CN104864994B - A kind of method and system for measuring crustal stress - Google Patents
A kind of method and system for measuring crustal stress Download PDFInfo
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- CN104864994B CN104864994B CN201510161863.1A CN201510161863A CN104864994B CN 104864994 B CN104864994 B CN 104864994B CN 201510161863 A CN201510161863 A CN 201510161863A CN 104864994 B CN104864994 B CN 104864994B
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Abstract
The invention discloses a kind of method for measuring crustal stress, and the normal strain in three planes, and the strain along the angular bisector direction of intersecting plane two-by-two are included by collection, according to shear strain reciprocal theorem, it is determined that the components of stress of description core sample strain regime.The present invention also provides a kind of measurement crustal stress system, measure to obtain the normal strain in the plane by the displacement transducer of the plane contact with core sample, the displacement transducer contacted with the seamed edge of core sample measures to obtain the strain on two intersecting planes for sharing the seamed edge, decompose the strain and obtain the shear strain on intersecting plane, so as to readily obtain six components of strain of the strain regime of description core sample；And the bubble caused by avoiding stickup foil gauge possible between angular deviation and foil gauge and core sample, thus greatly improve the precision of measurement.
Description
Technical field
The invention belongs to oilfield prospecting developing technical field, more particularly to one kind to be used to evaluate stress state residing for core
Measurement crustal stress method and system.
Background technology
Crustal stress is the distribution of control Accumulation zone, hydraulically created fracture extension, Reservoirs are distributed, oil well casing is broken
One of key factor such as bad, it is formulation and the indispensable basic data of oil well engineering design of Oil and gas field development scheme.Therefore
Study on Rock Stress has highly important meaning in oil-gas exploration and development.
It is geostress survey to evaluate the most directly reliable method of core stress state.Differential strain analysis method is common interior
Core measuring method, good effect is achieved in the method numerous geostress survey applications at home and abroad, is a kind of very promising
Earth stress measuring method.
The general principle of differential strain analysis method is：Core is in stratum depths due to the presence of crustal stress and in compression shape
State, its intrinsic fracture contained are also at closure state.When core is taken out to ground, core departs from the production of crustal stress environment
Raw elastic stress release.Due to the numerical value of three-dimensional stress, with the release of crustal stress, generate proportional to unloading degree
Strain, it is described strain it is relevant with the stress field residing for core, be the reflection of underground stress field.In the stress bar of three-dimensional confined pressure
Under part, restorative loading is carried out to the core for drilling through out, the recovery strain of different directions is also different, maximum in primitive stress
Direction strain value it is maximum, it is minimum in the minimum direction strain value of primitive stress.Rock under simulation stratum condition is obtained by measurement
The strain of core all directions, so that it may know core suffered stress state in the earth formation.
Refer to Fig. 1.For conventional differential strain analysis method, required experiment core will at least have 3 planes to intersect each other,
3 foil gauges are at least pasted in each plane, wherein 2 foil gauges are parallel with the seamed edge for testing core, the 3rd foil gauge position
In on the angular bisector of preceding 2 foil gauges, the angle with preceding 2 foil gauges is 45 °.
After experiment core is sealed, it is put into application confined pressure in pressure chamber and is tested, can obtain 9 by strain measurement should
Become the strain value ε of piecei(i=1,2 ... 9), according to obtained strain value εi(i=1,2 ... 9), are calculated, obtained using formula (1)
It can be used for six components of strain for describing the strain regime of core：
Six components of strain once it is determined that, then test core strain regime just completely determine.
After the strain regime determination for testing core, using the constitutive relation between stress and strain, experiment can be calculated
The stress state of core, it then can determine whether its residing crustal stress states.
From the principle of above-mentioned poor strain measurement crustal stress, be intended to obtain the strain regime of description experiment core six should
Become component, must be pasted in experiment 3 planes to intersect each other of core and amount to 9 foil gauges.Therefore, not only being pasted before measurement should
Becoming piece wastes time and energy；And after measurement obtains 9 strain datas, it is still very cumbersome to calculate the components of strain using formula (1).
The content of the invention
During for prior art using crustal stress states residing for foil gauge method measurement core are pasted, take because pasting foil gauge
When laborious, and the deficiency that post-processing data are cumbersome, the present invention, which provides, measures a kind of method and system of crustal stress.Its technical side
Case is as follows：
A kind of method for measuring crustal stress, comprises the following steps：
Core sample to be measured is prepared, the core sample has at least three planes intersecting each other；
Confined pressure is applied to the core sample, brings it about deformation；
The strain value of core sample is gathered, the strain value of collection includes the normal strain in three planes, and intersecting along two
The strain in the angular bisector direction of plane；According to shear strain reciprocal theorem, to along the angular bisector direction of intersecting plane two-by-two
Strain is decomposed, and obtains the shear strain in three planes；
Using the normal strain in three obtained planes and shear strain, the crustal stress of core sample is calculated.
