Mwd Manual

8/15/2019 Mwd Manual

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Approved ByDirector

Document & Revision No.JIN-DD-MWD-INDUCTION.MANUAL-01

Reviewed ByGM

Date of issue August 2011

Prepared byBase Coordinator

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Title MWD/DD-INDUCTION.MANUAL

DIRECTIONAL DRILLING

INDUCTION MANUAL


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DIRECTIONAL DRILLING

INDUCTION MANUAL-01

Issue/Revision : JIN-DD-MWD.IND.MANUAL-01

Compiled By

Kamlesh Unadkat / Vaishali Sali

Base Coordinator

Reviewed By

Umesh Thakur / Satish Jawanjal

GM (Directional Drilling)

Approved By

Dr. I N Chatterjee

Director


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Table of Contents

1. Introduction to Jindal 7

2. Oil exploration & drilling 10

2.1 Forming oil 102.2 Locating Oil 11 2.3 Oil Drilling Preparation 12 2.4 Oil Rig Systems 14 2.5 Testing For Oil 19

3. Directional Drilling 21

3.1 Applications of Directional Drilling 213.1.1 Sidetracking 21 3.1.2 Inaccessible Locations 21 3.1.3 Salt Dome Drilling 22 3.1.4 Offshore Multiwell Drilling 23

3.2 Types of Directional Wells 233.2.1 “L” profile (Build and Hold) 243.2.2 “S” Type Well 243.2.3 “J” Type Well 253.2.4 Horizontal Well 25

3.3 Geometry of A Directional well 25

4. Drilling of Directional Well 28

4.1 Bottom Hole Assembly 294.2 Sizes of BHA Component 304.3 Parts of A BHA 30

4.3.1 Drill bit 304.3.2 Steerable Downhole Mud Motor 324.3.3 Float Sub 364.3.4 UBHO (Universal Bore Hole Orienting subs) 374.3.5 NMDC (Non Magnetic Drill Collar) 38

4.3.6 Heavy Weight Drill Pipes 384.3.7 Drill Collars 394.3.8 Stabilizers 394.3.9 Crossovers 40


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6.14.3 Pressure Pulses 71 6.14.4 Drilling Fluid 71

6.15 Factors Affecting the Mud Pulse 726.16 Reliability 727. Tensor MWD Battery Manual 74

7.1 Procedure for Leaking or Vented Batteries 767.2 Procedure for Hot Batteries 77 7.3 Procedure for Exploding Batteries 77 7.4 Procedure for Lithium Fire 787.5 Lithium Battery Safety 787.6 Storage and Disposal Tips 807.7 Handling and Inspection Guidelines 817.8 Handling during Product Assembly 82

8. QMWD-SAP System 84

8.1 System Description 848.2 Toolface Offset Procedures 878.3 Summary of the Features Of Qmwd V 01.30 908.4 Summary of Features of Qmwdpc V 01.20 928.5 Summary of New Features in Qmwd V02.02 95

9. TRU-VU User Guide 97

9.1 Tru Vu Data Wise System Setup 97 9.2 Printing Plots 1039.3 Calibration 112 9.4 Miscellaneous Notes 114 9.5 Tru-Vu Renewal Procedure 115

10. Drill Well User Guide 117

10.1 Configuration 117 10.2 Loading Parameters From A Device 12010.3 Xxtalk Utility 12010.4 Drillwell Main Screen 12210.5 Tools Screen 12510.6 Depth Tracking Setup 12610.7 TFO Procedure 12610.8 Wits Setup 128


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11. Ring Out Test Sheet 145

12. Poppet Orifice Chart 147


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1. INTRODUCTION

This is the official “Jindal Drilling MWD Training Guide.” This manual is designed

to help novice and seasoned oilfield worker make the transition into becoming an

MWD Engineer specializing in the use of probe based positive pulse telemetry

MWD system.

This manual is intended to be used with your in-field training to give you the best

possible chance for success.

The only dumb question is the one you didn‟t ask and should have. By not asking

a question you may inadvertently miss an important point that could cause

trouble in field and cost thousands of dollars.

Guide to Safety

You must take adequate precautions before you start working on any operations.

A health and safety introduction will be conducted before you can go to any rig

sites.

You‟ll be shown current handling and cleaning methods for all equipment that

your job requires you to use.

Ensure your equipment is in good working order to prevent accidents from

happening.


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In case of an accident, report it to management immediately.

PERSONAL PROTECTIVE EQUIPMENT

When working on an oil rig, appropriate attire, coverall is required. Any

clothing underneath the coverall should be fire retardant or at very least

breathable and slow burning.

The uniform should be clean and in good repair when you go to a job site.

You should look professional when at any jobsite.

For safety reasons your hair must be cut short. If you have longer hair it must be

tied back or put in a pony tail and you should come clean shaven for work.

MWD uniforms consist of:

Fire retardant coveralls

CSA approved Hard hat

CSA approved steel toed Boots

Hearing protection

Gloves

TAKE PRIDE IN YOUR WORK AND WHERE YOU WORK!

You are responsible for maintaining your equipment.

Ensure all tools and equipment is clean and in good working order, ensure your

toolboxes have adequate supplies to complete a job professionally – all the time.


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Please keep any living/work area clean for yourselves and your co-workers.

Ensure you clean up any shacks properly before leaving a job site.

Work Smart – Work Safe

MWD ENGINEER RESPONSIBILITIES

The MWD Engineer must know how a rig operates as the rig operations

affect the working of the MWD tool. In this knowing the BHA( bottom hole

assembly) in hole is a must.

An MWD Engineer must know how the different components of an MWD

string operate and how they contribute to drilling.

An MWD Engineer must reduce the problems and downtime.

An MWD Engineer must always remember that they are representing their

company in front of the client hence proper behavior is expected of the

operator always in their shift.


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2. Oil exploration & Drilling

2.1 Forming oil

Oil comes from organic matter that died and sank into the sand at the bottom of

the sea.

Over the years, the organisms decayed in the sedimentary layers. In these

layers, there was little or no oxygen present so microorganisms broke the

remains into carbon-rich compounds that formed organic layers which formed

the source rock. As new sedimentary layers were deposited, they exerted intense

pressure and heat on the source rock. The heat and pressure distilled the

organic material into crude oil and natural gas. The oil flowed from the source

rock and accumulated in thicker, more porous limestone or sandstone,

called reservoir rock. Oil and natural gas in the reservoir rocks got trapped

between layers of impermeable rock, or cap rock.

The different types of trap systems are:

Structural traps

Folds - Horizontal movements press inward and move the rock layers upward

into a fold.

Faults - The layers of rock crack, and one side shifts upward or downward.

Stratigraphic traps


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Pinch out - A layer of impermeable rock is squeezed upward into the reservoir

rock.

