CN109064016A - A kind of hypotonic coal seam hydraulic fracture antireflective effect evaluation method - Google Patents
A kind of hypotonic coal seam hydraulic fracture antireflective effect evaluation method Download PDFInfo
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Abstract
The present invention relates to a kind of hypotonic coal seam hydraulic fracture antireflective effect evaluation methods, include following steps: (1) determining the applicability of hypotonic coal seam hydraulic fracture；(2) determine that coal seam can pressure break indexI 1 ；(3) hydraulic fracture expanding index is determinedI 2；(4) hydraulic fracture closed index is determinedI 3；(5) hypotonic coal seam hydraulic fracture antireflective effect evaluation number is constructedIQuantitative calculation；(6) hypotonic coal seam hydraulic fracture antireflective effect evaluation criterion is determined；(7) the hydraulic fracturing anti-reflection effect in hypotonic coal seam is evaluated.The beneficial effects of the present invention are: the present invention is according to the anti-reflection mechanism of coal seam hydraulic fracture, construct hypotonic coal seam hydraulic fracture antireflective effect evaluation model and method, the quantitative assessment for realizing hypotonic coal seam hydraulic fracture antireflective effect has great importance for accurately selecting the anti-reflection region of coal seam hydraulic fracture and improving coal bed gas extraction effect.
Description
Technical field
The invention belongs to hydraulic fracturing technology field more particularly to a kind of hypotonic coal seam hydraulic fracture antireflective effect evaluation sides
Method.
Background technique
Technology that coal seam hydraulic fracture is anti-reflection is to overcome minimum crustal stress and coal and rock anti-by the pressure of water in injection coal seam
Coal seam plane of weakness is made to occur to open, extend and extend to form crack for tensile strength so that a kind of method for reaching increase coal seam permeability is arranged
Apply, due to its have it is anti-reflection, inhibit Gas, change the multiple actions such as coal mass strength and depositing dust make it in many mines in China
Well is tested and has been applied.The result shows that the test effect of only part mine is preferable, and the application effect of most of mine
It is poor, the reason is that causing hydraulic fracturing anti-reflection technology to have some limitations since China's condition of coal seam occurrence is extremely complex
And blindness.Hydraulic fracturing anti-reflection technology is a kind of special anti-reflection measure of coal seam reinforcing, such as without effect before implementation
Evaluation, can not only waste a large amount of human and material resources, and can not reach target due to pressure break, influence coal-bed gas pumping
It adopts, leaves serious security risk to subsequent coal production.
Currently, researcher has recognized that the importance of fracturing effect evaluation, using Geological stength index or coal
Criterion of the body structure as hydraulic fracturing technology applicability.Since coal seam hydraulic fracture is related to multiple processes such as pressure break and draining,
It is influenced again by coal seam, roof and floor mechanical characteristic and crustal stress, influence factor is numerous, influencing mechanism is complicated.It is strong using geology
On the one hand the effect for spending index or Coal Pore Structure to differentiate hydraulic fracturing is that cannot cover all since these indexs are single
The influence factor of hydraulic fracturing；On the other hand it is that these indexs belong to qualitative description, determines to need higher professional technique
Knowledge and experience such as carries out identification by field technician and has certain difficulty, will certainly be to hydraulic fracturing antireflective effect
Evaluation brings certain deviation.
Summary of the invention
The present invention, will according to the antireflective mechanism of hypotonic coal seam hydraulic fracture in order to solve shortcoming in the prior art
The hypotonic anti-reflection process of coal seam hydraulic fracture is divided into the crack initiation of hydraulic fracture, extension extends and closure three phases, is based on waterpower pressure
Split the three phases being related to and influence factor propose coal seam can pressure break index, hydraulic fracture expanding index and hydraulic fracture closure
Index establishes hypotonic coal seam hydraulic fracture antireflective effect evaluation model and method, can be to hypotonic coal seam water using this method
It forces and splits antireflective effect progress quantitative assessment, improve the precision of coal seam hydraulic fracture effect assessment, be that coal seam hydraulic fracture is anti-reflection
The selection in region provides technical support, simultaneously for popularization and application hydraulic fracturing anti-reflection technology and improves coal bed gas extraction effect
Have great importance.
In order to solve the above technical problems, the present invention adopts the following technical scheme: a kind of anti-reflection effect of hypotonic coal seam hydraulic fracture
Fruit evaluation method, includes the following steps,
(1), determine the applicability of hypotonic coal seam hydraulic fracture；
(2), determine that coal seam can pressure break indexI 1 ；
(3), hydraulic fracture expanding index is determinedI 2；
(4), hydraulic fracture closed index is determinedI 3；
It (5), can pressure break index using the coal seam that step (2) obtainI 1, step (3) obtain hydraulic fracture expanding indexI 2And step
Suddenly the hydraulic fracture closed index that (4) obtainI 3, construct hypotonic coal seam hydraulic fracture antireflective effect evaluation numberIQuantitatively calculate mould
Type；
(6), hypotonic coal seam hydraulic fracture antireflective effect evaluation criterion is determined；
(7), the hydraulic fracturing anti-reflection effect in hypotonic coal seam is evaluated.
