2. Well Planning - Drilling Engineeringdrilling-engineering.com/lec/2_Well_Planning.pdf2. Well Planning Oktay Mamedbekov. Directional Drilling. Well Planning . 2.1 Types of Directional

2. Well Planning

Oktay Mamedbekov. Directional Drilling. Well Planning .

2.1 Types of Directional Well Profiles

2.2 Directional Well Profile Calculations

2.3 Types of Horizontal Well Profiles

2.4 Horizontal Well Profile Calculations



Vertical Section

KOP - Kick off Point

Build Section EOB - End of Build or

SOH - Start of Hold

Hold or Tangent Section

Target

Horizontal Displacement

DIRECTIONAL WELL PROFILE

TYPE 1 BUILD - HOLD

Tru

e V

erti

cal d

epth

Applications:

• Single targets

• Deep wells with large

horizontal displacements

• Extended reach drilling

Features:

• Shallow kick-off-point

• Build section may have

more than one build up

rate


Applications:

• Multiple pay zones

• Reduced final angle in

reservoir

• Target limitations

• Deep wells with small

horizontal displacements

Disadvantages:

• Increased torque & drag

• Risk of keyseating

• Logging problems due to

inclination

TYPE 2 BUILD - HOLD - DROP

Vertical Section


EOB - End of Build or

Build Section SOH - Start of Hold

EOH - End of Hold or

Hold or Tangent Section SOD - Start of Drop

Drop Section

Target



Tru

e V

ert

ical

de

pth



Vertical Section


Build Section

Target



TYPE 3 CONTINIOUS BUILD

Tru

e V

ert

ica

l d

ep

th

Applications:

• Salt dome drilling

• Fault drilling

• Sidetracking

• Re-drilling

Features:

• Deep KOP

• Moderately deep wells with

short horizontal displacement

Disadvantages:

• Kick off in hard formations

due to deep KOP

• Hard to achieve desired TFO

(more reactive torque)



Section Parameter

Vertical Kick off point (KOP)

Build Build rate

Hold or Tangent Inclination angle

Drop Drop Rate

Four main sections of directional well profiles are:

Any type of directional well profile is a combination of

these sections


Oktay Mamedbekov. Directional Drilling. Well Planning.


INPUT DATA GENERAL FOR ALL TYPES OF DIRECTIONAL

WELL PROFILE CALCULATIONS:

H – True Vertical Depth, ft

L – Horizontal Displacement, ft


(Build – Hold)

h3

h2

h1

R

R

O D

C

B

A

S3

S1

S2

L

l3 l2

H

α

α



(Build – Hold)

Example 1

Given:

R – Radius of Curvature of Build Section, ft

α – Inclination Angle of Hold Section, deg

Determine:

S3 – Length of Hold Section, ft

L – R ∙ (1 – cos α) S3 = ------------------------------ sin α

S1 – Kick off Point (KOP), ft

S1 = H – R ∙ sin α – [L – R ∙ (1 – cos α)] ∙ cot α



(Build – Hold)

Example 2

Given:

S1 – Kick off Point (KOP), ft

α – Inclination Angle of Hold Section, deg

Determine:

R – Radius of Curvature of Build Section, ft

L – (H – S1) ∙ tan α R = ------------------------------------- 1 – cos α – sin α ∙ tan α


L – R ∙ (1 – cos α) S3 = ------------------------------ sin α



(Build – Hold)

Section Measured Depth,

ft

Horizontal Displacement,

ft

True Vertical Depth,

ft

Vertical S1 — h1 = S1

Build R ∙

S2 = ---------

57,3

l2 = R ∙ (1 - cos)

h2 = R∙ sin

Hold or

Tangent L – R ∙ (1 – cos α)

S3 = -------------------------

sin

l3 = S3 ∙ sin h3 = S3 ∙ cos

Total S= S1+ S2+ S3 L= l2 + l3 H = h1+ h2+ hз



(Build – Hold – Drop)

S4

G

F

E

R2

R2 h4

l4

O2

h3

h2

h1

R1

R1

O1

D

C

B

A

S3

S1

S2

L

l3 l2

α2

α1

α1

α2

α1

H




Example 1

Given:

R1 – Radius of Curvature of Build Section, ft

R2 – Radius of Curvature of Drop Section, ft

α1 – Inclination Angle of Hold Section, deg

α2 – Inclination Angle at the End of Drop Section, deg

Determine:


L - R2 ∙ (cos α2 – cos α1) – R1 ∙ (1 – cos α1) S3 = ------------------------------------------------------------------ sin α1

S1 – Kick Off Point (KOP), ft

S1 = H – R2 ∙ (sin α1 – sin α2) - S3 ∙ cos α1




Example 2

Given:

R1 – Radius of Curvature of Build Section, ft

S1 – Kick Off Point (KOP), ft

α1 – Inclination Angle of Hold Section, deg

α2 – Inclination Angle at the End of Drop Section, deg

Determine:

R2 – Radius of Curvature of Drop Section, ft

L – R1 (1 – cos α1 ) – (H – S1 – R1 ∙ sin α1) ∙ tan α1

R2 = ---------------------------------------------------------------------------- cos α2 – cos α1 – (sin α1 – sin α2) ∙ tan α1


H – S1 – R1 ∙ sin α1 – R2 ∙ (sin α1 – sin α2) S3 = ---------------------------------------------------------------- cos α1





ft

Horizontal Displacement,

ft

True Vertical Depth, ft

Vertical S1 — h1 = S1

Build R1∙ 1

S2 = -----------

57.3

l2 = R1 ∙ (1 - cos1)

h2 = R1 ∙ sin1

Hold or

Tangent S3 l3 = S3 ∙ sin1 h3 = S3 ∙ cos1

Drop

Total

R2 ∙ (1 – 2)

S4 = ---------------------

57.3

S= S1+ S2+ S3

l4 = R2 ∙ (cos2 - cos1)

L= l2 + l3

h4 = R2 ∙ (sin1 - sin2)

H = h1+ h2+ hз


2.3 Types of Horizontal Well Profiles Courtesy SPE/IADC

Radius of

Curvature

Build Rate Build Radius Hole Size

Long up to 6°/100ft 1000ft – 3000ft No

Limitation

Medium 6° – 35°/100ft 955ft – 286ft 4 ¾”; 6 ⅛”

8 ½”; 9 ⅞”

Short 1.5° – 3°/1ft 20ft – 40ft 4 ¾”; 6 ½”



Type 1 - Single Build Section

Type 2 - Double Build Section

Type 3 - Double Build Section with

Hold Section in Between



а) - с одним интервалом набора зенитного угла; б) - с двумя интервалами набора

зенитного угла; в) - с двумя интервалами наборами зенитного угла и интервалом

стабилизации между ними

R

а)

R1

б)

R2

в)

R1

R2

Рис. 3.1 Типы профилей горизонтальных скважин

Type 1 Type 2 Type 3



INPUT DATA GENERAL FOR ALL TYPES OF HORIZONTAL WELL

PROFILE CALCULATIONS:

Hh – Vertical Depth of Horizontal/Lateral Section Start Point, ft

Lh – Horizontal Displacement of Horizontal/Lateral Section Start Point, ft

αh – Inclination Angle of Horizontal/Lateral Section, deg

Sh – Length of Horizontal/Lateral Section, ft


Vertical Section


EOB - End of Build

SOH - Start of Horizontal or Lateral

Build Section

Target

Horizontal or Lateral Section

HORIZONTAL WELL PROFILES

TYPE 1 - SINGLE BUILD SECTION

Lhαh

Hh



Нг

hпл

Hпл

Lг

пл

Рис. 3.2

Продуктивный пласт

Hh = Hr + hr/2 + Lh ∙ tanαr

Reservoir

r

hr

Hr

Hh

L h



(Type 1)

HГ

X0 A

S1

DO

R

S2

LГ

S3

B

Г

Рис. 3.3

C

R

l2 l3

H h

h

L h



(Type 1)

Determine:

Lh

R – Radius of Curvature, ft R = --------------

1 – cos αh

Xo – Kick Off Point, ft Xo = Hh – R sin αh



(Type 1)

Section Measured Depth, ft Horizontal Displacement,

ft


ft

Vertical S1 = h1 = Хо — h1

Build

R •

S2 =

57.3

l2 = R • (1 - cos)

h2 = R • sin

Horizontal or

Lateral S3 = Sh l3 = S3 • sin h3 = S3• cos

Total S= S1+ S2+ S3 L= l2 + l3 H = h1+ h2+ hз


Vertical Section KOP - Kick off Point

EOB - End of Build (I)

SOB - Start of Build (II)

Build Section (I)

EOB - End of Build (II)

SOH - Start of Horizontal or Lateral

Build Section (II)

Target

Horizontal or Lateral Section


TYPE 2 - DOUBLE BUILD SECTION



(Type 2)

X0

D

B1

O1

O2

D1

F1

F

E

LГ

HD

HГ

1

1

2

2=Г

K

Рис. 3.4

l2 l3 l4

1

С

B

A

R1 = O1B = O1D

R2 = O2D = O2F

α2

α2 = αh Hh

Lh



(Type 2)

Given:

HD – Vertical Depth of Build Section (II) Start Point, ft

R2 – Radius of Curvature of Build Section (II), ft

Determine:

α1 – Inclination Angle at the End of Build Section (I), deg

sin α1 = sin αh – (Hh – HD) / R2

R1 – Radius of Curvature of Build Section (I), ft

Lh - R2 ∙ (cos α1 – cos αh)

R1 = -----------------------------------------

1 – cos α1

Xo – Kick Off Point, ft

X0 = HD – R1 ∙ sin α1



(Type 2)


ft

Horizontal

Displacement, ft


ft

Inclination

at the End

of Section,

degree

Radius of

Curvature, ft

Vertical S1 = h1 0 h1 = X0 0 0

Build I

R11

S2 =

57.3

l2 = R1(1-cos1) h2 = R1sin1 1 R1

Build II

R2(2-1)

S3=

57.3

l3=R2(cos1-cos2) h3=R2(sin2-sin1) 2 R2

Horizontal

or Lateral S4 = Sh l4 = S4 sin2 h4= S4 cos2 2 0

Total S=S1+S2+S3+S4 L= l 2+ l 3+ l 4 H=h1+h2+h3+h4 -- --


Vertical Section KOP - Kick off Point

EOB - End of Build (I)

SOH - Start of Hold

Build Section (I)

EOH - End of Hold

SOB - Start of Build II

Hold or Tangent Section

EOB - End of Build II

Build Section (II) SOH - Start of Horizontal or Lateral

Horizontal or Lateral Section Target


TYPE 3 - DOUBLE BUILD SECTION WITH

HOLD SECTION IN BETWEEN



(Type 3)

A

X0

B

D

R1 O1

R 2

C

HD

HГ

HEE2 E

F

O2

R 2E1

G1G

l2 l3 l4 l5

LГ

2= Г

1

1

1D2

R 1

2

Рис. 3.5

Hh

Lh

h



(Type 3)

Given: HD – Vertical Depth of Hold Section Start Point, ft

HЕ – Vertical Depth of Build Section (II) Start Point, ft

R2 – Radius of Curvature of Build Section (II), ft

Determine:

α1 – Inclination Angle at the End of Build Section (I), deg

sin α1 = sin αг – (Hг – HЕ) / R2

R1 – Radius of Curvature of Build Section (I), ft

Lг - R2 ∙ (cos α1 – cos αг) – (HЕ – HD) ∙ tan α1

R1 = ---------------------------------------------------------------------

1 – cos α1

Xo – Kick Off Point, ft

X0 = HD – R1 ∙ sin α1



(Type 3)

Section Measured Depth, ft Horizontal

Displacement, ft

True Vertical

Depth, ft

Inclination at

the End of

Section,

degree

Radius of

Curvature,

ft

Vertical S1 = h1 0 h1 = X0 0 0

Build I

R11

S2 =

57.3

l2 = R1(1-cos1) h2 = R1sin1 1 R1

Hold or

Tangent

h3

S3 =

cos1

l3 = h3 tan 1 h3 = HE - HD 1 0

Build II

R2(2-1)

S4=

57.3

l4=R2(cos1-cos2) h4=R2(sin2-sin1) 2 R2

Horizontal

or Lateral S5 = Sh l5 = S5 sin2 h5= S5 cos2 2 0

Total

S=S1+S2+S3+S4+S5 L= l 2+ l 3+ l 4+ l 5 H=h1+h2+h3+h4+h5 -- --


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