Directional Drilling

Presenter - Craig Hughes

Sperry Drilling Services
Training Manager
Halliburton Energy Services
 Controlled Directional Drilling
The science of deviating a wellbore along a planned course to subsurface
target whose location is at a given lateral distance and direction from the
vertical, at a specified vertical depth.
Drilling a wellbore with planned deviation from vertical to pre-determined
target(s)

target
Reasons for Drilling Directional Wells ...

Surface reasons
Ð

Ð Subsurface reasons

Special needs
Ð
 Surface Reasons ...

» Surface Obstructions (well positioning problems)

» Restrictions (Health, Safety Environmental)
» Economics
 Surface Location Considerations

ƒ Unsuitable terrain (sloped ground, marsh, forest, sand

dunes, etc)
ƒ Proximity to other wells, pipelines, oilfield facilities
ƒ Populated area (city or rural area, farmhouse,
industrial facility)
ƒ Proximity to power lines
ƒ Airports, radar or radio stations
ƒ Site accessibility and preparation difficulties
ƒ Health, Safety or Environmental regulations
ƒ Rig positioning issues (landfills, access road,
transportation problems)
Surface Obstructions
Economic Reason -Reservoir Drainage

ƒ More contact of the wellbore

with the productive formation

ƒ More productive intervals in a

given formation sequence
Economic Reason - Return On Investment

ƒ Multiple Wells from a

Single Surface Location

ƒ Extended Reach - 5-6 miles

ƒ Extended Reach Re-entry

and Re-drilling Options
Sub-surface Reasons ...

Horizontal Drain(s) Needed

» Re-entering Producing Formations
» Drilling Extended Reach Wells (ERD)
 Horizontal

ƒ Deep kick off

ƒ Minimum uncased hole
ƒ Short directional control
critical
ƒ Short horizontal Kickoff Point KOP

displacement Build Angle

ƒ Smallest measured depth Target

Re-entering Producing Formations
 Horizontal Adjustment

ƒ Extended reach
ƒ Accurate target approach
ƒ Set casing into target zone
Kickoff Point KOP
ƒ Larger measured depth
ƒ Case off troublesome Adjustment Section
zones
ƒ Large lease size Build Angle Target
Build Angle
Sub-surface Reasons ...
» Collision Risk exists
» Multiple Targets are Assigned to the Well
Directional Drilling Reality
The Goal is to HIT the Target(s)
Sub-surface Reasons ...

»Relief Well Required (blowouts, mine rescue)

Relief Well Required
Sub-surface Reasons ...

» Faults, Floating Blocks, Salt Domes

» Known Natural Deviation Tendencies
» Significant Formation Dip
Fault Drilling
 Formation Dip Effects

ƒ Laminar formation dipping 45° or less

ƒ Each layer fractures perpendicular
to bedding planes
ƒ Bit tilt is significant contributor
ƒ Bit is forced up dip
ƒ Formation strike

ƒ Laminar formation dipping >45° ?

Note : dip angle is measured

from horizontal !
Sub-surface Reasons ...

» Sidetracking Downhole Objects

Sidetracking ...
Reasons for Horizontal ...

ƒ Expose more target formations

ƒ Maintain or increase production

Effect of Well Spacing -
Vertical Wells
Drainage Pattern - Horizontal wells
Reasons for Multi-Lateral ...

Application Examples
Draining a Single Reservoir
More Efficiently
The Lateral Tie-Back System
Reservoir Drainage Using Multilaterals
Up-Dip and Down-Dip Laterals
Down Dip Reentry
Up Dip Reentry
Draining Multiple Reservoirs
TVD (ft) Middle East Quad Lateral Well

Horizontal Departure (ft)

SperryFlex™ motors were used to drill this penta-lateral well in the Middle East. The unique non-
articulated design allowed the open-hole laterals to be kicked-off, the lateral drilled, and then the
next lateral kicked-off without pulling out. Build-rates of up to 60 degrees per hundred feet were
achieved and straight, 1,000-ft laterals were drilled with none of the directional control problems
typical of articulated drilling systems.
 Directional Profiles