The method of measurement crustal stress as described above, using the strain value of collection, obtain describing core sample strain regime
The components of strain the step of be：
The strain along the angular bisector direction of intersecting plane two-by-two is decomposed, the direction of decomposition is the tangential side of two intersecting planes
To；
Strain to the angular bisector direction of at least three planes intersecting each other is decomposed, obtain three it is intersecting each other flat
The shear strain in face；
Using the normal strain of at least three plane intersecting each other collected, obtain describing core sample strain shape
The components of strain of state.
The method of measurement crustal stress as described above, the strain bag in the angular bisector direction along two intersecting planes of collection
Include：Strained along the either direction in the angular range of two intersecting planes.
A kind of system for measuring crustal stress, including：
Egf block is held, the egf block of holding includes being used for the base for placing core sample to be measured, the core sample
With at least three first planes intersecting each other, the second plane and the 3rd plane, the first plane and the second plane, the 3rd plane
Shared seamed edge is respectively the first seamed edge and the second seamed edge, and the seamed edge that the second plane and the 3rd plane share is the 3rd seamed edge；
Confined pressure module, the confined pressure module can apply confined pressure to the core sample；
Strain acquirement module, the strain acquirement module include：
First displacement transducer, second displacement sensor and triple motion sensor, first displacement transducer, second
The contact jaw of displacement transducer and triple motion sensor can connect with first plane, the second plane and the 3rd plane respectively
Touch；
4th displacement transducer, the 5th displacement transducer and the 6th displacement transducer, the 4th displacement transducer, the 5th
The contact jaw of displacement transducer and the 6th displacement transducer can connect with first seamed edge, the second seamed edge and the 3rd seamed edge respectively
Touch；
Strained handling module, the strained handling module can be handled the strain value of collection；The strain value bag of collection
Include the first plane, the normal strain in the second plane and the 3rd plane, and along the first plane, the second plane and the 3rd plane are two-by-two
The strain in the angular bisector direction of intersecting plane；According to shear strain reciprocal theorem, to along the angular bisector side of intersecting plane two-by-two
To strain decomposed, obtain the shear strain in three planes.
Geostress survey system as described above, including stuck-module, the stuck-module include：
The first fixed arm being fixedly arranged on the base, first displacement transducer, second displacement sensor and the 4th
Displacement transducer is installed on first fixed arm；
The second fixed arm being fixedly arranged on the base, the triple motion sensor are installed in second fixed arm
On；
The 3rd fixed arm being fixedly arranged on the base, the 5th displacement transducer and the 6th displacement transducer are installed in
On 3rd fixed arm.
Geostress survey system as described above, the base have orthogonal first direction and second direction, with
And between the first direction and second direction angle at 45 ° third direction, and these three directions are in the same of the base
On one base plane；
First fixed arm is fixedly arranged on the base plane in the first direction, and the second described fixed arm is along second party
To being fixedly arranged on the base plane, the 3rd described fixed arm is fixedly arranged on the base plane along third direction.
Geostress survey system as described above, including：The 4th be fixedly arranged in the first direction on the base plane is solid
Fixed arm, on the 4th fixed arm can fixed three displacement transducers, three fixed displacement sensings on the 4th fixed arm
The contact jaw of the two of which displacement transducer of device can respectively with the core sample two plane contacts, and the two planes
It is relative with first plane and the second plane respectively, another contact jaw of described three displacement transducers and the two
The seamed edge contact shared between plane, the shared seamed edge are relative with first seamed edge.
Geostress survey system as described above, including：The 5th be fixedly arranged in a second direction on the base plane is solid
Fixed arm, on the 5th fixed arm can a fixed displacement transducer, a fixed displacement sensing on the 5th fixed arm
The contact jaw of device can be relative with the 3rd plane with a plane contact of the core sample, the plane.
Geostress survey system as described above, including：The 6th be fixedly arranged on along third direction on the base plane is solid
Fixed arm, on the 6th fixed arm can fixed two displacement transducers, on the 6th fixed arm fixed two displacements pass
The contact jaw of sensor can contact with two intersecting seamed edges of the core sample respectively, and described two intersecting seamed edge institutes are really
Fixed plane is relative with the 3rd plane.
Geostress survey system as described above, the egf block of holding include supporting table, and the supporting table is fixedly arranged on described
Base plane, the supporting table are used to place and support the core sample.
