SY/T 5322-2000 Casing string strength design method SY/T5322-2000 standard download decompression password: www.bzxz.net

ICS 75.180.10
Registration number: 8143—2001
Petroleum and natural gas industry standard of the People's Republic of China SY/T 5322—2000
Design nethod of casing string strength2000-12-12 Issued
State Administration of Petroleum and Chemical Industry
Implementation on 2001-06-01
SY/T 5322—2000
1 Scope
2 Reference standards
3 Definitions
4 Symbols and codes
5 Calculation of casing strength
6 Calculation of effective external load
7 Design of casing string strength
Appendix A (Appendix to the standard)
Derivation of axial strength design.
Appendix B (Suggested Appendix)
Casing design example
Appendix ((Suggested Appendix) Parallel port set load calculation
SY/T5322-2000
This standard is a revision of SYT5322-88 "Recommended method for strength design of directional wellbore": after the revision, casing strength calculation and directional well axial tension calculation are added; effective external load is calculated according to well type and casing type; axial stress strength design is adopted and the design steps are listed. This standard is effective from From now on, it will replace SY/T5322-88. Appendix A of this standard is the standard appendix. Appendix B and Appendix C of this standard are reminder appendices. This standard is proposed by China National Petroleum Corporation. The oil drilling non-engineering professional standardization committee in this standard belongs to this standard. Drafting unit of this standard: Southwest Petroleum University. The main drafters of this standard are Du Chunchang, Guo Xiaoyin and Liu Chongjian. This standard was first issued in April 1988. This is the first revision. 1 Scope
Petroleum and natural gas industry standard of the People's Republic of China. Casing string strength design method
Design method of casing string strength This standard specifies the calculation method of casing strength, calculation method of casing effective external load and strength design. This standard is applicable to the strength design of casing strings in oil and gas wells. 2 Reference standards
SY/T 5322-2000
Replaces SY/T5322-88
The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. When this standard is published, the versions shown are valid: All standards will be revised, and the parties using this standard should explore the possibility of using the latest versions of the following standards: SY/r5313-93 Drilling Engineering Terminology
3 Definitions
This standard adopts the following definitions,
3.1 Yield collapse strength yitid collajs:strength The external pressure value that produces the minimum yield stress on the inner wall of the casing! 3.2 Plastic collapse strength plastic collapse stress The minimum collapse pressure value of the casing within the plastic collapse range. 3.3 Transitian Collaist: Sirungth Minimum collapse pressure value of casing in transition zone from plastic to elastic 3.4 Elastic collapse strength Elastic. Collapse strength Minimum collapse pressure value of casing in elastic collapse range 3.5 Pipe borly yield slrength Axial load value required to make the belt body yield. 3.6 Joint strength of casing Minimum axial load to make casing coupling thread slip or break. 3.7 Triaxial stress strength Triaxial stress strength Casing strength under combined action of internal and external pressure and axial load 3.8 Casing bending force Casing bending resistance Axial force generated when casing bends in bending stop. 3.9 Installatic load of wellhead After the wellhead installation operation is completed, the axial force required to lift or lower the casing when installing the wellhead is 3.10 # Load well head loadl
and. Load is the general term for various loads including the wellhead installation load: 4 Symbols and codes
Symbols and codes are shown in Table 1
National Petroleum and Chemical Industry Bureau 2K Sichuan-12-12 approved 201-06 01 implementation
HmeHrm
H,H2, Hus
Casing outer diameter
Casing inner diameter
Coupling outer diameter
Coupling inner diameter
Casing outer radius
Casing inner radius
SY/T5322—2000
Table 1 Symbols and codes
Design section casing inner radius
Design section casing outer radius
Casing wall thickness
Thread matching length
Curvature radius of deflection section| |tt||Length of casing section
Length of casing that can be lowered according to tensile strength
Length of casing that can be lowered according to triaxial tensile strength
Drop value of liquid level outside pipe after cementing
Drop value of liquid level inside pipe after cementing
Length of casing in cement-sealed section
Length of casing in non-cement-sealed section
Length of casing lifted or lowered when installing at wellhead Depth of casing lowered or casing shoe depth||tt| |The depth of the first section casing
Well depth at calculation point
Measurement depth at calculation point
Respectively, the measurement of the bottom of the deflection section and the steady deflection section, and the depths are respectively the vertical section, the deflection section, and the vertical depth of the straight section. Cross-sectional area of ​​the pipe end
Cross-sectional area of ​​the coupling
Cross-sectional area of ​​the pipe wall at the last buckle
Cross-sectional area of ​​the first section casing
Drilling fluid density during cementing
Maximum drilling fluid density for the next drilling
Minimum drilling fluid density for the next drilling Well fluid density
Formation water density (1.03-1.06)