Further, the detailed process of the step (1) is, according to table 1 to the applicability of hypotonic coal seam hydraulic fracture into
Row determines:
The applicability criterion of the hypotonic coal seam hydraulic fracture of table 1
If the Geological stength index in hypotonic coal seamGSI>=30 and solid coefficientf>=0.4 and Coal Pore Structure be primary structure coal
Either fragmentation coal can continue according to step (2)~step (7) then hypotonic coal seam is suitable for the implementation of hydraulic fracturing technology
The hydraulic fracturing anti-reflection effect in hypotonic coal seam is evaluated；
If the Geological stength index in hypotonic coal seamGSI< 30 or solid coefficientf< 0.4 or Coal Pore Structure are granulated coal
Either rotten rib coal, then hypotonic coal seam is not suitable for the implementation of hydraulic fracturing technology, direct basis step (7) is to hypotonic coal seam
Hydraulic fracturing anti-reflection effect evaluated.
Further, the step (2) refers to that coal seam has the specific steps are, the compressibility of coal body and can effectively be pressed
It splits to form crack to increase the property of permeability, the mechanical characteristic of coal plays an important role the compressibility in coal seam and shadow
It rings, it is generally recognized that the elasticity modulus of coal is bigger, coal seam Geological stength index is bigger, Poisson's ratio is smaller, the compressibility in coal seam
Better；Calculating coal seam using formula (1)~formula (4) accordingly can pressure break indexI 1:
(1)
(2)
(3)
(4)
In formula,I 1It can pressure break index for coal seam；E n Withv n Respectively elasticity modulus index and Poisson ratio index；E maxWithE minRespectively
It is minimum and maximum elasticity modulus in coal seam；v maxWithv minIt is minimum and maximum Poisson's ratio in coal seam respectively；GSIFor the ground in coal seam
Matter intensity index, value range are 0~100；GSI n For the Geological stength index index in coal seam；EFor the elasticity modulus of coal body,v
For the Poisson's ratio of coal body.
Further, the step (3) the specific steps are, in hydraulic fracture forming process, the fracture toughness of coal body, water
Flat principal stress coefficient of variation and vertical principal stress coefficient of variation are the principal elements for influencing hydraulic fracture extension and extending, and coal body breaks
Split that toughness is lower, the extension for being more conducive to hydraulic fracture extends；Horizontal principal stress coefficient of variation is bigger, is more conducive to hydraulic fracture
Extension, the range of hydraulic fracture is also bigger；Vertical principal stress coefficient of variation is smaller, more advantageously forms chicken-wire cracking net
Network；I type fracture toughness of coal body is calculated using formula (5) accordinglyK IC :
(5)
In formula,K IC For I type fracture toughness；σ t For coal and rock tensile strength；a、bIt, can be by having been measured in collecting zone for coefficient
Coal petrography sample tensile strength and I type fracture toughness outKIC, coefficient is then determined using linear fit methodaWithb；
The horizontal principal stress coefficient of variation in coal seam is calculated using formula (6):
(6)
In formula,K H For horizontal principal stress coefficient of variation,σ 1For maximum horizontal principal stress,σ 2For minimum horizontal principal stress；
The vertical principal stress coefficient of variation in coal seam is calculated using formula (7):
(7)
In formula,K V For vertical principal stress coefficient of variation,σ H For vertical principal stress,σ 2For minimum horizontal principal stress；
To I type fracture toughnessK IC , horizontal principal stress coefficient of variationK H With vertical principal stress coefficient of variationK V It is normalized
Obtain hydraulic fracture expanding indexI 2:
(8)
(9)
(10)
(11)
In formula,K Icn For I type fracture toughness index,K Hn For horizontal principal stress coefficient of variation index,K Vn For vertical principal stress difference
Coefficient indices；K ICmaxWithK ICminIt is minimum and maximum I type fracture toughness in coal seam respectively；K HmaxWithK HminBe respectively in coal seam most
Big and minimum horizontal principal stress coefficient of variation；K VmaxWithK VminIt is minimum and maximum vertical principal stress coefficient of variation in coal seam respectively；I 2For hydraulic fracture expanding index.
Further, the step (4) the specific steps are with the row of water in coal seam in post-fracturing drainage procedure
Out, pore-fluid pressure reduction in coal seam, effective stress increase, and waterpower crack will appear different degrees of closure in coal seam.Shadow
Ring coal seam waterpower closing of fracture principal element have coal body uniaxial compressive strength, coal solid coefficient, minimum horizontal principal stress and
Coal seam buried depth, coal body uniaxial compressive strength and coal solid coefficient are bigger, and the ability that characterization coal body resists crack closure is got over
By force, more it is unfavorable for the closure in coal seam waterpower crack, minimum horizontal principal stress and coal seam buried depth are bigger, and characterization is applied to coal body
The external force of crack closure is bigger, is more conducive to the closure in coal seam waterpower crack；Coal seam is calculated using formula (12)~formula (16) accordingly
Hydraulic fracture closed indexI 3:
(12)
(13)
(14)
(15)
(16)
In formula,σ Cn For coal body uniaxial compressive strength index；f n For coal body solid coefficient index；σ 2n For minimum horizontal principal stress
Index；H n For coal seam buried depth index；I 3For hydraulic fracture closed index；σ CmaxWithσ CminRespectively coal body is maximum uniaxial anti-
Compressive Strength and minimum uniaxial compressive strength；f maxWithf minRespectively coal body maximum solid coefficient and minimum solid coefficient；σ 2maxWithσ 2minThe respectively maximum minimum horizontal principal stress in coal seam and the smallest minimum horizontal principal stress；H maxWithH minRespectively
Coal seam paleogeothermal gradient and minimum buried depth；σCFor coal body uniaxial compressive strength,fFor coal body solid coefficient, σ2For waterpower
Fracture zone coal seam minimum horizontal principal stress,HFor the buried depth in coal seam.
