U.S. patent application number 17/257004 was filed with the patent office on 2021-05-13 for quantitative scoring and optimization method of drilling and completion loss-control material.
The applicant listed for this patent is Southwest Petroleum University. Invention is credited to Chao Jiang, Yili Kang, Chong Lin, Chuan Liu, Chengyuan Xu, Xiaopeng Yan, Bin Yang, Lijun You, Jingyi Zhang, Hexiang Zhou.
Application Number | 20210141984 17/257004 |
Document ID | / |
Family ID | 1000005398826 |
Filed Date | 2021-05-13 |
![](/patent/app/20210141984/US20210141984A1-20210513\US20210141984A1-2021051)
United States Patent
Application |
20210141984 |
Kind Code |
A1 |
Xu; Chengyuan ; et
al. |
May 13, 2021 |
QUANTITATIVE SCORING AND OPTIMIZATION METHOD OF DRILLING AND
COMPLETION LOSS-CONTROL MATERIAL
Abstract
A quantitative scoring and optimization method of a drilling and
completion loss-control material includes: extracting key
performance parameters of drilling and completion loss-control
materials in loss-circulation zone, sequencing the key performance
parameters according to their importance; performing weight
calculation on the key performance parameters of the loss-control
material by an analytic hierarchy process; determining scores of
the key performance parameters of conventional loss-control
materials according to an experimental evaluation table of the
performance parameters of the loss-control materials; calculating
comprehensive scores of all loss-control materials and performing
optimal selection on the loss-control materials according to the
comprehensive scores. The present disclosure provides a
quantitative evaluation table of performance parameters of the
loss-control materials, and an optimal selection method of the
loss-control materials for different loss-control formations
according to the analytic hierarchy process.
Inventors: |
Xu; Chengyuan; (Chengdu,
Sichuan, CN) ; Kang; Yili; (Chengdu, Sichuan, CN)
; You; Lijun; (Chengdu, Sichuan, CN) ; Jiang;
Chao; (Chengdu, Sichuan, CN) ; Yan; Xiaopeng;
(Chengdu, Sichuan, CN) ; Zhang; Jingyi; (Chengdu,
Sichuan, CN) ; Lin; Chong; (Chengdu, Sichuan, CN)
; Zhou; Hexiang; (Chengdu, Sichuan, CN) ; Yang;
Bin; (Chengdu, Sichuan, CN) ; Liu; Chuan;
(Chengdu, Sichuan, CN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Southwest Petroleum University |
Chengdu, Sichuan |
|
CN |
|
|
Family ID: |
1000005398826 |
Appl. No.: |
17/257004 |
Filed: |
January 8, 2020 |
PCT Filed: |
January 8, 2020 |
PCT NO: |
PCT/CN2020/070778 |
371 Date: |
December 30, 2020 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G06F 30/25 20200101;
G06F 2111/10 20200101 |
International
Class: |
G06F 30/25 20060101
G06F030/25 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 29, 2019 |
CN |
201910356871.X |
Claims
1. A quantitative scoring and optimization method of a drilling and
completion loss-control material comprising: step 1: obtaining
performance parameters of drilling and completion loss-control
materials and then extracting key performance parameters from the
performance parameters; step 2: sequencing the key performance
parameters obtained in the step 1 according to their relative
importance; step 3: performing weight calculation on the key
performance parameters of the loss-control materials by an analytic
hierarchy process (AHP); step 4: obtaining key performance
parameters of conventional loss-control materials and then
performing evaluation on the key performance parameters of the
conventional loss-control materials; step 5: calculating
comprehensive scores of each conventional loss-control material
according to results of the step 3 and the step 4; step 6:
obtaining an optimal type of the loss-control materials according
to the comprehensive score of the conventional loss-control
material calculated in the step 5.
2. The quantitative scoring and optimization method of a drilling
and completion loss-control material as claimed in claim 1, wherein
the performance parameters in the step 1 comprises: mechanical
parameters, chemical parameters and geometric parameters, the
mechanical parameters comprising but not limited to friction
coefficient, compressive resistance, abrasion resistance and fiber
tensile strength; the chemical parameters comprising but not
limited to acid solubility and temperature resistance; the
geometric parameters comprising but not limited to a shape, an
aspect ratio of fiber, a degree of sphericity and a particle size
distribution.
3. The quantitative scoring and optimization method of a drilling
and completion loss-control material as claimed in claim 1, wherein
an extraction basis of extracting the key performance parameters
from the performance parameters in the step 1 comprises but is not
limited to a prediction model of a loss control effect extracted
from the performance parameters according to a specific geological
condition of loss-circulation zone.
4. The quantitative scoring and optimization method of a drilling
and completion loss-control material as claimed in claim 1, wherein
the step of sequencing the key performance parameters in the step 2
is qualitatively determined by researchers based on a specific
situation and experiences, and a scale of the importance is carried
out by researchers according to a specific situation and
experiences.