2.2 Locating Oil

Searching for oil over water using seismology

Whether employed directly by an oil company or under contract from a private

firm, geologists are the ones responsible for finding oil. Their task is to find the

right conditions for an oil trap -- the right source rock, reservoir rock and

entrapment. Modern oil geologists also examine surface rocks and terrain, with

the additional help of satellite images. However, they also use a variety of other

methods to find oil. They can use sensitive gravity meters to measure tiny


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changes in the Earth's gravitational field that could indicate flowing oil, as well as

sensitive magnetometers to measure tiny changes in the Earth's magnetic field

caused by flowing oil. They can detect the smell of hydrocarbons using sensitive

electronic noses called sniffers. Finally, and most commonly, they

use seismology, creating shock waves that pass through hidden rock layers and

interpreting the waves that are reflected back to the surface.

In seismic surveys, a shock wave is created by the following:

Compressed-air gun - shoots pulses of air into the water (for exploration

over water)

Thumper truck - slams heavy plates into the ground (for exploration over

land)

Explosives - detonated after being drilled into the ground (for exploration

over land) or thrown overboard (for exploration over water)

The shock waves travel beneath the surface of the Earth and are reflected back

by the various rock layers. The reflections travel at different speeds dependingupon the type or density of rock layers through which they must pass. Sensitive

microphones or vibration detectors detect the reflections of the shock waves --

hydrophones over water , seismometers over land. Seismologists interpret the

readings for signs of oil and gas traps.

Once geologists find a prospective oil strike, they mark the location

using GPS coordinates on land or by marker buoys on water.


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2.3 Oil Drilling Preparation

Once the site has been selected, scientists survey the area to determine its

boundaries, and conduct environmental impact studies if necessary. The oil

company may need lease agreements, titles and right-of way accesses before

drilling the land. For off-shore sites, legal jurisdiction must be determined.After

the legal issues are settled, the crew goes about preparing the land:

1. The land must be cleared and leveled, and access roads may be built.

2. Because water is used in drilling, there must be a source of water nearby.

If there is no natural source, the crew drills a water well.

3. The crew digs a reserve pit, which is used to dispose of rock cuttings and

drilling mud during the drilling process, and lines it with plastic to protect

the environment. If the site is an ecologically sensitive area, such as a

marsh or wilderness, then the cuttings and mud must be disposed of

offsite -- trucked away instead of placed in a pit.

Once the land has been prepared, the crew digs several holes to make way forthe rig and the main hole. A rectangular pit called a cellar is dug around the

location of the actual drilling hole. The cellar provides a work space around the

hole for the workers and drilling accessories. The crew then begins drilling the

main hole, often with a small drill truck rather than the main rig. The first part of

the hole is larger and shallower than the main portion, and is lined with a large-

diameter conductor pipe. The crew digs additional holes off to the side to

temporarily store equipment -- when these holes are finished, the rig equipment

can be brought in and set up.

Depending upon the remoteness of the drill site and its access, it may be

necessary to bring in equipment by truck, helicopter or barge. Some rigs are built


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on ships or barges for work on inland water where there is no foundation to

support a rig (as in marshes or lakes).

In the next section, we'll look at the major systems of an oil rig.

2.4 Oil Rig Systems

PARTS OF A RIG

No diagram can ever explain a drilling r ig completely unless you don‟t see

one for yourself but in trying to familiarize you with the different parts here is a rig

schematic.

Parts of the rig are shown in the next page.


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One can divide the rig into three major sections:

a) Power system

Large diesel engines - burn diesel-fuel oil to provide the main source of

power

Electrical generators - powered by the diesel engines to provide

electrical power

b) Mechanical system - driven by electric motors


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Hoisting system - used for lifting heavy loads; consists of a mechanical

winch (draw works) with a large steel cable spool, a block-and-tackle

pulley and a receiving storage reel for the cable.

Turntable - part of the drilling apparatus

c) Rotating equipment - used for rotary drilling

Swivel - large handle that holds the weight of the drill string; allows the

string to rotate and makes a pressure-tight seal on the hole

Kelly - four- or six-sided pipe that transfers rotary motion to the turntable

and drill string

Turntable or rotary table - drives the rotating motion using power from

electric motors

Drill string - consists of drill pipe (connected sections of about 30 feet (10

meters) and drill collars (DC) and heavy weight drill pipes

(HWDP) (larger diameter, heavier pipe that fits around the drill pipe and

places weight on the drill bit which helps in drilling)

Drill bit - end of the drill that actually cuts up the rock; comes in many

shapes and materials (tungsten carbide steel, diamond) that are

specialized for various drilling tasks and rock formations.

A few other parts are:

Derrick - support structure that holds the drilling apparatus; tall enough to

allow new sections of drill pipe to be added to the drilling apparatus as

drilling progresses


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CIRCULATORY SYSTEM

The mud pump is like the heart of the rig whereas the mud is like the blood that

flow through the system. Pumps drilling mud (mixture of water , clay, weighting

material and chemicals, used to lift rock cuttings from the drill bit to the surface)

under pressure through the kelly, rotary table, drill pipes and drill collars A

diagrammatic representation of the circulatory system is:


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Pump - sucks mud from the mud pits and pumps it to the drilling

apparatus

Pipes and hoses - connects pump to drilling apparatus

Mud-return line - returns mud from the hole

Shale shaker - shaker/sieve that separates rock cuttings from

the mud

Shale slide - conveys cuttings to the reserve pit

Reserve pit - collects rock cuttings separated from the mud

Mud pits - where drilling mud is mixed and recycled

Mud-mixing hopper - where new mud is mixed and then sent

to the mud pits

Blowout preventer - high-pressure valves (located under the land rig or on

the sea floor) that seal the high-pressure drill lines and relieve pressure when

necessary to prevent a blowout (uncontrolled gush of gas or oil to the surface,

often associated with fire).

Fig : BOP


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2.5 Testing For Oil

Drilling continues in stages: The crew drills, then runs and cements new casings,

then drills again. When the rock cuttings from the mud reveal the oil sand from

the reservoir rock, the crew may have reached the well's final depth. At this point,

crew members remove the drilling apparatus from the hole and perform several

tests to confirm this finding:

Wire line logging – lowering nuclear, density, sonic and various other

tools to take measurements of the rock formations there

Drill-stem testing - lowering a device into the hole to measure the

pressures, which will reveal whether reservoir rock has been reached

Core samples - taking samples of rock to look for characteristics of

reservoir rock

On confirming the presence of oil the major steps involved in oil production are:

a) Perforation: A perforating gun into the well to the production depth. The

gun has explosive charges to create holes in the casing through which oil

can flow. a) After the casing has been perforated, they run a small-

diameter pipe (tubing) into the hole as a conduit for oil and gas to flow up

through the well. A device called a packer is run down the outside of the

tubing. When the packer is set at the production level, it's expanded to

form a seal around the outside of the tubing. Finally, they connect a multi-

valve structure called a Christmas tree to the top of the tubing and cement

it to the top of the casing. The Christmas tree allows them to control the


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flow of oil from the well. After the well is completed, the crew must start

the flow of oil into the well. For limestone reservoir rock, acid is pumped

down the well and out the perforations. The acid dissolves channels in the

limestone that lead oil into the well.

