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4. Deflection Tools and Technique 4.1 Whipstocks 4.2 Jetting 4.3 Downhole motor with bent sub 4.4 Downhole motor with bent housing 4.5 Steerable Motor Assemblies 4.6 Rotary Steerable Systems Oktay Mamedbekov. Directional Drilling. Deflection Tools.
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4. Deflection Tools and Technique - Drilling Engineeringdrilling-engineering.com/lec/4_Deflection_Tools_final.pdf · 4. Deflection Tools and Technique 4.1 Whipstocks 4.2 Jetting 4.3

Mar 07, 2018

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Page 1: 4. Deflection Tools and Technique - Drilling Engineeringdrilling-engineering.com/lec/4_Deflection_Tools_final.pdf · 4. Deflection Tools and Technique 4.1 Whipstocks 4.2 Jetting 4.3

4. Deflection Tools and Technique

4.1 Whipstocks

4.2 Jetting

4.3 Downhole motor with bent sub

4.4 Downhole motor with bent housing

4.5 Steerable Motor Assemblies

4.6 Rotary Steerable Systems

Oktay Mamedbekov. Directional Drilling. Deflection Tools.

Page 2: 4. Deflection Tools and Technique - Drilling Engineeringdrilling-engineering.com/lec/4_Deflection_Tools_final.pdf · 4. Deflection Tools and Technique 4.1 Whipstocks 4.2 Jetting 4.3

4. Deflection Tools and Technique

Whipstocks – main deflection tool in 1930-1950

Jetting – technique was developed in mid-1950s

Downhole motors with bent sub – superseded whipstocks and jetting

Most commonly used today:

• Downhole motors with fixed bent housing

• Steerable motor assemblies with adjustable bent housing

• Rotary steerable systems

Oktay Mamedbekov. Directional Drilling. Deflection Tools.

Page 3: 4. Deflection Tools and Technique - Drilling Engineeringdrilling-engineering.com/lec/4_Deflection_Tools_final.pdf · 4. Deflection Tools and Technique 4.1 Whipstocks 4.2 Jetting 4.3

4.1 Whipstocks Courtesy: Baker Hughes

1 – Standard Removable Whipstock

is used to kick off wells

2 – Circulating Whipstock

permits more efficient cleaning

of the bottom

3 – Casing Whipstock

is used where a “window” is to

be cut in casing for sidetracking

1 2 3

Oktay Mamedbekov. Directional Drilling. Deflection Tools.

Page 4: 4. Deflection Tools and Technique - Drilling Engineeringdrilling-engineering.com/lec/4_Deflection_Tools_final.pdf · 4. Deflection Tools and Technique 4.1 Whipstocks 4.2 Jetting 4.3

4.1 Standard Removable Whipstock Courtesy: French Oil & Gas Industry Association

1 2 3

1 – Lowering and orientating

whipstock assembly

2 – Drilling the rat hole.

Pulling whipstock out of

the hole

3 – Running the hole opener

assembly

Oktay Mamedbekov. Directional Drilling. Deflection Tools.

Page 5: 4. Deflection Tools and Technique - Drilling Engineeringdrilling-engineering.com/lec/4_Deflection_Tools_final.pdf · 4. Deflection Tools and Technique 4.1 Whipstocks 4.2 Jetting 4.3

4.1 Standard Removable Whipstock

Oktay Mamedbekov. Directional Drilling. Deflection Tools.

Advantages:

• Simple equipment

• Requires little maintenance

• No temperature limitations

Disadvantages:

• Large number of trips for kick-off (at least three)

• Produces high initial DLS (dogleg severity)

Page 6: 4. Deflection Tools and Technique - Drilling Engineeringdrilling-engineering.com/lec/4_Deflection_Tools_final.pdf · 4. Deflection Tools and Technique 4.1 Whipstocks 4.2 Jetting 4.3

4.2 Jetting Courtesy: Short. Directional & Horizontal Drilling

Oktay Mamedbekov. Directional Drilling. Deflection Tools.

Jetting is a technique used to deviate wellbores in soft formations

Page 7: 4. Deflection Tools and Technique - Drilling Engineeringdrilling-engineering.com/lec/4_Deflection_Tools_final.pdf · 4. Deflection Tools and Technique 4.1 Whipstocks 4.2 Jetting 4.3

4.2 Procedure for Jetting Courtesy: French Oil & Gas Industry Association

1 – Jetting

2 – Spudding

3 – Drilling

1 2 3

Oktay Mamedbekov. Directional Drilling. Deflection Tools.