Further, the step (5) the specific steps are can pressure break index according to the coal seam in step (2)I 1, step
(3) the hydraulic fracture expanding index inI 2With the hydraulic fracture closed index in step (4)I 3, construct hypotonic coal seam hydraulic fracture
Antireflective effect evaluation numberIQuantitative calculation:
(17)
In formula,IFor hypotonic coal seam hydraulic fracture antireflective effect evaluation number；w 1、w 2、w 3Respectively coal seam can pressure break index, waterpower
The weight that crack expanding index and hydraulic fracture closed index influence fracturing effect,w 1+w 2+w 3=1,w 1、w 2、w 3It can adopt
It is obtained with analytic hierarchy process (AHP) determination.
Further, the step (6) the specific steps are according to the calculated hypotonic coal seam hydraulic fracture of step (5)
Antireflective effect evaluation number value provides hypotonic coal seam hydraulic fracture antireflective effect in conjunction with hypotonic coal seam hydraulic fracture performance
Grading standard, as shown in table 2:
The hypotonic coal seam hydraulic fracture antireflective effect grading standard of table 2
。
Further, the step (7) the specific steps are, according to the judgement of step (1) as a result, as hypotonic coal seam be applicable in
In the implementation of hydraulic fracturing technology, quasi- progress hydraulic fracturing place related data is collected, based on step (2)~step (5)
Calculate the quasi- hydraulic fracturing anti-reflection effect assessment index for carrying out coal seam hydraulic fracture placeI, the determining hypotonic coal of foundation step (6)
The layer hydraulic fracturing anti-reflection gradation of effects criteria for classifying evaluates hydraulic fracturing anti-reflection effect；As hypotonic coal seam is not suitable for water
The implementation of power fracturing technique, then the hydraulic fracturing anti-reflection effect assessment in hypotonic coal seam is poor.
By adopting the above technical scheme, the beneficial effects of the present invention are: the method for the present invention is according to the anti-reflection machine of coal seam hydraulic fracture
Hydraulic fracturing anti-reflection process is divided into the crack initiation of waterpower crack, extension extends and is closed three phases, fully considers each stage by reason
Influence waterpower crack develop factor propose coal seam can pressure break index, hydraulic fracture expanding index and hydraulic fracture closure refer to
Number, constructs hypotonic coal seam hydraulic fracture antireflective effect evaluation model and method, realizes the anti-reflection effect of hypotonic coal seam hydraulic fracture
The quantitative assessment of fruit, for accurately selecting the anti-reflection region of coal seam hydraulic fracture and improving coal bed gas extraction effect with important
Meaning.
Detailed description of the invention
Fig. 1 is flow diagram of the invention.
Specific embodiment
As shown in Figure 1, a kind of hypotonic coal seam hydraulic fracture antireflective effect evaluation method of the invention, includes the following steps,
(1), determine the applicability of hypotonic coal seam hydraulic fracture；
(2), determine that coal seam can pressure break indexI 1 ；
(3), hydraulic fracture expanding index is determinedI 2；
(4), hydraulic fracture closed index is determinedI 3；
It (5), can pressure break index using the coal seam that step (2) obtainI 1, step (3) obtain hydraulic fracture expanding indexI 2And step
Suddenly the hydraulic fracture closed index that (4) obtainI 3, construct hypotonic coal seam hydraulic fracture antireflective effect evaluation numberIQuantitatively calculate mould
Type；
(6), hypotonic coal seam hydraulic fracture antireflective effect evaluation criterion is determined；
(7), the hydraulic fracturing anti-reflection effect in hypotonic coal seam is evaluated.
Further, the detailed process of the step (1) is, according to table 1 to the applicability of hypotonic coal seam hydraulic fracture into
Row determines:
The applicability criterion of the hypotonic coal seam hydraulic fracture of table 1
If the Geological stength index in hypotonic coal seamGSI>=30 and solid coefficientf>=0.4 and Coal Pore Structure be primary structure coal
Either fragmentation coal can continue according to step (2)~step (7) then hypotonic coal seam is suitable for the implementation of hydraulic fracturing technology
The hydraulic fracturing anti-reflection effect in hypotonic coal seam is evaluated；
If the Geological stength index in hypotonic coal seamGSI< 30 or solid coefficientf< 0.4 or Coal Pore Structure are granulated coal
Either rotten rib coal, then hypotonic coal seam is not suitable for the implementation of hydraulic fracturing technology, direct basis step (7) is to hypotonic coal seam
Hydraulic fracturing anti-reflection effect evaluated.
