preset granularity is 6-10 mm;
Hydraulically cutting each rock debris fragment into square rock debris;
Sequentially stacking a plurality of rock fragments from top to bottom, and placing the rock fragments in a cylindrical mold to wait for casting;
introducing and injecting an epoxy cementing liquid into the cylindrical mold through a glass rod to solidify the cuttings;
cutting and polishing the solidified rock fragments to obtain rock fragment samples.
In an embodiment of the invention, the step of cutting and polishing the solidified cuttings to obtain a cuttings sample comprises:
removing the solidified rock debris from the cylindrical mold;
cutting redundant cement on the upper surface and the lower surface of the rock debris to optimize the parallelism between the upper surface and the lower surface of the rock debris;
and polishing and grinding the cut rock fragments to obtain rock fragment samples meeting the requirements.
In an embodiment of the invention, the step of cutting excess cement on the upper and lower sides of the cuttings to optimize parallelism between the upper and lower sides of the cuttings comprises:
Selecting four positions on the outer side wall of the rock debris, and measuring the heights of the four positions;
Controlling the height difference values of the four positions to be within a preset range;
The matching degree test of the sample and the instrument sensor is carried out by adopting a micron indentation instrument mechanical sensor;
judging whether the stress of the instrument sensor is uniform or not;
and when the stress of the instrument sensor is uneven, repeating the steps in sequence until the parallelism meets the preset requirement.
In an embodiment of the present invention, the step of obtaining the indentation elastic modulus of the rock debris sample through the rock debris micro indentation test includes:
carrying out a micrometer indentation test for each rock debris sample for at least 10 times to obtain indentation elastic modulus;
the multiple test values for each cuttings sample are averaged to obtain the indentation elastic modulus of the cuttings sample.
In an embodiment of the present invention, the step of establishing a compressive strength relation prediction model of rock and rock chips according to the confining pressure-free compressive strength of the core and the indentation elastic modulus of the rock chip sample includes:
selecting the indentation elastic modulus of a rock debris sample as an independent variable, wherein the non-confining pressure compressive strength of the rock core is a dependent variable, and drawing scattered points under the same coordinate system;
carrying out regression analysis on the scattered points by adopting different mathematical models, and obtaining linear correlation coefficients corresponding to the different mathematical models;
And selecting a mathematical model with the maximum linear correlation coefficient as a prediction model of the compressive strength of the rock.
In an embodiment of the present invention, the indentation elastic modulus of the rock debris sample is obtained by adopting the following calculation formula:
Wherein,
Where E is the indentation elastic modulus of the cuttings sample, E r is the reduced elastic modulus, μ d is the Poisson's ratio of the cuttings sample, μ i is the Poisson's ratio of the indenter material, E i is the modulus of the indenter material, C is the contact compliance, which is equal to the curve dh/dF (inverse of the contact stiffness) at maximum test force at which the test force is unloaded, and A p is the contact projected area.
In an embodiment of the invention, the predictive model of compressive strength of the rock can be expressed by the following formula:
UCS=0.1099E2-3.0353E+60.55
where UCS represents the compressive strength of the rock and E represents the indentation elastic modulus of the cuttings.
In the embodiment of the invention, the hammer stone machine comprises a supporting frame, a rock chip groove, an impact hammer and drill teeth, wherein the rock chip groove is used for placing rock and is positioned on the bottom end surface of the supporting frame, the impact hammer is hung on the top end of the supporting frame through a connecting rod and is used for applying impact force to the drill teeth so as to drive the drill teeth to move towards the rock, and the center lines of the drill teeth and the rock chip groove are coincident.