By above technical scheme, the beneficial effects of the present invention are：The core sample collection for applying confined pressure is strained, adopted
The strain of collection includes the normal strain in three planes intersecting each other, and answering along the angular bisector direction of intersecting plane two-by-two
Become, the strain is the synthesis of the shear strain of two intersecting planes, and according to shear strain reciprocal theorem, decomposition is obtained on two intersecting planes
Shear strain, so as to easily and quickly obtain describing the components of strain of core sample strain regime；
The beneficial effect of geostress survey system provided by the invention is：Pass through the position of the plane contact with core sample
Displacement sensor measures to obtain the normal strain in the plane；The displacement transducer that is contacted with the seamed edge of core sample measures to obtain
The shear strain in two planes of the seamed edge is shared, according to shear strain reciprocal theorem, decomposition obtains cutting on each intersecting plane should
Become, so as to readily obtain the components of strain of the strain regime of description core sample；
In addition, being strained by displacement sensor, prior art is avoided to paste the method for foil gauge on core sample
Measuring strain may caused by angular deviation, while also solve prior art when pasting foil gauge, may in foil gauge and
Bubble is produced between core sample, the problem of causing measurement error, thus greatly improve the precision of measurement；
The core sample prepared is directly placed in supporting table in measurement, then can apply confined pressure by the present invention
Directly measure, it is easy to operate, so as to improve measurement efficiency.
Brief description of the drawings
Technical scheme in order to illustrate the embodiments of the present invention more clearly, make required in being described below to embodiment
Accompanying drawing is briefly described, it should be apparent that, drawings in the following description are only some embodiments of the present invention, for
For those of ordinary skill in the art, on the premise of not paying creative work, other can also be obtained according to these accompanying drawings
Accompanying drawing.
Fig. 1 is the experiment core schematic diagram that foil gauge is pasted with prior art difference strain experiment；
Fig. 2 is the flow chart of the measurement crustal stress method of embodiment of the present invention；
Fig. 3 is the components of strain schematic diagram for straining strain regime residing for unit under complex stress condition；
Fig. 4 is core sample schematic diagram in the measurement crustal stress method of embodiment of the present invention；
Fig. 5 is close-up schematic view in Fig. 4；
Fig. 6 is schematic illustration of strain of the collection along unspecified angle direction in the range of two intersecting plane included angles；
Fig. 7 be embodiment of the present invention measurement crustal stress system in hold egf block and the structure of strain acquirement module is shown
It is intended to；
Fig. 8 is the schematic diagram for measuring core sample in crustal stress system of embodiment of the present invention.
Embodiment
Below in conjunction with the accompanying drawing in the embodiment of the present invention, the technical scheme in the embodiment of the present invention is carried out clear, complete
Site preparation describes, it is clear that described embodiment is only part of the embodiment of the present invention, rather than whole embodiments.It is based on
Embodiment in the present invention, those of ordinary skill in the art are obtained every other under the premise of creative work is not made
Embodiment, belong to the scope of protection of the invention.
Refer to Fig. 2.A kind of earth stress measuring method that the application embodiment provides, comprises the following steps：Preparation is treated
The core sample of measurement, the core sample have at least three planes intersecting each other；Confined pressure is applied to the core sample,
Bring it about deformation；Gathering the strain value of core sample, the strain value of collection includes the normal strain in three planes, and along two
The strain in the angular bisector direction of two intersecting planes；According to shear strain reciprocal theorem, to the angular bisector along intersecting plane two-by-two
The strain in direction is decomposed, and obtains the shear strain in three planes；Using the normal strain in three obtained planes and cut should
Become, the crustal stress of core sample is calculated.
Present embodiment strains to the core sample collection for applying confined pressure, and the strain of collection includes three and intersecting each other put down
Normal strain on face, and the strain along the angular bisector direction of intersecting plane two-by-two, the strain are cut for two intersecting planes
The synthesis of strain, according to shear strain reciprocal theorem, decomposition obtains the shear strain on two intersecting planes, so as to easily and quickly obtain
To the components of strain of description core sample strain regime.
The committed step of measurement crustal stress is to obtain six components of strain that can describe to strain stress state residing for unit.