For sandstone reservoir rock, a specially blended fluid

containing proppants (sand, walnut shells, aluminum pellets) is pumped down

the well and out the perforations. The pressure from this fluid makes small

fractures in the sandstone that allow oil to flow into the well, while the proppants

hold these fractures open. Once the oil is flowing, the oil rig is removed from thesite and production equipment is set up to extract the oil from the well.


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3. Directional Drilling

Directional drilling is a subsection of drilling which involves deviating a well bore

along a planned course to a subsurface target whose location is a given lateral

distance and direction from the vertical.

3.1 Applications of Directional Drilling

3.1.1 Sidetracking: Side-tracking was the original directional drilling technique.

Initially, sidetracks were “blind”. The objective was simply to get past a fish in

vertical hole. Oriented sidetracks are performed to hit a specific target. It may benecessary due to an unsuccessful fishing job in a deviated well. Oriented

sidetracks are most widely used. They are performed when, for example, there

are unexpected changes in geological configuration (Figure 1-1).

Figure 1-1 Side tracking


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3.1.2 Inaccessible Locations: Targets located beneath a city, a river or in

environmentally sensitive areas make it necessary to locate the drilling rig some

distance away. A directional well is drilled to reach the target (Figure 1-2).

Figure 1-2 Inaccessible locations

3.1.3 Salt Dome Drilling: Salt domes have been found to be natural traps of oil

accumulating in strata beneath the overhanging hard cap. There are severe

drilling problems associated with drilling a well through salt formations. These

can be somewhat alleviated by using a salt-saturated mud. Another solution is to

drill a directional well to reach the reservoir (Figure 1-3), thus avoiding the

problem of drilling through the salt.


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Figure 1-3 Salt dome drilling

3.1.4 Offshore Multiwell Drilling: Directional drilling from a multiwell offshore

platform is the most economic way to develop offshore oil fields (Figure 1-4).

Onshore, a similar method is used where there are space restrictions e.g. jungle,

swamp. Here, the rig is skidded on a pad and the wells are drilled in “clusters".

Figure 1-4 Offshore multiwell drilling


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3.2 Types of Directional Wells

A carefully conceived directional drilling program based on geological

information, knowledge of mud and casing program, target area etc., is used to

select a hole pattern suitable for the operation. However, experience has shown

that most deflected holes will fit one of the following types.

Directional Patterns

L profile well (Build And Hold)

S profile well (Build and Drop)

J profile well (Deep Kick-Off and Build)

Horizontal well (can be a sub category of J profile well)

– Single

– Extended reach drilling (ERD)

– Multilateral

3.2.1 “L” profile (Build and Hold)

The well is drilled at shallow depth and the inclination is locked in until the target

zone is penetrated.

Fig. “L” profile well Fig. “S” profile well


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3.2.2 “S” Type Well

The well is deflected at a shallow depth until the maximum required inclination is

achieved. The well path is then locked in and, finally, the inclination is reduced to

a lower value or, in some cases, the well is returned back to vertical by gradually

dropping off the angle.

3.2.3 “J” Type Well

The well is deflected at a much deeper position and after achieving the desired

inclination the well is locked in until the target zone is penetrated.

Fig: “J” type well Fig: Horizontal well


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3.2.4 Horizontal Well

The well is deflected at a deeper depth and the angle of inclination achieved is

90 degree.

3.3 Geometry of a Directional Well

A directional well is drilled from the surface to reach a target area along the

shortest possible path. Owing to changing rock properties, the hole path rarely

follows a single plane but, instead, changes its inclination and direction

continuously. Thus, the deviated well should be viewed in three dimensions, such

that hole inclination and hole direction are specified at each position. Terms that

are commonly used in directional drilling are defined below.


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Fig: S profile showing different parts.

A simple build/hold/drop well profile, known as an "S" well, is shown in Figure

above.

The kickoff point (KOP) is the beginning of the build section. A build section is

frequently designed at a constant buildup rate (BUR) until the desired hole angle

or end-of-build (EOB) target location is achieved.

Hole angle, or inclination, is always expressed in terms of the angle of the

wellbore from vertical.

The direction or azimuth of the well is expressed with respect to some reference

plane, usually true north. The location of a point in the well is generally


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expressed in Cartesian coordinates with the wellhead or the rig's rotary kelly

bushing (RKB) usually as the reference location.

True vertical depth (TVD) is expressed as the vertical distance below RKB.

Measured depth (MD) The distance measured along the actual course of the bore

hole from the surface reference point to the survey point.

Departure / drift is the distance between two survey points as projected onto the

horizontal plane.

The EOB specification also contains another important requirement, which is the

angle and direction of the well at that point. The correct angle and direction are

critical in allowing the next target to be achieved; also, it may be necessary to

penetrate the pay zone at some optimum angle for production purposes.

A tangent/hold section is shown after the build section. The purpose of the

tangent is to maintain angle and direction until the next target is reached.

In the example well, a drop section is shown at the end of the tangent. The

purpose of a drop is usually to place the wellbore in the reservoir in the optimum

orientation with respect to formation permeability or in-situ formation stress;

alternatively, a horizontal extension may be the preferred orientation in the case

of a pay zone that contains multiple vertical fractures or that has potential for gas

or water coning.


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4. DRILLING OF DIRECTIONAL WELL

Directional wells are drilled with specialized equipments which are placed in the

Bottom Hole Assembly. There are many specialized equipments which are used

to drill directional wells. Some of the combinations of the specialized directional

equipments are:

1. Steerable Downhole Mud Motor (SDMM) & Measurement While Drilling

(MWD).

2. Whipstock & MWD.

3. Jetting & MWD.

In all these combinations the former refers to directional equipment which

actually deviates the well from the vertical. The latter refers to a measurement

system which detects the change in orientation of the well caused due to the

former. Earlier a magnetic single shot or multiple shot was used to determine the

direction and orientation of the well. However a MWD system has completely

replaced the magnetic single or multiple shot as it gives readings in real time.

Largely, a combination of SDMM and MWD system is used in the drilling

industry.


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4.1 Bottom Hole AssemblyThe diagrammatic representation of a BHA is as follows:


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The bottom hole assembly is connected to the rig through a series of drill pipes.

