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Introduction to Directional Drilling. Khalifah Al-Amri Senior Drilling & Workover Engineer. Outline . Definition What Are Directional Wells ? Directional Well Types Why Drill Directionally? Planning A Directional Well Path How To Drill Directionally? Horizontal Drilling Complex Wells.
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Introduction to Directional Drilling Khalifah Al-Amri Senior Drilling & Workover Engineer
Outline • Definition • What Are Directional Wells ? • Directional Well Types • Why Drill Directionally? • Planning A Directional Well Path • How To Drill Directionally? • Horizontal Drilling • Complex Wells
Definition • Directional drilling is the science of deviating a well bore along a planned course to a subsurface target whose location is a given lateral distance and direction from the vertical.
What Are Directional Wells ? • Directional wells are deviated from vertical (straight) • Directional wells are drilled with intentional control to hit a pre-determined target: • inclination (angle) • azimuth (direction). • Think 3-D when directional
Slant (J) Type Vertical Type “S” Type Horizontal Type Directional Well Types
Inaccessible Locations Salt Dome Drilling Fault Controlling Why Drill Directionally? Sidetracking
Dir 0 N KOP Inc MD EOW TVD HD Planning A Directional Well Path • Kick Off Point • Build Up Rate • Azimuthal Direction • Inclination Angle • True Vertical Depth • Measured Depth • Horizontal Displacement
Slide & Rotate Mode Downhole Motor Bent Sub Fixed Adjustable Surveying Tool Media of Transmission How To Drill Directionally?
Horizontal Drilling • Types of Horizontal Wells: • Long Radius (2°-8°/100’) • Medium Radius (8°-30°/100’) • Short Radius (30°-60°/100’) • Ultra Short Radius (60°-200°/100’)
Horizontal Drilling • Applications: • Gas and Water Coning: • Longer horizontal drain hole increases the exposure of the pay-zone • Allows a higher production rate at lower drawdown pressure resulting in less coning Horizontal Wells Gas Vertical Wells Oil Water Water Coning Gas Coning
Horizontal Drilling Other Major Applications: • Maximum reservoir exposure • Naturally fractured tight reservoirs • Thin dry reservoirs • Less wells needed to develop a field
Complex Wells • Stacked Laterals
Complex Wells • Fishbone Wells
Complex Wells • Stacked Fishbone Wells
Complex Wells • Multiple-Branch Multilateral Wells