Course Scope

This short course is designed to provide individuals with an advanced knowledge needed to design and analyse drilling hydraulics. The course will cover theory, hands-on exercises and a mini project on real-life example. It is intended for individuals with prior knowledge in drilling fluids.



At the end of the course, participants will be able to:

  1. Describe the rheological models generally used to approximate drilling fluid behaviour.
  2. Analyze the total system frictional pressure losses, surge/swab pressures and ECD in a wellbore using different flow regimes and fluid rheological models.
  3. Design a hydraulic programme for optimizing pump operating condition and bit nozzle sizes.
  4. Evaluate various particle slip velocity models, cuttings transport mechanisms, and hole cleaning models for efficient hole cleaning and ECD management.


  Flow Regimes and Fluid Rheology: (1 day)

  • Characteristics of pipe flow
  • Types of flow regimes, Flow entrance region and entry length for laminar & turbulent flows
  • Types of fluids
  • Reynolds number as a function of fluid types
  • Description of fluid rheology, Rheological models
  • Shear-thinning and shear-thickening fluids
  • Temperature and pressure effects on fluid rheology
  • Rheological properties measuring methods

  Pressure Losses in Pipe-Annulus/Bit Pressure Drop/ Surge & Swab Pressures: (2 days)

  • Factors influencing pressure loss
  • Estimating system pressure losses
  • Pressure loss as a function of fluid type and flow regime
  • EMW & ECD for vertical and deviated wells
  • Nozzle velocity and bit pressure drop
  • Equivalent bit nozzle size, Hydraulic horse power
  • Practical applications
  • Fundamental principles of surge and swab pressures,
  • Annular velocity for open-ended and closed-ended pipes
  • Annular pressure loss for Newtonian fluid in terms of effective velocity
  • Clinging constant equations & charts for non-Newtonian fluids

  Hydraulics Optimization Criteria: (1 day)

  • Types of hydraulic optimization criteria
  • Maximum hydraulic requirement to clean the hole for various criteria
  • Factors affecting the choice of hydraulic optimization criterion
  • Graphical method for selecting bit nozzle sizes

  Evaluation of Hole Cleaning Performance: (1 day)

  • Particle slip velocity estimation using the Moore and Chien correlation
  • Factors affecting hole cleaning efficiency
  • Cuttings transport mechanisms in vertical, inclined & horizontal wellbores
  • Effect of drillpipe rotation on cuttings transport
  • The PHAR factor concept in selecting drillpipe rotation speed
  • Transport ratio and hole cleaning models: using charts and correlations