5. The quantitative scoring and optimization method of a drilling
and completion loss-control material as claimed in claim 1, wherein
a specific operation process of the step 3 comprises as follows:
step S1: performing pairwise comparison on relative importance of
elements in a same formation by an unified standard, and then
constructing the judgment matrix, the judgment matrix of the key
performance parameters in the loss-circulation zone shown below: B
= [ b 11 b 12 b 1 .times. j b 21 b 2 .times. 2 b 2 .times. j b i
.times. .times. 1 b i .times. .times. 2 b ij ] ##EQU00020## wherein
the formula (1) shown below is represented a proportion of the
importance of the parameter i relative to the parameter j: b ij = {
1 , i = j 1 b j .times. .times. i , i .noteq. j ; ( 1 )
##EQU00021## and a proportion scale of the importance in the key
performance parameters is shown in the following table:
TABLE-US-00014 scale Importance of parameters 1 Parameter i is
important same as parameter j. 3 Parameter i is slightly more
important than parameter j. 5 Parameter i is significantly more
important than parameter j. 7 Parameter i is more important than
parameter j. 9 Parameter i is extremely important than parameter j.
2 4 6 8 Taking a median when a relative importance grade is between
adjacent importance grades.
step S2: performing a normalization on each column element of the
judgment matrix, and a general term of the element is: b ij _ = b
ij i = 1 n .times. .times. b ij , ( i , j = 1 , 2 , .times. , n )
##EQU00022## wherein: b.sub.ij represents an element of the ith row
and the jth column of the judgment matrix, and n represents the
order of the judgment matrix; step S3: adding the normalized
judgment matrixes of each column according to rows, namely: W _ i =
j = 1 n .times. b ij _ , ( j = 1 , 2 , .times. , n ) ##EQU00023##
step S4: the vector quantity W=.left brkt-bot.W.sub.1,W.sub.2, . .
. , W.sub.j.right brkt-bot. (j=1, 2, . . . , n), performing a
normalization on the vector quantity W so that an obtained result
is an eigenvector, that is: W = W _ j = 1 n .times. W j _ , ( j = 1
, 2 , .times. , n ) ##EQU00024## wherein an element in the
eigenvector W is a weight of a corresponding parameter; step S5:
calculating the maximum feature root by the judgment matrix and the
eigenvector, namely: .lamda. max = i = 1 n .times. ( B .times. W )
i nW j ##EQU00025## wherein: (BW) represents the ith element of the
vector; step S6: calculating a consistency of the judgment matrix,
and then verifying by the following formulas: CR = CI RI
##EQU00026## CI = .lamda. max - n n - 1 ##EQU00026.2## wherein: CI
represents a consistency parameter and RI represents a random
consistency parameter, with values being shown in the following
table: TABLE-US-00015 n 1 2 3 4 5 6 7 8 9 RI 0 0 0.58 0.94 1.12
1.24 1.32 1.41 1.45
if CR<0.1, a degree of inconsistency of the judgment matrix is
determined within a permissible range, and the eigenvector of the
judgment matrix is a weight vector; otherwise, returning back the
step S1 to adjust a relative importance of two elements until
satisfy the consistency condition.
6. The quantitative scoring and optimization method of a drilling
and completion loss-control material as claimed in claim 1, wherein
the step of performing evaluation on the key performance parameters
of the conventional loss-control materials in the step 4 comprises:
according to an established parameter evaluation standard, dividing
the key performance parameters of the conventional loss-control
materials into five grades: a high grade, a medium-high grade, a
medium grade, a medium-low grade and a low grade respectively
corresponding to a different score, and wherein the parameter
evaluation standard is obtained through performing performance
evaluation on a large number of loss-control materials, and some of
the performance parameter evaluation is shown in the following
table: TABLE-US-00016 Performance parameter Parameter evaluation
Degree of .ltoreq.0.3 0.3-0.5 0.5-0.7 0.7-0.9 >0.9 sphericity
low medium- medium medium- high low high Friction .ltoreq.0.5
0.5-0.8 0.8-1.1 1.1-1.4 >1.4 coefficient low medium- medium
medium- high low high Temperature >0.3 0.2-0.3 0.1-0.2 0.05-0.1
.ltoreq.0.05 resistance low medium- medium medium- high low high
Abrasion >0.3 0.2-0.3 0.1-0.2 0.05-0.1 .ltoreq.0.05 resistance
medium- medium medium- high low low high Aspect ratio .ltoreq.100
100-200 200-400 400-600 >600 of fiber low medium- medium medium-
high low high Soluble rate .ltoreq.0.2 0.2-0.4 0.4-0.6 0.6-0.8
>0.8 low medium- medium medium- high low high Temperature
>0.3 0.2-0.3 0.1-0.2 0.05-0.1 .ltoreq.0.05 resistance of low
medium- medium medium- high particle size low high Strength >0.3
0.2-0.3 0.1-0.2 0.05-0.1 .ltoreq.0.05 temperature low medium-
medium medium- high resistance low high
7. The quantitative scoring and optimization method of a drilling
and completion loss-control material as claimed in claim 1, wherein
a formula for calculating comprehensive scores of each conventional
loss-control material in the step 5 is: S = i = 1 n .times. .phi. i
.function. ( x ) .times. .PHI. i .function. ( x ) ##EQU00027##
Wherein: S represents a final score of the loss-control materials
or plugging formula, .phi..sub.i(x) and .PHI..sub.i(x) respectively
represents the weight of each key performance parameter and a score
value of a corresponding parameter.