Through the technical scheme, the method for acquiring the compressive strength of the rock by using the drilling cuttings provided by the embodiment of the invention has the following beneficial effects:
The method comprises the steps of obtaining the non-confining pressure compressive strength of a rock core through an indoor uniaxial compression experiment, obtaining rock scraps of preset size from rock corresponding to a rock core sample, preparing a plurality of rock scraps and rock samples through the rock scraps and epoxy resin glue, obtaining the indentation elastic modulus of the rock scraps sample through a rock scraps micron indentation experiment, establishing a compressive strength relation prediction model of the rock and the rock scraps according to the non-confining pressure compressive strength of the rock core and the indentation elastic modulus of the rock scraps sample, and selecting different types of rock cores in different strata to conduct experiments so as to verify universality of the compressive strength relation prediction model. Based on the method, the rock breaking process of the stratum drill bit is simulated to prepare corresponding rock scraps, the micro indentation experiment of the rock scraps sample is carried out to measure the indentation hardness and the elastic modulus of the rock scraps, analysis and processing are carried out according to experimental data results and related mechanical parameters of the rock core, the mathematical relationship of the related mechanical parameters of the rock core and the rock scraps is discussed by utilizing a related mathematical model and a data processing method, and a mathematical relationship model between the rock scraps and the mechanical parameters of the rock is established, so that the mechanical properties of stratum rock can be more accurately researched according to a prediction model. In addition, the invention can evaluate the compressive strength of the rock while drilling by utilizing the rock scraps (sand samples) on site, and has important practical significance for drill bit type selection, parameter optimization, technological measure formulation and the like in drilling engineering.
Additional features and advantages of the invention will be set forth in the detailed description which follows.
Drawings
The accompanying drawings are included to provide an understanding of the invention, and are incorporated in and constitute a part of this specification, illustrate the invention and together with the description serve to explain, without limitation, the invention. In the drawings:
FIG. 1 is a flow chart of a method for deriving rock compressive strength using drill cuttings in accordance with an embodiment of the invention;
FIG. 2 is a schematic flow chart illustrating one embodiment of a method for deriving rock compressive strength using drill cuttings in accordance with the present invention;
FIG. 3 is a schematic flow chart of another embodiment of a method for deriving rock compressive strength using drill cuttings in accordance with the present invention;
FIG. 4 is a schematic view of the construction of a hammer machine for making rock debris according to the present invention;
FIG. 5 is a graph of indentation load versus displacement for one of the samples obtained from a micro-indentation test seed according to the present invention;
fig. 6 is a graph of the relationship between compressive strength obtained by uniaxial compression test and elastic modulus obtained by micro indentation test according to the present invention.
Description of the reference numerals
| Reference numerals | Name of the name | Reference numerals | Name of the name |
| 1 | Supporting frame | 4 | Connecting rod |
| 2 | Rock debris groove | 5 | Drilling tooth |
| 3 | Impact hammer | 6 | Rock |
Detailed Description
Specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for purposes of illustration and explanation only and are not intended to limit the present invention.
A method for obtaining compressive strength of rock using drill cuttings according to the present invention will be described below with reference to the accompanying drawings.
As shown in fig. 1, in an embodiment of the present invention, there is provided a method for obtaining compressive strength of rock using drill cuttings, comprising the steps of:
Step S10, obtaining the confining pressure-free compressive strength of the rock core through an indoor uniaxial compression experiment;
S20, rock scraps with preset sizes are obtained from rock corresponding to the rock core sample, and a plurality of rock scraps and rock samples are prepared by using the rock scraps and epoxy resin glue;
s30, obtaining an indentation elastic modulus of a rock debris sample through a rock debris micro indentation experiment;
S40, establishing a compressive strength relation prediction model of the rock and the rock chips according to the confining pressure-free compressive strength of the rock core and the indentation elastic modulus of the rock chip sample;
And S50, selecting different types of rock cores in different strata to perform experiments so as to verify universality of the compressive strength relation prediction model.
Among them, before the rock chip micro indentation experiments were carried out, the following five aspects were mainly considered.
(1) Core selection and cuttings selection. And the consistency, the relativity and the accuracy of the mechanical parameters of the rock core and the rock scraps obtained through experiments are ensured.
(2) And (5) manufacturing and selecting rock scraps. Because the rock chips produced by the rock core have uncertainty and contingency, how to produce the rock chips from the rock core and how to select the rock chips produced into samples are all keys for reducing experimental errors and ensuring experimental precision.
(3) The selection of the number of indentation points and the distribution of the indentation on the rock debris surface in the micro indentation experiment. In order to improve the indentation efficiency and the experimental precision of the micro indentation experiment, the arrangement condition of each indentation point on the surface of the rock debris sample is determined, and the density distribution and the position distribution of the indentation points on the surface of the sample are not influenced by the thickness of the rock debris sample.
(4) Influence of indentation load-displacement curve on experimental result in the process of micro indentation experimental test.
