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Fundamentals of Drilling – Course Outline

(1)Basics of Rotary Drilling(2)Rotary Operations/Coring(3) Directional Drilling(3)Directional Drilling-Fields of Application(4)Fishing -(5)Casing/Cementing-Reasons for (6)Well Control-Measuring(7)Principles of Drilling Fluid Technology-Steering Equipment

(8)Principles of Borehole Stability(9)Principles of Hydraulic Testing

Planning of Well CourseHole Deviation

Equipment

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Reasons for Directional Drilling/Deviation Control

(1) to reach a planned target areaTargets beneath inaccessible Sites

Many Wells from the sameSite (offshore)

Relief wellsto control a blowout

Paired Geothermal Wells

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Reasons for Directional Drilling/Deviation Control

Drilling Horizontal Wells

Dogleg Abrupt ChangeOf Inclination/Azimuth

Preventing Hole DeviationLimiting Crookedness(Dog Leg Severity )

(2) to obtain/control

a planned hole trajectory

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Reasons for Directional Drilling/Deviation Control(3) to sidetrack or abandon a portion of a hole

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Terminology of Directional Well Profiles

Kickoff PointKOP

Tangent Section

Radius of Curvature = Buildup Rate

True Vertical DepthTVD

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Classification of Buildup-Rates

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Measuring the Wellbore Course A Wellbore Course is a Curve in 3D-Space

3D-Curve is determined by 3 CoordinatesX= West-EastY= South-NorthZ= Vertical Depth

Inclination I2Azimuth A2Measured DepthMD2

Coordinates must be determined fromMeasurements between 2 Points of the Hole

Point 2

Inclination I1Azimuth A1Measured DepthMD1

Point 1

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Calculation of Coordinates by Radius of Curvature Method

Section between 2 Survey Points is assumed to be a spherical arc

Sphericalarc

3D-Coordinates

DLS =100/ MD*arccos(cos I1*cos I2+sin I1*sin I2*cos(A2-A1))

Dogleg Severity (DLS ) means Curvatureof the Hole expressed in Degrees/100ft

Radius of Curvature

DLS is critical for ! Building of Keyseats! Torque and Drag! Casing Running

Operation! Running Logging Sondes

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Instruments for Directional Measurements

Gyroscope

The Challenge is to integrate these sensible instruments in thedownhole equipment and to transmit data while drilling

i i l i h i li i i

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Directional Measurements with Wireline TransmissionSide Entry SubPrinciple of Steering Tool

Drillstring non-rotating

Bit rotatedby DHM

M Whil D illi (MWD) T h i

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Measurement While Drilling (MWD) TechniquesPositive PressureSignal transmitted

by Mud

ElectromagneticTransmission

Wh h l d i i

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Why hole deviation occursEquilibrium of Forces at Bit – Cartwheel Analogy

Point of Tangency

Wh h l d i i

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Influence of Formation Anisotropy

Formations have higher

drillability perpendicular tothe bedding plane than parallelto it

Why hole deviation occurs

Equilibrium Angle

Basic AssumptionSituation withoutFormation Influence

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Equilibrium Angle dependent on Foliation Dip Angle, Factor of Anisotropy and WOB

Calculated for 6“-Borehole

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Principle of Packed Hole Assemblies

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Principle of Packed Hole AssembliesBasic Idea

3 Points define BoreholeCurvature

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Controlling Hole Inclination with Adjustable Stabilizers

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Controlling Hole Inclination with Adjustable Stabilizers

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Types of Downhole Motors used for Directional Drilling

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Types of Downhole Motors used for Directional DrillingPositive Displacement Motor (PDM) Turbine Type Motor

Characteristics of PDMLow – Medium RPMHigh TorqueIdeal for Roller Cone Bits

Characteristics of TurbinesHigh RPM

Ideal for Diamond Bits

Positive Displacement Motor Components

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Positive Displacement Motor Components

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Performance Characteristic of Drilling Turbines

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Performance Characteristic of Drilling Turbines

Power and Rotational Speed

slow down when high torque is required

Rotational Speed

Stalling Torque

Vertical Drilling System used in KTB Ultradeep Hole

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Vertical Drilling System used in KTB Ultradeep Hole

Wellbore Course of KTB Pilothole and Ultradeep hole

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p

North

East

Horizontal Projection

Ultradeep holeDrilled withVertical Drilling Systems

KTB Pilothole

KTB vertical drilling syste

Directional Drilling with DHM-Steering Systems

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KTB - vertical drilling systeDirectional Drilling with DHM Steering Systems

Open Hole and Cased Hole Sidetracking with a cement plug

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