Further, the step (2) refers to that coal seam has the specific steps are, the compressibility of coal body and can effectively be pressed
It splits to form crack to increase the property of permeability, the mechanical characteristic of coal plays an important role the compressibility in coal seam and shadow
It rings, it is generally recognized that the elasticity modulus of coal is bigger, coal seam Geological stength index is bigger, Poisson's ratio is smaller, the compressibility in coal seam
Better；Calculating coal seam using formula (1)~formula (4) accordingly can pressure break indexI 1:
(1)
(2)
(3)
(4)
In formula,I 1It can pressure break index for coal seam；E n Withv n Respectively elasticity modulus index and Poisson ratio index；E maxWithE minRespectively
It is minimum and maximum elasticity modulus in coal seam；v maxWithv minIt is minimum and maximum Poisson's ratio in coal seam respectively；GSIFor the ground in coal seam
Matter intensity index, value range are 0~100；GSI n For the Geological stength index index in coal seam；EFor the elasticity modulus of coal body,v
For the Poisson's ratio of coal body.
Further, the step (3) the specific steps are, in hydraulic fracture forming process, the fracture toughness of coal body, water
Flat principal stress coefficient of variation and vertical principal stress coefficient of variation are the principal elements for influencing hydraulic fracture extension and extending, and coal body breaks
Split that toughness is lower, the extension for being more conducive to hydraulic fracture extends；Horizontal principal stress coefficient of variation is bigger, is more conducive to hydraulic fracture
Extension, the range of hydraulic fracture is also bigger；Vertical principal stress coefficient of variation is smaller, more advantageously forms chicken-wire cracking net
Network；I type fracture toughness of coal body is calculated using formula (5) accordinglyK IC :
(5)
In formula,K IC For I type fracture toughness；σ t For coal and rock tensile strength；a、bIt, can be by having been measured in collecting zone for coefficient
Coal petrography sample tensile strength and I type fracture toughness outKIC, coefficient is then determined using linear fit methodaWithb；
The horizontal principal stress coefficient of variation in coal seam is calculated using formula (6):
(6)
In formula,K H For horizontal principal stress coefficient of variation,σ 1For maximum horizontal principal stress,σ 2For minimum horizontal principal stress；
The vertical principal stress coefficient of variation in coal seam is calculated using formula (7):
(7)
In formula,K V For vertical principal stress coefficient of variation,σ H For vertical principal stress,σ 2For minimum horizontal principal stress；
To I type fracture toughnessK IC , horizontal principal stress coefficient of variationK H With vertical principal stress coefficient of variationK V It is normalized
Obtain hydraulic fracture expanding indexI 2:
(8)
(9)
(10)
(11)
In formula,K Icn For I type fracture toughness index,K Hn For horizontal principal stress coefficient of variation index,K Vn For vertical principal stress difference
Coefficient indices；K ICmaxWithK ICminIt is minimum and maximum I type fracture toughness in coal seam respectively；K HmaxWithK HminBe respectively in coal seam most
Big and minimum horizontal principal stress coefficient of variation；K VmaxWithK VminIt is minimum and maximum vertical principal stress coefficient of variation in coal seam respectively；I 2For hydraulic fracture expanding index.
Further, the step (4) the specific steps are with the row of water in coal seam in post-fracturing drainage procedure
Out, pore-fluid pressure reduction in coal seam, effective stress increase, and waterpower crack will appear different degrees of closure in coal seam.Shadow
Ring coal seam waterpower closing of fracture principal element have coal body uniaxial compressive strength, coal solid coefficient, minimum horizontal principal stress and
Coal seam buried depth, coal body uniaxial compressive strength and coal solid coefficient are bigger, and the ability that characterization coal body resists crack closure is got over
By force, more it is unfavorable for the closure in coal seam waterpower crack, minimum horizontal principal stress and coal seam buried depth are bigger, and characterization is applied to coal body
The external force of crack closure is bigger, is more conducive to the closure in coal seam waterpower crack；Coal seam is calculated using formula (12)~formula (16) accordingly
Hydraulic fracture closed indexI 3:
(12)
(13)
(14)
(15)
(16)
In formula,σ Cn For coal body uniaxial compressive strength index；f n For coal body solid coefficient index；σ 2n For minimum horizontal principal stress
Index；H n For coal seam buried depth index；I 3For hydraulic fracture closed index；σ CmaxWithσ CminRespectively coal body is maximum uniaxial anti-
Compressive Strength and minimum uniaxial compressive strength；f maxWithf minRespectively coal body maximum solid coefficient and minimum solid coefficient；σ 2maxWithσ 2minThe respectively maximum minimum horizontal principal stress in coal seam and the smallest minimum horizontal principal stress；H maxWithH minRespectively
Coal seam paleogeothermal gradient and minimum buried depth；σCFor coal body uniaxial compressive strength,fFor coal body solid coefficient, σ2For waterpower
Fracture zone coal seam minimum horizontal principal stress,HFor the buried depth in coal seam；Coal body compression strength and coal solid coefficient are bigger,
More it is unfavorable for the closure in coal seam waterpower crack, minimum horizontal principal stress and coal seam buried depth are bigger, are more conducive to coal seam waterpower
The closure in crack.
Further, the step (5) the specific steps are can pressure break index according to the coal seam in step (2)I 1, step
(3) the hydraulic fracture expanding index inI 2With the hydraulic fracture closed index in step (4)I 3, construct hypotonic coal seam hydraulic fracture
Antireflective effect evaluation numberIQuantitative calculation:
(17)
In formula,IFor hypotonic coal seam hydraulic fracture antireflective effect evaluation number；w 1、w 2、w 3Respectively coal seam can pressure break index, waterpower
The weight that crack expanding index and hydraulic fracture closed index influence fracturing effect,w 1+w 2+w 3=1,w 1、w 2、w 3It can adopt
It is obtained with analytic hierarchy process (AHP) determination.
Further, the step (6) the specific steps are according to the calculated hypotonic coal seam hydraulic fracture of step (5)
Antireflective effect evaluation number value provides hypotonic coal seam hydraulic fracture antireflective effect in conjunction with hypotonic coal seam hydraulic fracture performance
Grading standard, as shown in table 2:
The hypotonic coal seam hydraulic fracture antireflective effect grading standard of table 2
。
Further, the step (7) the specific steps are, according to the judgement of step (1) as a result, as hypotonic coal seam be applicable in
In the implementation of hydraulic fracturing technology, quasi- progress hydraulic fracturing place related data is collected, based on step (2)~step (5)
Calculate the quasi- hydraulic fracturing anti-reflection effect assessment index for carrying out coal seam hydraulic fracture placeI, the determining hypotonic coal of foundation step (6)
The layer hydraulic fracturing anti-reflection gradation of effects criteria for classifying evaluates hydraulic fracturing anti-reflection effect；As hypotonic coal seam is not suitable for water
The implementation of power fracturing technique, then the hydraulic fracturing anti-reflection effect assessment in hypotonic coal seam is poor.
It is illustrated by taking the quasi- progress hydraulic fracturing place antireflective effect evaluation in certain mine coal seam as an example below:
Step (1): it carries out hydraulic fracturing place samples of coal pulled to pass through test to obtain the Coal Pore Structure in hypotonic coal seam being fragmentation quasi-
Coal, Geological stength indexGSI=70, solid coefficientf=1.2.According to table 1, which is suitable for the implementation of hydraulic fracturing technology,
The hydraulic fracturing anti-reflection effect in hypotonic coal seam can so be evaluated according to step (2)~step (7)；
Step (2): carrying out the test of coal petrography mechanics parameter in the quasi- hydraulic fracturing place samples of coal pulled that carries out, obtain coal elasticity modulus,
The parameters such as Geological stength index and Poisson's ratio, by measurementE=1500MPa,GSI=70 Hesv=0.3, substituted into formula (1)~formula
(4) calculating coal seam can pressure break indexI 1.Wherein,E max=2000MPa, andE min=800MPa；v max=0.4 Hev min=0.25.By
It calculatesI 1=0.65。
Step (3): the I type fracture toughness and coal and rock Tensile strength data determined in collecting zone is linearly returned
Return analysis availablea=0.03,b=0.12；Then the survey of coal petrography mechanics parameter is carried out in the quasi- hydraulic fracturing place samples of coal pulled that carries out
Examination obtains coal and rock tensile strength parameter, by measurementσ t =2MPa, I type fracture toughness can be obtained by being substituted into formula (5)K IC , pass through
It can be calculatedK IC =0.18MPa。
It collects quasi- progress hydraulic fracturing place maximum horizontal principal stress and minimum horizontal principal stress data, maximum horizontal master answers
Powerσ 1For 12MPa, minimum horizontal principal stressσ 2For 8MPa, horizontal principal stress coefficient of variation is calculated using formula (6)K H .By calculating
It can obtain,K H =0.5。
Collect the vertical principal stress in quasi- progress hydraulic fracturing place, vertical principal stressσ H For 10MPa, minimum horizontal principal stressσ 2
For 8MPa, vertical principal stress coefficient of variation is calculated using formula (7)K V .By can be calculated,K V =0.25。
Using formula (8)~formula (11) to I type fracture toughnessK IC , horizontal principal stress coefficient of variation and vertical principal stress difference system
NumberK V It is normalized to obtain hydraulic fracture expanding indexI 2.Wherein,K ICmax=0.27,K ICmin=0.12；K Hmax=0.8,K Hmin=0.2；K Vmax=0.5,K Vmin=0.1.By can be calculated,I 2=0.575。
Step (4): coal and rock uniaxial compressive strength test and firm is carried out in the quasi- hydraulic fracturing place samples of coal pulled that carries out
Property coefficient test, can obtainσ C =15MPa,f=1.2；Related data is collected according to quasi- progress hydraulic fracturing place situation, can be obtainedσ 2=
8MPa,H=450m.Coal seam waterpower crack closure index can be calculated by being substituted into formula (12)~formula (16)I 3.Whereinσ Cmax=20MPa,σ Cmin=3MPa；f max=1.5,f min=0.2；σ 2max=12MPa,σ 2min=5MPa；H max=800m,H min=400m.By can be calculated,I 3=0.7。
Step (5): determine that coal output layer can pressure break index, hydraulic fracture expanding index and waterpower using analytic hierarchy process (AHP) first
The weight that crack closure exponent pair fracturing effect influences, obtainsw 1=0.3、w 2=0.3、w 3=0.4；Then according to step (2)
Calculating coal output layer can pressure break indexI 1, the calculated hydraulic fracture expanding index of step (3)I 2With step (4) calculated waterpower
Crack closure indexI 3, hypotonic coal seam hydraulic fracture antireflective effect evaluation number is calculated using formula (17)I.By can be calculated,I
=0.648。
Step (6): according to the hypotonic coal seam hydraulic fracture performance of the mine, hypotonic coal seam hydraulic fracture antireflective effect is provided
Grading standard (table 2):
The hypotonic coal seam hydraulic fracture antireflective effect grading standard of table 2
Step (7): the quasi- implementation for carrying out hydraulic fracturing place and being suitable for hydraulic fracturing technology, by calculating, hypotonic coal seam waterpower
Pressure break antireflective effect evaluation numberI=0.655, the antireflective effect that the table of comparisons 2 can must intend carrying out hydraulic fracturing place is evaluated as
Deng.
Hydraulic fracturing test is carried out in evaluation place, sealing of hole networking carries out extraction after the completion of test, takes out by measurement day
The amount of adopting is up to 95 cubic metres, 3.3 times when being non-pressure break, the effect of hydraulic fracturing anti-reflection be it is medium, with calculating knot of the invention
Fruit matches.Illustrate present invention accuracy with higher, hypotonic coal seam hydraulic fracture antireflective effect can be predicted, it can
Guidance early period is provided for the selection in the anti-reflection region of hypotonic coal seam hydraulic fracture.
The present embodiment not makes any form of restriction shape of the invention, material, structure etc., all according to this hair
Bright technical spirit any simple modification, equivalent change and modification to the above embodiments, belong to the technology of the present invention side
The protection scope of case.
Claims (8)
1. a kind of hypotonic coal seam hydraulic fracture antireflective effect evaluation method, it is characterised in that: include the following steps,
(1), determine the applicability of hypotonic coal seam hydraulic fracture；
(2), determine that coal seam can pressure break indexI 1 ；
(3), hydraulic fracture expanding index is determinedI 2；
(4), hydraulic fracture closed index is determinedI 3；
It (5), can pressure break index using the coal seam that step (2) obtainI 1, step (3) obtain hydraulic fracture expanding indexI 2And step
Suddenly the hydraulic fracture closed index that (4) obtainI 3, construct hypotonic coal seam hydraulic fracture antireflective effect evaluation numberIQuantitatively calculate mould
Type；
(6), hypotonic coal seam hydraulic fracture antireflective effect evaluation criterion is determined；
(7), the hydraulic fracturing anti-reflection effect in hypotonic coal seam is evaluated.
2. a kind of hypotonic coal seam hydraulic fracture antireflective effect evaluation method according to claim 1, it is characterised in that: described
The detailed process of step (1) is to be determined according to applicability of the table 1 to hypotonic coal seam hydraulic fracture:
The applicability criterion of the hypotonic coal seam hydraulic fracture of table 1
If the Geological stength index in hypotonic coal seamGSI>=30 and solid coefficientf>=0.4 and Coal Pore Structure be primary structure coal
Either fragmentation coal can continue according to step (2)~step (7) then hypotonic coal seam is suitable for the implementation of hydraulic fracturing technology
The hydraulic fracturing anti-reflection effect in hypotonic coal seam is evaluated；
If the Geological stength index in hypotonic coal seamGSI< 30 or solid coefficientf< 0.4 or Coal Pore Structure are granulated coal
Either rotten rib coal, then hypotonic coal seam is not suitable for the implementation of hydraulic fracturing technology, direct basis step (7) is to hypotonic coal seam
Hydraulic fracturing anti-reflection effect evaluated.
3. a kind of hypotonic coal seam hydraulic fracture antireflective effect evaluation method according to claim 1 or 2, it is characterised in that:
The step (2) refers to that coal seam has the specific steps are, the compressibility of coal body and can form crack by effective pressure break to increase
Add the property of permeability, the mechanical characteristic of coal is played an important role and influenced on the compressibility in coal seam, it is generally recognized that coal
Elasticity modulus is bigger, coal seam Geological stength index is bigger, Poisson's ratio is smaller, and the compressibility in coal seam is better；It uses accordingly
Formula (1)~formula (4) calculates coal seam can pressure break indexI 1:
(1)
(2)
(3)
(4)
In formula,I 1It can pressure break index for coal seam；E n Withv n Respectively elasticity modulus index and Poisson ratio index；E maxWithE minRespectively
It is minimum and maximum elasticity modulus in coal seam；v maxWithv minIt is minimum and maximum Poisson's ratio in coal seam respectively；GSIFor the ground in coal seam
Matter intensity index, value range are 0~100；GSI n For the Geological stength index index in coal seam；EFor the elasticity modulus of coal body,v
For the Poisson's ratio of coal body.
4. a kind of hypotonic coal seam hydraulic fracture antireflective effect evaluation method according to claim 1, it is characterised in that: described
Step (3) the specific steps are the fracture toughness of coal body, horizontal principal stress coefficient of variation and hang down in hydraulic fracture forming process
Straight principal stress coefficient of variation is the principal element for influencing hydraulic fracture extension and extending, and the fracture toughness of coal body is lower, is more conducive to
The extension of hydraulic fracture extends；Horizontal principal stress coefficient of variation is bigger, is more conducive to the extension of hydraulic fracture, the model of hydraulic fracture
It encloses also bigger；Vertical principal stress coefficient of variation is smaller, more advantageously forms chicken-wire cracking network；It is calculated accordingly using formula (5)
I type fracture toughness of coal bodyK IC :
(5)
In formula,K IC For I type fracture toughness；σ t For coal and rock tensile strength；a、bIt, can be by having been measured in collecting zone for coefficient
Coal petrography sample tensile strength and I type fracture toughness outKIC, coefficient is then determined using linear fit methodaWithb；
The horizontal principal stress coefficient of variation in coal seam is calculated using formula (6):
(6)
In formula,K H For horizontal principal stress coefficient of variation,σ 1For maximum horizontal principal stress,σ 2For minimum horizontal principal stress；
The vertical principal stress coefficient of variation in coal seam is calculated using formula (7):
(7)
In formula,K V For vertical principal stress coefficient of variation,σ H For vertical principal stress,σ 2For minimum horizontal principal stress；
To I type fracture toughnessK IC , horizontal principal stress coefficient of variationK H With vertical principal stress coefficient of variationK V It is normalized
To hydraulic fracture expanding indexI 2:
(8)
(9)
(10)
(11)
In formula,K Icn For I type fracture toughness index,K Hn For horizontal principal stress coefficient of variation index,K Vn For vertical principal stress difference system
Number index；K ICmaxWithK ICminIt is minimum and maximum I type fracture toughness in coal seam respectively；K HmaxWithK HminIt is maximum in coal seam respectively
With minimum horizontal principal stress coefficient of variation；K VmaxWithK VminIt is minimum and maximum vertical principal stress coefficient of variation in coal seam respectively；I 2
For hydraulic fracture expanding index.
5. a kind of hypotonic coal seam hydraulic fracture antireflective effect evaluation method according to claim 1, it is characterised in that: described
Step (4) the specific steps are, with the discharge of water in coal seam in post-fracturing drainage procedure, pore-fluid pressure drop in coal seam
Low, effective stress increases, and waterpower crack will appear different degrees of closure in coal seam；
The principal element for influencing coal seam waterpower closing of fracture has coal body uniaxial compressive strength, coal solid coefficient, minimum level master
Stress and coal seam buried depth, coal body uniaxial compressive strength and coal solid coefficient are bigger, and characterization coal body resists crack closure
Ability is stronger, is more unfavorable for the closure in coal seam waterpower crack, and minimum horizontal principal stress and coal seam buried depth are bigger, and characterization applies
It is bigger in the external force of coal body crack closure, be more conducive to the closure in coal seam waterpower crack；It is counted accordingly using formula (12)~formula (16)
Calculate coal seam waterpower crack closure indexI 3:
(12)
(13)
(14)
(15)
(16)
In formula,σ Cn For coal body uniaxial compressive strength index；f n For coal body solid coefficient index；σ 2n Refer to for minimum horizontal principal stress
Number；H n For coal seam buried depth index；I 3For hydraulic fracture closed index；σ CmaxWithσ CminRespectively coal body maximum uniaxial compressive
Intensity and minimum uniaxial compressive strength；f maxWithf minRespectively coal body maximum solid coefficient and minimum solid coefficient；σ 2max
Withσ 2minThe respectively maximum minimum horizontal principal stress in coal seam and the smallest minimum horizontal principal stress；H maxWithH minRespectively coal seam
Paleogeothermal gradient and minimum buried depth；σCFor coal body uniaxial compressive strength,fFor coal body solid coefficient, σ2For hydraulic fracturing
Regional coal-seam minimum horizontal principal stress,HFor the buried depth in coal seam.
6. a kind of hypotonic coal seam hydraulic fracture antireflective effect evaluation method according to claim 1, it is characterised in that: described
Step (5) the specific steps are can pressure break index according to the coal seam in step (2)I 1, the hydraulic fracture extension in step (3) refers to
NumberI 2With the hydraulic fracture closed index in step (4)I 3, construct hypotonic coal seam hydraulic fracture antireflective effect evaluation numberIIt is quantitative
Computation model:
(17)
In formula,IFor hypotonic coal seam hydraulic fracture antireflective effect evaluation number；w 1、w 2、w 3Respectively coal seam can pressure break index, waterpower
The weight that crack expanding index and hydraulic fracture closed index influence fracturing effect,w 1+w 2+w 3=1,w 1、w 2、w 3It can adopt
It is obtained with analytic hierarchy process (AHP) determination.
7. a kind of hypotonic coal seam hydraulic fracture antireflective effect evaluation method according to claim 1, it is characterised in that: described
Step (6) the specific steps are, according to the calculated hypotonic coal seam hydraulic fracture antireflective effect evaluation number value of step (5), knot
Hypotonic coal seam hydraulic fracture performance is closed, hypotonic coal seam hydraulic fracture antireflective effect grading standard is provided, such as 2 institute of table
Show:
The hypotonic coal seam hydraulic fracture antireflective effect grading standard of table 2
。
8. a kind of hypotonic coal seam hydraulic fracture antireflective effect evaluation method according to claim 1, it is characterised in that: described
Step (7) the specific steps are, according to step (1) judgement as a result, as hypotonic coal seam be suitable for hydraulic fracturing technology implementation,
Quasi- progress hydraulic fracturing place related data is collected, is calculated based on step (2)~step (5) and intends carrying out coal seam hydraulic fracture
The hydraulic fracturing anti-reflection effect assessment index in placeI, the determining hypotonic coal seam hydraulic fracture antireflective effect grade of foundation step (6)
The criteria for classifying evaluates hydraulic fracturing anti-reflection effect；It is if hypotonic coal seam is not suitable for the implementation of hydraulic fracturing technology, then low
It is poor for seeping the hydraulic fracturing anti-reflection effect assessment in coal seam.
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110411795A (en) * | 2019-06-21 | 2019-11-05 | 中国矿业大学 | A kind of method of analog equivalent scene cherry coal in laboratory |
| CN113032956A (en) * | 2021-02-18 | 2021-06-25 | 重庆大学 | Method for rapidly determining hydraulic slotting technical parameters |
| WO2022205622A1 (en) * | 2021-03-31 | 2022-10-06 | 中煤科工集团重庆研究院有限公司 | Method for evaluating effect of uniform pressure relief by horizontal slitting in hole drilled along coal seam |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102635351A (en) * | 2012-03-13 | 2012-08-15 | 河南理工大学 | Method for determining fracture pressure of hydraulic fracturing on basis of geological strength index |
| CN104314563A (en) * | 2014-10-21 | 2015-01-28 | 西安科技大学 | Logging quantitative evaluation method of coal bed methane reservoir fracturing capability |
| CN106097125A (en) * | 2016-06-17 | 2016-11-09 | 延长油田股份有限公司 | A kind of Sandstone Gas Reservoir pressure break evaluation methodology |
| US20170218729A1 (en) * | 2014-01-24 | 2017-08-03 | King Fahd University Of Petroleum And Minerals | Method and system for hydraulic fracturing based on skin factor analysis |
| CN107092032A (en) * | 2017-05-15 | 2017-08-25 | 西安石油大学 | A kind of method of utilization well-log information quantitative assessment coal-bed gas exploitation complexity |
-
2018
- 2018-07-30 CN CN201810852755.2A patent/CN109064016B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102635351A (en) * | 2012-03-13 | 2012-08-15 | 河南理工大学 | Method for determining fracture pressure of hydraulic fracturing on basis of geological strength index |
| US20170218729A1 (en) * | 2014-01-24 | 2017-08-03 | King Fahd University Of Petroleum And Minerals | Method and system for hydraulic fracturing based on skin factor analysis |
| CN104314563A (en) * | 2014-10-21 | 2015-01-28 | 西安科技大学 | Logging quantitative evaluation method of coal bed methane reservoir fracturing capability |
| CN106097125A (en) * | 2016-06-17 | 2016-11-09 | 延长油田股份有限公司 | A kind of Sandstone Gas Reservoir pressure break evaluation methodology |
| CN107092032A (en) * | 2017-05-15 | 2017-08-25 | 西安石油大学 | A kind of method of utilization well-log information quantitative assessment coal-bed gas exploitation complexity |
Non-Patent Citations (2)
| Title |
|---|
| 曾青东 等: "幂律型压裂液对裂缝扩展影响的数值模拟", 《大庆石油地质与开发》 * |
| 李俊乾 等: "基于无量纲裂缝导流能力的煤储层压裂效果分析", 《高校地质学报》 * |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110411795A (en) * | 2019-06-21 | 2019-11-05 | 中国矿业大学 | A kind of method of analog equivalent scene cherry coal in laboratory |
| CN110411795B (en) * | 2019-06-21 | 2020-06-30 | 中国矿业大学 | Method for simulating equivalent field soft coal in laboratory |
| CN113032956A (en) * | 2021-02-18 | 2021-06-25 | 重庆大学 | Method for rapidly determining hydraulic slotting technical parameters |
| CN113032956B (en) * | 2021-02-18 | 2022-09-02 | 重庆大学 | Method for quickly determining hydraulic slotting technical parameters |
| WO2022205622A1 (en) * | 2021-03-31 | 2022-10-06 | 中煤科工集团重庆研究院有限公司 | Method for evaluating effect of uniform pressure relief by horizontal slitting in hole drilled along coal seam |
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