(5) Size effect regularity research of the mechanical properties of the rock core and the rock cuttings is carried out, the rock cores with different types and mechanical properties of different strata are selected for experiment, and then rock cuttings sample preparation and experimental test are carried out to ensure universality of a regularity result.
According to the invention, corresponding rock scraps are prepared by simulating the rock breaking process of the stratum drill bit, the indentation hardness and the elastic modulus of the rock scraps are measured by carrying out a micron indentation experiment of the rock scraps sample, analysis and treatment are carried out according to experimental data results and related mechanical parameters of the rock core, the mathematical relationship between the related mechanical parameters of the rock core and the rock scraps is discussed by utilizing a related mathematical model and a data processing method, and a mathematical relationship model between the rock scraps and the mechanical parameters of the rock is established, so that a good foundation is laid for the subsequent study of the mechanical properties of stratum rock, and the accuracy of the measurement of the compressive strength of the stratum rock is greatly improved. In addition, the invention can evaluate the compressive strength of the rock while drilling by utilizing the rock scraps (sand samples) on site, and has important practical significance for drill bit type selection, parameter optimization, technological measure formulation and the like in drilling engineering.
As shown in fig. 2, in one embodiment, the step of obtaining the confining pressure-free compressive strength of the core through the indoor uniaxial compression experiment includes:
S11, selecting a core sample with a preset size from stratum rock, and heating and sealing the core sample by adopting a heat-shrinkable sleeve;
step S12, placing the core sample in a confining pressure chamber and loading the core sample along the axial direction until the core sample is destroyed;
step S13, recording the stress suffered by the core sample in the loading process in real time, and drawing a stress-strain curve;
and S14, obtaining the compressive strength of the core sample according to the stress-strain curve.
The uniaxial compression experiment is a rock mechanics experiment for carrying out unconfined axial pressurization on the standard rock core so as to damage the standard rock core. The compressive strength and deformation of the rock core can be obtained through the experiment, and corresponding elastic mechanical parameters such as elastic modulus, poisson ratio and the like can be obtained through calculation. The experiment uses a rock mechanics triaxial stress test system (which is conventional stress test system equipment in the prior art) of the Kanga laboratory instruments Co., ltd. The test system comprises a shaft pressure control system, a confining pressure control system, a pore pressure control system and a computer acquisition and control system, wherein the shaft pressure control system a provides axial pressure by an LX-50 servo loading system. The axle pressure is controlled by the computer control system to control the strain or pressure servo. And b, the confining pressure control system is used for simulating the underground horizontal stress condition and consists of a phi 45 servo loading system and a supercharger. The change of the confining pressure can be monitored by a pressure sensor and a pressure gauge, and the highest confining pressure can be simulated to 70MPa. And c Kong Yakong, the system is used for simulating the condition of downhole pore pressure, and the LX-45 servo loading system is used for providing pressure. Pore pressure changes can be monitored by pressure sensors and pressure gauges, and the highest pore pressure can be simulated to 40MPa. And d, a computer acquisition and control system, wherein various loading paths and test processes can be controlled in real time through a computer when rock sample testing is carried out. The computer automatically collects voltage signals through the sensor and converts the voltage signals into stress and displacement data to be stored in the computer, and the related experimental steps and methods are as follows:
1. Preparing a core according to the requirement, wherein the radius of the ground is 25mm, and the height of the core is 50 mm. And sleeving the thermal shrinkage sleeve on the core to be tested, and heating and plastically packaging the core sample.
2. The strain gauge is clamped and placed in the confining pressure chamber without lowering the confining pressure cylinder. The strain sensor and ram positions are then adjusted to close the safety door.
3. Opening computer software, editing and adjusting a computer control mode, a protection mode and the like, setting an experimental loading mode, and starting axial loading of the core sample until the core is damaged.
4. In the experimental loading process, relevant data are recorded at any time, and equipment and core conditions are observed.
5. After the core is damaged, relevant experimental data are led out, a stress-strain curve is drawn, and relevant elastic mechanical parameters of the final core are calculated.