4.2 SIZES OF BHA COMPONENT

Sizes of BHA components for different hole section

Hole

section

CASING

SIZE SDMM TUBULARS MULESHOE

THREAD

CONNECTIONS26” 20” 9 5/8” 8” 5” 7 5/8” R 7 5/8” R

17 ½ “ 13 3/8“ 9 5/8” 8” 5” 6 5/8” R 7 5/8” R

12 ¼” 9 5/8”” 8” 8” 5” 6 5/8” R 6 5/8” R

8 ½” 7” 6 ¾” 6 ¾” 3 ½” 4 ½” R 4” IF

6“ 5” 4 ¾” 4 ¾” 2 7/8” 3 ½” R 3 ½” IF

All sizes in inches

4.3 PARTS OF A BHA 4.3.1 Drill bit

The drilling bit will perform the cutting of the formation. There are different types

of drill bits which are suitable for different formations and downhole applications.


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Every bit has an IADC (International Association of Drilling Contractors)

nomenclature e.g. A tricone bit might have an IADC number as 117 where the 1st

digit refers to the formation, 2nd to the teeth, 3rd to the bearing. A few examples

of bits are Poly Crystalline Diamond Cutter bit (PDC), Tricone Roller Bit (TCR),

coring bit.

Fig. PDC Bit Fig. TCR Bit


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4.3.2 Steerable Downhole Mud Motor

Fig. Steerable Down Hole Mud Motor


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Steerable Downhole Mud Motor

The above figure shows a steerable downhole mud motor connected to a bit.

Motor Selection

• These are the three common motor configurations which provide a broad range

of bit speeds and torque outputs required satisfying a multitude of drilling

applications.

• High Speed / Low Torque - 1:2 Lobe

• Medium Speed / Medium Torque – 4:5 Lobe

• Low Speed / High Torque – 7:8 Lobe

High Speed / Low Torque (1:2) motor typically used when:

• Drilling with diamond bits.

• Drilling with tri-cone bits in soft formations.

• Directional drilling using single shot orientations.

• Medium Speed / Medium Torque (4:5) motor typically used for:

• Conventional and directional drilling

• Diamond bit and coring applications

• Sidetracking wells

Low Speed / High Torque (7:8) motor typically used for:

• Most directional and horizontal wells.

• Medium to hard formation drilling.

• PDC bit drilling applications

Components of PDM Motors

• Dump Sub Assembly

• Power Section


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• Drive Assembly

• Adjustable Assembly

• Sealed Bearing Section

Dump Sub Assembly

• Hydraulically actuated valve located at the top of the drilling motor

• Allows the drill string to fill when running in hole.

• Drain when tripping out of hole

• When the pumps are engaged, the valve automatically closes and directs

all drilling fluid flow through the motor .

Power Section

• Converts hydraulic power from the drilling fluid into mechanical power to drive

the bit

• Stator – steel tube containing a bonded elastomer insert with a lobed, helical

pattern bore through the center.

• Rotor – lobed, helical steel rod

• When drilling fluid is forced through the power section, the pressure drop across

the cavities will cause the rotor to turn inside the stator.

• Pattern of the lobes and the length of the helix dictate the output characteristics

• Stator always has one more lobe than the rotor.

• Stage – one full helical rotation of the lobed stator.

Dump Sub

• Allows Drill String Filling and Draining

• Operation

- Pump Off - Open

- Pump On - Closed

• Discharge Plugs

• Connections


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• With more stages, the power section is capable of greater differential pressure,

which in turn provides more torque to the rotor .

The stator elastomer can be made of different materials, such as NBR, HNBR,

EPDM etc. The elastomer is chosen considering the type of operation involved.

For higher temperature and pressure conditions, where oil based mud is used;

better elastomers such as HNBR is used.

Drive Assembly

• Converts Eccentric Rotor Rotation into Concentric Rotation – Universal Joint

Adjustable Assembly

• Can be set from zero to three degrees

• Field adjustable in varying increments to the maximum bend angle

• Provides a wide range of potential build rates in directional and horizontal wells

Sealed Bearing Section

DriveSealed Bearing


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• Transmits axial and radial loads from the bit to the drillstring

• Thrust Bearing • Radial Bearing

• Oil Reservoir • Balanced Piston

• High Pressure Seal •Bit Box Connection

Operation modes

Rotating mode- In this mode the entire drill string is rotated with the help of rotary

table. The drill bit is rotating due to the combined action of mud motor and the

rotary table speed.

Sliding mode- In this mode the entire drill string is not rotated. The drill bit is only

rotating due to the mud motor. The bend of the mud motor is made to face in a

specified direction or angle. Drilling carried out in this way is called sliding.

4.3.3 Float Sub

Fig. Float sub and float valve


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Float sub houses the float valve which acts as a non return valve and

prevents the backflow of mud into our tool during a sudden pressure shoot

up.

4.3.4 UBHO (Universal Bore Hole Orienting subs)

Fig. UBHO

UBHO‟s are also called mule shoe subs as they house the mule shoe.

The muleshoe is inserted for the alignment of the MWD string. At the

bottom of the MWD tool is a cut with mates with the landing key in the

muleshoe. The key helps in orienting the MWD string with the bent in the

mud motor.


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4.3.5 NMDC (Non Magnetic Drill Collar)

Fig. NMDC

NMDCs house the MWD tool. Usually 2 non magnetic drill collars are used

in the BHA in order to reduce the magnetic interference between the

earths magnetic field and the magnetic field from the other magnetic

components in the drill.string. NMDC‟s are made up of stainless steel.

4.3.6 Heavy Weight Drill Pipes

Fig. A stand of HWDP comprising 3 HWDPs

As the name suggests the HWDP‟s are heavier than normal drill pipes and

impart weight to the BHA. But we must be careful as to how many weights

are used as the weight given to the bit will be difficult to control


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4.3.7 Drill Collars

Drill Collars also contribute weight to the BHA which in turn provides the

pressure to the bit required for drilling. Drill collars are larger than normal

drill pipes.

There are a few more important components in the BHA that have not been

shown in the schematic diagram

4.3.8 Stabilizers

Stabilizers provide stiffness to the BHA and they are of the same size of

the hole being drilled or 1/8”, ¼”, ½” underguaged. The placement of

stabilizers is extremely critical in a BHA as it would help in the building,

holding and dropping sections of a well.

There are majorly two types of stabilizers:

1) Near bit stabilizers: They are screw on stabilizers and are

screwed on the bearing assembly of the mud motor.

2) String stabilizers: As the name suggests the string stabilizers

are present in the string or the BHA usually at 30 or 60 feet

from the bit.

Stabilizers can also be classi0fied by the nature of the blades.

1) Integral blades: Stabilizers which are manufactured along with the blades

2) Welded blades: Such stabilizers have welded blades.

Note: The blades can be spiral or straight.


