4.Total Dynamic Head

The total pump head refers to feet (meters) of liquid being pumped and is calculated to be the sum of:

1) Net well lift (dynamic lift); 2) well tubing friction loss; and 3) wellhead discharge pressure

TDH = total dynamic head in feet (meters) delivered by the pump when pumping the desired volume.

Hd = vertical distance in feet (meters) between the wellhead and the estimated producing fluid level at the expected capacity

Ft = the head required to overcome friction loss in tubing measured in feet (meters).

1 Pound of water in a container measuring 1in² would fill the container to a height of 2.31 Ft  For every 1 psi increase in pressure, the water level has to rise 2.31 Ft

1 Pound of water in a container measuring 1in² would fill the container to a height of 2.31 Ft  For every 1 psi increase in pressure,  the water level has to rise 2.31 Ft

Specific Gravity is the relative density of a liquid compared to water. Ambient fresh water (Sea level & 60°F) has a SpGr of 1. Other liquids may be denser (heavier) or less dense than water. Gasoline has a SpGr of 0.75 so an equal volume of gasoline would weigh ¾ (or 75%) the weight of water. We use American Petroleum Institute (API) method for specifying SpGr    i.e. SpGr1 = 10 degrees API

                                                                 Height =  Pressure ÷    0.433       x      SpGr

1.Net vertical Lift

TDH = PD + Tf + TP – PIP

Where: PD = Pump Depth (true vertical pump setting)  ,Tf = Tubing friction losses,  TP = Surface pressure necessary to move the fluid to production facilities ,PIP = Pump Intake Pressure

TDH = PD + Tf + (TP/MG) - (PIP/MG) Surface  PD given by customer, equal to Tubing Length

PIP = PBHP - (Datum - PD) (SGm) (0.433) or

PIP= PBHP -(Datum -PD) (MG) 

Dynamic Level to surface = PD - PIP(ft)

PD less PIP equals distance to surface (PIP converted to feet)

_{Where: PD = Pump Depth Tf = Tubing Friction Losses PIP = Pump Intake Pressure}

_{TP = Surface Pressure necessary to move the fluid to production facilities}

2.Friction Losses

Can be calculated or read from a graph Hazen Williams formula traditionally used for high HC wells Not to be used for viscous wells

Tf = [1.487 x (Q / 34.3)1.85] / ID4.8655

_Where:

_{F = Friction Loss Factor}

_{C = Correction factor (100 for old pipe, 140 for new pipe, 120 for typical value)}

_{Q = Volumetric flow rate}

_{ID = Tubing ID}

3.Tubing Pressure

Typically given by customer

Stage performance for a given RPM and fluid viscosity

As  more stages are added to the pump the head (pressure) developed increases for any given well . More stages will increases the production. As  can be seen here for "small pump" a few stages can make a big difference . As the number of stages increases the gain in the production is less significant.p17 curve.pdf