ƒ Describe the planned path of a wellbore as it

deviates from vertical.
Well
Profile RKB
Terminology KOP

Build Section
• TVD - True Vertical Depth EOB

TVD, ft
• TMD - Total Measured Depth
Tangent
• DLS - Dog-Leg Severity

• BUR - Build-Up Rate

Drop
Section
• Inclination - The Angle from
Vertical

• Azimuth - The Direction of the

Well
Departure, ft
 Basic Well Profiles

ƒ B&H

ƒ S-
S

ƒ J-
B&H
ƒ Undercut UC
J
 Build and Hold

ƒ Simplest
ƒ Inclination 15 -55°
Kickoff Point KOP

ƒ KOP determines inclination

Build Angle

ƒ Large horizontal End of Build EOB

displacements at shallow
depths
Target
Hold Angle
 Build Hold and Drop

ƒ More difficult control

ƒ Increased torque and drag
Kickoff Point KOP
ƒ Multiple target
intersection Build Angle
Hold Angle
End of Build EOB
ƒ Small horizontal
displacement Drop Angle

ƒ Near vertical target Target

penetration
 Basic Well Profiles

ƒ B&H

ƒ S-
S
ƒ J-
B&H
ƒ Undercut UC
J
 Horizontal Continuous build

ƒ Deep kick off

ƒ Minimum uncased hole
ƒ Short directional control
ƒ Short horizontal Kickoff Point KOP

displacement Build Angle

ƒ Smallest measured Target

depth
 Horizontal Adjustment

ƒ Extended reach
ƒ Accurate target approach
ƒ Set casing into target
Kickoff Point KOP
zone
ƒ Larger measured depth Adjustment Section

ƒ Case off troublesome

zones Build Angle Target
Build Angle

ƒ Large lease size

Directional Drilling Reality
Directional Drilling today's “Designer Wells”
3-D Visualization
The Goal is to HIT the Target(s)
Phillips China
3D Profile
“Designer”
Well
 High Displacement vs. TVD
1996, Maersk Qatar, Al Shaheen A-11

1000
TVD (feet)

2000

3000
0

Displacement (feet)
9,000

18,000

Displacement = 17,233 ft, TVD= 3,300 ft, Ratio>5

 Combination Build
Mobil’s Camelot
Well 53/1a - A6

Actual

Planned
Designer Well
Designer Well
 Directional Drilling
Bottom Hole Assemblies

How in the heck do we drill these

crooked holes?

ƒ Steerable Assemblies
ƒ Rotary Assemblies
Sperry-Drill Motor Types

Standard

22’

Performance

27’

Tandem Power Head

35’
Rotor / Stator Configurations
The sum of the cross-sectional
areas of any plane is a constant.
As a result, the speed of the
motor is constant for a given
flow rate.
 How the Motor Works

The differential pressure causes drilling fluid to enter

the cavities at the top of the motor. As it moves through
the motor, the fluid pushes on the rotor causing it to
rotate.
 PDM Torque and Speed

Comparison of 6-1/4” motors at 350 gpm

Cross Section of a Stator

7/8 Lobe
Cross Section of a Stator

7/8 Lobe
Rotors
Adjustable Bent Housing
 Adjustable Bent Housing Details

adjusting ring

bent insert

teeth

bearing housing
 Fluid Flow Path

ƒ A 5-8% fluid bypass is required

for cooling and lubrication
ƒ Specific range of ΔPbit required to
ensure correct bypass :
ƒ for Low Pressure Flow Restrictor
0 - 400 psi ( 0 - 27.6 bar)
ƒ for High Pressure Flow Restrictor
200 - 1,200 psi (13.8 - 82.7 bar)
Bearing Cartridge - Disassembled

Balls
Ball track (race)

( thrust bearing )
 Reading the Performance Graph

1. Off bottom
Assume: 9 5/8”, circulating
3/4 lobe,
pressure.
6.0 stage motor 1,000 gpm,
400 psi, 220ºF
2. Differential pressure =
400psi.

3. Free running speed =

250 rpm.

4. On bottom speed =
225 rpm.

5. Torque delivered to bit

= 5,000 ft-lbs.

6. Horsepower delivered
to bit = 250
 Kick-off in Open Hole

The bit, motor and stabilizers form 3

contact points for a defined circular
path

3-point geometry applies

hole bottom
 Sidetracking from Cement Plug

Time drilling : 4-5 in/hr progress low WOB

monitor cement to formation
cuttings ratio

100% cement

50% cement
50% formation

side force
100% formation
CMT Plug
 What was the build rate for
that motor?!
These
Who
motors can
planned the
really build
target on
angle!!
this well?
Fs
WOB
Integral Blade Stabilizers
 Adjustable Gauge Stabilizer

ƒ Hole Sizes : 5-7/8” - 17-1/2”

ƒ Gauge Change : 0.5” - 1.06”
ƒ 2- and 3- position tool
ƒ Operates on 400 psi
ƒ Cycles every time pump cycled
ƒ Pistons locked into body
ƒ Position indication by SPP shift
ƒ Normal drilling position:
buttons retracted
CAST Example of Hole Spiraling
 Comparison of Short- and Long-Gauge
Wood Bits
ƒ Forstner bit on left
resembles the
conventional mud
motor driveshaft and
bit used today

ƒ Standard bit on right

has a long bit gauge for
drilling a straight hole

3/4” 3/4”
 Comparison of Holes Drilled by Short
and Long-Gauge Wood Bits (continued)
 SlickBore Concept*
Matched Drilling System including:

Specially Designed PDM Motor

ƒ Shorter Bit-to-Bend gives better
steering with less bend angle on
motor.

Long Gauge Bit

ƒ Optimized cutting structure for
better toolface control

ƒ Incorporation of new directional drilling

techniques

* PATENTED
Extended-Gauge Bits

ƒ Designed and
manufactured by
Security DBS
ƒ Mostly PDC (left)
ƒ New roller cone (right)
ƒ Extended gauge to
drill a straight hole
ƒ Box-up connection to
match pin-end drive
shaft
 SlickBore vs.
Conventional Motor

Shortened Bit-to-Bend Length

ƒ Permits adding gauge

length

ƒ Reduces the required Bent

θ1 Housing angle for the same
θ2 build rate

L1 ƒ Reduces moment arm

L2
ƒ Reduces radius of rotation
B2
B1

D1 D2
BHA Stability Short
Gauge
Bit

Lower Angle Setting on ABH

SlickBore
Bit
 CAST Image -
Conventional Steerable Assembly
CAST Image - SlickBore
18” Gauge Bit after Bit Runs
(Total bit length 35”)
 New Era of Automatic Downhole
Navigation Geo-Pilot

New Generation of Drilling Tools

z 2nd Generation Rotary Steerable System

z Allow drilling of smoother, more precise well paths than

ever before (even other R/S’s)

z Longer reach is possible

z Ability to place wellbore through multiple targets greatly

improves recovery from single well
 Benefits of Geo-Pilot Steering
DRILL FASTER - Higher Overall Rate of Penetration
due to:
ƒ Elimination of sliding and resulting friction

ƒ Less time spent on short trips and back reaming

ƒ Fewer sticking pipe incidences

DRILL FARTHER - Beyond the technical limit of

conventional steerable technology
ƒ Longer reach with lower drag due to rotating 100% of
the time.
Geo-Pilot Basic Operating Principle

ƒ Rotating Shaft is
deflected in center
between bearings
with dual
eccentric cams

ƒ Results in bit tilt in

opposite direction
Geo-Pilot Rotary Steerable System
 System Description
) 2nd Generation - “Point-the-Bit”
z Capable of utilizing long gauge bits
) Tool Length - 20 ft. + 10 ft. flex collar
) At-Bit Inclination (ABI™) - 3 ft. from bit
z 3-axis Azimuthal Gamma
) 6 of 8 electronics boards come from proven
Sperry-Sun LWD tools
) Completely integrated into LWD system for
real-time data transmission
) 2-way tool communication from surface
) Backup tool communication via RPM and
pump sequences
Geo-Pilot Ready to Run
 Latest Development for Geo-Pilot

Accelerometer Scintillator
Package and ƒ Added Azimuthal
Temp Sensor
Gamma Ray to current
Processor At-Bit Inclination
sensor package
120° 120°
ƒ Sensor Distance - 3 ft
120°

Scintillator
Scintillator

Pressure Sleeve
Latest Development
for Geo-Pilot

At-Bit Inclination (ABI™)

3-axis Azimuthal Gamma
Further Developments for
Geo-Pilot
TM
IN-BIT TECHNOLOGY

ƒ Box-up design allows room

for instrumentation package

ƒ Currently testing with

vibration and temperature
Recipe for Successful Directional Drilling

ƒ Geological goals / limitations

ƒ Casing design / hole program
ƒ Monitoring the well path
ƒ Anti-collision
ƒ Torque and drag
ƒ Drilling tendencies
ƒ Hydraulics
ƒ Drilling tubulars
ƒ Drilling fluid
ƒ Rig selection
ƒ MWD/LWD tool selection
ƒ Directional Drilling tool
selection