6. Closing the power supply of the laboratory, and making the finishing equipment and the finishing laboratory sanitary.
Through an indoor core experiment, 10 different cores are selected in total in the research, and the test results of the related mechanical parameters of the cores are shown in a table one:
Table one indoor core test results
As shown in fig. 3, in another embodiment of the present invention, the steps of obtaining rock chips with a preset size from rock corresponding to a core sample, and preparing a plurality of rock chip rock samples using the rock chips and epoxy resin glue include:
S21, crushing rock corresponding to a rock core sample by using a hammer and selecting a plurality of rock fragments with preset granularity from the rock core sample, wherein the range of the preset granularity is 6-10 mm;
step S22, hydraulically cutting each rock debris fragment into square rock debris;
S23, sequentially stacking a plurality of rock fragments from top to bottom, and placing the rock fragments in a cylindrical mold to wait for casting;
s24, guiding and injecting epoxy resin cementing liquid into the cylindrical mold through a glass rod to solidify rock fragments;
And S25, cutting and polishing the solidified rock fragments to obtain rock fragment samples.
Along with the continuous progress of drilling technology, the rock cuttings collected on the drilling site generally show small particle size trend, the particle size range is mainly between 1 and 10mm, and in order to simulate the condition of the rock cuttings in the field as far as possible, a hammer is required to continuously simulate the rock breaking process of the underground drill bit on the rock core as shown in fig. 4, so that corresponding rock cuttings are produced. In addition, in the process of manufacturing rock fragments, rock fragments with larger or smaller particle size are not suitable to be selected, rock fragments with moderate particle size are required to be selected, so that the thickness and the area of a manufactured rock fragment sample can be ensured, the effect of indentation is not affected, boundary effects can be avoided, meanwhile, the size of a sample base can be ensured to meet the size requirement of a micrometer indentation instrument, specific numerical values are determined according to the indentation parameter setting and the distribution of indentation points of the micrometer indentation experiment, the micrometer indentation instrument used in the micrometer indentation experiment is conventional equipment in the prior art, and the indentation principle is well known to those skilled in the art and is not repeated.
And carrying out fractal experiments on the prepared rock fragments. And (3) screening out rock fragments with various granularities by using sieves with the granularity of 0.8mm, 1mm, 2mm, 4mm, 6mm, 8mm and 10mm respectively, and selecting the rock fragments with the granularity of 6-10mm as much as possible for bonding in order to facilitate the preparation of rock fragment samples. The thickness and the area of the rock sample are based on the condition that the indentation effect is not affected, the boundary effect is avoided and the size of the sample substrate is suitable, and specific numerical values are determined according to the indentation depth parameter setting and the indentation point distribution of the indentation experiment. In the micro indentation experiment, rock scraps are made into small rock samples with the bottom radius of 20mm and the height of 20mm by using epoxy resin glue, and the rock samples are polished and cut for the experiment as shown in the following figure 3.
The hammer stone machine comprises a supporting frame 1, a rock chip groove 2, an impact hammer 3 and a drilling tooth 5 impact hammer 3, wherein the rock chip groove 2 is used for placing rock 6 and is positioned on the bottom end surface of the supporting frame 1, the impact hammer 3 is hung on the top end of the supporting frame 1 through a connecting rod 4, the impact hammer 3 is used for applying impact force to the drilling tooth 5 to drive the drilling tooth 5 to move towards the rock 6, and the center lines of the drilling tooth 5 and the rock chip groove 2 are coincident. During experiments, the rock 6 is placed in the rock chip groove 2, and the impact hammer 3 is applied with acting force through external driving force, so that the impact hammer 3 drives the drilling teeth 5 to move towards the surface of the rock 6 and applies drilling force to the rock 6, and then the rock 6 is broken.
In an embodiment of the invention, the step of cutting and polishing the solidified cuttings to obtain a cuttings sample comprises:
removing the solidified rock debris from the cylindrical mold;
Cutting redundant cement on the upper surface and the lower surface of the rock debris to optimize the parallelism between the upper surface and the lower surface of the rock debris;
And polishing and grinding the cut rock fragments to obtain rock fragment samples meeting the requirements.
Specifically, the step of cutting the excess cement on the upper and lower sides of the cutting to optimize parallelism between the upper and lower sides of the cutting comprises:
Selecting four positions on the outer side wall of the rock debris, and measuring the heights of the four positions;
Controlling the height difference values of the four positions to be within a preset range;
The matching degree test of the sample and the instrument sensor is carried out by adopting a micron indentation instrument mechanical sensor;
judging whether the stress of the instrument sensor is uniform or not;
and when the stress of the instrument sensor is uneven, repeating the steps in sequence until the parallelism meets the preset requirement.
