This document provides an overview of directional well trajectory types and calculations. It discusses the importance of well planning, defining the surface and target locations using a local coordinate system. During drilling, the wellbore trajectory is constantly monitored in relation to the predefined target. The acceptable target size must be defined to make cost-effective decisions and ensure the well objectives are met, as drilling costs depend on the required accuracy. It also notes that the target size should reflect geological needs rather than just conventions.

1. DIRECTIONAL DRILLING COURSE
Operational Perspective

2. COURSE AGENDA
• Introduction of Directional
Drilling
• Reference and Coordinates
SYSTEM
• Types AND Calculation of
DIRECTIONAL Well
Trajectories
• Directional SURVEY & TOOLS
• DIRECTIONAL DRILLING
OPERATION
• BHA BASIC DESIGN & APPLICATION

3. DIRECTIONAL DRILLING FOOT PRINT

4. Copyright by. PT.Prodrill Mitra Mandiri @ 2016. www.prodrill.co.id
DIRECTIONAL DRILLING SCOPE OF WORK
PDSI SAFETY POLICY
Pre-Job Meeting with
Client in Town
Well Planning
Analyzing Previous
Well Data
Drilling Program
Proposal
Arriving On Rig Prior
Spud-In
Equipment Inventory
Bottom Hole Assembly
Design
Kick Off Procedures
General Duties on
The Rig
Drilling Problems
Drilling Fluids
▪ Well Planning
▪ Bottom Hole
Assembly
▪ Mule Shoe
Orientation Method
▪ Sidetracking And
Correction Run
▪ Operating
Guidelines for
Steerable System
▪ Survey Methods
Procedures &
Equipment
▪ Care & Handling of
PDC Bits
▪ Forms
▪ Positive
Displacement Motor
▪ Drilling Jar
▪ Stabilizers
▪ Drill Collar & Hevi
wate Drill Pipe
▪ Cross Over & Saver
Subs
▪ Shock Tools
▪ Other Deflecting
Tools
▪ Variable Gauge
Stabilizer
▪ Directional Vibration
Tools

5. • Well Classification
Introduction of Directional Drilling : OBJECTIVES OF THE WELL
Vertical Well Wells with less than 10º deviation
High Inclination Well Wells between 60 and 85º deviation
Horizontal Well Wells with more than 85º deviation
Extended Reach Well Horizontal/TVD displacement greater than 2.5
Designer Well Wells with significant turn in the horizontal plane of 30
to 180 degrees, and turn not restricted by inclination
• Well Utilization/Purposes :
• Data – Exploration Well → sensitivity to Measurements of Rock & Fluid
Characteristics.
• Production – Exploitation Well → Sensitivity to Production Equipment
Application & Placement.
• Others – Relief Well, Injection Well
VS
Hi Tortuosity well Bore
Smooth Well Bore

6. INTRODUCTION DIRECTIONAL DRILLING : DIRECTIONAL APPLICATION
Multi Target EXP Well Production Well Avoid Potential Hole
Problems
Avoid Conservation Area
Multi Lateral Completion Reservoir Maintenance Application

7. INTRODUCTION DIRECTIONAL DRILLING : CLASSIFICATION
REVERSE ENGINEERING :
DICTATED BY PRODUCTION
DESIGN
➢ Casing DLS Limitation
➢ Artificial Lift Equipment
➢ Artificial Lift Placement
➢ Work Over / Well
Intervention Planning
Directional DRILLER’S Point of
View :
✓ Level of Experienced
✓ Directional Tools
✓ Drilling Rig Capacity
✓ Formation Information
✓ Client’s Support

8. REFERENCES & COORDINATES SYSTEM
Directional Drilling Key
Factor :
❖ Depth
▪ Measured Depth (MD)
▪ True Vertical Depth (TVD)
❖ Survey
▪ Magnetic Field (Azimuthal
Ref)
▪ Tools D&I Calibration (%
Tool Error)

9. DRILLING DEPTH REFERENCE

10. DEPTH REFERENCING _ DATUM
Depth Referencing
Reference Datum, Chart Datum (CD), Mean Sea Level (MSL), High Tide (HT), Low Tide
(LT), Water Level (WL), Lowest Astronomical Tide (LAT), Depth Subsea (SS)

11. DEPTH REFERENCING _ DATUM
Reference Datum
For operations involving a rig, either onshore or offshore, all depths (either along hole or true
vertical) are referred to the drill floor of the rig which initially drilled the well (original drill
floor).
These depths below drill floor (BDF) measured from the rotary table kelly bushings (RTKB)
are in turn referred to a universal datum, the Chart Datum (CD), for the local area.
Note: For onshore operations, the reference point for depth is the mean sea level (MSL) and
the rotary table kelly bushings (RTKB).
Chart Datum (CD)
CD is a constant reference datum which has the following features:
It is a fixed datum
The actual level of the water (A) will not normally fall below it. The height of the sea surface
above CD at a particular time of the day is published in Tide Tables for the local area.
It is the reference for water depth on a chart (B).
The height of Mean Sea Level (MSL) above CD is usually known (C)
Mean Sea Level (MSL)
The overall average level of the sea calculated over a period of time for the local area. The
height of MSL is fixed distance above CD.