The principle that the earth stress measuring method of embodiment of the present invention obtains this six components of strain is：According to shear strain reciprocal theorem,
The shearing stress numerical value strained in unit on two intersecting planes is equal, and direction is pointed to simultaneously or the shared rib away from two intersecting plane
Side.It is two intersecting planes specifically to refer to Fig. 3, face a and face b, then points to both shared seamed edge AB shear strain numerically phase
Deng i.e. εxy=εyx。
Embodiment of the present invention utilizes shear strain reciprocal theorem, obtains describing the components of strain of core sample strain regime
Step is：
Core sample as shown in Figure 4 has three flat surface-to-surface c, face d and face e intersecting each other, and three intersecting each other flat
The shared seamed edge in face is respectively seamed edge FC, seamed edge FD, seamed edge FE.After applying confined pressure, core sample deforms.Collection is along two-by-two
The strain in the angular bisector direction of intersecting plane, respectively εFC、εFDAnd εFE。
To clearly show that decomposing schematic representation, face c and face d are stripped out, refer to Fig. 5.εFEIt is that cutting for face c and face d should
The synthesis of change, is decomposed to it, and the direction of decomposition is face c and face d tangential direction, and tangential direction shares with face c and face d
Seamed edge FE is perpendicular.Obtained after decomposition strain stress ' be face c and face d shear strain, due to εFEIt is the angular bisector along face c and face d
Direction, therefore the shear strain of face c and face d shear strain is equal, this meets shear strain reciprocal theorem.In this way, face c and face d
A shear strain determined.
Similarly, to εFCDecomposed, determine a face c and face e shear strain；To εFDDecomposed, determine face d and face e
A shear strain.
The another embodiment of the acquisition pattern of the shear strain of intersecting plane is that collection intersects plane included angle scopes along two
Interior either direction strain.Refer to Fig. 6.Assuming that face f and face g are two intersecting planes, direction in core sampleIt is two intersecting
Any one direction in the range of plane included angle, directionIt is the angular bisector direction of two intersecting planes, two intersecting planes
The resultant strain of shear strain, it is maximum along angular bisector direction.Assuming that during measurement, collection is edgeThe strain in direction
ε ", the then direction strain stress " is directionStrain stress " ' one-component.Known directionWith directionAngle
α ', solving a triangle OPQ, then ε " '=ε "/cos α '.Obtain along angular bisector directionStrain stress " ' after, then by it along face f
Decomposed with face g tangential direction, you can obtain the shear strain on two intersecting planes：
According to shear strain reciprocal theorem, with the aforedescribed process, the shear strain of three planes intersecting each other can be all true for profit
It is fixed.
Normal strain on collection surface c, face d and face e, respectively εx、εyAnd εz.Three intersecting planes of core sample are total to
Six components of strain of meter are determined.
The strain regime of six components of strain descriptions is as shown in Figure 3.By above-mentioned six components of strain, rock can be further obtained
The strain tensor ε of core sampleij, as shown in formula (2).
From Elasticity knowledge, under any strain regime, three mutually orthogonal directions can be at least found,
Only have normal strain on these three directions, and all shear strains are zero.Direction with this property is referred to as principal strain directions, main
It is principal strain to answer nyctitropic strain.
If strain tensor εijPrincipal strain be εii(i=1,2,3), corresponding principal strain directions are l, m, n, then solve master
The linear homogeneous equa tion set of strain is：
Because of l2+m2+n2=1, l, m, n can not possibly be 0 simultaneously, therefore equation group (3) must have untrivialo solution, then its coefficient ranks
Formula is zero, i.e.,：
Formula (4) is deployed, you can obtain that principal strain ε can be solvediiThe equation (5) of (i=1,2,3), the equation is referred to as
Strain characteristics equation：
ε3-J1ε2+J2ε-J3=0 (5)
Wherein：J1=Σ εii=εx+εy+εz；
J2=εxεy+εyεz+εzεx-(εxy 2+εyz 2+εzx 2)；
J1、J2、J3For strain invariant, first, second, and third invariant is referred to as.According to strain characteristics equation
(5), you can solve three principal strains.Bring three principal strain values that solution obtains into equation group (3) respectively, you can obtain phase
Answer the direction (l, m, n) of principal strain.
According to obtained three-dimensional principal strain ε11、ε22、ε33, three-dimensional principal stress σ can be drawn by following formulaV、σH、σhMutual ratio
Value：
σV:σH:σh=[μ (ε22+ε33)+(1-μ)ε11]:[μ(ε22+ε11)+(1-μ)ε33]:[μ(ε11+ε33)+(1-μ)ε22] (6)
Wherein：μ-Poisson's ratio.
According to Generalized Hu can law, strain unit under complex stress condition, the constitutive relation between stress and strain is such as
Under：
Wherein：εx、εy、εzRespectively strain the normal strain of unit in the x, y, z-directions；εxy、εyz、εzxRespectively strain is single
Shear strain on first three faces intersecting each other；E is the modulus of elasticity of material, and μ is Poisson's ratio, and G is shear modulus,Elastic modulus E, shear modulus G are the characteristics of material, are not changed with environmental change.Utilize formula (7)
Six components of stress and stress tensor of stress state residing for description core sample are calculated, so that it is determined that the ground of core sample
Stress state.
