CN106401576A - Complex shale stratum ground stress test method - Google Patents
Complex shale stratum ground stress test method Download PDFInfo
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- CN106401576A CN106401576A CN201610152903.0A CN201610152903A CN106401576A CN 106401576 A CN106401576 A CN 106401576A CN 201610152903 A CN201610152903 A CN 201610152903A CN 106401576 A CN106401576 A CN 106401576A
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- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B49/00—Testing the nature of borehole walls; Formation testing; Methods or apparatus for obtaining samples of soil or well fluids, specially adapted to earth drilling or wells
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Abstract
The invention discloses a complex shale stratum ground stress test method. The complex shale stratum ground stress test method comprises the following steps that a, in the drilling process, after well cementation is completed, a stratum fracture test is conducted nearby a casing shoe, and the fracture pressure of a stratum is measured; b, a differential strain analysis test is carried out in equal confining pressure bins, the outdoor stress value is estimated, and then the outdoor state stress value is determined; and c, the ground stress is measured through a differential strain analysis test device. Aiming at the situation whether a complex shale stratum is subjected to coring or not, the problem that only the fracture pressure of a stratum can be obtained, and the ground stress cannot be obtained on the basis of the result of an existing shale stratum ground stress test method is solved through the method by combining the stratum fracture test with differential strain, the result of the test is reliable, and the requirements of rock cores for continuous and integral performance are met.
Description
Technical field
The present invention relates to a kind of shale gas exploration engineering field and in particular to a kind of complexity shale formation crustal stress test
Method.
Background technology
Control one of key factor of borehole well instability in drilling process during the virgin state of stress of stratum.Grasp stratum primitively
Stress state is conducive to correctly recognizing and effective evaluation underground complex surrounding rock environment, thus reach high-quality, safe efficient and low become
This drilling well purpose.
The main hydraulic fracturing of method of testing of shale formation crustal stress at present, Kaiscr effect method, difference strain under confined pressure
Method and pluripolarity logging method etc..
Water causes fracturing valve typically to carry out in formation fracturing, and it explains that data is rubbed by the leak-off on stratum and oil, sleeve pipe sky eye
Resistance and the impact of completion mode, and result differed farther out with the shale dependency studied, and the formation fracturing test of drilling well
Typically can only obtain formation fracture pressure, and the crustal stress that is in no position to take possession of.
Under confined pressure, the pressure of deep formation can preferably be tested by Kaiser effect valve, but is subject to drilling extracting core technique or core work
The limitation of skill itself, often up to continuous whole less than 15cm requirement.The method combines Wave Velocity Anisotropy and tests crustal stress, fall
The low requirement of core continued integrity, but still need to reach the requirement of 10cm, the anisotropy of shale frequently results in ripple simultaneously
Fast anisotropy and make test result have unreliability.
Difference Strain Method is passed through indoor core test and is determined field triaxiality direction and stress value, and the method requires to survey simultaneously
Measure the strain of more than 9 roads, deformeter will not have preferable concordance between people having a common goal, and experimental technique difficulty is big, greatly reduces core
Continued integrity requires, and the stress direction recording need to be combined with paleomagnetism test and just can determine that, and the stress value recording is relatively
The stress value of size.
Multi-pole logging method is to record shear wave anisotropy together using cross dipole acoustic to calculate maximum, minimum master
The size and Orientation of stress, but interpretation model is limited by elastic oscillation mechanic constitutive model and material constant, measures difficulty relatively
Greatly.
Content of the invention
The technical problem to be solved is that the method for existing test shale formation crustal stress all has certain defect
Accurate Determining crustal stress can not be realized simultaneously and be easy to operate, test difficulty is little, reduces the requirement of core continued integrity, this
Bright purpose is to provide a kind of method of testing of complexity shale formation crustal stress, solves individually can only obtain using hydraulic fracturing
Obtain fracture pressure it is impossible to obtain crustal stress, difference Strain Method examination low using Kaiscer effect method test result reliability under confined pressure
Test technical difficulty big, the low problem of core continued integrity.
The present invention is achieved through the following technical solutions：
A kind of method of testing of complexity shale formation crustal stress, comprises the following steps：
Step a：In drilling process, after well cementation terminates, carry out formation fracturing test near casing shoe, measure the rupture pressure on stratum
Power；
Step b：Carry out differential strain analysis test, estimation field stress value in waiting confined pressure storehouse, determine the stress value of field state；
Step c：Crustal stress is measured using differential strain analysis assay device.