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Integral Blades Welded Blades

Fig. String stabilizer

Reasons for Using Stabilizers

• Placement / Gauge of stabilizers control directional

• Stabilizers help concentrate weight on bit

• Stabilizers minimize bending and vibrations

• Stabilizers reduce drilling torque less collar contact

• Stabilizers help prevent differential sticking and key seating.

4.3.9 Crossovers

Drill pipe, drill collar and other specialized drill string items do not have

standardized threads. In order to assemble two drill string elements having

different connections a cross over is used.

Types of cross overs:

A) Box by box

B) Box by pin

C) Pin by pin


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Fig. Showing A, B, C types of crossovers.


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5. Measurement

5.1 INCLINATION/ AZIMUTH/ MEASURED DEPTH

Any form of measuring instrument has to measure the values of azimuth,inclination and measured depth to know the location of the well bore that has

been drilled by the directional driller. These values let a directional driller know

whether he is in the right path or not

Hole Direct ion/ A zimu th is the angle, measured in degrees, of the

horizontal component of the borehole or survey instrument axis from a

known north reference. This reference is true north and is measured

clockwise by convention. Hole direction is measured in degrees and

expressed in either azimuth form (0° to 360°) or quadrant form (NE, SE,

NW, SW)


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Inclination is the angle, measured in degrees, by which the wellbore or

survey instrument axis varies from a true vertical line.

Measured depth refers to the actual length of hole drilled from the surface

location (drill floor) to any point along the wellbore.

5.2 True North and Magnet ic North

Geographic North or True North is one end of the line drawn through the center

of the earth‟s rotational axis. Magnetic North is one end of the line drawn

through the center of the earth‟s magnetic field. The lines lie near each other but

they are not aligned. They diverge and provide two different points of reference.


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5.3 Earth’s Magnetic Field

The outer core of the earth contains iron, nickel and cobalt and is ferromagnetic

so the earth can be imagined as having a large bar magnet at its center, lying

(almost) along the north-south spin axis. The magnetic field lines emerging from

the magnetic North are parallel to the surface of the Earth at the equator and

point steeply at the poles.

5.4 Earth’s Magnetic Components


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• B = Total field strength of the local magnetic field

• Bv = Vertical component of the local magnetic field.

• Bh = Horizontal component of the local magnetic field.

Magnetic Dip Angle/ Magnetic Inclination Angle

Lines of magnetic force radiate from earth‟s core. The angles at which magnetic

force lines penetrate the earth surface determine the strength of magnetic field.

Magnet ic Decl inat ion

It is the difference in degrees between magnetic north and true north at a given

location.An uncorrected azimuth called the raw reading is first corrected for

magnetic declination and then for others.


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6. Measurement While Drilling

6.1 Introduction As we know most of the wells today are deviated wells. Thus while drilling such

wells it is important to know the exact orientation and location of the wells. A

Measurement While Drilling system provides the orientation of the well in real

time.

6.2 What Is MWD?

Measurement While Drilling (MWD) systems measure formation properties

(natural gamma rays), wellbore geometry (inclination, azimuth), drilling systemorientation (toolface), and mechanical properties of the drilling process.

Traditionally MWD has fulfilled the role of providing wellbore inclination and

azimuth in order to maintain directional control in real time.

6.3 Mud Pulse Telemetry

The MWD tool is normally placed in the bottom hole assembly of the drillstring,

as close to the drill bit as possible. The MWD tool is an electromechanical device

which makes the measurements described above, and then transmits data to

surface by creating pressure waves within the mud stream inside the drillpipe.

These pressure waves or pulses are detected at the surface by very sensitive

devices (standpipe pressure transducers with pre-amplifiers) which continuously

monitor the pressure of the drilling mud. These data are passed on to

sophisticated decoding computers which deconvolute the encoded data from

downhole. This whole process is virtually instantaneous, thus, enabling key

decisions to be made as the wellbore is being drilled. Other, more exotic

transmission systems do exist e.g. drillpipe acoustic, electromagnetic and

hardwire telemetry. But the vast majority of all commercial systems utilize mud

pulse telemetry by generating either a pulse or a modulated carrier wave which is

propagated through the drilling fluid at roughly the speed of sound in mud (i.e.


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6.4 MWD Principles

Three Basic Telemetry Types:

6.4.1 Positive Mud Pulse Telemetry

Positive mud pulse telemetry (MPT) uses a hydraulic poppet valve to

momentarily restrict the flow of mud through an orifice in the tool to generate an

increase in pressure in the form of a positive pulse or pressure wave which

travels back to the surface and is detected at the standpipe.

6.4.2 Negative Mud Pulse Telemetry

Negative MPT uses a controlled valve to vent mud momentarily from the

interior of the tool into the annulus. This process generates a decrease in

pressure in the form of a negative pulse or pressure wave which travels back to

the surface and is detected at the standpipe.


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6.4.3 Continuous Wave Telemetry

Continuous wave telemetry uses a rotary valve or “mud siren” with a

slotted rotor and stator which restricts the mud flow in such a way as to generate

a modulating positive pressure wave which travels to the surface and is detected

at the standpipe.

6.4.4 Electromagnetic Telemetry

The electromagnetic telemetry (EMT) system uses the drill string as a

dipole electrode, superimposing data words on a low frequency (2 - 10 Hz)

carrier signal. A receiver electrode antenna must be placed in the ground at the

surface (approximately 100 meters away from the rig) to receive the EM signal.

Offshore, the receiver electrode must be placed on the sea floor. Currently,

besides a hardwire to the surface, EMT is the only commercial means for MWD

data transmission in compressible fluid environments common in underbalanced

drilling applications. While the EM transmitter has no moving parts, the most


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common application in compressible fluids generally leads to increased

downhole vibration. Communication and transmission can be two-way i.e.

a) downhole to uphole: Mud telemetry

b) uphole to downhole. The EM signal is attenuated with increasing well

depth and with increasing formation conductivity.


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6.5 MWD TOOL Components

6.5.1 Dummy Switch

It is the up hole end component of the MWD tool. It helps in lowering

down the tool and retrieving the tool when a stuck up takes place.

6.5.2 Centralizer


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Centralizer has the function of keeping the MWD tool centered inside the Monel.

It prevents excessive lateral vibrations and also provides electrical connections

between battery, electronics and pulsar driver.

6.5.3 Electronics Module

The electronics module can be easily identified as it is the longest component in

the MWD string. Electronics module is also known as the Direction and

Inclination (DnI) module and it is the brain of the string. It is majorly composed of

a circuit with three important sensors temperature, accelerometers and

magnetometers being at 1.6 feet away from the downhole end of the DnI module.

Sensors

A) Temperature

Our tool works efficiently within the range 0- 150 degree Celsius hence it is

important that the DnI module houses a temperature sensor. The temperature

sensor is activated earlier than the accelerometers and magnetometers are.