8. The quantitative scoring and optimization method of a drilling
and completion loss-control material as claimed in claim 1, wherein
the best type of the loss-control materials in the step 6 is a kind
of loss-control material with the highest score, or a score is
ranked in the top 5% of scores of the loss-control materials from
the top to the bottom under considering an economic cost of the
loss-control materials.
Description
1. TECHNICAL FIELD
[0001] The present disclosure generally relates to a technical
field of loss control, and relates to a quantitative scoring and
optimization method of a drilling and completion loss-control
material based on an analytic hierarchy process.
2. DESCRIPTION OF RELATED ART
[0002] A large amount of working fluids is lost into
lost-circulation zone so that a drilling and completion cost and a
construction cycle are increased during developing an oil-and-gas
field, and even lead to a stuck drilling and other accidents,
thereby a process of exploration and development of oil-and-gas
resources is seriously affected. Such situation is always a major
technical problem to plague oil exploration and development at home
and abroad without being completely solved up to now.
[0003] As a supplement, a loss control is a main method to solve
the loss of working fluid in the loss-circulation zone, however,
with continuous development of loss control technology,
loss-control materials have become various. So, different
loss-control materials need to be selected according to an actual
loss of different strata due to complex well conditions. However,
researchers usually choose the loss-control materials based on
their experience or after a large number of experiments, but it is
uncertain whether the selected loss-control material is an optimal
loss-control material at last. Furthermore, none unified selection
standard or method is to select the loss-control materials.
SUMMARY
[0004] The technical problems to be solved: in view of the
shortcomings of the related art, the present disclosure relates to
a quantitative scoring and optimization method of a drilling and
completion loss-control material based on an analytic hierarchy
process (AHP) for scoring drilling and completion loss-control
materials, so as to provide a basis for researchers to optimally
select loss-control materials from plugging formula.
[0005] The technical solution adopted for solving technical
problems of the present disclosure is:
[0006] a quantitative scoring and optimization method of a drilling
and completion loss-control material based on an analytic hierarchy
process according to an embodiment of the present disclosure
includes the following steps:
[0007] step 1: obtaining performance parameters of drilling and
completion loss-control materials and then extracting key
performance parameters from the performance parameters; wherein the
performance parameters including mechanical parameters, chemical
parameters and geometric parameters, the mechanical parameters
including but not limited to friction coefficient, compressive
resistance, abrasion resistance and fiber tensile strength; the
chemical parameters including but not limited to acid solubility
and temperature resistance; the geometric parameters including but
not limited to shape, aspect ratio of fiber, sphericity and
particle size distribution; and an extraction basis of extracting
the key performance parameters from the performance parameters
including but not limited to a prediction model of a loss control
effect extracted from the performance parameters according to a
specific geological condition of loss-circulation zone;
[0008] step 2: sequencing the key performance parameters obtained
in the step 1 to determine their relative importance between each
two key performance parameters; wherein the sequence of the key
performance parameters is qualitatively determined by researchers
based on a specific situation and experience, and a scale of the
importance is carried out by the researchers according to the
specific situation and the experience;
[0009] step 3: performing weight calculation on each key
performance parameter of the loss-control material by an analytic
hierarchy process (AHP);
[0010] step 4: obtaining key performance experiment parameters of
conventional loss-control materials and then performing evaluation
on the key performance experiment parameters of the conventional
loss-control materials; and according to an established parameter
evaluation standard, dividing the key performance parameters of the
conventional loss-control materials into five grades: a high grade,
a medium-high grade, a medium grade, a medium-low grade and a low
grade respectively corresponding to a different score;
[0011] step 5: calculating comprehensive scores of each
conventional loss-control material according to results of the step
3 and the step 4;
[0012] step 6: obtaining the loss-control material with the highest
score as an optimal loss-control material according to the
comprehensive score of the each conventional loss-control material
calculated in the step 5, or scores ranked in the top 5% of the
loss-control materials from the top to the bottom under considering
an economic cost of the loss-control materials.
[0013] Furthermore, the prediction model of the loss control effect
in the step 1 is:
P z = a .function. ( 1 - .PHI. - A f A ) .times. k p .times. p
.times. tan .times. .delta. 1 .DELTA. .times. .times. H .times.
.times. .pi. .times. .times. d p 2 + 2 .times. P c .function. ( A f
A ) .times. ( 1 - sin .times. .delta. 1 .times. sin .function. (
.delta. 1 - 2 .times. .theta. i ) 3 .times. .times. .pi.cos 2
.times. .delta. 1 ) .times. ( l f d f ) .times. tan .times. .delta.
2 .times. sin .times. .times. a .function. ( cos .times. .times.
.theta. + sin .times. .times. .theta.tan .times. .delta. 1 )
.times. .times. wherein .times. : ##EQU00001## .theta. = arcsin
.times. sin .times. .times. .theta. i 1 + 2 .times. ( P c ' E f )
.times. ( 1 - sin .times. .times. .delta. 1 .times. sin .function.