Further, in order to preferably realize the present invention, limit the determination method of formation fracture pressure in described step a
For：Pressure rise pressure break ground city produced by when the drilling well fluid column in well is so as to original crack is opened, formed new crack
When borehole fluid pressure, according to poroelasticity, can obtain rock produce tensile failure when well in mud column pressure be：
Pf= 3σH-σh- αPp+St
In formula：σHFor level maximum crustal stress, σhFor level minimum crustal stress, PpFor formation pore pressure, α is effective stress system
Number, StFor tensile strength, PfFor formation fracture pressure.
Further, in order to preferably realize the present invention, limit in described step b, concrete method of testing is from oil
Column drill core is chosen at field scene, and the face of cylinder is cut into two orthogonal faces, two ends of this two faces and cylinder
Face is mutually perpendicular to, and after core sealing, puts into and encloses in storehouse, and the strain testing under each confined pressure storehouse provides 9 strain values, 9 strains
Value can state the strain regime in this this moment, constitutes strain variable [ε],
[ε]={ ε1 ε2 –(ε1+ε2)/2 ε8 –(ε7+ε9)/2 }
[ε]={ ε2 –(ε1+ε2)/2 ε3 ε5 –(ε4+ε6)/2 }
[ε]={ ε8 –(ε7+ε9)/2 ε5 –(ε4+ε6)/ 2 ε6 }
The three-dimensional ratio of principal stresses is：σH：σh：σv =[μ(εH+εh) +(1-μ) εH]：[μ(εv+εH) +(1-μ) εh] ：[μ(εH+
εh) +(1-μ) εv]
Wherein：εHFor level maximum stress direction dependent variable, εhFor level minimum stress direction dependent variable, εvFor vertically
Stress direction dependent variable, μ is Poisson's ratio.
Further, in order to preferably realize the present invention, limit in described step c),
σH：σh= m：n
m =μ(εh+εv) +(1-μ) εH
n=μ(εH+εv) +(1-μ) εh
Can determine that vertical stress σ v.
The present invention compared with prior art, has such advantages as and beneficial effect：
The present invention is directed to complicated shale formation, has or not the situation of coring, the side being combined with difference strain facies using formation fracturing test
Method, the result solving existing shale formation detecting earth stress method can only obtain the fracture pressure on stratum, and is in no position to take possession of
The problems such as crustal stress, reliable test result, and meet the requirement of core continued integrity.
Specific embodiment
For making the object, technical solutions and advantages of the present invention become more apparent, with reference to embodiment, the present invention is made
Further detailed description, the exemplary embodiment of the present invention and its explanation are only used for explaining the present invention, are not intended as to this
The restriction of invention.
Embodiment：
A kind of method of testing of present invention complexity shale formation crustal stress, comprises the following steps：Step a：In drilling process, well cementation
After end, carry out formation fracturing test near casing shoe, measure the fracture pressure on stratum；
In described step a, the determination method of formation fracture pressure is：When the pressure rise pressure produced by the drilling well fluid column in well
Split ground city so as to original crack is opened, formed borehole fluid pressure during new crack, according to poroelasticity,
Mud column pressure in well when rock produces tensile failure can be obtained is：
Pf= 3σH-σh- αPp+St(1)
In formula：σHFor level maximum crustal stress, σhFor level minimum crustal stress, PpFor formation pore pressure, α is effective stress system
Number, StFor tensile strength, PfFor formation fracture pressure.
Comprehensive above formula, as long as record fracture pressure, instantaneous characteristics and the crack weight on stratum by formation fracturing test
Open pressure, in conjunction with formation pore pressure it may be determined that going out the maximum of stratum depths, the main crustal stress of minimum level.
If formation fracturing test interval has core, can preferable definitely stress intensity in conjunction with difference strain-gauge test.Will（1）
Formula is transformed to
3σH-σh= M （2）
Wherein, M=Pt+αPp– St
Petroleum-logging data can be tested or be combined to the tensile strength of rock by Brazilian test and empirical equation obtains.
Step b：Carry out differential strain analysis test, estimation field stress value in waiting confined pressure storehouse, determine answering of field state
Force value；
In described step b, concrete method of testing is to choose column drill core from Oil Field, and the face of cylinder is cut into two phases
Mutually vertical face, this two faces are mutually perpendicular to two end faces of cylinder, after core sealing, put into and enclose in storehouse, each confined pressure storehouse
Under strain testing provide 9 strain values, 9 strain values can state the strain regime in this this moment, constitutes a strain variable
[ε],
[ε]={ ε1 ε2 –(ε1+ε2)/2 ε8 –(ε7+ε9)/2 }
[ε]={ ε2 –(ε1+ε2)/2 ε3 ε5 –(ε4+ε6)/2 }
[ε]={ ε8 –(ε7+ε9)/2 ε5 –(ε4+ε6)/ 2 ε6 }
The three-dimensional ratio of principal stresses is：σH：σh：σv= [μ(εH+εh)+(1-μ) εH]：[μ(εv+εH) +(1-μ) εh] ：[μ(εH+
εh) +(1-μ) εv]
Wherein：εHFor level maximum stress direction dependent variable, εhFor level minimum stress direction dependent variable, εvFor vertically
Stress direction dependent variable, μ is Poisson's ratio.
