About Course

The course is designed for drilling operational staff and drilling engineers. The objective of the course is to determine subsurface wellbore pressures during drilling operations under static and dynamic conditions. It starts with a calculation of hydrostatic pressure using high school mathematical equations and physical laws governing fluid dynamics. After refreshing basic concepts, the course explores how to calculate the forces and stresses in submerged tubular, the density of drilling fluids required to drill safely and efficiently, various rheological models for calculating frictional pressure losses in tubular and in annulus, the surge and swab pressures while moving the drill string, optimizing drilling rates by calculating the size of bit nozzle and optimizing the annular velocity for efficient cutting removal from the wellbore.

Course Outline

1. Introduction to Oil & Gas Drilling

   • Oil and gas development
   • Formations, rock pressure, fluid traps
   • Fundamentals of petroleum
   • Basic geology
   • Drilling hydraulics

2. Drilling fluid properties

   • Density
   • Compressibility of fluids
   • properties of gases
   • Z-Factor
   • Hydrostatic pressure
   • Annular pressure in complex fluid columns

3. Fluid Mechanics

   • Free body diagram
   • Buoyancy
   • Forces and stresses in submerged tubular

4. Well Control

   • Identification of a kick
   • Shut-in pressures
   • Kill mud weight calculations
   • Annular pressure during well control
   • Strength of casing shoe and maximum allowable annular pressure
   • Exercise

5. Formation Pressure

   • Pre-pressure development
   • Porosity and permeability
   • Pore pressure measurements
   • Fluid pressure gradient and mud weight requirements
   • Fluid level in annulus after loss circulation
   • Exercises

6. Prediction of Fracture Gradient

   • Definition
   • Estimate fracture gradient from correlations
   • Measurement of fracture gradient – Leak of Test (LOT)
   • LOT data Analysis
   • Exercises

7. Basic Laws of Fluid Flow

   • Introduction
   • Conservation of mass
   • Velocity equation
   • Energy and pressure balance equations
   • Hydraulic calculations
   • Pressure drop through bit nozzles

8. Rheological Models

   • Introduction
   • Calculation of frictional pressure losses
   • Newtonian model
   • Bingham Plastic model
   • Power-Law model
   • Flow regimes, laminar and turbulent
   • Frictional pressure loss equations
   • Exercises

9. Bit Hydraulics

   • Introduction
   • Bit nozzle size design
   • Optimization of bit hydraulics
   • Bit hydraulic horsepower
   • Jet impact force
   • Exercise

10. Hole Cleaning in Vertical Wells

    • Introduction
    • Particle slip velocity
    • Cutting transport ratio
    • Factors affecting hole cleaning
    • Empirical correlations
    • Exercise

11. Hole Cleaning in Directional Wells

    • Same rules don’t apply
    • Cutting transport in directional wells
    • Difficulties in hole cleaning at different angles
    • Factors affecting hole cleaning in directional wells
    • Flow rate requirements for hole cleaning in different hole conditions
    • Exercises

12. Swab and Surge

    • Definitions
    • Burkhardt method
    • Mitchell method
    • Recommended speeds for running in hole and pulling out of hole
    • Exercises