12. DEPTH REFERENCING _ DATUM
High Tide (HT), Low Tide (LT)
Daily extreme water levels during High Tide and Low Tide respectively. Heights and times of HT
and LT vary daily.
Water Level (WL)
The Level of the sea surface at any instant.
Lowest Astronomical Tide (LAT)
The lowest level which can be predicted to occur under average meteorological conditions under
any combination of astronomical conditions. It can only be obtained properly by studying tidal
predictions covering , ideally, 19 years.
Depth Subsea (SS)
The vertical depth, usually to a specific formation or target of a deviated well, measured from
MSL.
Tide Tables
For offshore operations the Drilling Supervisor shall ensure that the correct Tide Tables are
available on the rig. Tide Tables are predictions and may not be accurate because of local
environmental conditions e.g. changes in atmospheric pressure and surges caused by conditions
outside the immediate area. Marine department may be consulted if additional guidance is
required.

13. DEPTH REFERENCING _ DATUM
Well Depth References
On a new well, depths shall be recorded in feet Below Drill Floor (BDF) measured from rotary
table kelly bushings (RTKB). The datum shall be mean sea level (MSL).
On a side track or workover well depths shall be recorded in feet Below Drill Floor (BDF) but
shall also be referenced to the "Original" rig drill floor elevation.
Reservoir Depth Reporting
For reservoir engineering purposes the depths shall be reported below MSL or subsea (SS).
Offshore Existing Structures
In the case of an existing structure, the elevation of a marker e.g. the top of the skid beam,
above MSL shall be obtained from the Engineering Department before the rig arrives on
location and shall be noted in the Drilling Programme. The distance to the actual water level
(D) plus the tide correction to MSL shall be added to (C) to obtain RTKB above CD.
RTKB above CD = D + tide correction + C

14. DEPTH REFERENCING _ DATUM
Offshore Single Well (Open Location)
The RTKB height above CD shall be established
by measuring the distance from the Drill Floor
(DF) to the actual water level (D) and adding
including the tide correction. The air gap (D)
shall be determined by the Drilling Contractor
Toolpusher and verified by the Drilling
Supervisor.
RTKB above MSL = D + tide correction
During the rig move a Marine representative will
be on board to establish the exact location. He
shall be advised of the agreed DFE prior to his
departure from the rig.
Land Locations
The land elevation above MSL shall be provided
by Petroleum Engineering and shall be noted in
the drilling programme.
For individual wells the depths are referenced to
RTKB.

15. REFERENCES : COORDINATES SYSTEM

16. REFERENCES : COORDINATES SYSTEM
➢ Latitude, Longitude and Drilling Map Projection
✓ Directional drilling maps are flat, but the Earth is an oblate spheroid.
✓ One of the most important concepts of mapping is latitude and longitude.
Latitude is a
coordinate used to
specify the north-south
position of a location
on the surface of the
Earth. Latitude is an
angle which starts from
0° at the equator to
90° at the Earth
North-South poles. It is
simply defined like this;
0 ° at the equator
+90 ° at the North
pole
-90 ° at the South
pole
Latitude & Longitude, it is described in
degrees, minutes and seconds
Longitude is a coordinate used
to specify the east-west location
on the surface of the Earth by
describing as an angular
measurement. Meridian lines
are lines running from the North
Pole to the South Pole which
connect points with the same
longitude. The prime meridian
line, passing through the Royal
Observatory, Greenwich,
England, is defined at 0
degrees. From the prime
meridian line to the East, it is
identified as 0 to + 180 degrees.
From the prime meridian line to
the West, it is identified as 0 to –
180 degrees.
the longitude and latitude of London written in degrees, minutes and seconds is
51°30′ 26″ N 0° 7′ 39″ W.

17. REFERENCES : EARTH SHAPE →MAPPING
Earth Shape
The actual Earth’s shape is an oblate spheroid because the Earth’s equatorial diameter is slightly
bigger than the Earth’s polar diameter. Even though the flatting of the Earth is one in three
hundred, it makes a big difference in scale calculation in maps used in the directional drilling
field. For map projections, different regions/countries use different reference ellipsoids and
nowadays there are more than 50 ellipsoid models. Approximately, 15 ellipsoids can cover 98% of
oil countries in the World. In order to accurately identify locations of the Earth, it is required to
identify a Geodetic Datum which consists of ellipsoid, orientation of ellipsoid, unit of length,
region of the Earth and office name.
❑ DJAKRTA DATUM

18. REFERENCES : MAP PROJECTION
Map Projection
Map projection is a method used to convert the position (latitude-longitude) on the
surface of a sphere into another method of positioning that can be drawn on a flat
map with known accuracy and a controlled degree of error. X-Y Cartesian
coordinate is the most common map positioning method. Two commonly used
methods for map projection are Lambert Conformal Conic Projection and
Transverse Mercator (TM).
1. Lambert Conformal
Conic Projection
Lambert conformal conic
projection (Figure 3), which
was introduced by Johann
Heinrich Lambert in 1772,
is a projection method of
the Earth onto a cone. The
cone axis coincides with
the geographic pole axis of
the Earth.

