B.1 Introduction

This Appendix summarizes the plunger lift equations developed in Reference 1 for a plunger lifted well as illustrated in Figure B-1.

Figure B-1: Schematic of plunger lift before release and just as plunger and liquid reach the surface

B.1 Minimum Casing Pressure

The minimum casing pressure at the moment that the plunger and liquid slug arrive at the surface is given by:

where P _P = pressure required to lift the plunger, psi

P _C = pressure required to lift one barrel of liquid and overcome friction, psi

S _V = liquid slug volume above plunger, bbl

K = factor to account for gas friction below the plunger

D = plunger depth, ft

Approximate values for K and P _C are given in Table B-1. In Equation B-1, K is calculated from:

where T _avg = the average temperature, F

Z = the average gas deviation factor

? _G = the produced gas gravity

f _gas = friction factor for gas flow in tubing

V = average gas velocity, ft/sec

OD _TBG = tubing OD, inches

The factor P _Cis calculated from:

where ? _L = produced liquid gravity

f _L = friction factor for liquid flow in tubing

L _S =...