Determine that the test method of field state strain value is as follows：（1）Remaining column after processing difference strain-gauge test sample
A diameter of 25mm is drilled through on drill core, length is 50mm column, as wave velocity test sample, sample is pressed triaxial strength and tries
Test requirement and put into three-axis tester, the rock elasticity steel speed of isobaric test plus confined pressure process, find out measurement velocity of wave close to field ripple
Confined pressure P when fastC；（2）In difference stress test, it is substantially inconvenient that confined pressure is linearly forced into the ratio of principal stresses, is divided using method of least square
Do not return out the strain value of each passage and the functional relationship of confined pressure, by confined pressure value PCSubstitute into the relational expression returning, determine open country
Outer state strain value.
Field velocity of wave is the rock elasticity velocity of wave on stratum residing for sample, can be obtained by oil sonic log data.Sound
Ripple well logging is the elastic wave velocity that oil well depth section is continuously measured from bottom to top with rock.
Step（c）：Crustal stress is measured using differential strain analysis assay device.
Described step（c）In, σH：σh = m：n
m =μ(εh+εv) +(1-μ) εH
n=μ(εH+εv) +(1-μ) εh
σ can be obtained by above-mentioned formulaH=[ m(Pf+αPp- St)]/(3n-m)]
Can determine that vertical stress σ v.
Test core is the sand shale at the 3609.5m of oil field, and the Poisson's ratio of rock is 0.30, and tensile strength is 4.24MPa,
Elastic modelling quantity is 39500MPa.Formation fracturing test pressure is 89.55MPa, and formation pore pressure is 38.01MPa, effective stress
Coefficient is 0.93, and drilling fluid density is 1.24g/cm3, increase the rock elasticity velocity of wave of confined pressure process by test under the conditions of equipressure
Change, have found the confined pressure measuring close to field velocity of wave and encloses 46.86MPa.
In difference stress test, it is substantially inconvenient that confined pressure is linearly forced into the ratio of principal stresses, is returned respectively respectively using method of least square
The strain value of individual passage, and the functional relationship of confined pressure, confined pressure value 46.86MPa are substituted into regression equation, calculate principal strain, meter
Calculating stress axis is σH：σh：σv=1.21：1.00：1.27, σ can be obtainedHFor 81.56MPa, σhFor 67.41 MPa, σvFor
85.62 MPa.
Above-described specific embodiment, has been carried out to the purpose of the present invention, technical scheme and beneficial effect further
Describe in detail, be should be understood that the specific embodiment that the foregoing is only the present invention, be not intended to limit the present invention
Protection domain, all any modification, equivalent substitution and improvement within the spirit and principles in the present invention, done etc., all should comprise
Within protection scope of the present invention.
Claims (4)
1. a kind of method of testing of complexity shale formation crustal stress is it is characterised in that comprise the following steps：
Step a：In drilling process, after well cementation terminates, carry out formation fracturing test near casing shoe, measure the rupture pressure on stratum
Power；
Step b：Carry out differential strain analysis test in waiting confined pressure storehouse, calculate field stress value, determine the stress value of field state；
Step c：Crustal stress is measured using differential strain analysis assay device.
2. a kind of method of testing of complexity shale formation crustal stress according to claim 1 is it is characterised in that described step
In a, the determination method of formation fracture pressure is：Pressure rise pressure break ground city produced by when the drilling well fluid column in well is so as to former
Some cracks open, form borehole fluid pressure during new crack, according to poroelasticity, can obtain rock and produce and draw
Stretching mud column pressure in well during destruction is：
Pf=3 σH-σh-αPp+St
In formula：σHFor level maximum crustal stress, σhFor level minimum crustal stress, PpFor formation pore pressure, α is effective stress system
Number, StFor tensile strength, PfFor formation fracture pressure.