The requirement of parallelism of the rock debris sample is that the curve of indentation load-displacement (wherein the abscissa indicates displacement and the ordinate indicates indentation load) measured by the micro indentation test shown in fig. 5 is the key of experimental acquisition data, so that the parallelism of the test sample has higher requirement. And the first surface of grinding and polishing is used as a reference, the second surface is polished again, the flatness and parallelism of the two surfaces of the sample are ensured, and four positions are measured around the rock sample by using a micrometer after grinding and polishing, wherein the difference is controlled to be less than 100 mu m, and preferably less than 50 mu m, so that the accuracy of experimental data is greatly improved. In order to ensure that the parallelism of the horizontal plane of the sample meets the requirement, the matching degree test of the sample and the instrument sensor is also required to be carried out by using a micron indentation meter mechanical sensor after polishing, and if the sensor shows uneven stress, the parallelism of the sample is required to be further optimized. (3) The distribution of indentation points requires that at least 10 different indentation point tests should be performed for each sample in order to ensure the accuracy of the data of the micro indentation experiments. Meanwhile, as the rock sample is mostly formed by cementing a clay matrix into a plurality of mineral deposits, different roughness exists on the rock surface, experiments are carried out on the smooth surface according to the lattice layout of 50-100 mu m intervals in a test area, and if the surface is rough, manual point selection is needed for testing.
In an embodiment of the present invention, the step of obtaining the indentation elastic modulus of the rock chip sample through the rock chip micro indentation test comprises:
carrying out a micrometer indentation test for each rock debris sample for at least 10 times to obtain indentation elastic modulus;
the multiple test values for each cuttings sample are averaged to obtain the indentation elastic modulus of the cuttings sample.
The micro indentation experimental object is derived from corresponding rock debris samples prepared from 10 rock cores tested by a uniaxial compression experiment, the experimental mode adopts a mode of uniaxial crush samples, and each experimental sample is subjected to a micro indentation experiment. A total of 10 cuttings samples were tested, each of which was subjected to 10-15 point indentation tests, and a total of 145 micro indentation experiments were performed, resulting in 290 experimental data, the specific data being shown in table two (outliers removed).
Data record of surface two-micrometer indentation experiment
And then processing according to the data of the elastic modulus of the sample obtained by the micro indentation test, removing part of abnormal points (probably caused by the fact that cementing positions or crystallization parts are tested in rock fragments), and respectively calculating the average value of the related mechanical parameters measured by each rock fragment sample to obtain the following test results, wherein the details are shown in a table three.
Table three rock sample micrometer indentation experimental result
Wherein the calculation formula of the inhomogeneity coefficient V isS represents the standard deviation of the data, RMav represents the average value of the data.
Further, the step of establishing a compressive strength relation prediction model of rock and rock chips according to the confining pressure-free compressive strength of the rock core and the indentation elastic modulus of the rock chip sample comprises the following steps:
selecting the indentation elastic modulus of a rock debris sample as an independent variable, the non-confining pressure compressive strength of a rock core as an independent variable, and drawing scattered points under the same coordinate system;
carrying out regression analysis on the scattered points by adopting different mathematical models, and obtaining linear correlation coefficients corresponding to the different mathematical models;
And selecting a mathematical model with the maximum linear correlation coefficient as a prediction model of the compressive strength of the rock.
In an embodiment of the invention, the indentation elastic modulus of the rock debris sample is obtained by adopting the following calculation formula:
Wherein,
Where E is the indentation elastic modulus of the cuttings sample, E r is the reduced elastic modulus, μ d is the Poisson's ratio of the cuttings sample, μ i is the Poisson's ratio of the indenter material, E i is the modulus of the indenter material, C is the contact compliance, which is equal to the curve dh/dF (inverse of the contact stiffness) at maximum test force at which the test force is unloaded, and A p is the contact projected area.
