The
Drill Collars are made of modified AISI
4145 H Chromium Molybdenum alloy Steel.
These Drill Collars bars are full length
heat treated, quenched to obtain mechanical
properties as per ASTM A-370. All Drill
Collars are provided with a set of Mill
Test Certification as per BS EN 10204
– latest edition. These mill test
certification assures a hardness range
of 285-341 BHN and a Charpy V Notch impact
value of 40 ft lbs at room temperature
one inch below the surface. Connections
are precision machined to API specifications.
To
ensure close tolerance bores, all drill
collars bars are trepanned then drifted
to API Spec 7-1 requirements. Bar surface
finish is “as rolled” which
is original mill finish.
CONNECTIONS
:
All
connections are precision machined to
API Spec 7-1 (API Relief Groove Pin and
Bore Back Box Stress Relief Features are
available on request). Thread roots are
cold rolled to offer a greater resistance
to fatigue. All connections are then phosphated
to minimize galling during makeup. API
dope or thread compound is applied on
connections. Pressed steel thread protectors
or Cast steel lifting bail type thread
protectors (As per customer requirements)
are installed to ensure adequate joint
protection during Handling, Packaging,
Storage & Delivery.
SPIRAL
DRILL COLLARS :
The
Spiral cut is added to a Drill Collar
to prevent the likelihood of differential
wall sticking by reducing wall contact
between the Drill Collar and the wall
of the Hole. The box end of the Spiral
collar is left uncut 79 inches from Box
shoulder and the pin end is left uncut
30 inches from Pin shoulder as per Standard
Practices.
DIMENSIONAL
DATA
(STANDARD
SIZES, BORES, AND CONNECTIONS FOR DRILL
COLLARS)
Size
OD
Inch
Bore
Connection
Style and Size
Approx.
Weight 31ft. Lbs.
Standard
In
Optional
In
For
Standard Bore
NC
API
For
Optional Bore
NC
API
3
1/8
1
1/4
1
NC
23
---
---
2
3/8 Reg
682
3
1/2
1
1/2
1
1/4
NC
26
2
3/8 IF
NC
26
2
3/8 IF
837
4
1/8
2
1
3/4
NC
31
2
7/8 IF
NC
31
2
7/8 IF
1085
4
3/4
2
2
NC
35
NC
38
3
1/2 IF
1550
5
2
1/4
2
NC
38
3
1/2 IF
NC
38
3
1/2 IF
1643
6
2
1/4
2
13/16
NC
44
---
NC
40
4
1/2 FH
2573
6
1/4
2
1/4
2
13/16
NC
44
---
NC
46
4
IF
2821
6
1/4
2
13/16
2
13/16
NC
46
4
IF
NC
46
4
IF
2573
6
1/2
2
1/4
2
13/16
NC
46
4
IF
NC
50
4
1/2 IF
3069
6
1/2
2
13/16
2
13/16
NC
46
4
IF
NC
50
4
1/2 IF
2821
6
3/4
2
1/4
2
13/16
NC
46
4
IF
NC
50
4
1/2 IF
3348
7
2
1/4
2
1/4
NC
50
4
1/2 IF
NC
50
4
1/2 IF
3627
7
2
13/16
2
1/4
NC
50
4
1/2 IF
NC
50
4
1/2 IF
3410
7
1/4
2
13/16
3
NC
50
4
1/2 IF
---
5
1/2 FH
3689
7
3/4
2
13/16
3
NC
56
6
5/8 Reg
NC56
6
5/8 Reg
4309
8
2
13/16
3
NC
56
6
5/8 Reg
NC
56
6
5/8 Reg
4650
8
1/4
2
13/16
3
---
6
5/8 Reg
---
6
5/8 Reg
4960
9
2
13/16
2
13/16
NC
61
7
5/8 Reg
NC
61
7
5/8 Reg
6045
9
1/2
3
2
13/16
---
7
5/8 Reg
---
7
5/8 Reg
6696
9
3/4
3
2
13/16
NC
70
8
5/8 Reg
NC
70
8
5/8 Reg
7099
10
3
2
13/16
NC
70
8
5/8 Reg
NC
70
8
5/8 Reg
7533
11
3
2
13/16
---
8
5/8 Reg
---
8
5/8 Reg
9269
Interdril offers severals hardbanding options
from Fine Particle, Flush Raised Carbide
or special hardbanding options supplied
by third parties.
Interdril recommended Hardbanding design
is as follows
1
Drill
Collars without slip & elevator recess:10"
long wear bands at 30" minimum from
the pin end.
2
Drill
Collars with slip & elevator recess:
4" long wear bands above elevator recess,
1" band between elevator & slip
recess & 10" long wear band bellow
slip recess.
3
Drill
Collars with slip recess only: 10"
long wear band bellow slip recess.