Embodiment of the present invention also provides a kind of measurement crustal stress system.Please also refer to Fig. 7 and Fig. 8.In order to clear
The geostress survey system of embodiment of the present invention and the position relationship of core sample are shown to Chu, peels away both in accompanying drawing
Come.
A kind of measurement crustal stress system of embodiment of the present invention includes：Egf block is held, the egf block of holding includes being used for
The base 25 of core sample 10 to be measured is placed, the core sample 10 has at least three first planes intersecting each other
31, the second plane 32 and the 3rd plane 33, the first plane 31 and the shared seamed edge of the second plane 32, the 3rd plane 33 are respectively the
The shared seamed edge of one seamed edge 41 and the second seamed edge 42, the second plane 32 and the 3rd plane 33 is the 3rd seamed edge 43.Confined pressure module, institute
Confined pressure can be applied to the core sample 10 by stating confined pressure module.Strain acquirement module, the strain acquirement module include：First
Displacement sensor 37, second displacement sensor 41 and triple motion sensor 35；First displacement transducer 37, second displacement sensor
41 and the contact jaw of triple motion sensor 35 contacted respectively with first plane 32, the second plane 32 and the 3rd plane 33.
4th displacement transducer 39, the 5th displacement transducer 12 and the 6th displacement transducer 14, the 4th displacement transducer the 39, the 5th
The contact jaw of the displacement transducer 14 of displacement transducer 12 and the 6th and first seamed edge 41, the second seamed edge 42 and the 3rd seamed edge 43
Contact.Strained handling module, the strained handling module can be handled the strain value of collection；The strain value of collection includes the
One plane, the normal strain in the second plane and the 3rd plane, and intersect two-by-two along the first plane, the second plane and the 3rd plane
The strain in the angular bisector direction of plane；According to shear strain reciprocal theorem, to along the angular bisector direction of intersecting plane two-by-two
Strain is decomposed, and obtains the shear strain in three planes.
Embodiment of the present invention measures to obtain the plane by the displacement transducer of the plane contact with core sample 10
On normal strain；The strain that the displacement sensor being in contact with the seamed edge of core sample 10 obtains is share the seamed edge two
The resultant strain of shear strain on intersecting plane.Resultant strain is learnt in measurement, the angle and measurement direction of two intersecting planes, it is known that
Then the shear strain value in intersecting plane, which can calculate, learns, using strained handling module, can fast, easily obtain core examination
The crustal stress states of sample 10.
Prior art is using the method for pasting foil gauge measuring strain, and the stickup of foil gauge is it is possible that angular deviation；
And precision is bad may to cause its uneven surface because making due to rock sample surface to be tested, thus the foil gauge pasted with it is to be tested
Bubble is there may be between rock sample.And the operation principle of foil gauge is that the dependent variable of test specimen is converted into resistance change,
Foil gauge is stretched with test specimen, and the measurement of dependent variable is realized by the change of resistance value；And the foil gauge once pasted
Angle of arrival deviation, or it has bubble between rock sample, then the dependent variable that its measurement obtains will be unable to that true reflection is actual should
Variable, it is larger so as to cause finally to measure obtained crustal stress error.Embodiment of the present invention should by displacement sensor
Become, avoid prior art from pasting angular deviation caused by the method measuring strain possibility of foil gauge on core sample 10, simultaneously
Also solve prior art when pasting foil gauge, bubble may be produced between foil gauge and core sample 10, cause to measure
The problem of error, thus greatly improve the precision of measurement.
For stable displacement sensor, plane and seamed edge of its contact jaw all the time well with core sample 10 is set to keep
Contact.Embodiment of the present invention sets fixed arm on the relevant position of base 25, and displacement transducer is fixedly arranged on into the fixation
On arm.Specifically scheme is that the first fixed arm 15 is installed with base 25, the first displacement transducer 37, second displacement sensor
41 and the 4th displacement transducer 39 be installed on the first fixed arm 15.Due to fixed three displacement sensings on the first fixed arm 15
Device, in order that corresponding displacement transducer can contact with the corresponding site of core sample 10, the first fixed arm 15 is designed to fit
Answer three folding shapes of the change in shape of core sample 10.For example, when core examination 10 is regular hexahedron shape, then the shape of the first fixed arm 15
Shape can make that the first displacement transducer 37 and second displacement sensor 41 are in 90 °, and the 4th displacement transducer 39 is in the first displacement sensing
On the folder bisector of angle direction of device 37 and second displacement sensor 41, so that the first displacement transducer 37 passes with second displacement
Sensor 41 can connect with the first plane 31 and the perpendicular contact of the second plane 32, the 4th displacement transducer 39 with the first seamed edge 41 respectively
Touch, its direction and the first plane 31 and the second plane 32 angle at 45 °.
