Drill Collar Weight
Drill collar provides weight to the bit to prevent drill pipe buckling and estimate enough enough to the bit.
$$ \text{WDC} = \frac{\text{WOB} \times \text{SF}}{\text{BF}} $$
Go CalculationEffective Mud Density
Represents the equivalent density of the drilling fluid with the effect of flow rate and ROP.
$$ \rho_{eff} = \frac{\text{MW} \times \text{Q} + \text{ROP} \times D_{h}^2}{\text{Q} + ROP \times D_h^2} $$
Go CalculationECD using YP w/ MW lte 13ppg
This formula below is used to calculate the ECD and it is good for mud weight less than or equal to 13.0 ppg.
$$ \text{ECD} = \text{MW} + \frac{0.1 \times \text{YP} \times \text{Q}} {{D_h}-{D_p}} $$
Go CalculationECD using YP w/ MW gt 13ppg
This formula below is used to calculate the ECD and it is good for mud weight greater than 13.0 ppg.
$$\text{ECD} = \text{MW} + \frac{0.1}{D_{h} - D_{p}} \times \left[...\right] $$
Go CalculationLag Time
Two factors, affecting lag time calculation, are annulus volume of drilling fluid and drilling mud flow rate.
$$\text{Lag time} = \frac{AV}{Q/42} $$
Go Calculation