Completion fluid density
SY/T5322—2000
Table 1 (continued)
Density change of liquid outside pipe after cement injection
Density of liquid inside pipe during cement injection
Density change of liquid inside pipe after cement injection
Density of cement slurry
Density of casing steel
Relative density of natural gas (0.5~0.55）
Tube yield strength
Tube minimum ultimate strength
Coupling minimum ultimate strength
Anti-collapse strength
Internal pressure resistance
Triaxial anti-collapse strength
Triaxial anti-internal pressure strength
Axial stress
Maximum internal pressure at casing shoe
Maximum internal pressure at calculation point
Effective internal pressure
Effective external pressure
Liquid column pressure inside the pipe
Liquid column pressure outside the pipe
Formation or reservoir pressure
Anti-collapse strength of casing section
Effective external collapse of casing section Pressure
Triaxial collapse strength of casing section
Axial stress of casing section
Yield strength of casing material
Liquid column pressure outside casing section
Liquid column pressure inside casing section
Internal pressure resistance of casing section
Effective internal pressure of casing section
Triaxial internal pressure resistance of casing section
Minimum liquid column pressure inside the designed section
Maximum liquid column pressure outside the designed section
Wellhead annulus pressure during cementing
Change of wellhead annulus pressure after cementing
g/cmm3
SY/T 5322—2000
Table 1 (Continued)
Internal pressure during cementing
Change of internal pressure after cementing
Positive force of oil layer or formation
Gradient force gradient of overburden formation
Effective external pressure gradient of first casing section
Fracturing pressure gradient
Tensile strength
Triaxial tensile strength
Yield strength of pipe body
Internal force
Weight of first casing section below calculation section
General average load
Tensile force at the top of deflecting section
Tensile force at any depth of vertical section
Tensile force at the measured depth of deflecting section
Tensile force at the top of steady deflection section
Tensile force at any measured depth of steady deflection section
Bending angle of casing||tt ||Tension of casing in bending section
Strength of casing in first section
Axial tensile strength of casing in first section
Effective tension of casing in first section
Tensile strength of casing in design section
Initial tension of casing
Auxiliary force caused by axial tension
Bearing capacity of casing in cementing section
Weight of cement slurry in sealing section
Weight of liquid in pipe
Weight change of liquid outside the pipe
Weight change of liquid in pipe
Axial force caused by change of annular pressure
Axial force caused by change of internal pressure
Axial force caused by drop of liquid level outside the pipe
Axial force caused by drop of liquid level inside the pipe,
Yi-Zai-Xian
SY/T 5322—2000
Table 1 (end)
Selected parallel port rated load
Axial force caused by temperature change
Weight of all pipes in air
Weight of cement slurry
Weight of liquid outside the pipe
Weight of liquid inside the pipe
Change of liquid outside the pipe
Change of liquid weight inside the pipe
Axial force caused by annular pressure of parallel port
Axial force caused by pressure inside the parallel port
Outside the pipe Axial force caused by liquid level drop, knife
Axial force caused by liquid level drop
Casing mass per unit length
Design section: Mass per unit length of casing in the design section
Mass per unit length of casing in the unsealed section
Average mass per unit length of casing
Mass per unit length of casing in the sealed section
Mass per unit length of casing in the vertical section
Mass per unit length of casing in the deflecting section
Mass per unit length of casing in the stable deflection section| |tt||Average value of humidity change after consolidation
Well inclination
Increase in slope of inclination section
Hollowout coefficient (=()-1), indicating Poisson coefficient of rock in fully hollow formation u-: 0.3~0.5
Established internal pressure resistance coefficient
Specified tensile coefficient
Current anti-squeezing coefficient
Internal pressure resistance coefficient of the first section casing
Tensile coefficient of the first section casing
Anti-squeezing coefficient of the first section casing
Designed casing section No.
Buoyancy coefficient
Diameter-to-thickness ratio of intersection of ductile collapse and plastic collapseDiameter-to-thickness ratio of intersection of elastic collapse and excessive collapseDiameter-to-thickness ratio of intersection of transitional collapse and elastic collapseUnit
lkg/tnt
(\）/()m
5 Casing strength calculation
5.1 Collapse strength
5.1.1 Yield collapse strength
When D/(D/8)
SY/T5322—2000
po= 2y[(De/8)-17
(A-2)2+8(B+0.0068947C/Y.)+(A-2)2(B+0.0068947C/Y,)
A=2.8 762+1.5485×10-4Y,+4.47×10-7Y2-1.62×10-10Y.3B=0.026233+7.34x10-5Y
C=-465.93 +4.475715Y.-2.2×10-4Y.2+1.12×10-7Y.35.1.2 Plastic collapse strength
When (D/8)≤D/8≤(D/8)
Pm=[Da-B]-0.0068947C
5.1.3 Transition collapse strength
Y,(AF)
(D,/8)=0.0068947C+Y,(BG)|| tt||3.238×10
Y2+B/A
G=FB/A
When (D8)p≤D8(D/8)
5.1.4 Elastic collapse strength
When D/8(D/8),
5.2 Pipe yield strength
5.3 Internal pressure resistance
5.4 Tensile strength
5.4.1 Round thread connection
Thread Fracture strength:
3.238X105
=(D8)(D/8-1)2
T,=7.85×10-4(D2-D.2)Y,
（1）
（10）
（11)
（12)
·（13)
Thread slip strength:
SY/T5322—2000Www.bzxZ.net
T. =9.5×104AU
『4.99D0.59U,
T. =9.5×10-ApL0.5L,+0.14D
+L,+0.14D.