In order to fix triple motion sensor 35, the second fixed arm 11, triple motion sensor are installed with base 25
35 are installed on second fixed arm 11.Because 11 need of the second fixed arm fix a displacement transducer, therefore can be by it
It is shaped to the strip relatively simply, integrally extended along lengthwise.
The 3rd fixed arm 21 is installed with base 25, the 5th displacement transducer 12 and the 6th displacement transducer 14 are installed in
On 3rd fixed arm 21.Because the 5th displacement transducer 12 and the 6th displacement transducer 14 are connect with the seamed edge of core sample 10
Touch, therefore be equally the three folding shapes that the 3rd fixed arm 21 is arranged to adapt to the change in shape of core sample 10, its shape and first
Fixed arm 15 is similar, repeats no more.
In addition, in order to ensure that can be contacted well with the plane and seamed edge of core sample 10, displacement transducer is using can
The flat or sharp contact jaw exchanged.For example, due to smaller with the area of seamed edge, the contact jaw contacted may be configured as tack
Type, or the other shapes being adapted to seamed edge, to increase contact area, it is ensured that contact it is good.
For simplified operation, strain unit is fabricated to regular hexahedron under normal circumstances.Therefore, in order to adapt to strain unit
This shape, embodiment of the present invention is made that the design of adaptability.Refer to Fig. 7.Base 25 has orthogonal the
One direction w and second direction l, wherein widths of the first direction w along base 25, length of the second direction l along base 25
Spend direction；And between first direction w and second direction l angle at 45 ° third direction d.And these three directions define
One plane, i.e. base plane 27.W is fixedly arranged on base plane 27 first fixed arm 15 in the first direction, the second fixed arm 11
L is fixedly arranged on base plane 27 in a second direction, and the 3rd fixed arm 21 is fixedly arranged on base plane 27 along third direction d.
After the core sample of regular hexahedron to be measured is in place, due to the regular shape of core sample, and it is each solid
Fixed arm being arranged symmetrically relative to core sample on base plane 27, therefore passed with the tactile displacement of the flat face of core sample
The contact jaw of sensor will be perpendicular with the plane；And the contact jaw for the displacement transducer being in contact with the seamed edge of core sample will be flat
It is divided to the angle for two intersecting planes for sharing the seamed edge.The core sample 10 of regular hexahedron is to be mutually perpendicular between two intersecting faces
, if therefore the displacement sensor that is in contact with seamed edge of contact jaw to obtain strain be ε, share the seamed edge two are intersecting flat
The shear strain in face is
For isotropic material, the strain of six components of strain composition in three orthogonal intersecting planes
Tensor, it has been enough to describe to strain the strain regime residing for unit, and then the stress state suffered by it can be obtained.And normal conditions
Under, most of materials are anisotropic, and for anisotropic material, it is orthogonal intersecting to sample above-mentioned three
Six components of strain on face describe its strain regime, may cause error to its suffered stress state.
Therefore, in order to eliminate influence of the anisotropy of core sample to measurement result, embodiment of the present invention is existing
Three fixed arms on the basis of, three fixed arms are set up using symmetrically arranged mode again, with realize to regular hexahedron core
Comprehensive description of strain on six faces of sample.
Refer to Fig. 7.In order to eliminate the anisotropy of w in the first direction to influence, this embodiment party caused by measurement result
The geostress survey system of formula includes：W is fixedly arranged on the 4th fixed arm 17 on base plane 27, the 4th fixed arm in the first direction
Fixed three displacement transducers of energy (in order to simplify accompanying drawing, are only shown in the drawings partial dislocation sensor and make schematic diagram on 17
Property explanation.The displacement transducer set for elimination anisotropy is identical with the displacement sensor structure having shown that, and symmetrically sets
Put, therefore by its economization and repeat no more), on the 4th fixed arm 17 the two of which displacement of three fixed displacement transducers pass
The contact jaw of sensor can respectively with core sample 10 two plane contacts, and the two planes respectively with the first plane 31 and
Two planes 32 are relative, and the seamed edge shared between another contact jaw of three displacement transducers and the two planes contacts, should
Shared seamed edge is relative with the first seamed edge 41.
In order to eliminate the anisotropy of l in a second direction to influence, the crustal stress of present embodiment caused by measurement result
Measuring system includes：L is fixedly arranged on the 5th fixed arm 13 on base plane 27 in a second direction, can be fixed on the 5th fixed arm 13
One displacement transducer, the contact jaw of a fixed displacement transducer can be with one of core sample 10 on the 5th fixed arm 13
Plane contact, the plane are relative with the 3rd plane 33.