3. a kind of method of testing of complexity shale formation crustal stress according to claim 2 is it is characterised in that described step
In b, concrete method of testing is to choose column drill core from Oil Field, and the face of cylinder is cut into two orthogonal faces,
This two faces are mutually perpendicular to two end faces of cylinder, after core sealing, put into and enclose in storehouse, the strain testing under each confined pressure storehouse
Provide 9 strain values, 9 strain values can state the strain regime in this this moment, constitute strain variable [ε],
[ε]={ ε1ε2 –(ε1+ε2)/2 ε8 –(ε7+ε9)/2 }
[ε]={ ε2 –(ε1+ε2)/2 ε3ε5 –(ε4+ε6)/2 }
[ε]={ ε8 –(ε7+ε9)/2 ε5 –(ε4+ε6)/ 2 ε6}
The three-dimensional ratio of principal stresses is：σH：σh：σv=[μ(εH+εh) +(1-μ) εH]：[μ(εv+εH) +(1-μ) εh] ：[μ(εH+εh)
+(1-μ) εv]
Wherein：εHFor level maximum stress direction dependent variable, εhFor level minimum stress direction dependent variable, εvFor vertically
Stress direction dependent variable, μ is Poisson's ratio.
4. a kind of method of testing of complexity shale formation crustal stress according to claim 3 is it is characterised in that described step
C determines vertical stress σ using below equationv
σH：σh= m：n
m =μ(εh+εv) +(1-μ) εH
n=μ(εH+εv) +(1-μ) εh.
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Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107524439A (en) * | 2017-08-11 | 2017-12-29 | 中国石油大学(北京) | The Forecasting Methodology and device of marine facies shale formation cracking depth |
| CN109630098A (en) * | 2019-02-15 | 2019-04-16 | 中国地质科学院地质力学研究所 | A method of poor stress is measured using core |
| CN111749678A (en) * | 2020-07-06 | 2020-10-09 | 宋立才 | Method and device for determining occurrence time of shale gas reservoir failure event |
| CN111948029A (en) * | 2020-09-18 | 2020-11-17 | 中南大学 | Rock mass ground stress measuring method and tensile strength uniformity measuring method |
| CN115655133A (en) * | 2022-11-01 | 2023-01-31 | 中国石油大学(北京) | Optical fiber strain sensing pipe column and ground stress measuring method |
| CN115655133B (en) * | 2022-11-01 | 2024-05-03 | 中国石油大学(北京) | Ground stress measuring method based on optical fiber strain sensing tubular column |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4344484A (en) * | 1978-08-17 | 1982-08-17 | Occidental Oil Shale, Inc. | Determining the locus of a processing zone in an in situ oil shale retort through a well in the formation adjacent the retort |
| CN104775810A (en) * | 2015-03-03 | 2015-07-15 | 西南石油大学 | Method for evaluating compressibility of shale gas reservoir |
| CN104853822A (en) * | 2014-09-19 | 2015-08-19 | 杨顺伟 | Method for evaluating shale gas reservoir and searching sweet spot region |
-
2016
- 2016-03-17 CN CN201610152903.0A patent/CN106401576A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4344484A (en) * | 1978-08-17 | 1982-08-17 | Occidental Oil Shale, Inc. | Determining the locus of a processing zone in an in situ oil shale retort through a well in the formation adjacent the retort |
| CN104853822A (en) * | 2014-09-19 | 2015-08-19 | 杨顺伟 | Method for evaluating shale gas reservoir and searching sweet spot region |
| CN104775810A (en) * | 2015-03-03 | 2015-07-15 | 西南石油大学 | Method for evaluating compressibility of shale gas reservoir |
Non-Patent Citations (1)
| Title |
|---|
| 金衍等: "复杂泥页岩地层地应力的确定方法研究", 《岩石力学与工程学报》 * |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107524439A (en) * | 2017-08-11 | 2017-12-29 | 中国石油大学(北京) | The Forecasting Methodology and device of marine facies shale formation cracking depth |
| CN109630098A (en) * | 2019-02-15 | 2019-04-16 | 中国地质科学院地质力学研究所 | A method of poor stress is measured using core |
| CN111749678A (en) * | 2020-07-06 | 2020-10-09 | 宋立才 | Method and device for determining occurrence time of shale gas reservoir failure event |
| CN111948029A (en) * | 2020-09-18 | 2020-11-17 | 中南大学 | Rock mass ground stress measuring method and tensile strength uniformity measuring method |
| CN115655133A (en) * | 2022-11-01 | 2023-01-31 | 中国石油大学(北京) | Optical fiber strain sensing pipe column and ground stress measuring method |
| CN115655133B (en) * | 2022-11-01 | 2024-05-03 | 中国石油大学(北京) | Ground stress measuring method based on optical fiber strain sensing tubular column |
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Application publication date: 20170215 |