Page 8: 4. Deflection Tools and Technique - Drilling Engineeringdrilling-engineering.com/lec/4_Deflection_Tools_final.pdf · 4. Deflection Tools and Technique 4.1 Whipstocks 4.2 Jetting 4.3

4.2 Jetting

Requirements for jetting:

• A special jet bit or standard soft formation tri-cone bit, with one

very large nozzle and two smaller ones can be used

• The formations must be soft enough (penetration rates of

greater than 80 ft/hr using normal drilling parameters) to be

suitable for jetting

• Adequate rig hydraulic horsepower must be available (mud

velocity through the large jet should be at least 500 ft/sec)

Oktay Mamedbekov. Directional Drilling. Deflection Tools.

Page 9: 4. Deflection Tools and Technique - Drilling Engineeringdrilling-engineering.com/lec/4_Deflection_Tools_final.pdf · 4. Deflection Tools and Technique 4.1 Whipstocks 4.2 Jetting 4.3

4.3 Downhole Motor with Bent Sub Courtesy: Baker Hughes

10-30

Oktay Mamedbekov. Directional Drilling. Deflection Tools.

Downhole motor with bent

sub may be used for:

• kicking off wells

• correction runs

• sidetracking

Bent sub is placed directly

above the motor

Page 10: 4. Deflection Tools and Technique - Drilling Engineeringdrilling-engineering.com/lec/4_Deflection_Tools_final.pdf · 4. Deflection Tools and Technique 4.1 Whipstocks 4.2 Jetting 4.3

4.3 Bent Sub

10-30

Oktay Mamedbekov. Directional Drilling. Deflection Tools.

Bent sub’s lower thread (on the pin)

is inclined 1° - 3° from the axis of the

sub body

Dogleg severity (DLS) depends on:

• Bent sub angle

• OD of motor, bent sub, and drill

collars

• Length of motor

• Hole diameter

Usually DLS= 1°- 2°/10m (10° -

20°/30ft)

Page 11: 4. Deflection Tools and Technique - Drilling Engineeringdrilling-engineering.com/lec/4_Deflection_Tools_final.pdf · 4. Deflection Tools and Technique 4.1 Whipstocks 4.2 Jetting 4.3

4.4 Downhole Motor with Bent Housing Courtesy: Baker Hughes

Bit Bearing Section

Bent Housing

Motor Section

Stabilizer Stabilizer

MWD

Oktay Mamedbekov. Directional Drilling. Deflection Tools.

Page 12: 4. Deflection Tools and Technique - Drilling Engineeringdrilling-engineering.com/lec/4_Deflection_Tools_final.pdf · 4. Deflection Tools and Technique 4.1 Whipstocks 4.2 Jetting 4.3

4.4 Turbine with Bent Housing Courtesy: Neyrfor Turbodrill

Drive Shaft

Turbine Section Body

Turbine Stages

Replaceable Stabilizer

Bent Housing

Thrust Bearing

Lower Stabilizer

Flexible Drive Shaft

Lower Bearing

Bit

Oktay Mamedbekov. Directional Drilling. Deflection Tools.

Page 13: 4. Deflection Tools and Technique - Drilling Engineeringdrilling-engineering.com/lec/4_Deflection_Tools_final.pdf · 4. Deflection Tools and Technique 4.1 Whipstocks 4.2 Jetting 4.3

4.4 Bent Housing vs Bent Sub

Bent housing is more effective than the bent sub because of a shorter bit to bend distance, which:

• Reduces the bit offset

• Creates a higher build rate for a given bend angle

• Reduces the moment arm

• Reduces the bending stress at the bend

• Allows assembly easier to orient

Oktay Mamedbekov. Directional Drilling. Deflection Tools.

Page 14: 4. Deflection Tools and Technique - Drilling Engineeringdrilling-engineering.com/lec/4_Deflection_Tools_final.pdf · 4. Deflection Tools and Technique 4.1 Whipstocks 4.2 Jetting 4.3

4.5 Steerable Motor Assemblies

DTU ABH

Steerable Motor Assemblies are used in two modes:

- Oriented (non-rotational) mode – for drilling a curved path

- Rotary mode – for drilling a straight path

Benefits:

• Elimination of trips for directional assembly changes, saving rig

time

• More complex well paths can be drilled

• Wells are drilled more closely to the plan at all times

Oktay Mamedbekov. Directional Drilling. Deflection Tools.

