Drilling with Casing
Defyer™ DV Series
The Weatherford Defyer DV is a drillable casing bit designed for drilling
with casing in very soft and soft unconsolidated formations with confined
compressive strengths up to 4,000 psi (27.6 MPa).
The innovative design incorporates an aluminum inner core with integral
cutting blades. The blades are coated with a thin layer of tungsten
carbide to resist abrasion during drilling. Carbide inserts are mounted on
the shoulder, outside drift diameter, to reduce shoulder wear and ensure
effective cutting operations.
Available in sizes from 9-5/8 to 20 in., the Defyer DV can be easily made
up on conductor and surface casing strings. A range of interchangeable
drillable nozzles is available to ensure optimal hydraulic performance.
Applications
• Drilling surface and conductor casing in very soft and soft
unconsolidated formations
• Reaming casing through unstable hole conditions or excessive
borehole caving or in severely swelling formations
• Reaming of swelling formations and tight spots to improve hole
quality using the backreaming feature
Photo depicts the 9 5/8- × 12-in. Defyer DV 300.
10
9
8
6
ft
So
UCS x1000
× 1,000psi
psi
Ver y
So f t
1
0
14
15
16
82.5
80.8
77.8
75.3
17
18
19
73.2
72.2
20
71.3
84.5
69.7
89.5
3
2
13
rd
Ha
4
12
Medium
7
5
11
68.2
92.8
21
22
23
97.1
66.9
108.9
65.6
24
25
Sonic Transit Time (DT), µs/ft
Defyer DV
DV Series
Series
Defyer
Unconfined Compressive Strength (UCS) Range
1,000to
- 4,000
1,000
4,000 psi
psi
weatherford.com
1
© 2005–2014 Weatherford. All rights reserved.
4671.02
Drilling with Casing
Defyer DV Series
™
Features, Advantages, and Benefits
The tungsten carbide cutting structure
has high-standoff fishtail blades and
a wave cutting profile. This design
enhances cutting efficiency, rate of
penetration, and durability.
The fully drillable center nose section enables
rapid, damage-free drillout with conventional
polycrystalline-diamond-compact (PDC) bits,
roller-cone bits, or another Defyer assembly.
This eliminates the need for a special drillout
run or retrieval of the bottomhole assembly
after drilling to total depth.
Gauge pads with tungsten carbide
inserts maintain gauge protection
and reduce the potential for
undergauge hole.
Total Blade
Count
Interchangeable, drillable nozzles increase
hydraulic horsepower at the bit to optimize
hydraulics and improve penetration rates.
Cutter Size (mm)
D V 3 00 *
Defyer
Primary Cutting
Structure
P – PDC
T – TSP
V – HVOF
Special Feature
B – Bicenter or dual axis
G – Enhanced gauge protection
K – Backreaming
L – Light version
N – Nudging
S – Special drift
V – Extra face volume
or blade standoff
Nomenclature for the Defyer DV series
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2
© 2005–2014 Weatherford. All rights reserved.
4671.02
Drilling with Casing
Defyer DV Series
™
Specifications
Nominal size (in.)
9-5/8 × 10-5/8
Defyer code
DV300-095105 DV300-095116U DV300-095120 DV300-095120U DV300-095122U DV300-133152 DV300-133170
OD (in., mm)
10-5/8
269.9
9-5/8 × 11-3/4
9-5/8 × 12
11-3/4
298.5
9-5/8 × 12-1/4 13-3/8 × 15-1/4
12
304.8
12-1/4
311.2
Casing weight and grade
13-3/8
339.7
2.27
0.69
Length (ft, m)
150.0
68.0
170.0
77.0
178.6
81.0
Number of blades
2.59
0.79
170.0
77.0
178.0
80.7
3
Dense, thin layer of tungsten carbide
Cutting structure
(on casing body)
Carbide
6.60
167.6
6.89
175.0
6.74
171.2
6.89
175.0
Tungsten
carbide
briquettes
Machined
steel
Tungsten
carbide
briquettes
Machined steel
11.98
77.3
18.27
117.9
22.07
142.4
Total flow area
9.42
239.3
8.55
217.2
Tungsten carbide briquettes
Dependent on nozzle selection
Equivalent casing grade
(ksi, MPa)
21.75
140.3
25.32
163.4
16.06
103.6
41.38
267.0
51
352
Nose material
weatherford.com
383.6
174.0
6
Cutting structure
(drillable core)
Junk slot area
(in.2, cm2)
273.4
124.0
3
Number of nozzles
Gauge protection
17
431.8
As requested
Connection
Gauge length
(in., mm)
13-3/8 × 17
15-1/4
387.4
9-5/8
244.5
Casing size (in., mm)
Weight (lb, kg)
9-5/8 × 12
Drillable alloy
3
©2005–2014 Weatherford. All rights reserved.
4671.02
Drilling with Casing
Defyer DV Series
™
Specifications (continued)
Nominal size (in.)
Defyer code
18-5/8 × 21
18-5/8 × 21
18-5/8 × 24
21
533.4
OD (in., mm)
2.18
0.66
Length (ft, m)
2.41
0.73
418.9
190.0
Weight (lb, kg)
440.0
199.6
Number of blades
3
6
9
Cutting structure
(drillable core)
Dense, thin layer of tungsten carbide
Cutting structure
(on casing body)
Carbide
6.85
174.0
6.35
161.6
Gauge protection
Tungsten carbide briquettes
Total flow area
Dependent on nozzle selection
39.08
252.1
76.95
496.5
Equivalent casing grade
(ksi, MPa)
51
352
Nose material
weatherford.com
20
508.0
As requested
Connection
Junk slot area (in.2, cm2)
20 × 24
24
609.6
Casing weight and grade
Gauge length (in., mm)
20 × 24
18-5/8
473.1
Casing size (in., mm)
Number of nozzles
18-5/8 × 24
DV300-185210 DV300-185210W DV300-185240 DV300-185240W DV300-200240 DV300-200240W
Drillable alloy
4
© 2005–2014 Weatherford. All rights reserved.
4671.02
Weatherford products and services are subject to the Company’s standard terms and conditions, available on request or at weatherford.com. For more information contact an authorized Weatherford representative.
Unless noted otherwise, trademarks and service marks herein are the property of Weatherford and may be registered in the United States and/or other countries. Weatherford products named herein may be
protected by one or more U.S. and/or foreign patents. Specifications are subject to change without notice. Weatherford sells its products and services in accordance with the terms and conditions set forth in the
applicable contract between Weatherford and the client.