According to the test result of the rock core indoor uniaxial compression test and the micro indentation test result of the rock debris correspondingly prepared, the parameter analysis corresponding to the elastic modulus and the compressive strength is carried out to obtain the rock core indoor uniaxial compression test and the rock debris corresponding parameter analysis shown in figure 5. Regression analysis is performed on the respective scattered points of fig. 5 using different mathematical models, in which the data on the X-axis is an independent variable and the data on the Y-axis is a dependent variable, and since there is a large error when performing regression analysis using one mathematical function, in order to improve the accuracy of analysis, the regression analysis is performed using 5 different mathematical models such as a straight line, a polynomial function, an exponential function, a logarithmic function, and a power function, respectively. And verifying the regression result by taking the correlation coefficient R2 as a judgment standard according to a single factor analysis of variance theory in mathematical statistics to respectively obtain final linear correlation coefficients between the regression result and the judgment standard, and selecting an optimal result and an optimal curve. The specific results are shown in Table four below.
Fitting relation between compressive strength of table four uniaxial compression test and elastic modulus measured by micron indentation test
Note that x in the table is the modulus of elasticity of the indentation measured by the micro indentation test, and y is the compressive strength measured by the uniaxial compression test.
It can be obviously seen that the compressive strength of the rock core has good positive correlation with the indentation elastic modulus of the corresponding rock scraps, the correlation coefficients of the 5 mathematical models are all above 0.75, and the prediction model of the compressive strength of the rock can be expressed by adopting the following formula:
UCS=0.1099E2-3.0353E+60.55
where UCS represents the compressive strength of the rock and E represents the indentation elastic modulus of the cuttings.
In the description of the present invention, it should be understood that the terms "first," "second," and the like are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In the description of the present invention, the meaning of "plurality" means at least two, for example, two, three, etc., unless specifically defined otherwise.
In the present invention, unless explicitly specified and limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally formed, mechanically connected, electrically connected, or communicable with each other, directly connected, indirectly connected through an intervening medium, or in communication between two elements or in an interactive relationship between two elements, unless otherwise explicitly specified. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art according to the specific circumstances.
In the description of the present specification, a description referring to terms "one embodiment," "some embodiments," "examples," "specific examples," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms are not necessarily directed to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, the different embodiments or examples described in this specification and the features of the different embodiments or examples may be combined and combined by those skilled in the art without contradiction.
While embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and not to be construed as limiting the invention, and that variations, modifications, alternatives and variations may be made to the above embodiments by one of ordinary skill in the art within the scope of the invention.
Claims (8)
1. A method for obtaining compressive strength of rock using drill cuttings, comprising the steps of:
Acquiring the confining pressure-free compressive strength of the core sample through an indoor uniaxial compression experiment;
obtaining rock scraps with preset sizes from rock corresponding to the core sample, and preparing a plurality of rock scraps and rock samples by using the rock scraps and the epoxy resin glue;
obtaining the indentation elastic modulus of a rock debris sample through a rock debris micron indentation experiment;
establishing a compressive strength relation prediction model of the rock and the rock chips according to the confining pressure-free compressive strength of the core sample and the indentation elastic modulus of the rock chip sample;
Selecting different types of core samples in different stratum for experiments to verify universality of the compressive strength relation prediction model;
The step of establishing a rock and rock chip compressive strength relation prediction model according to the confining pressure-free compressive strength of the core sample and the indentation elastic modulus of the rock chip sample comprises the following steps:
Selecting the indentation elastic modulus of a rock debris sample as an independent variable, wherein the non-confining pressure compressive strength of the rock core sample is a dependent variable, and drawing scattered points under the same coordinate system;
carrying out regression analysis on the scattered points by adopting different mathematical models, and obtaining linear correlation coefficients corresponding to the different mathematical models;
Selecting a mathematical model with the maximum linear correlation coefficient as a prediction model of compressive strength of the rock;
wherein, the prediction model of the compressive strength of the rock can be expressed by the following formula:
UCS=0.1099E2-3.0353E+60.55
where UCS represents the compressive strength of the rock and E represents the indentation elastic modulus of the cuttings.
2. The method of obtaining rock compressive strength using drill cuttings as recited in claim 1, wherein the step of obtaining the confining pressure-free compressive strength of the core sample by an indoor uniaxial compression experiment comprises:
selecting a core sample with a preset size from stratum rock, and heating and sealing the core sample by adopting a heat-shrinkable sleeve;
Placing the core sample in a confining pressure chamber and loading the core sample in the axial direction until the core sample is damaged;
Recording the stress suffered by the core sample in the loading process in real time, and drawing a stress-strain curve;
and obtaining the compressive strength of the core sample according to the stress-strain curve.
