HDD Calculation (Template)

PROJECT: Prepared by: Checked by: HORIZONTAL DIRECTIONAL DRILLING CALCULATION

Ldepth

Lcrossing

Rarc1

Rarc2

Fin

Fout

20

600

720

720

10

10

L1

Larc1

L2

Larc2

L3

Ltot

52.18

125.66

247.17

125.66

52.18

602.86

DESIGN DATA Pipeline Diameter

D

thickness (min)

t

36 inch

914.4 mm

15.9 mm

0.626 in Pipeline Material Grade

X60

SMYS of Pipeline

S

Steel Density

rs

415 Mpa 3 7850 kg/m

Water Density

rw

3 1000 kg/m 3 1800 kg/m

Soil Density

1437.8 kg/m

Mud Density

3

Drilling Fluid Density

rd

Soil friction Angle

f

30 degree

Poisson Ratio for Steel

n

0.3

Modulus of Elasticity

E

207000 Mpa

Installation Temperature

T1

Operating Temperature

T2

Steel Coefficient Thermal

a

Friction Factor of Soil

us

Fluid (mud) Drag Coefficient

umud

Test Pressue

PT

137.1 Bar

Design Pressure

P

63.5 Bar

11 lb/gal

2 60190.77 lb/in

3 112.37 lb/ft 3

89.76 lb/ft 3 1318.09 Kg/m

2 30022866 lb/in

13 degC 65 degC 0.0000117 mm/mm/°C 0.5 2 0.05 lb/in

Assumed 344.73785 Pa (Test pressure =95 % SMYS) 2 921 lb/in

CALCULATIONS Pipe Cross Sectional Area

2 656692.89 mm 2 mm 44881.26

Steel Cross Sectional Area

As

Uncorroded weight of Pipe

Ws

Displace Mud Weight

W mud

944.20 kg/m

Effective (submerged) weigth of pipe

W sub

-591.89 kg/m

352.32 kg/m

Wsub = Ws - Wmud Earth Pressure Coefficient

K

0.577

Arching Factor

k

0.148

Page 1 of 4

3 ft

18.3 mm (D/t should be < 60)

2 0.657 m 2 m 0.045

PROJECT: Prepared by: Checked by: HORIZONTAL DIRECTIONAL DRILLING CALCULATION INSTALLATION STRESSES Pulling Loads Straight Section L1 Frcition Force

|Ff1|

15208.75 kg

FD1

51678.38 kg

W p1

8555.98 kg

T1

58331.14 kg

|Ffarc1|

37189.31 kg

FDarc1

124447.14 kg

W parc1

0.00 kg

|Ff1| = W sub x L1 cos (Fin) x us Fluid Drag FD1 = p x D x L1 X umud Pipe Weight (longitudinal direction) W p1 = W sub x L1 sin (Fin) Pulling load at end of L1 T1 = |Ff1| + FD1 - W p1

Curve Section Larc1 Frcition Force

F considered 0deg for conservatism

|Ffarc1| = W sub x Larc1 cos (F) x us Fluid Drag FDarc1 = p x D x Larc1 X umud Pipe Weight (longitudinal direction)

F considered 0deg for conservatism

W parc1 = W sub x Larc1 sin (F) Pulling load at end of Larc1

Tarc1

219967.59 kg

Tarc1 = T1 + |Ffarc1| + FDarc1 - W parc1

Straight Section L2 Frcition Force

|Ff2|

73146.80 kg

FD2

244772.22 kg

W p2

0.00 kg

F = 0deg for straight section

|Ff2| = W sub x L2 cos (F) x us Fluid Drag FD2 = p x D x L2 X umud Pipe Weight (longitudinal direction)

F = 0deg for straight section

W p2 = W sub x L2 sin (F) Pulling load at end of L1

T2

537886.61 kg

T2 = Tarc1 + |Ff2| + FD2 - W p2

Curve Section Larc2 Frcition Force

|Ffarc2|

37189.31 kg

FDarc2

124447.14 kg

W parc2

118652.20 kg

Tarc2

818175.26 kg

F considered 0deg for conservatism

|Ffarc2| = W sub x Larc2 cos (F) x us Fluid Drag FDarc2 = p x D x Larc2 X umud Pipe Weight (longitudinal direction) W parc2 = W sub x Larc2 sin (F) Pulling load at end of Larc2