Page 15: 4. Deflection Tools and Technique - Drilling Engineeringdrilling-engineering.com/lec/4_Deflection_Tools_final.pdf · 4. Deflection Tools and Technique 4.1 Whipstocks 4.2 Jetting 4.3

4.5 Steerable Motor Assemblies Courtesy: Baker Hughes

DTU ABH

DTU – Double Tilted

U-joint Housing

ABH – Adjustable

Bent Housing

Oktay Mamedbekov. Directional Drilling. Deflection Tools.

Page 16: 4. Deflection Tools and Technique - Drilling Engineeringdrilling-engineering.com/lec/4_Deflection_Tools_final.pdf · 4. Deflection Tools and Technique 4.1 Whipstocks 4.2 Jetting 4.3

4.5 Adjustable Bent Housing (ABH)

Oktay Mamedbekov. Directional Drilling. Deflection Tools.

Page 17: 4. Deflection Tools and Technique - Drilling Engineeringdrilling-engineering.com/lec/4_Deflection_Tools_final.pdf · 4. Deflection Tools and Technique 4.1 Whipstocks 4.2 Jetting 4.3

4.5 Downhole Motor with ABH

Benefits:

• Bent angle easily can be changed by drilling crew on a rig floor

• Shorter bit to bent distance (between bearing and motor

sections)

• Wider variety of DLS from 0 (tangent section) to 4 degrees/30 ft

• Possibility to use in two modes: oriented and rotary

• MWD system allows continual control on borehole trajectory

and high accuracy of bent housing orientation

Oktay Mamedbekov. Directional Drilling. Deflection Tools.

Page 18: 4. Deflection Tools and Technique - Drilling Engineeringdrilling-engineering.com/lec/4_Deflection_Tools_final.pdf · 4. Deflection Tools and Technique 4.1 Whipstocks 4.2 Jetting 4.3

4.5 Downhole Motor with ABH

Rotation of the drill string while drilling with downhole motor

and adjustable bent housing (ABH):

• Negates the effect of bit tilt and allows to drill the straight hole

• Drills slightly oversize hole

• Decreases the risk of stuck pipe

• Improves hole cleaning

• Decreases friction between drill string and borehole

• Increases ROP due to higher power at bit

Oktay Mamedbekov. Directional Drilling. Deflection Tools.

Page 19: 4. Deflection Tools and Technique - Drilling Engineeringdrilling-engineering.com/lec/4_Deflection_Tools_final.pdf · 4. Deflection Tools and Technique 4.1 Whipstocks 4.2 Jetting 4.3

4.5 Maximum Recommended Bend Angle for Rotary

Mode (Speeds up to 100 RPM) Courtesy: Tomahawk Downhole

Oktay Mamedbekov. Directional Drilling. Deflection Tools.

6- ¾” Down Hole Motor Hole Size, inch Maximum Bend, degrees

Slick 7-7/8 1.25

8-1/2 1.50

8-3/4 1.50

9-7/8 1.75

Partially Stabilized Motor has a 1/8” under gauge near-bit stabilizer

7-7/8 1.25

8-1/2 1.50

8-3/4 1.75

9-7/8 1.75

Fully Stabilized Motor has a 1/8” under gauge near-bit stabilizer and a 1/8” under gauge top stabilizer above the motor

7-7/8 1.25

8-1/2 1.25

8-3/4 1.25

9-7/8 1.25

Page 20: 4. Deflection Tools and Technique - Drilling Engineeringdrilling-engineering.com/lec/4_Deflection_Tools_final.pdf · 4. Deflection Tools and Technique 4.1 Whipstocks 4.2 Jetting 4.3

4.5 Bit Offset Courtesy: Short. Directional & Horizontal Drilling

DTU Bent Sub Bent Sub & Bent Housing

Oktay Mamedbekov. Directional Drilling. Deflection Tools.

Page 21: 4. Deflection Tools and Technique - Drilling Engineeringdrilling-engineering.com/lec/4_Deflection_Tools_final.pdf · 4. Deflection Tools and Technique 4.1 Whipstocks 4.2 Jetting 4.3

4.5 Theoretical Build Rates

“Three-Point-Curvature” Calculations

Oktay Mamedbekov. Directional Drilling. Deflection Tools.

