Pressure Gradient

**Pressure gradient, psi/ft, using mud weight, ppg**

psi/ft = mud weight, ppg x 0.052

Example: 12.0ppg fluid

psi/ft = 12.0ppg x 0.052

psi/ft = 0.624

**Pressure gradient, psi/ft, using mud weight, lb/ft**

^{3}psi/ft = mud weight, lb/ft

^{3 }x 0.006944

Example: 100 lb/ft

^{3}fluidpsi/ft = 100lb/ft

psi/ft = 0.6944

OR

^{3 }x 0.006944psi/ft = 0.6944

OR

psi/ft = mud weight, lb/ft

^{3}: 144

Example: 100lb/ft

^{3}fluidpsi/ft = 100lb/ft

^{3 }: 144psi/ft = 0.6944

**Pressure gradient, psi/ft, using mud weight, specific gravity (SG)**

psi/ft = mud weight, SG x 0.433

Example: 1.0SG fluid

psi/ft = 1.0SG x 0.433

psi/ft = 0.433

psi/ft = 0.433

**Metric calculations**

Pressure gradient, bar/m = drilling fluid density kg/l x 0.0981

Pressure gradient, bar/10m = drilling fluid density kg/l x 0.981

**S.I. units calculations**

Pressure gradient, kPa/m = drilling fluid density, kg/m

^{3}: 102

**Convert pressure gradient, psi/ft, to mud weight, ppg**

ppg = pressure gradient, psi/ft : 0.052

Example: 0.4992psi/ft

ppg = 0.4992psi/ft : 0.052

ppg = 9.6

ppg = 9.6

**Convert pressure gradient, psi/ft, to mud weight, lb/ft**

^{3}lb/ft

^{3}= pressure gradient, psi/ft : 0.006944

Example: 0.6944psi/ft

lb/ft

lb/ft

^{3}= 0.6944psi/ft : 0.006944lb/ft

^{3}= 100**Convert pressure gradient, psi/ft, to mud weight, SG**

SG = pressure gradient, psi/ft : 0.433

Example: 0.433psi/ft

SG = 0.433psi/ft : 0.433

SG = 1.0

**Metric calculations**

Drilling fluid density, kg/l = pressure gradient, bar/m : 0.0981

Drilling fluid density, kg/l = pressure gradient, bar/10m : 0.981

**S.I units calculations**

Drilling fluid density. kg/m

^{3}= pressure gradient, kPa/m x 102