19. REFERENCES : MAP PROJECTION
2. Transverse Mercator
Transverse Mercator is most widely used for map projection and this is the basic
principle of the Universal Transverse Mercator system. This method overcomes
the scale error at high latitudes which will happen with the Mercator projection.
The details in the map are projected into an imaginary cylinder for all latitudes
with a narrow area of longitude.

20. REFERENCES : Shape of the Earth and Geodetic Datum for Directional
Drilling
Directional drilling relies on mapping system to
accurately identify location of the wells.
Over 100 well-defined
datum worldwide!
REMEMBER!!!
Latitudes and
Longitudes
are not
unique unless
qualifiedwith
a Datum

21. REFERENCES :Scale Factor in UTM Mapping System and its Application
in Directional Drilling
o Geodetic datums are the reference systems describing the size and shape of the
Earth and the origin and orientation of the coordinate systems used to map the
Earth.
o there are hundreds of different datums used around the world by different industries.
o Modern geodetic datums range from simple flat Earth modes to complex models.
o Different countries and organizations use different geodetic datums for their work in
order to identify positions.
o Therefore, it is extremely important to reference the correct geodetic system in order
to get the correct position.
o Using different systems can cause position errors.
o With current positioning technology, the accuracy of position can be less than meter
accuracy.
o The following are Geodetic Datums used.
1. Flat Earth Models
Flat Earth Models
are still used for
plan survey where
survey distance is
short

22. o The following are Geodetic Datums used.
1. Flat Earth Models
2. The Spherical Earth Models
describe the Earth shape with a
sphere with specific radius. They do
not truly represent the shape of the
Earth, however, these models are
frequently used for short range
navigation and for global distance
estimation.
3. Ellipsoidal Earth Models are often
used for accurate range calculation
over a long distance. Each
ellipsoidal Earth model defines a
shape of the Earth with a polar
radius and an equatorial radius.
Loran-C and GPS navigation
receivers use ellipsoidal Earth
models to calculate position and
waypoint information.
REFERENCES :Scale Factor in UTM Mapping System and its Application
in Directional Drilling

23. REFERENCES :Scale Factor in UTM Mapping System and its Application
in Directional Drilling

24. Scale factor represents distortion from a mapping system since the Earth is mapped
into a flat surface, but the actual surface is in curvature.
REFERENCES :Scale Factor in UTM Mapping System and its Application
in Directional Drilling
Figure 1
If the location is
above the map
projection plan, the
scale factor will be
less than 1.0.
means that the
actual distance on
the Earth’s surface
is longer than the
actual distance on
the map.
if the location is below the mapping
projection, the scale factor will be more than
1.0.
the scale factor of more than 1 demonstrates
that the actual distance on the Earth is
shorter than the map distance.
a scale factor with a reference location of the Earth’s surface

25. REFERENCES :Scale Factor in UTM Mapping System and its Application
in Directional Drilling
Figure 2 – Scale Factor
Depending on Location
for each UTM zone
For UTM, the central meridian
(CM) has a scale factor of 0.9996.
The locations where the scale
factor is one are 320,000m E and
680,000m N

26. use the scale factor to calculate the distance projected in the map
REFERENCES :Scale Factor in UTM Mapping System and its Application
in Directional Drilling
Figure 3- Surface and
Target Location
The surface location is located in UTM 30N.
The location coordination is 400,000 E and 6,900,000 N. and the
target is located at 401,000 E and 6,899,500N and the UTM zone
is 30N.
The scale factor at the location is 0.999685.
Distance from Surface Location to Target
ΔN = 6,899,500 – 6,900,000 = – 500 m
ΔE = 401,000 – 400,000 = 1,000 m
Map Distance = 1118.034 m
True Distance
This distance must be applied to the scale factor in order to get
the true distance.
True Distance (m) = Map Distance ÷ scale factor
True Distance (m) = 1118.034 ÷ 0.999685 = 1118.3863 m
The true distance is the horizontal displacement referencing
from the surface location to the target.
Target Azimuth
The target in reference to the surface location is located in 2nd quadrant; therefore
the target azimuth is calculated by the following relationship;
Target AZI = 90 + tan-1(ΔN÷ΔE)
Target AZI = 90 + tan-1((500) ÷ (1000))
Target AZI = 116.565 degree

27. Direction/Angle––Azimuthal map projections
preserve true direction
REFERENCES :Scale Factor in UTM Mapping System and its Application
in Directional Drilling
Convergence
is the TRUE
Direction of
Map North
UTM PROJECTION,
the Convergence
within one map
zone can vary from
–3o to +3o