( .delta. 1 - 2 .times. .theta. i ) cos 2 .times. .delta. 1 )
.times. ( l f d f ) .times. tan .times. .delta. 2 .times. sin
.times. .times. .theta. i ##EQU00001.2##
[0014] wherein: P.sub.z is sealing capacity which represents the
loss control effect (unit: MPa); .DELTA.H is a height of a shear
destruction portion of crevice loss-control formation (unit: mm); W
is a width of loss-control crevice (unit: mm); H is a height of a
crevice (unit: mm); h is a height of loss-control formation (unit:
mm); .PHI. is a void-ratio of the loss-control formation (unit: %);
A.sub.f is an area of fiber in a cross section (unit: mm.sup.2); A
is a total area of a cross section (unit: mm.sup.2); k.sub.p is a
stiffness of particle materials (unit: N/mm); .epsilon..sub.p is a
particle contact deformation (unit: mm); E.sub.f is a fiber elastic
modulus (unit: Mpa); P.sub.c is a fracture closure pressure (unit:
Mpa); Pc/ is a fracture horizontal pressure (unit: Mpa); .delta.1
is a particle surface friction angle (unit: .degree.); .delta.2 is
a fiber surface friction angle (unit: .degree.); .delta.3 is an
angle between the loss-control formation and a fracture surface
(unit: .degree.); d.sub.p is an average particle diameter (unit:
mm); l.sub.f is a length of fiber (unit: mm); .alpha. is an initial
inclination angle of fiber (unit: .degree.); d.sub.f is a fiber
diameter (unit: mm); .theta..sub.i is an original inclination angle
of fiber (unit: .degree.); .theta. is an inclination angle after
the fiber is sheared (unit: .degree.); .sigma..sub.fc is fiber
tensile strength (unit: MPa); a is a height of loss-control
formation (unit: mm).
[0015] Furthermore, a specific operation process of the step 3
includes as follows:
[0016] step 3.1: performing pairwise comparison on relative
importance of elements in a same formation by an unified standard,
and then constructing a judgment matrix, the judgment matrix of the
key performance parameters in the loss-circulation zone shown
below:
B = [ b 11 b 1 .times. 2 b 1 j b 21 b 2 .times. 2 b 2 j b i .times.
.times. 1 b i .times. .times. 2 b ij ] ##EQU00002##
[0017] wherein the formula (1) shown below is represented a
proportion of the importance of the parameter i relative to the
parameter j: and
b ij = { 1 , i = j 1 b ji , i .noteq. j ; ( 1 ) ##EQU00003##
[0018] a proportion scale of the importance in the key performance
parameters is shown in the following table:
TABLE-US-00001 scale Importance of parameters 1 Parameter i is
important same as parameter j. 3 Parameter i is slightly more
important than parameter j. 5 Parameter i is significantly more
important than parameter j. 7 Parameter i is more important than
parameter j. 9 Parameter i is extremely important than parameter j.
2 4 Taking a median when a 6 8 relative importance grade is between
adjacent importance grades.
[0019] step 3.2: performing a normalization on each column element
of the judgment matrix, and a general term of the element is:
b ij _ = b ij i = 1 n .times. .times. b ij , ( i , j = 1 , 2 ,
.times. , n ) ##EQU00004##
[0020] wherein: b.sub.ij represents an element of the ith row and
the jth column of the judgment matrix, and n represents the order
of the judgment matrix;
[0021] step 3.3: adding the normalized judgment matrixes of each
column according to rows, namely:
W i _ = j = 1 n .times. .times. b ij _ , ( j = 1 , 2 , .times. , n
) ##EQU00005##
[0022] step 3.4: a vector quantity W=[W.sub.1,W.sub.2, . . . ,
W.sub.j] (j=1, 2, . . . , n), performing a normalization on the
vector quantity W so that an obtained result is an eigenvector,
that is:
W = W _ j = 1 n .times. W j _ , ( j = 1 , 2 , .times. , n )
##EQU00006##
[0023] wherein an element in the eigenvector W is a weight of a
corresponding parameter;
[0024] step 3.5: calculating the maximum feature root by the
judgment matrix and the eigenvector, namely:
.lamda. max = i = 1 n .times. ( B .times. W ) i n .times. .times. W
j ##EQU00007##
[0025] wherein: (BW) represents the ith element of the vector;
[0026] step 3.6: calculating a consistency of the judgment matrix,
and then verifying by the following formulas:
C .times. R = CI RI .times. .times. C = .lamda. max - n n - 1
##EQU00008##
[0027] wherein: CI represents a consistency parameter and RI
represents a random consistency parameter, with values being shown
in the following table:
TABLE-US-00002 n 1 2 3 4 5 6 7 8 9 RI 0 0 0.58 0.94 1.12 1.24 1.32
1.41 1.45
[0028] if CR<0.1, a degree of inconsistency of the judgment
matrix is determined within a permissible range, and the
eigenvector of the judgment matrix is a weight vector; otherwise,
returning back the step 3.1 to adjust a relative importance of two
elements until satisfy the consistency condition.