B) Accelerometer Accelerometers are used to measure the earth‟s local gravitational field.

Each accelerometer consists of a magnetic mass (pendulum) suspended in an

electromagnetic field. Gravity deflects the mass from its null position. Sufficient


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current is applied to the sensor to return the mass to the null position. This

current is directly proportional to the gravitational force acting on the mass. The

gravitational readings are used to calculate the hole inclination, toolface, and the

vertical reference used to determine dip angle.

There are 3 accelerometers aligned in the 3 axis directions to read the

gravity field individually in the X, Y, Z direction and then the effective gravity field

is calculated.

C) Magnetometer

Magnetometers are used to measure the earth‟s local magnetic field. Each

magnetometer is a device consisting of two identical cores with a primary winding

around each core but in opposite directions. A secondary winding twists around

both cores and the primary winding. The primary current (excitation current)

produces a magnetic field in each core. These fields are of equal intensity, but

opposite orientation, and therefore cancel each other out such that no voltage is

induced in the secondary winding. When the magnetometer is placed in an

external magnetic field which is aligned with the sensitive axis of the

magnetometer (core axis), an unbalance in the core saturation occurs and a

voltage directly proportional to the external field is produced in the secondary

winding. The measure of voltage induced by the external field will provide precise

determination of the direction and magnitude of the local magnetic field relative to

the magnetometer‟s orientation in the borehole.

There are 3 magnetometers aligned in the 3 axis directions to read the

magnetic field individually in the X, Y, Z direction and then the effective magnetic

field is calculated.


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6.5.4 Gamma Tool

The tool consists simply of a highly sensitive gamma ray detector in the form of a

scintillation counter. The scintillation counter is composed of a thalium activated

single sodium iodide crystal backed by a photomultiplier. When a gamma ray

strikes the crystal a small flash of light is produced. This flash is too small to be

measured using conventional electronics. Instead, it is amplified by a

photomultiplier, which consists of a photocathode and a series of anodes held at

progressively higher electrical potentials, all of which are arranged serially in a

high vacuum.

The Gamma tool can be easily identified in the string as it is the shortest

component of the string.


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6.5.5 Battery

• Lithium thynoil chloride battery.

• Rated voltage 28.8 V & 26 amp-hour

• Thresh hold voltage is 21.5 v

Battery is discussed in detail towards the end.


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6.5.6 Pulsar Driver System

The Pulsar driver can be identified easily in the MWD string as it has screen

housing at the down hole end. The pulsar driver system possessed by Jindal has

a BL 3 phase DC motor which is controlled by the Electronic module through the

electrical pin connections present in the various MWD tool components. The up

hole connections of pulsar driver system have 6 pin male connection. The downhole end is connected to the stringer assembly.

The pulsar driver is divided into 3 major sections

A) Snubber assembly- mainly consists of the electric circuit

B) Oil fill housing- mainly houses the 3 phase BL DC motor and capacitor bank.

C) Screen housing- consists mainly of the bellow, servo shaft, servo poppet.


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6.5.7 STRINGER ASSEMBLY

The different components used to assemble the stringer assembly are shown in

the diagram below.

The components of the stringer assembly are 4, 5, 6, 7, 8, 6, 10, polypack and

servo orifice.

The piston shaft is hollow and on top of the shaft is fixed lower piston cap, poly

pack, upper piston cap and servo orifice in sequence. This assembly is then

placed inside the helix/stinger. This combination is then screwed in the

planum/stringer barrel which has a spring inside. A poppet is now attached to the

end of the stringer shaft. Our stringer assembly is now prepared. The stringer

assembly is attached to the downhole end of the pulsar driver.


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Fig Stringer Assembly


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6.6 MWD STRING

6.6.1 Gamma Job

D/I Module – Centralizer – Battery Module – Centralizer – Gamma Module –

Centralizer – Pulsar Driver – Stringer Assembly

6.6.2 Non-Gamma Job

Battery 2 – Centralizer – D/I Module – Centralizer – Battery 1 – Centralizer –

Pulsar Driver – Stringer Assembly


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Fig. String for Gamma Job Fig. String for Non-Gamma Job Fig. Monel


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6.7 Placing MWD tool in the BHA


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Fig. showing

the placement ofMWD

1. Above the SDMM, a

Universal Bent Housing

Orienting (UBHO) sub is

torqued. A mule shoe is

oriented inside the UBHO insuch a way that the

landing key is in line with the

bend of the mud motor.

This process is called

scribing.

2. The mule shoe is then

fixed inside the UBHO with

the help of 2 set screws.

3. Non Magnetic Drill

Collars are torqued above

the UBHO.

4. The programmed

MWD tool with the helix facing

down hole are lifted from the

spear point of dummy switch

and lowered into the

NMDC. The helix of the

MWD tool sits inside the


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landing key of mule shoe (in the UBHO).

5. Further one more NMDC is torque, if required, followed by Drill collars and

Heavy weight drill pipe.

6.8 KINTEC PIN CONNECTIONS


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6.9 Working of MWD tool

When the pumps are switched on the single axised accelerometer in the

snobber assembly of the Pulser Driver senses the vibrations and sends

the same message to the DnI through pin 7.

The DnI awaits for a few seconds known as the transmit delay time before

it activates the pulsing action in the Pulsar Driver through pin 6.

The to and fro motion of the servo poppet produces the pressure waves

which contains the data from the DnI module. The amplitude of these

pressure waves are very low and are required to be amplified in order to

be transmitted to the transducer at the surface.

1

2

3

5

6

7

8

1

2

4

9

10

PIN 1 GROUND 0 VPIN 2 BATTERY-1 28.8V

PIN 3 BATTERY-2 28.8VPIN 4 B- BUS 27.9VPIN 5 Q-BUS 0-2.5VPIN 6 PULSE 05VPIN 7 FLOW 05VPIN 8 GAMMA 05VPIN 9 MOD-1 ----PIN 10 MOD-2 ----


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The amplification of the pressure amplitude is done by the stringer

assembly. When the tool is placed in the muleshoe, the servo poppet as

well as the stringer poppet are in the closed position.

When mud flows through the NMDC housing the MWD tool, there is a

pressure difference because of which the stringer poppet retracts and

compresses the spring in the plenum. The stringer poppet is now in the

open position.

The 3- phase DC motor controls the movement of the servo poppet. The

servo poppet when is in the open position provides a free path to the mud

to enter the plenum. Hence the pressure inside and outside are balanced.

The spring will now try to reach its least energy position as all forces are

balanced except for the spring force. Hence the spring now expands

pushing the poppet back to its closed position. This causes an increase in

pressure & cause the pulse magnitude to increase.

The servo poppet closes and the process is repeated.