28. TYPES & CALCULATION OF DIRECTIONAL WELL TRAJECTORY
Basic Well Planning
➢ Single most important factor of a project.
➢ Each directional well is unique in the sense that it has specific objectives.
➢ Ensure that all aspects of the well are tailored to meet those objectives.
➢ The hole can then be used for its intended purpose.
➢ To be able to do this we must first define the surface and target locations.
MANDATORY !: Location, The first thing to do is to define a local coordinate system originating at the structure
reference point. In many land wells, this will be the surface location. The target location is then converted to this
local coordinate system, if necessary.
IN OPERATION PHASE! : Target Size, During the drilling phase of a directional well, the trajectory of the
wellbore in relation to the target is constantly monitored. Often, costly decisions have to be made in order to
ensure that the objectives of the well are met. A well defined target is essential in making these decisions. The
technology available today allows us to drill extremely accurate wells. The cost of drilling the well is largely
dependent on the accuracy required so the acceptable limits of the target must be well defined before the well is
commenced.
DRILLING COST/AFE CONTROL! : Cost versus Accuracy, is the key consideration here. In many cases,
operator companies adopt an arbitrary in-house target size (or radius of tolerance), particularly in multi-well
projects. The size of the target radius often reflects the convention rather than the actual geological
requirements of the well. It is common for specific restrictions or hard lines to be specified only when they depict
critical features such as fault lines, pinch outs or legal restrictions such as leaseline boundaries. Many
directional wells have been unnecessarily corrected or sidetracked in order to hit a target radius which in fact
did not represent the actual objective of the well.
ENSURE !!! : Good communication, with the relevant department (Geology or Exploration) before beginning
the well can help to avert this kind of error.

29. In general, Directional wells can be either:
❑ Straight
❑ Slant type
❑ “S" type
❑ Horizontal
Wellbore Profile Knowing the position of the surface
location and given the location of the Target, its TVD and
rectangular coordinates, it is possible to determine the best
geometric well profile from surface to the bottom-hole
target
TYPES & CALCULATION OF DIRECTIONAL WELL BOR PROFILE
The selection of the Kick-off point is made by considering
the geometrical well-path and the geological characteristics.
The optimum inclination of the well is a function of the
maximum permissible build rate (and drop rate if applicable)
and the location of the target.
The maximum permissible build/drop rate is normally
determined by one or more of the following:
TD well, Formation Responded, Limitation Mechanical
Properties of BHA & Csg, E-Log & Compl String, Torque &
Drag.
Optimum build/drop rates in conventional wells vary
from place to place but are commonly in the range of
1.5° to 3° per 100 ft (30m).

30. WELL BOR PROFILE : SLANT TYPE
Slant type well; R > total target displacement.
GIVEN :
▪ Wellhead coordinates
▪ Target coordinates
▪ Target TVD, V3
To determine:
▪ KOP vertical depth, V1
▪ Build up rate, BUR
•
•
•
KOP
V1
V2
Kick-off point.
TVD of straight section/surface to
KOP. TVD of end of build up.
V2 - V1 TVD of Build up section with BUR corresponding to
radius of curvature R.
• V3 - V2 TVD of Tangent section to total depth.
• D1 Displacement at end of build up.
• D2 Total horizontal displacement of target.
•  Maximum inclination of well.

31. WELL BOR PROFILE : SLANT TYPE
R < D2

32. WELL BOR PROFILE : “S” TYPE

33. WELL BOR PROFILE : “S” TYPE

34. Work carried out by the Industry Steering Committee on Wellbore Accuracy (ISCWA) aimed
to provide a standard method of quantifying positional uncertainties with associated
confidence levels.
The key sources of error were classified:
❑ Sensor errors
❑ Magnetic interference from the BHA
❑ Tool misalignment
❑ Magnetic-field uncertainty
SURVEY : Industry Steering Committee on Wellbore Accuracy
(ISCWA)
ISCWA Component should be verified prior taking Wellbore SURVEY

35. DIRECTIONAL SURVEY & TOOLS
Magnetic & Non-Magnetic Requirements

36. Magnetic Interference
There are two types of magnetic interference:
1. Drill string magnetic interference.
2. External magnetic interference, which
can include interference from:
▪ A fish left in the hole.
▪
▪ Nearby casing.
▪
▪ A magnetic "hot spot" in the drill
collar
▪
▪ Fluctuation in the Earth’s magnetic
field.
▪
▪ Certain formations (iron pyrite,
hematite and possibly hematite
mud).
WELL BORE DIRECTION SURVEY ERROR
DIRECTIONAL SURVEY & TOOLS : COMPASS SPACING BY EARTH’S
MAGNETIC ZONE

37. DIRECTIONAL SURVEY & TOOLS : EARTH’S MAGNETIC FIELD ZONE
EARTH’S MAGNETIC FIELD ZONE

38. DIRECTIONAL SURVEY & TOOLS : COMPASS SPACING BY EARTH’S
MAGNETIC ZONE
EMPIRICAL DATA CHART

39. DIRECTIONAL SURVEY METHOD

40. DIRECTIONAL SURVEY METHOD

41. DIRECTIONAL SURVEY METHOD
Regardless of which conventional survey method is used (single-shot,
multishot, steering tool, surface readout gyro, MWD), the following three
pieces of information are known at the end of a successful survey:
✓ Survey Measured Depth
✓ Borehole Inclination
✓ Borehole Azimuth (corrected to relevant North).
Definitions of Terms used in survey
calculations methods
A number of survey calculation methods have been
used in directional drilling. Of these, only four have
had widespread use:
▪ Tangential → never be used
▪ Average Angle → common field use
▪ Radius of Curvature → more widely used
▪ Minimum Curvature → official survey reports

42. TANGENTIAL METHOD
DIRECTIONAL SURVEY METHOD
This method uses only the inclination and direction at the latest survey station. The well bore is
then assumed to be tangential to these angles. On any curved section of the hole there are flaws
in this assumption and this method of survey calculation cannot provide realistic results for
anything but a hold section of the well.
DNorth = D MD sin I2 cos A2
DEast = D MD sin I2 sin A2
DTVD = D MD cos I2
D Displacement = D MD sin I2
On an "S" type well, if the build and drop rates are the same, and
over similar intervals, then the error at the end of the well would be
small since errors introduced in the build and drop sections would
tend to negate one another.
In a build and hold well, the TVD would be less (i.e.
shallower) than the true TVD. With the well turning
to the right in the North East quadrant, one would
introduce errors that would result in a position too
far to the East, and not far enough to the North.

43. DIRECTIONAL SURVEY METHOD
▪ This tries to make a closer approximation of the well path by using both the current and the
previous survey results.
▪ Effectively, the course length between the two survey points is divided into two, equal
length, straight line segments.
▪ Thus, if A1 and I1 are the azimuth and inclination respectively at the previous survey point,
then:
BALANCED TANGENTIAL
▪ The main reason for the higher
accuracy of the balanced tangential
method, on well paths that change
direction and inclination, is that errors
introduced into one calculation are
largely canceled by the subsequent
calculation.
▪ The errors that remain tend to show
too great a TVD, and too little
displacement during the build section.
▪ Although its accuracy is comparable
to the average angle method, this
method is not commonly used since
the formulae are more complicated.

44. DIRECTIONAL SURVEY METHOD
• This method of calculation simply averages
the angles of inclination and azimuth at the
two survey stations.
• This is then the assumed well path, with a
length equal to the actual course length
between the two stations.
AVERAGE ANGLE
➢ Provided that the distance between the stations is not too great in relation to the curvature of
the well path, this method of survey calculations provides a simple, yet accurate means of
calculating a well bore survey.

45. DIRECTIONAL SURVEY METHOD
RADIUS CURVATURE
This calculation method seeks to fit the two survey station points onto the surface of a cylinder.
As such the well bore can be curved in both the vertical and horizontal planes .
Vertical Projection : →Taking a vertical section through the
well path, by “unwrapping” the cylinder, one has an arc
length of MD and a change of inclination from I1 to I2.
Assuming I and A to be measuredin
degrees,the radius is

46. DIRECTIONAL SURVEY METHOD
RADIUS CURVATURE – HORIZONTAL PROJECTION
To find the North and East displacements, one can consider a horizontal projection of the well
bore, having a radius of curvature Rh.
Accuracy Whereas the average angle method is quite accurate
when the well curvature is small and stations are close together,
the radius of curvature method is accurate for stations spaced
far apart, and with higher rates of curvature.

47. DIRECTIONAL SURVEY METHOD
This method effectively fits a spherical arc onto the two survey points. To be
more specific, it takes the space vectors defined by the inclination and
azimuth at each of the survey points and smooth's these onto the well bore
by use of a ratio factor which is defined by the curvature of the well bore
section. This curvature is the Dog-leg .
MINIMUM CURVATURE
This method provides one of the more
accurate methods for determining the
positionof the well bore.
DL = cos -1 [cos (I2-I1) -sin I1 sin I2 (1-cos (A2 - A1))]
1. DOG LEG

48. DIRECTIONAL SURVEY METHOD
MINIMUM CURVATURE
DL = cos -1 [cos (I2-I1) -sin I1 sin I2 (1-cos (A2 - A1))]1. DOG LEG
2. RATIO FACTOR
The course length MD is measured along a curve, whereas I and A define straight line
directions in space. It is necessary to smooth the straight line segments onto the curve
using a Ratio Factor, RF, above:
OR
WhereDL is in degrees.
For small angles (DL<.0001)
it is usualto set RF = 1.
✓ Then determine the increments
along the three axes, to define
the position of the second
survey point.
Minimum curvature is the
most accurate method in
common use today.

49. DIRECTIONAL SURVEY METHOD
MERCURY
• So called because it was used at Mercury, Nevada at the U. S. nuclear test site. It
combines the tangential and balanced tangential calculation methods, and takes into
account the length of the survey tool (STL).
• It treats the portion of the course over the length of the survey tool as a straight line
(i.e. tangential) and the rest of the course in a balanced tangential manner.

50. DIRECTIONAL SURVEY METHOD
RELATIVE ACCURACY OF THE DIFFERENT METHODS
Calculation
Method
Error on
TVD
(ft)
Error on
Displacemen
t (ft)
Tangential -25.38 +43.09
Balanced tangential -0.38 -0.21
Average angle +0.19 +0.11
Radius of Curvature 0.00 0.00
Minimum Curvature 0.00 0.00
Mercury (STL = 15’) -0.37 -0.04
Assuming a theoretical well in a due North direction, from zero to 2000’ MD, with a
3/100’build rate, and survey stations every 100’, we can calculate the relative accuracy
of the various methods.
Compared to
the "actual"
TVD of
1653.99’,
and North
displacement
of 954.93’,
we find the
following:
Clearly, this is only an indication of the relative accuracy, and favors those methods that assume
the well bore to be made up of a series of segments of arcs and circles. The actual well bore may
behave very differently.
In addition, this comparison does not include any turn, so reasonable amounts of caution should
be used when comparing on method to another. However, it is fairly reasonable to assume that
methods which compare badly in a single plane situation will almost certainly behave worse in a
three dimensional case.

51. DOGLEG SEVERITY
Dogleg severity is a measure of the amount of change of inclination and/or direction of a borehole.
It is usually expressed in degrees per 100 feet or degrees per 10 or 30 metres of course length.


The following formula is commonly used in estimating fatigue and strength criteria for
tubular goods. It makes no assumptions about the well path, and is therefore independent
of survey calculation methods.
1. Lubinski:
d  DI
2
 DA
2

DLS = 2sin −1
sin  +sin  •sin I1•sin I2
DMD

2   2 

2. For the Tangential Method (gives an approximation only):
DLS =
d
D MD
cos -1
(sin I1 • sin I2) (sin A1 • sinA2 + cos A1 • cos A2) + (cos I1 • cos I2)
3. For the Minimum Curvature Model (Mason & Taylor):
DLS =
d
D MD
cos -1
[cos D I - (sin I1 • sin I2) (1 - cos D A)]
❖ d = DLS Interval

52. DIRECTIONAL DRILLING SURVEY EQUIPMENT
PHOTOGRAPHIC SURVEYING TOOLS
It may be run and retrieved on wireline (sand-line).
It may be dropped down the drill-pipe, then retrieved by running an overshot on wireline.
It may be dropped free down the drill-pipe and retrieved when a trip is made (e.g. to change the
bit). When the instrument reaches bottom it sits inside a baffle plate called a Totco ring which
holds the instrument in position.
Magnetic Single / Multi Shot
The magnetic single shot was first used in the 1930’s for measuring the inclination and
direction of a well. The instrument consists of 3 sections:
An angle unit consisting of a magnetic compass, and an inclination measuring device.
A camera section.
A timing device or motion sensor unit.

53. DIRECTIONAL DRILLING SURVEY EQUIPMENT
PHOTOGRAPHIC SURVEYING TOOLS Magnetic Single / Multi Shot

54. DIRECTIONAL DRILLING SURVEY EQUIPMENT
▪ Running gyro surveys is nearly always a benefit to survey accuracy and provide verification of
the MWD surveys, but clearly the benefit has to be worth the cost.
▪ There are certain circumstances however, where running gyros are the only option for a safe
an adequately accurate survey.
GYROSCOPE
ATTENTION!!!
▪ Please note that in most of these scenarios apart from a) below, the assumption is that the
gyro used is of sufficient accuracy to exceed the accuracy of the MWD. That is not always the
case depending on the type of gyro and the expected performance of the gyro must be
ascertained by suitable QC to ensure adequate accuracy.
a) When magnetic interference from nearby steel preclude the use of MWD.
These circumstances include the following;
•Measuring inside casing
•Measuring close to casing shoe
•Measuring close to adjacent wells
•Measuring close to surface or shallow beneath the rig
•Measuring close to a fish or when side-tracking close to original casing.

55. When the rotor is spun at high speed, the rotor
axis continues to point in the same direction
despite the gimbals being rotated. This is a crude
example of a mechanical, or conventional,
displacement gyroscope.
DIRECTIONAL DRILLING SURVEY EQUIPMENT : GYROSCOPE
These rules apply to all spinning gyros:
1. A gyro rotor will always precess about an axis
at right angles to both the torque axis and the
spin axis.
2. A gyro rotor always precesses in a direction so
as to align itself in the same direction as the
axis about which the torque is applied.
3. Only those forces tending to rotate the gyro
rotor itself will cause precession.
4. Precession continues while torque is applied
and remains constant under constant torque.
5. Precession ceases when the torque is removed
or when the spin axis is in line with the torque
axis (the axis about which the force is applied).
GYROSCOPE BASIC PRINCIPLES

56. The term MWD refers to measurements taken downhole with an electromechanical device
located in the bottomhole assembly (BHA)
DIRECTIONAL DRILLING SURVEY EQUIPMENT : MWD
All MWD systems typically have three major subcomponents:
✓ Power system
▪ Battery - Lithium-thionyl chloride (high-energy density and superior performance
▪ Turbine - Rotational force is transmitted by a turbine rotor to an alternator through
a common shaft, generating a three-phase alternating current (AC) of variable
frequency. Electronic circuitry rectifies the AC into usable direct current (DC).
✓ Telemetry system
▪ Mud-pulse telemetry - positive-pulse, negative-pulse, and continuous-wave
systems.
▪ Low-frequency electromagnetic transmission - limited commercial use in MWD
and LWD systems.
▪ Integral hardwire telemetry - Expensive special drillpipe, Special handling,
Hundreds of electrical connections that must all remain reliable in harsh
conditions.
✓ Directional sensor
▪ The state of the art in directional-sensor technology is an array of three orthogonal
fluxgate magnetometers and three accelerometers.