[0029] Furthermore, a relationship between the key performance
parameter grades and score values in the step 4 is shown in the
table below:
TABLE-US-00003 score value 10 8 6 4 2 key performance high medium-
medium medium- low parameter grade high low
[0030] at the same time, a performance parameter evaluation table
is obtained by evaluating a large number of performance parameters
of the loss-control materials, which is applicable to all
loss-circulation zones; and some performance parameter evaluation
is shown in the following table:
TABLE-US-00004 Performance parameter Parameter evaluation Degree of
.ltoreq.0.3 0.3-0.5 0.5-0.7 0.7-0.9 >0.9 sphericity low medium-
medium medium- high low high Friction .ltoreq.0.5 0.5-0.8 0.8-1.1
1.1-1.4 >1.4 coefficient low medium- medium medium- high low
high Temperature >0.3 0.2-0.3 0.1-0.2 0.05-0.1 .ltoreq.0.05
resistance low medium- medium medium- high low high Abrasion
>0.3 0.2-0.3 0.1-0.2 0.05-0.1 .ltoreq.0.05 resistance low
medium- medium medium- high low high Aspect ratio .ltoreq.100
100-200 200-400 400-600 >600 of fiber low medium- medium medium-
high low high Soluble rate .ltoreq.0.2 0.2-0.4 0.4-0.6 0.6-0.8
>0.8 low medium- medium medium- high low high Temperature
>0.3 0.2-0.3 0.1-0.2 0.05-0.1 .ltoreq.0.05 resistance of low
medium- medium medium- high particle size low high Strength >0.3
0.2-0.3 0.1-0.2 0.05-0.1 .ltoreq.0.05 temperature low medium-
medium medium- high resistance low high
[0031] Furthermore, a formula for calculating comprehensive scores
of each conventional loss-control material in the step 5 is:
S = i = 1 n .times. .phi. i .function. ( x ) .times. .PHI. i
.function. ( x ) ##EQU00009##
[0032] Wherein: S represents a final score of the loss-control
materials or loss-control formula, .phi..sub.i(x) and
.PHI..sub.i(x) respectively represents the weight of each key
performance parameter and a score value of a corresponding
parameter.
[0033] Compared with the related art, the present disclosure
provides the advantages as below.
[0034] (1) the quantitative scoring and optimization method of a
drilling and completion loss-control material of the present
disclosure based on an analytic hierarchy process can
systematically consider geological condition and loss situation of
the loss information, so as to provide a scientific and reasonable
basis for researchers to choose the loss-control material, and
further minimize experiment cost and time and avoid researchers to
blindly choose loss-control materials.
[0035] (2) An accuracy and superiority of the evaluation system can
be achieved based on a performance parameter evaluation table
obtained by evaluating a large number of performance parameters of
the loss-control materials, based on key performance parameters
selected according to a specific loss-circulation zone, and based
on considering performance requirements of the loss-circulation
zone of the loss-control materials.
[0036] (3) A scoring system can be constructed by the analytic
hierarchy process (AHP) so as to perform weight calculation on each
performance parameter, and ensure accuracy results by consistency
tests.
BRIEF DESCRIPTION OF THE DRAWINGS
[0037] FIG. 1 is a flowchart of a hierarchical-order structure
model of a quantitative scoring and optimization method of a
drilling and completion loss-control material in accordance with an
embodiment of the present disclosure;
[0038] FIG. 2 is a flowchart of an optimal hierarchy of a
loss-control material in accordance with an embodiment of the
present disclosure;
[0039] FIG. 3 is a flowchart of an analytic hierarchy process in
accordance with an embodiment of the present disclosure.
DETAILED DESCRIPTION
[0040] In order to more clearly understand and implement the
present disclosure for one of ordinary skill in the related art,
the principles and characteristics of the present disclosure are
described on the basis of these drawings and embodiments; the
examples cited are provided only to interpret the present
disclosure, but not to limit the scope of the present
disclosure.
[0041] A quantitative scoring and optimization method of a drilling
and completion loss-control material based on an analytic hierarchy
process according to an embodiment of the present disclosure
includes the following steps:
[0042] step 1: extracting performance parameters of drilling and
completion loss-control materials;
[0043] according to a loss control mechanism of drilling and
completion and a prediction model of a loss control effect,
determining performance requirements of the loss information for
loss-control materials, and then extracting key performance
parameters of the drilling and completion loss-control materials
for the loss-circulation zone from the performance parameters,
wherein the prediction model of the loss control effect can refer
to but not limited to the following formula, and relevant
performance parameters include, but are not limited to, geometric
parameters, mechanical parameters and chemical parameters listed in
table 1 below.
P z = a .function. ( 1 - .PHI. - A f A ) .times. k p .times. p
.times. tan .times. .delta. 1 .DELTA. .times. .times. H .times.
.times. .pi. .times. .times. d p 2 + 2 .times. P c .function. ( A f
A ) .times. ( 1 - sin .times. .delta. 1 .times. sin .function. (
.delta. 1 - 2 .times. .theta. i ) 3 .times. .times. .pi.cos 2
.times. .delta. 1 ) .times. ( l f d f ) .times. tan .times. .delta.
2 .times. sin .times. .times. a .function. ( cos .times. .times.
.theta. + sin .times. .times. .theta.tan .times. .delta. 1 )
.times. .times. wherein .times. : ##EQU00010## .theta. = arcsin
.times. sin .times. .times. .theta. i 1 + 2 .times. ( P c ' E f )
.times. ( 1 - sin .times. .times. .delta. 1 .times. sin .function.
( .delta. 1 - 2 .times. .theta. i ) cos 2 .times. .delta. 1 )
.times. ( l f d f ) .times. tan .times. .delta. 2 .times. sin
.times. .times. .theta. i ##EQU00010.2##
[0044] wherein: P.sub.z is sealing capacity which represents the
loss control effect (unit: MPa); .DELTA.H is a height of a shear
destruction portion of crevice loss-control formation (unit: mm); W
is a width of loss-control crevice (unit: mm); H is a height of a
crevice (unit: mm); h is a height of loss-control formation (unit:
mm); .PHI. is a void-ratio of the loss-control formation (unit: %);
A.sub.f is an area of fiber in a cross section (unit: mm.sup.2); A
is a total area of a cross section (unit: mm.sup.2); k.sub.p is a
stiffness of particle materials (unit: N/mm); .epsilon..sub.p is a
particle contact deformation (unit: mm); E.sub.f is a fiber elastic
modulus (unit: Mpa); P.sub.c is a fracture closure pressure (unit:
Mpa); Pc/ is a fracture horizontal pressure (unit: Mpa); .delta.1
is a particle surface friction angle (unit: .degree.); .delta.2 is
a fiber surface friction angle (unit: .degree.); .delta.3 is an
angle between the loss-control formation and a fracture surface
(unit: .degree.); d.sub.p is an average particle diameter (unit:
mm); l.sub.f is a length of fiber (unit: mm); .alpha. is an initial
inclination angle of fiber (unit: .degree.); d.sub.f is a fiber
diameter (unit: mm); .theta..sub.i is an original inclination angle
of fiber (unit: .degree.); .theta. is an inclination angle after
the fiber is sheared (unit: .degree.); .sigma..sub.lc is fiber
tensile strength (unit: MPa); a is a height of loss-control
formation (unit: mm).
TABLE-US-00005 TABLE 1 Performance parameters of drilling and
completion loss-control materials; Loss-control Geometric Form
factor material parameter Aspect ratio of fiber Degree of
sphericity Particle size distribution Mechanical Friction
coefficient parameter Compressive resistance Abrasion resistance
Expansion rate Fiber tensile strength Chemical Acid-solubility rate
parameter Temperature resistance
[0045] step 2: according to a temperature, a pressure, a ground
stress and other geological characteristic parameters of the
loss-circulation zone, a type of the loss and requirements of a
loss-control construction, sequencing the key performance
parameters obtained in the step 1 according to their relative
importance; wherein their importance is scaled by researchers
according to a specific situation and experiences;
[0046] step 3: performing weight calculation on the key performance
parameters of the loss-control materials by an analytic hierarchy
process (AHP);
[0047] the importance of the loss-control materials is
qualitatively evaluated, and then the qualitative sorting is
converted into a quantitative sorting by the analytic hierarchy
process (AHP), which is shown as the weight of each key performance
parameter;
[0048] step 3.1: performing pairwise comparison on relative
importance of elements in a same formation by an unified standard,
and then constructing the judgment matrix, the judgment matrix of
the key performance parameters in the loss-circulation zone shown
below:
B = [ b 11 b 1 .times. 2 b 1 j b 21 b 2 .times. 2 b 2 j b i .times.
.times. 1 b i .times. .times. 2 b ij ] ##EQU00011##
[0049] wherein the formula (1) shown below is represented a
proportion of the importance of the parameter i relative to the
parameter j:
b ij = { 1 , i = j 1 b ji , i .noteq. j ; ( 1 ) ##EQU00012##
and a proportion scale of the importance in the key performance
parameters is shown in the following table 2:
TABLE-US-00006 TABLE 2 Proportional scale of importance in the key
performance parameters scale Importance of parameters 1 Parameter i
is important same as parameter j. 3 Parameter i is slightly more
important than parameter j. 5 Parameter i is significantly more
important than parameter j. 7 Parameter i is more important than
parameter j. 9 Parameter i is extremely important than parameter j.
2 4 Taking a median when a relative importance 6 8 grade is between
adjacent importance grades.