3. The method for obtaining rock compressive strength by using drill cuttings according to claim 1, wherein the step of obtaining cuttings of a predetermined size from the rock corresponding to the core sample and preparing a plurality of cuttings and rock samples by using the cuttings and the epoxy resin glue comprises:
crushing rock corresponding to the core sample by using a hammer and selecting a plurality of rock fragments with preset granularity from the rock fragments, wherein the range of the preset granularity is 6-10 mm;
Hydraulically cutting each rock debris fragment into square rock debris;
Sequentially stacking a plurality of rock fragments from top to bottom, and placing the rock fragments in a cylindrical mold to wait for casting;
introducing and injecting an epoxy cementing liquid into the cylindrical mold through a glass rod to solidify the cuttings;
cutting and polishing the solidified rock fragments to obtain rock fragment samples.
4. A method of deriving acoustic properties of formation rock according to claim 3, wherein the step of cutting and polishing the solidified cuttings to obtain a sample of cuttings comprises:
removing the solidified rock debris from the cylindrical mold;
cutting redundant cement on the upper surface and the lower surface of the rock debris to optimize the parallelism between the upper surface and the lower surface of the rock debris;
and polishing and grinding the cut rock fragments to obtain rock fragment samples meeting the requirements.
5. The method of deriving rock compressive strength utilizing drill cuttings according to claim 4, wherein the step of cutting excess cement on the upper and lower sides of the cuttings to optimize parallelism between the upper and lower sides of the cuttings comprises:
Selecting four positions on the outer side wall of the rock debris, and measuring the heights of the four positions;
Controlling the height difference values of the four positions to be within a preset range;
The matching degree test of the sample and the instrument sensor is carried out by adopting a micron indentation instrument mechanical sensor;
judging whether the stress of the instrument sensor is uniform or not;
and when the stress of the instrument sensor is uneven, repeating the steps in sequence until the parallelism meets the preset requirement.
6. The method of deriving rock compressive strength using drill cuttings as claimed in claim 1, wherein the step of deriving the indentation elastic modulus of the cuttings sample by cuttings micron indentation test comprises:
carrying out a micrometer indentation test for each rock debris sample for at least 10 times to obtain indentation elastic modulus;
the multiple test values for each cuttings sample are averaged to obtain the indentation elastic modulus of the cuttings sample.
7. The method of claim 6, wherein the indentation elastic modulus of the cuttings sample is obtained by the following calculation formula:
Wherein,
Where E is the indentation elastic modulus of the cuttings sample, E r is the reduced elastic modulus, μ d is the Poisson's ratio of the cuttings sample, μ i is the Poisson's ratio of the indenter material, E i is the modulus of the indenter material, C is the contact compliance, which is equal to the curve dh/dF at maximum test force, i.e. the inverse of the contact stiffness, at the time of unloading the test force, A p is the contact projected area.
8. A method of deriving rock compressive strength from drill cuttings according to claim 3, wherein the hammer comprises a support frame, a cuttings chute for holding rock and located at a bottom end face of the support frame, an impact hammer and drill teeth, the impact hammer being suspended at a top end of the support frame by a connecting rod, the impact hammer being adapted to apply an impact force to the drill teeth to drive the drill teeth towards the rock, the centre lines of the drill teeth and the cuttings chute being coincident.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210557691.XA CN114993820B (en) | 2022-05-19 | 2022-05-19 | Method for obtaining rock compressive strength using drilling cuttings |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210557691.XA CN114993820B (en) | 2022-05-19 | 2022-05-19 | Method for obtaining rock compressive strength using drilling cuttings |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN114993820A CN114993820A (en) | 2022-09-02 |
| CN114993820B true CN114993820B (en) | 2025-02-28 |
Family
ID=83026961
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210557691.XA Active CN114993820B (en) | 2022-05-19 | 2022-05-19 | Method for obtaining rock compressive strength using drilling cuttings |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114993820B (en) |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103278389A (en) * | 2013-04-28 | 2013-09-04 | 北京大学 | Method for synchronous measurements on dynamic and static elastic parameters of rocks |
