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B. Engeser/Fundamentals of Drilling (3)
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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