[0050] step 3.2: performing a normalization on each column element
of the judgment matrix, and a general term of the element is:
b ij _ = b ij i = 1 n .times. .times. b ij , ( i , j = 1 , 2 ,
.times. , n ) ##EQU00013##
[0051] wherein: b.sub.ij represents an element of the ith row and
the jth column of the judgment matrix, and n represents the order
of the judgment matrix;
[0052] step 3.3: adding the normalized judgment matrixes of each
column according to rows, namely:
W _ i = j = 1 n .times. b ij _ , ( j = 1 , 2 , .times. , n )
##EQU00014##
[0053] step 3.4: the vector quantity W=.left
brkt-bot.W.sub.1,W.sub.2, . . . , W.sub.j.right brkt-bot. (j=1, 2,
. . . , n), performing a normalization on the vector quantity W so
that an obtained result is an eigenvector, that is:
W = W _ j = 1 n .times. W j _ , ( j = 1 , 2 , .times. , n )
##EQU00015##
[0054] wherein an element in the eigenvector W is a weight of a
corresponding parameter;
[0055] step 3.5: calculating the maximum feature root by the
judgment matrix and the eigenvector, namely:
.lamda. max = i = 1 n .times. ( B .times. W ) i nW j
##EQU00016##
[0056] wherein: (BW) represents the ith element of the vector;
[0057] step 3.6: calculating a consistency of the judgment matrix,
and then verifying by the following formulas:
C .times. R = CI RI ##EQU00017## CI = .lamda. max - n n - 1
##EQU00017.2##
[0058] wherein: CI represents a consistency parameter and RI
represents a random consistency parameter, with values being shown
in the following table 3:
TABLE-US-00007 TABLE 3 average random consistency parameter n 1 2 3
4 5 6 7 8 9 RI 0 0 0.58 0.94 1.12 1.24 1.32 1.41 1.45
[0059] if CR<0.1, a degree of inconsistency of the judgment
matrix is determined within a permissible range, and the
eigenvector of the judgment matrix is a weight vector; otherwise,
returning back the step 3.1 to adjust a relative importance of two
elements to satisfy the consistency condition.
[0060] Step 4: experimentally evaluating key performance parameters
of conventional loss-control materials;
[0061] obtaining the key performance parameters of the conventional
loss-control materials, and then classifying the performance
parameters according to the performance parameter evaluation table
shown in Table 4, and finally obtaining scores of the key
performance parameters of the loss-control materials according to
Table 5 and Table 6 shown below.
TABLE-US-00008 TABLE 4 partial performance parameter evaluation
table of the loss-control materials Performance parameter Parameter
evaluation Degree of .ltoreq.0.3 0.3-0.5 0.5-0.7 0.7-0.9 >0.9
sphericity low medium- medium medium- high low high Friction
.ltoreq.0.5 0.5-0.8 0.8-1.1 1.1-1.4 >1.4 coefficient low medium-
medium medium- high low high Temperature >0.3 0.2-0.3 0.1-0.2
0.05-0.1 .ltoreq.0.05 resistance low medium- medium medium- high
low high Abrasion >0.3 0.2-0.3 0.1-0.2 0.05-0.1 .ltoreq.0.05
resistance low medium- medium medium- high low high Aspect ratio
.ltoreq.100 100-200 200-400 400-600 >600 of fiber low medium-
medium medium- high low high Soluble rate .ltoreq.0.2 0.2-0.4
0.4-0.6 0.6-0.8 >0.8 low medium- medium medium- high low high
Temperature >0.3 0.2-0.3 0.1-0.2 0.05-0.1 .ltoreq.0.05
resistance of low medium- medium medium- high particle size low
high Strength >0.3 0.2-0.3 0.1-0.2 0.05-0.1 .ltoreq.0.05
temperature low medium- medium medium- high resistance low high
[0062] Wherein: compressive resistance, abrasion resistance and
strength high temperature resistance of the loss-control materials
is evaluated by particle size with a D90 degradation rate under 25
MPa. The particle size with the D90 degradation rate after high
temperature aging is compared with the particle size with the D90
degradation rate before high temperature aging to evaluate the high
temperature resistance of the particle size. A final high
temperature resistance is a smaller value selected from the
particle size with the high temperature resistance and the particle
size with the strength high temperature resistance.
TABLE-US-00009 TABLE 5 scores corresponding to different grades of
partial performance parameters of the loss-control materials Score
10 8 6 4 2 Friction high medium- medium medium- low coefficient
high low Compressive high medium- medium medium- low strength high
low of particle Fiber tensile high medium- medium medium- low
strength high low Degree of low medium- medium medium- high
sphericity low high Temperature high medium- medium medium- low
resistance high low Abrasion high medium- medium medium- low
resistance high low Aspect ratio high medium- medium medium- low of
fiber high low
TABLE-US-00010 TABLE 6 scores corresponding to different grades of
the loss-control materials D90 Score 5 7 10 8 6 D90 First <0.7Wf
0.7-0.9Wf 0.9-1.1Wf 1.1-1.3Wf >1.3Wf grade Second <1/7Wf
1/7-1/3Wf 1/3-1/2Wf 1/2-2/3Wf >2/3Wf grade Third <1/49Wf
1/49-1/9Wf 1/9-1/4Wf 1/4-4/9Wf >4/9Wf grade
[0063] Step 5: calculating comprehensive scores of each
conventional loss-control material by a scoring method;
[0064] a comprehensive scoring function of the drilling and
completion loss-control material is as follows:
S = i = 1 n .times. .phi. i .function. ( x ) .times. .PHI. i
.function. ( x ) ##EQU00018##
[0065] Wherein: S represents a final score of the loss-control
materials or plugging formula, .phi..sub.i(x) and .PHI..sub.i(x)
respectively represents the weight of each key performance
parameter and a score value of a corresponding parameter.
[0066] Step 6: obtaining the loss-control material with the highest
score as an optimal loss-control material suitable for the
loss-circulation zone according to comprehensive scores of the
loss-control materials.
[0067] A first embodiment of the present disclosure:
[0068] The first embodiment of the present disclosure is provided
quantitative evaluation of bridging materials in a reservoir
section of a block in front of the Kuqa Mountain as an example. A
loss-circulation zone is a reservoir section with a high
temperature, a high pressure and a high-ground stress. According to
the loss control mechanism of drilling and completion, the
prediction model of the loss control effect and characteristics of
the loss-circulation zone, the key performance parameters of the
loss-control materials can be selected as follows: particle size
distribution D90, friction coefficient, degree of sphericity, high
temperature resistance, compressive resistance and abrasion
resistance.
[0069] The key performance parameters are sequenced according to
their importance to a loss effect of the reservoir section in the
block so that the degree of their importance is in descending
order: the particle size distribution D90>the friction
coefficient>the degree of sphericity>the high temperature
resistance>the pressure resistance>the abrasion
resistance.
[0070] A judgment matrix for the above key performance parameters
of the loss-control materials is as follows:
B = [ 1 2 5 6 7 8 1 .times. / .times. 2 1 4 5 6 7 1 .times. /
.times. 5 1 .times. / .times. 4 1 2 5 6 1 .times. / .times. 6 1
.times. / .times. 5 1 .times. / .times. 2 1 4 5 1 .times. / .times.
7 1 .times. / .times. 6 1 .times. / .times. 5 1 .times. / .times. 4
1 2 1 .times. / .times. 8 1 .times. / .times. 7 1 .times. / .times.
6 1 .times. / .times. 5 1 .times. / .times. 2 1 ] ##EQU00019##
[0071] The weight of each key performance parameter is calculated
by the analytic hierarchy process (AHP) as shown in Table 7:
TABLE-US-00011 TABLE 7 relative weight of key performance
parameters Performance Particle size Friction Degree of Temperature
Pressure Abrasion parameter distribution D90 coefficient sphericity
resistance resistance resistance Weight 0.418 0.295 0.130 0.090
0.039 0.028
[0072] Finally, final scores of the loss-control materials are
calculated so that the key performance parameters of the
loss-control materials with higher final scores and their final
scores are shown in Table 8 and Table 9, and then the loss-control
material with the highest score is selected to test a plugging
effect.
TABLE-US-00012 TABLE 8 Key performance parameter grades of bridging
materials in non-reservoir sections of the block Key performance
parameter grade Particle size Serial distribution Pressure Friction
Tempemture Degree of Abrasion number Number D90 (.mu.m) resistance
coefficient resistance sphericity resistance 1 LCM-K3 6836.2
medium-high high high medium-low high 2 LCM-K4 4207.9 medium high
medium-high medium-low medium-low 3 LCM-K5 2715.3 medium
medium-high high medium-low medium 4 LCM-D2 4308.4 high medium high
medium-high high 5 LCM-D3 4446.1 high medium-high high medium-high
high 6 LCM-D4 3384.6 high medium-high high medium-high
medium-high
TABLE-US-00013 TABLE 9 Scores of key performance parameters of
bridging materials in non-reservoir sections in the block and final
scores of materials Scores of key performance parameters Particle
size Serial distribution Pressure Friction Temperature Degree of
Abrasion Comprehensive number Number D90 (.mu.m) resistance
coefficient resistance sphericity resistance score 1 LCM-K3 7 8 10
10 8 10 8.41 2 LCM-K4 8 6 10 8 8 4 8.40 3 LCM-K5 6 6 8 10 8 6 8.10
4 LCM-D2 8 10 6 10 4 10 6.79 5 LCM-D3 8 10 8 10 4 10 7.79 6 LCM-D4
5 10 8 10 4 8 6.48
[0073] According to the comprehensive scores of the loss-control
materials, it can be seen that the loss-control material ICM-K3 has
the highest comprehensive score, that is, the loss-control material
ICM-K3 is most suitable as the bridging material of the reservoir
section in the block so as to be used for leakage plugging test.
The plugging experiment results are shown that the loss-control
material ICM-K3 is the best material, which can prove
predictability and superiority of the method of the present
disclosure.
[0074] The present disclosure is provided the analytic hierarchy
process (AHP) for a quantitative scoring and optimization method of
a drilling and completion loss-control material, which can
scientifically and effectively score and optimize an application
degree of the loss-control materials to a target formation, and
save time and cost for researchers.
[0075] The foregoing description is not in any form a limitation to
the present disclosure. Although the features and elements of the
present disclosure are described as embodiments in particular
combinations, but not intended to limit the protection scope of the
present disclosure, each feature or element can be used alone or in
other various combinations within the principles of the present
disclosure to the full extent indicated by the broad general
meaning of the terms in which the appended claims are expressed.
Any variation or replacement made by one of ordinary skill in the
related art without departing from the spirit of the present
disclosure shall fall within the protection scope of the present
disclosure.
* * * * *