| CN103852378A (en) * | 2014-01-17 | 2014-06-11 | 中国石油大学(北京) | Method for measuring mechanical properties of rocks through binding non-standard-sized rock cores into standard-sized rock cores |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103852379A (en) * | 2014-01-17 | 2014-06-11 | 中国石油大学(北京) | Method for measuring mechanical properties of rocks through replacing standard-sized rock cores with non-standard-sized rock cores |
| CN105259036B (en) * | 2015-11-03 | 2018-04-06 | 中国石油天然气股份有限公司 | Measuring method for stratum rock mechanical parameters |
| EP3405768A4 (en) * | 2016-01-18 | 2019-08-28 | British Columbia Institute of Technology | METHOD AND APPARATUS FOR NON-DESTRUCTIVE MEASUREMENT MODULE MEASUREMENT AND / OR ULTIMATE CAPABILITY OF MASONRY SAMPLES |
| CN110068502B (en) * | 2019-05-29 | 2021-08-10 | 西南石油大学 | Conglomerate strength determination method and device |
| CN112014215B (en) * | 2020-09-03 | 2022-06-24 | 山东大学 | Device and method for testing microcosmic compressive strength and elastic modulus of set cement |
| CN113776943A (en) * | 2021-11-05 | 2021-12-10 | 中国矿业大学(北京) | Rock compressive strength prediction method |
-
2022
- 2022-05-19 CN CN202210557691.XA patent/CN114993820B/en active Active
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103278389A (en) * | 2013-04-28 | 2013-09-04 | 北京大学 | Method for synchronous measurements on dynamic and static elastic parameters of rocks |
| CN103852378A (en) * | 2014-01-17 | 2014-06-11 | 中国石油大学(北京) | Method for measuring mechanical properties of rocks through binding non-standard-sized rock cores into standard-sized rock cores |
Also Published As
| Publication number | Publication date |
|---|---|
| CN114993820A (en) | 2022-09-02 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Zhao et al. | Thermal conductivity of thermally damaged Beishan granite under uniaxial compression | |
| Liu et al. | An experimental investigation on the shear mechanism of fatigue damage in rock joints under pre-peak cyclic loading condition | |
| CN113138107B (en) | Rock brittleness evaluation method based on while-drilling rock debris logging information | |
| KR100769499B1 (en) | Faceplate Design Method of Tunnel Excavator with Rock Cutter | |
| CN106289844B (en) | The experimental rig of tunnel bottom structure accumulated damage under a kind of cyclic load | |
| CN112179769A (en) | A method for evaluating elastic modulus of shale based on micro-nano indentation experiment of cuttings | |
| CN106442174A (en) | True triaxial test method for simulating shearing type rock burst | |
| CN111472741A (en) | An experimental method for studying the propagation law of multiple fractures in rock fracturing with volume expansion materials | |
| CN110318743B (en) | Fracturing simulation test method and device for thin interbed shale oil reservoir | |
| CN106501081A (en) | A kind of true triaxial test method of simulation tension type rock burst | |
| CN110261234B (en) | Fractured rock mass separation layer anchoring control simulation test device and method | |
| CN113420427B (en) | Rock structural surface shearing continuous-discontinuous numerical method under constant rigidity | |
| CN111781058B (en) | A device and method for testing rock cohesion and internal friction angle | |
| CN114925588A (en) | A Method for Determining Microscopic Parameters of Layered Rock 3D Block Discrete Element Model | |
| CN114091290A (en) | A method for evaluating rock drillability based on cuttings nanoindentation | |
| CN107063791B (en) | Test methods and test specimens for the bonding properties of disintegrated soft rock and concrete | |
| CN113484153A (en) | Indoor true triaxial hydrofracturing ground stress test simulation method and device | |
| CN114993820B (en) | Method for obtaining rock compressive strength using drilling cuttings | |
| Kang et al. | Evaluation of core disking rock stress and tensile strength via the compact conical-ended borehole overcoring technique | |
| CN118407745A (en) | Hydraulic fracturing stress conduction monitoring method | |
| CN112683645A (en) | Small probe abrasion test platform, test method and evaluation method | |
| CN107782620A (en) | A kind of determination method for the Rock Failure critical strain for considering time effect | |
| CN115931487A (en) | Method for testing cohesive force and internal friction angle of rock-like material | |
| CN107704718A (en) | A kind of method for calculating rock material elastic strain energy density at compression test peak strength point | |
| CN115163088A (en) | Underground engineering weak surrounding rock excavation compensation control method |
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 | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |