1. Basic Formulas
Table of Content
- Pressure Gradient
- Hydrostatic Pressure
- Converting Pressure into Mud Weight
- Specific Gravity
- Equivalent Circulation Density
- Maximum Allowable Mud Weight
- Pump Output
- Annular Velocity
- Capacity Formulas
- Control Drilling
- Buoyancy Factor
- Hydrostatic Pressure Decrease POOH
- Loss of Overbalance Due to Falling Mud Level
- Formation Temperature
- Hydraulic Horsepower
- Drill Pipe, Drill Collar Calculation
- Pump Pressure, Pump Strokes
- Cost Per Foot
- Temperature Conversion Formulas
1.14 Formation Temperature (FT)
FT, °F = (ambient surface temperature, °F) + (temp. increase °F per ft of depth × TVD, ft)
Example: If the temperature increase in a specific area is 0.0
12 °F/ft of depth and the ambient surface temperature is 70 °F,
determine the estimated formation temperature at a TVD of 15,000
ft:
FT, °F = 70 °F + (0.012 °F/ft × 15,000 ft)
FT, °F = 70 °F + 180 °F
FT = 250 °F (estimated formation temperature)