In order to eliminate the anisotropy along third direction d to influence, the crustal stress of present embodiment caused by measurement result
Measuring system includes：The 6th fixed arm 19 being fixedly arranged on along third direction d on base plane 27, can be fixed on the 6th fixed arm 19
Two displacement transducers, on the 6th fixed arm 19 contact jaw of fixed two displacement transducers can respectively with core sample 10
Two intersecting seamed edges contacts, plane determined by two articles of intersecting seamed edges is relative with the 3rd plane 33.
Using displacement transducer fixed on three fixed arms set up, the position sensing on existing three fixed arms in addition
Device, six planes of regular hexahedron core sample can be completely covered in the strain of measurement, therefore make retouching for core sample strain regime
State more perfect, influence of the elimination anisotropy to measurement result.
In order to facilitate the installation and dismounting of displacement transducer, the fixed arm of embodiment of the present invention is in fixed displacement transducer
Place offers fixing hole 22 and pin-and-hole 24, and displacement transducer can be actively located in fixing hole 22, and fixation can be inserted in pin-and-hole 24
Pin 16, with fixed displacement sensor.
In addition, being fixedly installed supporting table 29 on base plane 27, supporting table is used to place and support core sample 10.
During measurement, the core sample 10 prepared is directly placed in supporting table 29, then can apply confined pressure and directly measure,
It is easy to operate, so as to improve measurement efficiency.
Pressure chamber can be used by applying the confined pressure module of confined pressure to core sample 10；The strain that strain to collection is handled
The instrument with corresponding calculation procedure such as computer can be used in processing module.These are all prior art means, herein not to it
It is defined, can be according to being actually needed corresponding selection, the limitation of not paired enough embodiment of the present invention.
Several embodiments of the present invention are the foregoing is only, those skilled in the art is according to application documents disclosure
Various changes or modifications can be carried out without departing from the spirit and scope of the present invention to the embodiment of the present invention.
Claims (9)
- A kind of 1. method for measuring crustal stress, it is characterised in that comprise the following steps：Core sample to be measured is prepared, the core sample has at least three planes intersecting each other；Confined pressure is applied to the core sample, brings it about deformation；The strain value of core sample is gathered, the strain value of collection includes the normal strain in three planes, and flat along intersecting two-by-two The strain in the angular bisector direction in face；The strain along the angular bisector direction of two intersecting planes is decomposed, the direction of decomposition is the tangential direction of two intersecting planes；Strain to the angular bisector direction of at least three planes intersecting each other is decomposed, and obtains three planes intersecting each other Shear strain；Using the normal strain in three obtained planes and shear strain, the crustal stress of core sample is calculated.
- 2. the method for measurement crustal stress as claimed in claim 1, it is characterised in that：The angle bisection along two intersecting planes of collection The strain in line direction includes：Strained along the either direction in the angular range of two intersecting planes.
- A kind of 3. system for measuring crustal stress, it is characterised in that including：Egf block is held, the egf block of holding includes being used for the base for placing core sample to be measured, and the core sample has At least three first planes intersecting each other, the second plane and the 3rd plane, the first plane share with the second plane, the 3rd plane Seamed edge be respectively the first seamed edge and the second seamed edge, the seamed edge that the second plane shares with the 3rd plane is the 3rd seamed edge；Confined pressure module, the confined pressure module can apply confined pressure to the core sample；Strain acquirement module, the strain acquirement module include：First displacement transducer, second displacement sensor and triple motion sensor, first displacement transducer, second displacement The contact jaw of sensor and triple motion sensor can respectively with first plane, the second plane and the 3rd plane contact；4th displacement transducer, the 5th displacement transducer and the 6th displacement transducer, the 4th displacement transducer, the 5th displacement The contact jaw of sensor and the 6th displacement transducer can contact with first seamed edge, the second seamed edge and the 3rd seamed edge respectively；Strained handling module, the strained handling module can be handled the strain value of collection；The strain value of collection include by First displacement transducer, second displacement sensor and triple motion sensor measure the first obtained plane respectively, and second Normal strain in plane and the 3rd plane, and passed by the 4th displacement transducer, the 5th displacement transducer and the 6th displacement Sensor measures the shear strain on two intersecting planes of obtained shared first seamed edge, the second seamed edge and the 3rd seamed edge respectively Resultant strain；The strained handling module is used for according to shear strain reciprocal theorem, to angle of the resultant strain along intersecting plane two-by-two The strain in bisector direction is decomposed, and obtains the first plane, the shear strain in the second plane and the 3rd plane, and is used for basis The crustal stress of core sample is calculated in the normal strain and the shear strain.
- 4. the system of measurement crustal stress as claimed in claim 3, it is characterised in that including stuck-module, the stuck-module bag Include：The first fixed arm being fixedly arranged on the base, first displacement transducer, second displacement sensor and the 4th displacement Sensor is installed on first fixed arm；The second fixed arm being fixedly arranged on the base, the triple motion sensor are installed on second fixed arm；The 3rd fixed arm being fixedly arranged on the base, the 5th displacement transducer and the 6th displacement transducer are installed in described On 3rd fixed arm.
- 5. the system of measurement crustal stress as claimed in claim 4, it is characterised in that：The base has orthogonal first Direction and second direction, and between the first direction and second direction angle at 45 ° third direction, and these three sides To on the same base plane of the base；First fixed arm is fixedly arranged on the base plane in the first direction, and the second described fixed arm is solid in a second direction On the base plane, the 3rd described fixed arm is fixedly arranged on the base plane along third direction.
- 6. the system of measurement crustal stress as claimed in claim 5, it is characterised in that including：The bottom is fixedly arranged in the first direction The 4th fixed arm in seat plane, on the 4th fixed arm can fixed three displacement transducers, it is solid on the 4th fixed arm If three displacement transducers two of which displacement transducer contact jaw can respectively with the core sample two planes Contact, and the two planes are relative with first plane and the second plane respectively, three described displacement transducers it is another The seamed edge shared between individual contact jaw and the two planes contacts, and the shared seamed edge is relative with first seamed edge.
- 7. the system of measurement crustal stress as claimed in claim 6, it is characterised in that including：The bottom is fixedly arranged in a second direction The 5th fixed arm in seat plane, on the 5th fixed arm can a fixed displacement transducer, it is solid on the 5th fixed arm If the contact jaw of a displacement transducer can be with a plane contact of the core sample, the plane and the 3rd plane Relatively.
- 8. the system of measurement crustal stress as claimed in claims 6 or 7, it is characterised in that including：Institute is fixedly arranged on along third direction State the 6th fixed arm on base plane, on the 6th fixed arm can fixed two displacement transducers, the 6th fixed arm The contact jaw of upper fixed two displacement transducers can contact with two intersecting seamed edges of the core sample respectively, described Two articles of intersecting seamed edges determined by plane it is relative with the 3rd plane.
- 9. the system of measurement crustal stress as claimed in claim 8, it is characterised in that：The egf block of holding includes supporting table, institute State supporting table and be fixedly arranged on the base plane, the supporting table is used to place and support the core sample.
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2746920B1 (en) * | 1996-04-01 | 1998-05-07 | Inst Francais Du Petrole | TRIAXIAL CONSTRAINT TESTING DEVICE ON A ROCK SAMPLE |
| US6167964B1 (en) * | 1998-07-07 | 2001-01-02 | Shell Oil Company | Method of determining in-situ stresses |
| CN102818665A (en) * | 2012-08-28 | 2012-12-12 | 中国矿业大学 | Device and method for integrated collection of stress and displacement of surrounding rocks |
| CN103954386A (en) * | 2014-04-15 | 2014-07-30 | 沈阳建筑大学 | Three-dimensional space stress-strain measurement method based on fiber bragg grating sensor |
| CN104296897A (en) * | 2014-09-12 | 2015-01-21 | 上海卫星工程研究所 | Star arrow six-degree-of-freedom interface force computing method based on star arrow connecting ring strain measurement |
-
2015
- 2015-04-07 CN CN201510161863.1A patent/CN104864994B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2746920B1 (en) * | 1996-04-01 | 1998-05-07 | Inst Francais Du Petrole | TRIAXIAL CONSTRAINT TESTING DEVICE ON A ROCK SAMPLE |
| US6167964B1 (en) * | 1998-07-07 | 2001-01-02 | Shell Oil Company | Method of determining in-situ stresses |
| CN102818665A (en) * | 2012-08-28 | 2012-12-12 | 中国矿业大学 | Device and method for integrated collection of stress and displacement of surrounding rocks |
| CN103954386A (en) * | 2014-04-15 | 2014-07-30 | 沈阳建筑大学 | Three-dimensional space stress-strain measurement method based on fiber bragg grating sensor |
| CN104296897A (en) * | 2014-09-12 | 2015-01-21 | 上海卫星工程研究所 | Star arrow six-degree-of-freedom interface force computing method based on star arrow connecting ring strain measurement |
Non-Patent Citations (1)
| Title |
|---|
| 主方向差应变地应力测量方法;沈海超 等;《新疆石油地质》;20080430;第29卷(第2期);250-252 * |
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