1.05
our company are giving the calculation method as below：choose 4 points on the design crossing curve,to calculate at each point the force need to pull the pipe forward. Entry point 4#point 3#poin t
Conclusion：From the caculation above，among these four points
2
point's pull force is maximum
152.71
T，according to the theoretical calculation，the rig's pull force should over
Caculation Method for Horizontal Directional Drilling Pulling Force
Crossing Length L（m） Entry point elevation （m） 1500 Pipe Diameter D（mm） Exit point elevation （m） 813 Pipe Thicknes 16.0 sδ （mm） 1#point to2#poin t 254.20 distance L1（m） Drill Entry Incidence (α ) 2#point to3#point distance L2（m） 10 Drill Exit Incidence (β ) 3#point to4#point distance L3（m） 6 Pipe Depth H（m） Friction factor f1（outside hole）（0.1～ 0.3） 20.0 Curvature Radius R（m） Friction factor f2（inner hole）（0.1～ 0.3） mud density ρ 1219.50
piple get the net flotage,see below caculation: (T) (T) (T) (T) (T)
F静浮 （W-F浮） 4.75 = × H × ρ = unpulled-in pipe part get the fricitional resistance,see below caculation: F未 （L2+L3） f1 119.07 = W × × = at point 2#,get the final pull force are calculate as below: F2 F2－1 F静浮 F未 152.71 = + + = 3) at point 3#,the pipe go through the horizontal part, arriving to the second turning point,calculation as below： F2-3 （W-F浮） L2 f2 92.81 = × × = unpulled-in pipe part get the fricitional resistance,see below caculation: F未 L3 f1 21.04 = W × × =
544.80 (T) (T)
F1 1)when at point 1# = W × L × f 2)at point 2#，pull the pipe back to the first turning point，see below calculation： (f2cosβ +sinβ ) F2－1 （W-F浮） L1 = × × = when pull the pipe back to the point 2#，the pipe depth is 20.00
152.71
T,to fulfill the task.
Note：yellow partcontent should be filled according to the real project situation，blue part is automatic calculation。Author：翟新端
0.00
0.00
1025.68
220.12
0.3
0.40
Directional drilling's pull force calculation,is critical important when choosing the right drilling rig.The calculation below are based on the mud are full filled in the hole, and hole surface are unbroken.（pipe are steel pipe）
at point 3#,get the final pull force are calculated as below: F3 F2－1 F2-3 F静浮 = + +
+
F未 =
= 10.97 132.66
147.48
(T) (T) (T)
4)at point4#，pipe's head arriving to point 4#,pulling succeed ,the force at this point are caculated as below ： F3-4 （W-F浮） L3 (f2cosα -sinα ) = × × at point 4#,get the final pull force are calculated as below: F4 F2－1 F2-3 F3-4 = + + =
Depth H
Exit drill point
1#point 2#point
weight of each meter of the pipeW(kg)
318.59
each meter of the pipe get the flotage in the mud slurry F浮(kg) = 28.89 143.37