Page 3 - Petroleum Production Engineering, A Computer-Assisted Approach

Guo, Boyun / Petroleum Production Engineering, A Computer-Assisted Approach Guo-prelims Final Proof page xi 29.12.2006 10:39am

List of Symbols

A area, ft 2 f Ri flow performance function of the curvic
A b total effective bellows area, in: 2 section of lateral i
A eng net cross-sectional area of engine piston, in: 2 f sl slug factor, 0.5 to 0.6
2
A fb total firebox surface area, ft G shear modulus, psia
0 2 g gravitational acceleration, 32:17 ft=s 2
A i inner area of tubing sleeve, in:
0 2 G b pressure gradient below the pump, psi/ft
A o outer area of tubing sleeve, in: unit conversion factor, 32:17 lb m ft=lb f s 2
A p valve seat area, gross plunger cross-sectional g c design unloading gradient, psi/ft
area, or inner area of packer, in: 2 G fd initial gas-in-place, scf
A pump net cross-sectional area of pump piston, in: 2 G i cumulative gas production, scf
2
A r cross-sectional area of rods, in: 2 G p 1
A t tubing inner cross-sectional area, in: G p cumulative gas production per stb of oil at the
o API API gravity of stock tank oil beginning of the interval, scf
B formation volume factor of fluid, rb/stb G s static (dead liquid) gradient, psi/ft
2
b constant 1:5 10 5 in SI units G 2 mass flux at downstream, lbm=ft =sec
formation volume factor of oil, rb/stb GLR fm formation oil GLR, scf/stb
B o
formation volume factor of water, rb/bbl GLR inj injection GLR, scf/stb
B w
drainage area shape factor GLR min minimum required GLR for plunger lift, scf/
C A
C a weight fraction of acid in the acid solution bbl
C c choke flow coefficient GLR opt,o optimum GLR at operating flow rate, scf/stb
C D choke discharge coefficient GOR producing gas-oil ratio, scf/stb
C g correction factor for gas-specific gravity GWR glycol to water ratio, gal TEG=lb m H 2 O
C i productivity coefficient of lateral i H depth to the average fluid level in the annulus,
C l clearance, fraction ft, or dimensionless head
C m mineral content, volume fraction h reservoir thickness, ft, or pumping head, ft
C s structure unbalance, lbs h f fracture height, ft
C t correction factor for operating temperature HP required input power, hp
c t total compressibility, psi 1 Hp MM required theoretical compression power, hp/
C p specific heat of gas at constant pressure, lbf- MMcfd
ft/lbm-R H t total heat load on reboiler, Btu/h
Dh depth increment, ft
C C p specific heat under constant pressure
evaluated at cooler DHp m mechanical power losses, hp
C wi water content of inlet gas, lb m H 2 O=MMscf r hi pressure gradient in the vertical section of
D outer diameter, in., or depth, ft, or non-Darcy lateral i, psi/ft
flow coefficient, d/Mscf, or molecular J productivity of fractured well, stb/d-psi
2
diffusion coefficient, m =s J i productivity index of lateral i.
d diameter, in. J o productivity of non-fractured well, stb/d-psi
d 1 upstream pipe diameter, in. K empirical factor, or characteristic length for
d 2 choke diameter, in. gas flow in tubing, ft
d b barrel inside diameter, in. k permeability of undamaged formation, md, or
D ci inner diameter of casing, in. specific heat ratio
d f fractal dimension constant 1.6 k f fracture permeability, md
hydraulic diameter, in. the average horizontal permeability, md
D h k H
hydraulic diameter, ft k h the average horizontal permeability, md
D H
inner diameter of tubing, in. k i liquid/vapor equilibrium ratio of compound i
D i
outer diameter, in. k p a constant
D o
plunger outside diameter, in. k ro the relative permeability to oil
d p
minimum pump depth, ft k V vertical permeability, md
D pump
D r length of rod string, ft L length, ft , or tubing inner capacity, ft/bbl
E rotor/stator eccentricity, in., or Young’s L g length of gas distribution line, mile
modulus, psi L N net lift, ft
E v volumetric efficiency, fraction L p length of plunger, in.
e v correction factor M total mass associated with 1 stb of oil
e p efficiency M 2 mass flow rate at down stream, lbm/sec
MW a molecular weight of acid
F b axial load, lb f
F CD fracture conductivity, dimensionless MW m molecular weight of mineral
F F fanning friction factor N pump speed, spm, or rotary speed, rpm
F gs modified Foss and Gaul slippage factor n number of layers, or polytropic exponent for
f hi flow performance function of the vertical gas
section of lateral i N Ac acid capillary number, dimensionless
f Li inflow performance function of the horizontal N Cmax maximum number of cycles per day
section of lateral i n G number of lb-mole of gas
f M Darcy-Wiesbach (Moody) friction factor N i initial oil in place in the well drainage area, stb
F pump pump friction-induced pressure loss, psia n i productivity exponent of lateral i