1. Hydrostatic Pressure(HP) 静液柱压力
Hydrostatic pressure using ppg and feet as the units of measure
HP（psi）=mud weight,ppg0.052true vertical depth(TVD),ft
举例：
Example: mud weight =13.5ppg（泥浆密度）
True vertical depth =12,000ft（垂深）
HP=13.5ppg0.05212,000ft =8424psi （静液柱压力）
2．Annular Velocity(AV) 环空返速
AV,ft/min=
Where Q =circulation rate , gpm 排量
Dh=inside diameter of casing or hole size ,in. 套管内径或井眼尺寸
Dp=outside diameter of pipe,tubing or collars,in. 钻具或油管的外径
举例：
Example: pump output=530gpm
Hole size=12-1/4 in.
Pipe OD=4-1/2 in
AV==100ft/min
3．Pump output,gpm,required for a desired annular velocity,ft/min
给定所需环空返速后如何确定泥浆排量
Pump output,gpm=
Where AV =desired annular velocity,ft/min 所需要的环空返速
Dh =inside diameter of casing or hole size ,in 套管内径或井眼尺寸
Dp=outside diameter of pipe ,tubing or collars,in. 钻具或油管的外径
举例：
Example:desired annular velocity=120ft/min
Hole size =12-1/4 in
Pipe OD =4-1/2 in
PO=
4．Buoyancy Factor(BF) 浮力系数
Buoyancy factor using mud weight,ppg
BF=
举例：
Example:Determine the buoyancy factor for a 15.0ppg fluid :
确定泥浆密度为15.0ppg的浮力系数
BF = BF=0.77099
5．Pump Pressure/Pump Stroke Relationship 泵压和泵冲的简单换算关系
(Also Called the Roughneck’s Formula) Basic formula
New circulating Pressure,psi= present circulating Pressure
举例：
Example : Determine the new circulating pressure,psi using the following data:
确定新的循环泵压
Present circulating pressure =1800psi 现在的循环泵压
Old pump rate =60spm 现在的排量
New pump rate =30spm 新的排量
New circulating Pressure,psi = present circulating
=450psi 新的循环泵压