57. MWD TELEMETRY – MUD PULSE TELEMETRY
Positive Pulse Negative Pulse Continues wave
The pulses of the information signal in mud pulse telemetry vary in
width "A… and get substantially modified on the surface due to
various external factors and amplitude decay "B….

58. MWD TELEMETRY - Low-frequency electromagnetic transmission

59. MWD Wired Drill Pipe Telemetry (WDP)
DATA RATE COMPARISON

60. MWD Wired Drill Pipe Telemetry (WDP)
WDP Technology Network 1.The Network Controller
(including surface cabling)
2.Data Swivel
(Including saver sub)
3.WiredDrill Pipe
(including the coils & data cable)
4.Data Link
5.Interface-Sub
6.ASM (Along String Measurements)

61. MWD Wired Drill Pipe Telemetry (WDP)

62. MWD Wired Drill Pipe Telemetry (WDP)
LESSON LEARNED STATOIL NORTH SEA
EXTENDEDWELL – 5000 m.

63. MWD : D&I Package
Directional Sensor
The sensors used in steering tools and MWD/LWD are solid-state
electronic devicesknown as magnetometers and accelerometers
which respond to the earth’s magnetic fieldand gravitational field
respectively
DON’T LOOSEIT !!!

64. DIRECTIONAL DRILLING OPERATION : HISTORY

65. DIRECTIONAL DRILLING OPERATION : HSE
1. SAFETY : PERSONEL, EQUIPMENT, & OPERATION
2. Drilling & Directional Package
3. Meeting with Client Representative
4. Equipment Check & Inventory
5. Getting Ready to Drilling.
Note : SAFETY – RIG & OPERATION RELATION
1. Rig Safety Induction..
✓ Safety Meeting, Tool Box Meeting.
✓ Station Bill / Muster Point
✓ Escape Route
2. Rig Safety Alarm
✓ General Alarm
✓ Fire Alarm
✓ Abandon Alarm
✓ H2S Alarm
✓ Gas Alarm
3. Rig Safety Regulations
✓ Smoking Area
✓ Hot Work Permits
✓ Safety Harness/Ridding Belt
✓ Crane Operations
✓ Working at Height
Directional Driller Communication LINE
DD Coord/FSM in Town
Client in
Town
Co - Man Well Site G&G
Directional Driller
Mud Logging Rig TP / Driller Mud Engineer
Rig Crew
TOWN
RIG
FIRST LEVELCOMMUNICATION
Second LevelCommunication
Rig Communication Link

66. DIRECTIONAL DRILLING OPERATION : TOOLS & EQUIPMENT
DEFLECTING TOOLS : 1st Generation

67. DEFLECTING TOOLS : 2nd Generation → JETTING Rule of Thumb : JETTING
o KOP < 2500 ft
o Use TCB – 1 Open
o Nozzle Velocity
400ft/sec.
o Jetting BHA :
▪ TCB – 1 Open
▪ FG NB Stab
▪ MWD
▪ UBHO
▪ NMDC
▪ DC’s
▪ Drlg Jar
▪ HWDP’s
o Scribe Line
o Jetting & Rocking
o Attempt to Gain WOB
o Penetration 3-4 ft → 1o
DLS
o Reduce Flow Rate on
Rotation mode
DIRECTIONAL DRILLING OPERATION : TOOLS & EQUIPMENT
Recommended practice for NUDGING from Existing Well

68. DIRECTIONAL DRILLING OPERATION : TOOLS & EQUIPMENT
DEFLECTING TOOLS : 3rd Generation

69. DIRECTIONAL DRILLING OPERATION : TOOLS & EQUIPMENT
DEFLECTING TOOLS : 4th Generation
Four major parameters displayedon the Power Curve
format :
❖Output Torque (foot-pounds)
❖Output Rotational Speed(revolutionsper minute)
❖Total PressureDrop (pounds per square inch)
❖Drilling Fluid Flow Rate (gallons per minute)

70. DIRECTIONAL DRILLING OPERATION : TOOLS & EQUIPMENT

71. DIRECTIONAL DRILLING OPERATION : TOOLS & EQUIPMENT
DEFLECTING TOOLS : NEW TECHNOLOGY

72. DIRECTIONAL DRILLING OPERATION : TOOLS & EQUIPMENT
DEFLECTING TOOLS : NEW TECHNOLOGY BY MARKET LEADER
❖ SCHLUMBERGER
❖ HALLIBURTON
❖ BAKER HUGHES

73. DIRECTIONAL DRILLING OPERATION : TOOLS & EQUIPMENT
Drill Collar : Rule of Thumb
1. The “length of the
non-influence”
refers to the
distance at which
stabilizer will have
no effect on the
performance of the
as far as changing
the rate of drop-off
or build-up.
2. The “Pendulum
effect” is higher if
the lateral force is
higher. The lateral
force can be
increased by the
weight of the drill
collars below the
stabilizer or contact
point.