L2

θ

L1 Bit

Bent

Housing

Motor Top

Stabilizer

i – build rate, deg/100ft

θ – bent angle, deg

L1 – distance from bit to bent housing, ft

L2 – distance from bent housing to motor

top stabilizer, ft

Page 22: 4. Deflection Tools and Technique - Drilling Engineeringdrilling-engineering.com/lec/4_Deflection_Tools_final.pdf · 4. Deflection Tools and Technique 4.1 Whipstocks 4.2 Jetting 4.3

4.5 Build Rates (deg/100ft) for 6-3/4” Mud Motor Courtesy: Tomahawk Downhole

Oktay Mamedbekov. Directional Drilling. Deflection Tools.

Angle Hole Size(in) – Slick Sleeve Hole Size(in) – Stabilized

(deg) 7-7/8 8-1/2 8-3/4 9-7/8 7-7/8 8-1/2 8-3/4 9-7/8

0.50 0.82 0.93 2.92 3.39 3.58 4.42

0.75 2.80 1.05 0.36 4.47 4.94 5.13 5.97

1.00 4.78 3.03 2.34 6.02 6.49 6.68 7.52

1.25 6.76 5.02 4.32 1.18 7.57 8.04 8.22 9.07

1.50 8.74 7.00 6.30 3.16 9.12 9.58 9.77 10.61

1.75 10.72 8.98 8.28 5.14 10.66 11.13 11.32 12.16

2.00 12.70 10.96 10.26 7.12 12.21 12.68 12.87 13.71

2.25 14.69 12.94 12.24 9.10 13.76 14.23 14.42 15.26

2.50 16.67 14.92 14.22 11.08 15.31 15.78 15.97 16.81

2.75 18.65 16.90 16.20 13.06 16.86 17.33 17.51 18.36

3.00 20.63 18.88 18.18 15.04 18.41 18.88 19.06 19.91

Page 23: 4. Deflection Tools and Technique - Drilling Engineeringdrilling-engineering.com/lec/4_Deflection_Tools_final.pdf · 4. Deflection Tools and Technique 4.1 Whipstocks 4.2 Jetting 4.3

4.6 Rotary Steerable Systems

Auto Trak (Baker Hughes)

Power Drive (Schlumberger)

Geo-Pilot (Halliburton)

Oktay Mamedbekov. Directional Drilling. Deflection Tools.

Page 24: 4. Deflection Tools and Technique - Drilling Engineeringdrilling-engineering.com/lec/4_Deflection_Tools_final.pdf · 4. Deflection Tools and Technique 4.1 Whipstocks 4.2 Jetting 4.3

4.6 AutoTrak Courtesy: Baker Hughes

Oktay Mamedbekov. Directional Drilling. Deflection Tools.

Page 25: 4. Deflection Tools and Technique - Drilling Engineeringdrilling-engineering.com/lec/4_Deflection_Tools_final.pdf · 4. Deflection Tools and Technique 4.1 Whipstocks 4.2 Jetting 4.3

4.6 AutoTrak Courtesy: Baker Hughes

Oktay Mamedbekov. Directional Drilling. Deflection Tools.

Page 26: 4. Deflection Tools and Technique - Drilling Engineeringdrilling-engineering.com/lec/4_Deflection_Tools_final.pdf · 4. Deflection Tools and Technique 4.1 Whipstocks 4.2 Jetting 4.3

4.6 Power Drive Courtesy: Schlumberger

Control Unit Steering Unit

Oktay Mamedbekov. Directional Drilling. Deflection Tools.

Page 27: 4. Deflection Tools and Technique - Drilling Engineeringdrilling-engineering.com/lec/4_Deflection_Tools_final.pdf · 4. Deflection Tools and Technique 4.1 Whipstocks 4.2 Jetting 4.3

4.6 Power Drive Steering Unit

Courtesy: Schlumberger

Oktay Mamedbekov. Directional Drilling. Deflection Tools.

Page 28: 4. Deflection Tools and Technique - Drilling Engineeringdrilling-engineering.com/lec/4_Deflection_Tools_final.pdf · 4. Deflection Tools and Technique 4.1 Whipstocks 4.2 Jetting 4.3

4.6 Rotary Steerable Systems

• Deliver consistent steering and high ROP

• Improve hole quality by reducing tortuosity

• Reduce torque and drag due to continuous string rotation

• Better hole cleaning and less clean up time

• Recommended for use in offshore and extended reach

applications

Oktay Mamedbekov. Directional Drilling. Deflection Tools.