The servo orifice on the upper piston cap allows the mud to bleed during

the compression and expansion of the spring.

The magnified pulse now travels through the mud in the drill string and is

read by the pressure transducer.


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6.10 MWD Tool Retrieval Equipment

The outer diameter of our tool is 1.88” hence in the case of a stuck up it is

possible for us to retrieve the MWD string with the help of equipments above.

There are two types of assembly for tool retrieval depending upon the

angle of the well. Well the angle of inclination is less than 45 degrees we

use a overshot, sinker bar and cross over.

For angles more than 45 degrees we use a spring jar which provides

flexibility to the assembly.

The selection of overshot bell is integral and the difefernt sizes of overshot

bells are 1.75”, 2” and 2.25”


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The assembly is run along with the CCL (casing collar locator) tool of the

wireline unit.

Go down with the wireline unit while monitoring tension and depth.

One it has reached the bottom, rather found the tool, move up and down

while monitoring the tension.

6.11 TOOLFACE

The angle at which the steering tool is pointed is termed as the toolface.

Fig. Toolface

Toolfaces are used to change the hole direction. The low angles the

accelerometers are not as accurate as the magnetometers so low angle toolface

are based on magnetic readings. Using magnetic toolfaces means pointing the

steering tool in the direction of the target.


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Once the direction/azimuth is achieved the toolface changes from magnetic

toolface to gravity toolface. The well bore has achieved direction and can be

moved left or right of the original direction.

6.12 Fluidic Vortex

The fluidic pulser generates a vortex within a chamber by momentarily

restricting the mud flow, thus creating a turbulent flow regime. The resultingchange in pressure loss can be switched on and off rapidly, circa 1millisecond,

and the resultant pressure wave created can be of high amplitude (145 psi).

MWD directional survey instrument is used to monitor the direction (magnetic)

and inclination (the angle of the tool's long axis from vertical) of the borehole.

In the MWD drilling environment, there are many sources of magnetic

interference that can cause inaccurate directional measurements. A

ferromagnetic steel object that is placed in a magnetic field will become

magnetized. The amount of induced magnetism is a function of the external field

strength and magnetic permeability of the object. In order to prevent magnetic

interference, the directional survey instrument is housed in a nonmagnetic

stainless steel collar. The MWD tool is usually arranged in a section of the

bottom-hole assembly (BHA) which is made up of a series of non-magnetic

collars to reduce the impact of the drilling assembly's steel components on the

magnetic field at the location of the survey sensor.

It is possible to optimize the position of the survey instrument by

estimating the pole strength for various BHA configurations, based upon

downhole field measurements. However, even if the correct non-magnetic collar


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spacing is used, there could still be other sources of magnetic interference which

will cause erroneous directional readings. These include “hot spots” in the non -

magnetic steel or areas of mechanical damage caused by rethreading/welding or

manufacturing impurities. A continual quality assurance procedure ensures that

such anomalies are not present in MWD collars and stabilizers. More

significantly, other BHA components may be made of magnetic material and/or

already has magnetic anomalies that affect azimuth readings. Other sources of

magnetic interference may be caused by proximity to iron and steel

magnetic materials from previous drilling or production operations, magnetic

properties of the formation, and concentrations of magnetic minerals (iron pyrites,

etc) in excess of six percent.

6.13 Azimuth Correction Technique

It is often advantageous to reduce the number of non-magnetic drill collars

so that the directional and formation evaluation sensors can be located closer to

the bit. (This also eliminates the extra cost of using monel collars.) This will assist


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in real-time decision making by allowing readings to be made as soon as

possible following formation penetration. To address this problem, a number of

methods have been devised for making corrections to magnetic surveys. The

following correction techniques are designed to reduce the influence of spurious

magnetic fields associated with the BHA:

Magnetic Azimuth Correction Algorithm

This is a proprietary method by which magnetic azimuth can be calculated

in the event that the z-axis magnetometer reading is corrupted by a spurious

longitudinal field resulting from an insufficient length of nonmagnetic BHA

components. The tool senses such a spurious field as a bias on the z-

magnetometer measurement. The method requires the operator to specify

expected values for total magnetic field and dip angle, and it then computes the

azimuth angle which is consistent with a magnetic field vector as close as

possible to the expected value. Accuracy of this azimuth angle is dependent on

the accuracy of the input nominal values for the earth's magnetic field and gravity

field. The corrected magnetic azimuth accuracy is dependent on the surface

location of the well and the direction and inclination that is being drilled. At higher

latitudes and higher inclinations and the farther the direction is from north or

south, the accuracy of the corrected azimuth will degrade. The operator will have

to decide whether to use the corrected azimuth or the uncorrected azimuth based

on concerns for azimuth accuracy.

Rotation Algorithm

This is a refinement to the Magnetic Azimuth Correction Algorithm above,

which makes use of downhole tool rotation to reduce errors caused by bias in x-

axis and y-axis magnetometers, in addition to the z-axis magnetometer bias.

Also, accelerometer bias errors on the x-axis and y-axis can be reduced with this

procedure. Such biases may be caused not only by calibration drift, but also by

magnetic hot spots in the drill collar or by magnetic junk affixed to the outside of


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the collar. This method requires a minimum of three surveys at different tool face

angles, to define a circle centered at a point which represents the transverse

biases. This method can reduce errors caused by magnetic anomalies which

rotate as the survey tool is rotated. It does not reduce errors which do not rotate,

such as interference from an adjacent casing string.

6.14 Basic Hydraulics

6.14.1 System Pressure

System pressure is the pressure felt throughout the system. While drilling, the

cuttings must be removed either with the help of water, weighted mud, foam,

steam or air. The column of water or mud in the hole is called the drilling fluid and

they exert a hydraulic pressure against the formation. This is known as the

hydrostatic head or hydrostatic pressue. It is usually measured in pounds per

square inch

Bernoulli‟s principle

Fig. Hydraulic system with a restriction


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The diagram illustrates 3 different pressure regions. The pressure in or after the

restriction is higher. In the area of restriction the pressure is relatively low. After

the restricted area the pressure returns to normal.

6.14.2 Annular Velocity

It is the velocity the fluid is flowing with in closed pressure system such as the

annulus. Erosion on the metal surfaces of the MWD tool as well as around areas

where restriction occurs are directly related to annular velocity and the amount

od solids in the mud. There are two flow regimes Turbulent and Laminar.

Turbulent flow oocurs when the velocity reaches a critical point known as the

critical velocity. Below the critical velocity we have a laminar flow of mud.

Fig. Example of turbulent and laminar flow

A more turbulent flow gives better hole cleaning. But turbulent flows can cause

washout of the hole.


