1. Basic Formulas

Table of Content

  1. Pressure Gradient
  2. Hydrostatic Pressure
  3. Converting Pressure into Mud Weight
  4. Specific Gravity
  5. Equivalent Circulation Density
  6. Maximum Allowable Mud Weight
  7. Pump Output
  8. Annular Velocity
  9. Capacity Formulas
  10. Control Drilling
  11. Buoyancy Factor
  12. Hydrostatic Pressure Decrease POOH
  13. Loss of Overbalance Due to Falling Mud Level
  14. Formation Temperature
  15. Hydraulic Horsepower
  16. Drill Pipe, Drill Collar Calculation
  17. Pump Pressure, Pump Strokes
  18. Cost Per Foot
  19. Temperature Conversion Formulas

1.5 Equivalent Circulation Density (ECD), ppg

ECD, ppg = (annular pressure, loss, psi ) ÷ 0.052 ÷ TVD, ft + (mud weight, in use, ppg)

Example: annular pressure loss = 200 psi, and, true vertical depth = 10,000 ft
ECD, ppg = 200 psi ÷ 0.052 ÷ 10,000 ft + 9.6 ppg
ECD = 10.0 ppg

⬆ Table of Content