DRILCO Nonmagnetic Hevi-Wate Transition Drillpipe
Applications
■■
Provides intermediate weight on bit
(WOB) while isolating MWD tools from
drillstring magnetic interference
Benefits
■■
■■
■■
■■
■■
■■
Greater directional survey accuracy with
reduced drillstring magnetic interference
Improved drilling efficiency and directional control with reduced torque and
drag versus drill collars
Shorter trip time with easier handling
than drill collars
Reduced risk of differential sticking
Lower risk of drillpipe and tool joint
fatigue failure with gradual transition in
stiffness
Improved hole cleaning because of
higher flow rates than small-bore drill
collars
Features
■■
Low magnetic permeability
■■
Higher-than-API specifications
■■
Standard drillpipe dimensions
■■
■■
Center upset or wear pad (not available
on Type III)
API bore back box, and optional stressrelief groove on the pin connection
The low magnetic permeability of DRILCO nonmagnetic (NM)
Hevi-Wate* transition drillpipe enables it to isolate MWD tools from the
undesirable effects of drillstring magnetic interference. This intermediate-weight drillstring member is manufactured to specifications more
stringent than API specifications. It has corresponding drillpipe dimensions and can be picked up with the drillpipe elevators for fast, efficient
handling on the rig floor.
Reduced drag and extended service life
A unique center upset or wear pad keeps the tube away from the
borehole wall (for Types I and II NM Hevi-Wate drillpipe), increasing
tube life while reducing hole drag and differential sticking problems. The
API bore back box feature is standard for the box connection on 4-in
DRILCO Hevi-Wate drillpipe and larger, helping to extend the service
life of the connection. In addition, cold-rolling the thread roots on the
connections increases their ability to resist fatigue cracking.
Hardbanding can be optionally placed on the tool joints and center
wear pad to increase abrasion resistance. The API stress-relief groove
feature on the pin connection is another available option for sizes 4 in
and larger.
Directional drilling
DRILCO NM Hevi-Wate drillpipe acts as an effective WOB member in
extended-reach, horizontal, and conventional directional wells. It is
ideal for highly deviated wells, being less rigid than NM drill collars and,
therefore, able to negotiate bends more easily, improving directional
control by reduction of torque and drag. The center upset feature found
in Types I and II further reduces drag and the risk of differential sticking.
Vertical drilling
When drilling vertical wells, DRILCO NM Hevi-Wate drillpipe can
provide WOB in place of a portion of the drill collar string, reducing
torque, minimizing tool joint connection failures, and shortening trip time
with easier handling.
DRILCO Nonmagnetic Hevi-Wate Transition Drillpipe
DRILCO Nonmagnetic Hevi-Wate Transition Drillpipe Specifications
Nominal Size,
Nominal Tube Dimension
in
Inner Diameter, in
Wall Thickness, in
Area, in2
3 1/2
2 1/4
0.625
5.645
4 1/2
2 3/4
0.875
9.965
5
3
1
12.566
6 5/8
3 1/2
1.563
24.851
DRILCO Nonmagnetic Hevi-Wate Transition Drillpipe Specifications
Mechanical Properties of Tube Section
Tool Joint
Tensile Yield,
Torsional Yield,
Connection
Outer
lbm
ft.lbm
Size, in
Diameter,
in
620,950
36,920
3 1/2 IF
4 3/4
1,096,150
81,435
4 IF
6 1/4
1,382,260
112,990
4 1/2 IF
6 1/2
2,485,100
253,140
6 5/8 Reg
8
3 1/2
4 1/2
5
6 5/8
10.5
10.5
10.5
10.5
Center Upset Length,
in
Elevator Upset,
in
4 3/4
6 1/4
6 1/2
8
24
24
24
24
3 5/8
4 5/8
5 1/8
6 3/4
Inner
Diameter,
in
2 1/4
2 3/4
3
3 1/2
Type I - One Center Upset Specifications
Nominal Size,
Approximate
Approximate Weight, Including Tube
in
Overall Length,
and Tool Joints
ft
Weight Linear
Weight per Joint,
Foot, lbm/ft
lbm
3 1/2
30.5
25
750
20.5
28
560
15.5
31
465
4 1/2
30.5
44.5
1335
20.5
50
1000
15.5
55.3
830
5
30.5
52.3
1570
20.5
57
1140
15.5
62
930
6 5/8
30.5
95.7
2870
20.5
101.5
2030
15.5
107
1605
Type II - No Upsets Specifications
Nominal Size,
Approximate
in
Overall Length,
ft
Center Upset Outer Diameter,
in
Approximate
Overall Length
Pin/Box, in
28/22
29/22
30/22
31/22
Mechanical Properties of Tool Joint
Tensile Yield,
Torsional Yield,
lbm
ft.lbm
Makeup
Torque,
ft.lbm
724,995
1,085,255
1,298,465
1,493,865
10,000
23,400
29,700
43,900
17,600
41,175
52,285
70,130
Type II - Two Center Upsets, 24-in per Upset Specifications
Nominal Size,
Approximate
Approximate Weight, Including Tube
in
Overall Length,
and Tool Joints
ft
Weight Linear
Weight Per Joint,
Foot, lbm/ft
lbm
3 1/2
30.5
27
810
20.5
31
620
4 1/2
30.5
48.2
1445
20.5
55.5
1110
5
30.5
55.7
1670
20.5
62
1240
6 5/8
30.5
99.7
2990
20.5
107
2140
Approximate Weight, Including Tube
and Tool Joints
Weight Linear
Weight Per Joint,
Foot, lbm/ft
lbm
31
310
55
550
61.5
615
106
1060
www.slb.com/DRILCO
*Mark of Schlumberger
Other company, product, and service names
are the properties of their respective owners.
Copyright © 2011 Schlumberger. All rights reserved. 11-SH-0035