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6.14.3 Pressure Pulses

Most tools today use bernoulli‟s principle to communicate between tool and the

surface computer. The data from the tool is encoded as pressure pulses and

decoded at the surface. The high pressure pulses are formed due to the

restriction in the hydraulic system. A sensor at the surface converts the

mechanical pressure into electrical signals. The electrical signal is send to signal

converter and to a computer. The surface computer decodes the data and

displays it on the screen.

6.14.4 Drilling Fluid

In the oil and gas industry the drilling fluid is referred to mud exceptions being

foam and air. The fluid column (mud) acts as part of the communication system

also known as the qbus.

The mud system controls the quality of the mud and is critical for successfully

transmitting MWD data. Thick or more viscous mud affect pulses by creating less

sharp peaks. Sometimes when gas or mud enters the mud it gives symptoms

that look like pulse failure.

6.15 Factors Affecting the Mud Pulse

There are a number of sources of interference in the MWD drilling

environment, although the main ones are as follows:

6.15.1 Mud Pump Noise

Excessive noise, either from the mud pumps or high torque mud motors

can, in rare instances, create unacceptable signal to noise ratios. In order to

prevent this, some MWD companies deploy surface measurement of pump

strobes in order to characterize a mud pump signature. This is then used in the


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surface decoder as a pump subtraction filter. In many cases, the pump

subtraction filter can be used to detect premature pump damage before any other

physical signs are available.

6.15.2 Rig and Drill string Noise

Drill string vibration will, typically, generate high frequency noise which

can lead to a dramatic deterioration of the transmitted signal. Very often, by

simply making adjustments to the WOB and RPM, it is possible to avoid

damaging critical torsional and lateral resonance. A number of vibration

prediction programs are available which can estimate critical RPM for a given

drilling assembly. It is also possible to use high frequency surface measurement

devices, such as the Baker Hughes INTEQ ADAMS and DynaByte technology

provided by the Drilling Dynamics Group. (The Drilling Dynamics Group within

Baker Hughes INTEQ uses EXLOG (now part of Baker Hughes INTEQ), ARCO

and ELF patented surface measurement technologies).

6.16 Reliability

Reliability is the probability of a product performing without failure, aspecified function under given conditions for a given period of time. A unit of

measure is Mean Time Between Failure (MTBF). In this respect, the reliability

standard is expressed as follows:

Reliability = MTBF = Operating Hours (Perfect Hours)

Failure

Factors Affecting Reliability:

• Shock and Vibration

• Telemetry System


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• Downhole Temperature

• Drilling Practices

• Complexity of Tool

• Service Company Quality Assurance (TQM)

• Competition

• Training


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7. TENSOR MWD BATTERY MANUAL

GE Power Systems supplies this manual for information and insight to our

clients on safe handling and transportation of Lithium battery products. This

manual contains information supplied by battery and battery pack manufacturers

and suppliers. The information contained within is easily obtained via the Internet

or by contacting the Battery Suppliers listed in the front of the manual.

http://www.spectrumbatteries.com/supp2.htm

http://www.spectrumbatteries.com/Prod_in/chart.htm

http://www.batteryeng.com/safety.htm

http://www.spectrumbatteries.com/Prod_in/passivation_information.htm

http://www.batteryeng.com/func_perf.htm

PLEASE NOTE AND READ – THE ABOVE HYPERLINKS.

These hyperlinks can be used to access more detailed data about battery

manufacturers and battery pack assembly companies..

SAFE STORAGE AND HANDLING

In most cases, improper handling and storage, resulting in such problems

as overheating and short-circuiting cause damage to batteries. The common

safety practices have been outlined below; safety precautions to take with regard

to all aspects of battery storage and handling.

Storage:


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1. Shelf

Batteries should be stored in their original shipping boxes, if possible, to

keep them isolated from each other, preventing external short circuits. Do not

store batteries loosely, and do not place batteries on metal surfaces.

2. Temperatures and Environment

Batteries should be stored in a cool, dry, well-ventilated area with an

optimal storage temperature range of 0-25_C. If prolonged storage is anticipated,

batteries should be protected against excessive humidity. This will prevent

moisture from forming an electrical pathway between the feed-through terminal

and battery cover, which can lead to severe galvanic corrosion of the feed-

through pin, thus compromising the hermeticity of the battery.

3. Hazard Consideration

Lithium battery storage areas should be clearly marked and provided with

“Lith-X” fire extinguishing material. Batteries might burst if subjected to excessive

heating. In case of fire, only “Lith-X” fire extinguisher should be used, as water

will cause exposed lithium to ignite. Signs should clearly state – WATER IS NOTTO BE USED IN CASE OF FIRE.

LITHIUM BATTERY SAFETY MANUAL

The following paragraphs will discuss the safe handling of Lithium Thionyl

Chloride (LTC) batteries under the abnormal hazardous conditions of:

1. Leaking or venting batteries,

2. Hot batteries,

3. Exploding batteries,

4. Lithium fires.

Personnel Protective Equipment Required:


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Safety Glasses, Rubber Gloves, Helmet with full face shield, Flak Jacket

with gloves, Riot Shield, Respirator with canisters for Acid Gases or full-

face respirator with acid gas cartridges.

Other Equipment Required:

Infrared Temperature Probe, Sodium Carbonate (Soda Lime) or Sodium

Bicarbonate (Baking Soda), Vermiculite, Fire Extinguisher containing Lith-

X Graphite powder, extended Non-conductive pliers or tongs, Thermal

resistant gloves (welding gloves).

7.1 PROCEDURE FOR LEAKING OR VENTED BATTERIES

Leaking or vented batteries should be isolated from personnel and

equipment. If possible, the area should be vented to the outside. Prior to

handling, the temperature of the batteries should be checked with a remote-

sensing device such as an infrared temperature probe. If the batteries are at

ambient temperature, they should be handled with rubber gloves or non-

conductive pliers or tongs and placed in plastic bags containing Sodium

Carbonate. Spilled electrolyte should be absorbed with Sodium Carbonate and

placed in plastic bags. All bags should be placed in a sealed and labeled drum

with Vermiculite or other non-flammable cushioning material such as sand or

Sodium Carbonate to cushion the batteries. These materials should be disposed

as previously discussed under Safe Disposal in the Lithium Battery SafetyManual.


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7.2 PROCEDURE FOR HOT BATTERIES As soon as a hot battery is detected, all personnel should be

evacuated from the area. The temperature of the battery should be

monitored with a remote-sensing device such as an infrared temperature

probe. The area should remain evacuated until the battery has cooled to

ambient temperature. When the battery has returned to ambient temperature,

it can be handled by an operator wearing protective equipment (face shield,

flak jacket and gloves) with non-conductive pliers or tongs. The batteries

should be placed in plastic bags containing Sodium Carbonate and then

placed in labeled drums containing Vermiculite or other non-flammable

cushioning material such as sand or Sodium Carbonate. These materials

should be disp

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