74. BHA DIAGRAM BASIC OPERATION
▪ BHA Stated in Diagram effective in
Inclination of 30 ⁰.
▪ Inclination < 30 ⁰, BHA tends to
negative side force.
▪ Inclination > 30 ⁰, BHA tends to
positive side force.

75. Stabilizer historical Selection
Just Do It !!!!

76. BHA DIRECTIONAL OPERATION DESIGN
BASIC NEED OF DRILLING THE WELL = WEIGHT ON BIT !!! → HOW MUCH ???

77. BHA DIRECTIONAL OPERATION DESIGN
DIR DRILLER OBJECTIVES = KNOWING BHA TO BE ABLE TO DRILL &
THE LIMITATION !!!!

78. BHA DIRECTIONAL OPERATION DESIGN => weight component
THE LIMITATION !!!!
➢ Bit
➢ BHA Component
& Connection
➢ Drill Pipe
➢ Rig – Sizing

79. BHA DIRECTIONAL OPERATION DESIGN => weight component
✓ In case using Drilling Jar in the BHA, the
placement should be in 10,000 lbs in tension

80. • JAR
▪ Drilling Jar
▪ Fishing Jar*
❖ Single Acting
❖ Double Acting
➢ Hydraulics
➢ Mechanical
➢ HydroMechanical
Copyright by. PT.Prodrill Mitra Mandiri @ 2016. www.prodrill.co.id
DRILLING JAR: DRILL STRING ASSEMBLY DESIGN
INSURANCE POLICY

81. DOUBLE ACTING JAR TECHNICAL SPECIFICATION
Copyright by. PT.Prodrill Mitra Mandiri @ 2016. www.prodrill.co.id
DRILLING JAR: DRILL STRING ASSEMBLY DESIGN
Nominal
OD
(inch)
Length
(feet)
Thru
Bore
(inch)
Tensile
Yield
(lbs)
Torsional
Limit
(ft lbs)
Max Pull
During Delay
(lbs)
Free Stroke
Up / Down
(inch)
Total
Stroke
(inch)
3.38 14.3 1.50 234 900 9 000 50 000 7.0 21.0
4.25 16.9 2.00 300 800 16 300 70 000 8.0 25.0
4.75 17.4 2.25 370 600 21 500 85 000 8.0 25.0
6.25 17.9 2.25 938 900 50 700 160 000 8.0 25.0
6.50 18.1 2.75 1 220 000 51 000 175 000 8.0 25.0
6.75 17.9 2.75 1 220 000 51 500 190 000 8.0 25.0
8.00 18.2 2.81 1 293 900 103 200 240 000 8.0 25.0
9.50 19.0 3.00 2 106 900 189 300 300 000 8.0 25.0

82. JAR PLACEMENT BEST PRACTICES
1) Jar Life and Effectiveness
2) Maximize Jar Efficiency
3) Placement of the Jar
Copyright by. PT.Prodrill Mitra Mandiri @ 2016. www.prodrill.co.id
DRILLING JAR: DRILL STRING ASSEMBLY DESIGN
Operational Data Requirements :
➢ Normal pick up weight
➢ Normal set down weight
➢ BHA weight below Jar
➢ BHA weight above Jar
➢ Jar Pump Open Force
➢ Jar Up Latch Setting
➢ Jar Down Latch Setting
➢ Well Bor Friction

83. 1) Jar Live & Effectiveness
DO NOT :
❖ Place Jar at Neutral Point (+ 10,000 lbs)
❖ Place Jar within 90 ft of Stab, Reamer or Similar tool
❖ Place Jar within 60 ft of Drill Pipe
❖ Place Jar within 90 ft of a Shock Tool always above
❖ Place Jar within 90 ft of the Drill Bit
❖ Place Jar between 2 larger OD DC or HWDP
❖ Place Jar as X-Over or Transition OD String
Mandatory :
Place Jar between 2 Jts Drill Collar or HWDP
both above and below
Copyright by. PT.Prodrill Mitra Mandiri @ 2016. www.prodrill.co.id
DRILLING JAR: DRILL STRING ASSEMBLY DESIGN

84. 2) Maximize Jar Efficiency:
IT IS RECOMMENDED:
✓ Place 2 jts DC or HWDP above and below the
Jar to increase Mass Near Jar
✓ Place Jar Lower in BHA, if mechanical stuck
expected
✓ Place Jar Higher in BHA, if Differential stuck
expected.
3) Placement of Jar:
Jar may be placed in Tension or Compression
Run Mechanical Jar in Compression
Run Hydro Jar in Tension
DO NOT PLACE JAR IN, OR NEAR DRILL
PIPE
Copyright by. PT.Prodrill Mitra Mandiri @ 2016. www.prodrill.co.id
DRILLING JAR: DRILL STRING ASSEMBLY DESIGN
Recommended
Weight
above Jar
Drilling
Jar
Weight
below Jar

85. Hydraulics

86. LET’S DRILL A WELL
• Exercises…

87. DIRECTIONAL DRILLING COURSE
TERIMA KASIH ATAS PERHATIAN
DAN KERJASAMANYA
SEMOGA BERMANFAAT
Why better
drilling could
be the key to
a more
efficient oil
and gas
industry