Planning Well Drilling: Casing, Mud, Bits, Surveys
1. SECTION 1 : WELL PLANNING
BASIC DRILLING TECHNOLOGY AND EQUIPMENT
1 -2
1.2 Drilling Program - Initial Information
De ning well objectives
• exploration
• appraisal
• development / production
Obtaining Consent
• permission from relevant authorities
Collection of data
• well pressure data, seismic etc.
Establish subsurface pressure regimes
• differing pressure regimes
Establish formation fracture gradients
• forecast of fracture gradients or effective casing design
Well Plan Basics
Porosity
• Sedimentary rock has pores (small openings)
Permeability
• Connected pores allow uid to ow
Pore Pressure
• Normal, abnormal or subnormal pore uid pressure
Rock Stress
• Force imposed to the rock
Balance
• Mud weight must balance pore pressure and rock stress
2. SECTION 1 : WELL PLANNING
BASIC DRILLING TECHNOLOGY AND EQUIPMENT
1 -3
1.3 Drilling Program Preparation
Well Details
• location
• type
• depth
• operator / owner
• designation
• target size and depth
• contractor and rig name
Well Objectives
• to establish objectives at TD
Casing Design
• conductor
• surface casing
• intermediate casing
• production casing
• liners
• pressure pro le chart
• initial design
• setting depth
• reservoir uid gradient
• casing shoe setting depth
• burst, collapse, tension, compressional effects
• tensile failure
• shock loading
• overpull
• cement force
• position of packer
• centralisation
• running procedures
Well Head Selection
• correct pressure rating
• ease of operation
• cost
• operator preferences
3. SECTION 1 : WELL PLANNING
BASIC DRILLING TECHNOLOGY AND EQUIPMENT
1 -4
BOP Requirements
• bottom hole pressures
• company policy
• stack up con guration
Cementing Program
• volumes required
• bottom hole temperatures
• mud type
• formation type
• stinger technique
• liner cementing
• yield
• density
• thickening time
• mix water
• compressive strength
• uid loss
• ow characteristics
Deviation Program
• need for deviation
• realistic target needs
• extent of drift
• kick off point
• range of hole angles
• abrupt angle changes
• jetting techniques
• whipstocks
Survey Requirements
• minimum requirements
• totcos
• magnetic single shots
• magnetic multi shots
• electronic multi shots
• directional MWD
Mud Program
• mud weight requirements for primary control
• suitable trip margin
• con rm mud weight does not exceed formation strength
4. SECTION 1 : WELL PLANNING
BASIC DRILLING TECHNOLOGY AND EQUIPMENT
1 -5
• reaction of formations to drilling uid alternatives
• selection of mud type
• uid loss requirements
• pH requirements
• viscosity
• temperature/ stability
• analysis of mud treatment equipment
Bits and Hydraulic Program
• bit selection
• formation drillability
• mud systems in use
• directional implications
• bit drive methods
• annular velocity
• bit and hole cleaning
Drill String Design
• drill collars
• drill pipe
• speciality drilling tools
• cross-overs
Evaluation Requirements
• drilling log
• mud logging
• coring
• MWD (measurements while drilling)
• electric log
• testing
• plug and abandon
Operational Procedures and Time Graph Construction
• company policy
• contractor policy
• bridging document
• time graph
Site Plan
• license area
• position of well relative to other features
• obstructions
• pipelines
5. SECTION 1 : WELL PLANNING
BASIC DRILLING TECHNOLOGY AND EQUIPMENT
1 -6
Reporting Requirements
• what reports required
• frequency
• recipients/addresses
Completion Equipment
• Support Structure
• Wellhead
• Downhole Completion
• Tubing Hanger
• Xmas Tree
• Flowlines
• Control Systems
• Manifolds
• Production Risers
• Surface Production/ Processing Facility
• Export Facilities
Summary:
Drilling Program Preparation:
• Well Details
• Well Objectives
• Casing Design
• Wellhead Selection
• BOP Requirements
• Cementing Program
• Deviation Program
• Survey Requirements
• Mud Program
• Bits and Hydraulic Program
• Drill String design
• Evaluation Requirements
• Operational Procedures and Time Graph Construction
• Site Plan
• Reporting Requirements