Aip=0.785[(D-3.6195)2-D.2]
5.4.2 Trapezoidal thread connection
Pipe thread strength:
T. =9.5×10-4A,U,[25.623-1.007(1.083-Y,/U,)D Coupling thread strength:
T. = 9.5 X10-4A.U
5.5Triaxial stress strength
Triaxial collapse strength:
Triaxial internal pressure strength:
Ptea=Pt
Triaxial tensile strength:
Ap= 0.785(D?- D)
A. =0.785(D.2-d.2)
L3r4+r
faa+po
a. +p
1-3（）
Ta=10-3元(pir2-por)+T+3×106(p?-p)r5.6Tube yield strength
Use formula (25) to calculate the tube yield strength. Yp
Yuan (2-+2)
or steel grade code (such as N-80 code is 80) multiplied by 1000 divided by 145 to get the pipe yield strength (MPa). 6 Calculation of effective external load
6.1 Effective internal pressure
6.1.1 Vertical well
6.1.1.1 Surface casing and technical casing
a) Gas well
Calculate the maximum internal pressure at the casing shoe according to the maximum drilling fluid density used at the first time, that is, P=0.00981prmxH
The maximum internal pressure of the casing at any well depth is calculated using formula (27). Pbs
15x10-(Hb)g,
The effective internal pressure is calculated using formula (28).
Pre=ph-0.00981pch
b) The maximum internal pressure of the casing of an oil well
at any depth:
（15）
（16)
（18)
（19)
（20）
（22）
（23)
（24)
（25）
（26）
（27）
The effective internal pressure is calculated using formula (30).
6.1.1.2 Production casing and production tail pipe
a) Oil well
SY/T 5322—2000
Puh = 0.00981grmuxh
Phe = pPl.
0.00981@,
For production without tubing, use formula (31) to calculate the maximum internal pressure. For production with tubing, use formula (33) to calculate the maximum internal creeping force. put = GpH, + 0.00981pwh
Effective internal pressure:
Pa. - Ph - 0.00981pch
b) Gas well
is considered as if the pipe is fully filled with natural gas. That is, the maximum internal pressure at any well depth is: The effective internal pressure is:
6.1.2 Orientation and
Pbh - Pp
Plx.=Pbh-0.00981orh
Orientation and effective internal pressure should convert the measured depth of the inclined straight section and the curved section into vertical depth calculation. 6.2 Effective external pressure
6.2.1 Vertical well
6.2.1.1 Surface casing and technical casing
For non-plastic creep formation:
pe - 0.00981l pm- (1
km?pmin.h
For plastic creep formation:
6.2.1.2 Production casing and production tail pipe
For non-plastic creep formation:
G,- 0.00981(1 - *)pmim
pe - 0.00981[en -(1 - km)pwJh For plastic creep formations:
6.2.2 Directional
-G.- 0.00981(1 - km)pu +
Directional effective external pressure The measured depth of the curved section and the inclined straight section should be converted into vertical depth. 6.3 Effective axial force calculation
6.3.1 Vertical well
point effective axial force is calculated using formula (41)T (
T)-+-0.00981(H:-h)a,Jz
·(30)
（35）
（38）
（39)
（40)
6.3,2 Directional effective tension
6.3.2.1 Casing white weight tension
SY/T 5322--2000
As shown in Figure 1, the directional well section is parallel. The vertical section is parallel to the depth H1, and the curvature radius of the inclined section is: 5730
Inclined vertical length:
Hu2 Rsina
Vertical length of the stable inclined section:
Hu3 = (Hm - Hnu2)1sd
The tension at the wellhead is:
T.-0.00981(gH+9kHz-yH3)k
The tension at any measuring depth of the vertical section is:
T - Th - 0.009811Iml4k
The tension at the top of the deflection section is:
Th = Th-0.00981Hugkl
The tension at any measuring depth of the deflection section is:
Ta - T-0.0981[Hu + 9Rsin[Hm_H129]100
The tension at the top of the steady-inclination section is:
Tt=Th-0.00981(H9tH29k)bm
The tension at any measuring depth of the steady-inclination section is:
Ta = Th- 0.00981 Hq + H24h + Q(1- J -100%6.3.2.2 Casing bending force
F - 2.32 x 10-3D.929
·(46)
+ (49)
（50）
Jsinakt
f......(51)00981(H9tH29k)bm
Tension force at any measuring depth in the steady-state section:
Ta = Th- 0.00981 Hq + H24h + Q(1- J -100%6.3.2.2 Casing bending force
F - 2.32 x 10-3D.929
·(46)
+ (49)
（50）
Jsinakt
f......(51)00981(H9tH29k)bm
Tension force at any measuring depth in the steady-state section:
Ta = Th- 0.00981 Hq + H24h + Q(1- J -100%6.3.2.2 Casing bending force
F - 2.32 x 10-3D.929
·(46)
+ (49)
（50）
Jsinakt
f......(51)
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