Tarc2 = T2 + |Ffarc2| + FDarc2 + W parc2

Straight Section L3 Frcition Force

|Ff3|

15208.75 kg

FD3

51678.38 kg

W p1

8555.98 kg

|Ff3| = W sub x L3 cos (Fout) x us Fluid Drag FD3 = p x D x L3 X umud Pipe Weight (longitudinal direction) W p3 = Wsub x L3 sin (Fout) Pulling load at end of L1

T3

893618.37 kg

T3 = Tarc2 + |Ff3| + FD3 + W p3 Pulling Loads

=

893618.37 kg

Page 2 of 4

F considered 90deg for conservatism

PROJECT: Prepared by: Checked by: HORIZONTAL DIRECTIONAL DRILLING CALCULATION Tensile Stress st

Tensile stress

19.91 MPa

st = Pulling Loads / Steel Area Allowable Tensile Stress :

90% of SMYS Condition :

373.50 MPa OK

Bending Stress sb

Bending Stress

131.45 MPa

sb = E D / 2R Allowable Bending Stress D/t

57.51

for D/t < 24.92 < for D/t < for D/t >

24.921 Fb =

2 45143.08 lb/in

311.251 MPa

49.842 Fb =

2

38485.01 lb/in

265.345 MPa

49.842 Fb =

2 39312.27 lb/in

271.049 MPa

Allowable Bending Stress (Sb) : Condition :

271.05 MPa OK

Hoop (External Pressure) Stress External Pressure

Pext

60 kPa

(Ranging from 30 kPa to 60 kPa)

0.06 MPa Hoop Stress due to External Pressure

shext

1.73 MPa

Elastic Hoop Buckling Stress Fhe

87380194318 psi

6E+08 MPa

Critical Hoop Buckling Stress Fhc

87380194318 psi

Fhc

15728462063 psi

33104.92 < Fhe <

96305.2

Fhc

68565.10 psi

96305.23 < Fhe <

373183

Fhc

60190.77 psi

Critical Hoop Buckling Stress :

60190.77 psi

Fhe <

373182.77 < Fhe =

Allowable hoop stress = 67% of Critical Hoop Buckling Stress = Condition :

415.00 MPa 278.05 MPa

OK

Combined Installation Stress Combined Installation Stress should satisfy the following condition: st / 0.9S + sb / Sb < 1

Condition :

OK

A2 + B2 + 2n|A|B < 1

Condition :

OK

A = [ (st + sb - 0.5shext) / 1.25] / S

0.4533

B = 1.5 shext / Fhc

0.0062

Page 3 of 4

33104.9

PROJECT: Prepared by: Checked by: HORIZONTAL DIRECTIONAL DRILLING CALCULATION OPERATING STRESSES Hoop Stress due to Internal Pressure

sh

182.59 MPa

sb

131.45 MPa

sth

-125.94 MPa

sh = P D / 2t Bending Stress sb = E D / 2R Thermal Expansion sth = E a (T1-T2) External Pressure

Pe

52108.43 Pa

0.0521 MPa

Allowable Operating Stress Total circumferential stress

sC

180.87 MPa

sL

59.77 MPa

sC = sh - shext Net Logitudinal Stress sL = sb + sth + sC n sL ≤ 0.9 S =

373.50 MPa

(1) SE1 = | sC - sL |

sE1

121.10 MPa

(2) SE2 = ( sC2 + sL2 - sCsL )1/2

sE2

159.61 MPa

sE

159.61 MPa

SE ≤ 0.9 S =

373.50 MPa

CRITERIA :

Hence :

OK

Hence :

OK

Combined stress

Combined stress, SE = Max (SE1, SE2) CRITERIA :

Page 4 of 4

7.56 psi