Formelark / Formula sheet
Omregningsfaktorer/ Conversion factors
1 cp
= 10-3 Pas
1 bar
-12
2
1 Darcy = 0.9869  10 m
1 dyn/cm
= 105Pa
= 10-3 N/m
Konstanter/Constants
Standard temperatur :288 Kelvin
Standard trykk/pressure: 1.01 bar
Generell gasskonstant/ General gas constant: 8314 Molvekt luft/air: 28.97 kg/kmol
Tyngdens akselerasjon/ Acceleration of gravity :9.81 … m/s2
4
Formulae
Fluidegenskaper/Fluid properties (SI, trykk i bar/SI, pressure in bar):
Tetthet olje/Oil density:
 l    o o   g o Rs  / Bo
  g
Formasjonsfaktor/FVF: Bo  0.9759  9.52  10 4  
  o

0.5


 Rs  0.410 T  103 



1.2
Over metningstrykket/ Above saturation pressure:
104  2.81 Rt 3.10 T 171  o 118  g 1102 
Bo  Bob  pb p 
Løysbarhet/Solubility : Rs  5.90  10 3  g 10
2.14 /  o
10 0.00198 T 0.797 p  1.4 
1.205
1
Gasstetthet/ Gas density:  g  pM zRT  
o
g
 p k
Bg ,  g   i  
 pi 
Enfase strømning/ Single phase flow
Hydraulisk potensial/Hydraulic potential: P  p   dh
Strømning i røyr/Pipe flow:
dP   v d v 
  vd 
f  0.16 

  
Friksjonsfaktor/Friction factor correlation:
Gass/ Gas in pipes:
pth2  pw2 e
Dysestrøm/Orifice flow:
Pumpeeffekt/Pump power:
2
2
g x L
zRT
Røyrstrøm/Pipe flow:

8 f  zRT 


2
 gxd 5   
pc  0.5 Q / Ac 
2
0.172
 g x L
2

 2
zRT
1

e

m


2
E  Qp p 
  g x L 
8 f  zRT 
Gass/Gas: pth2   e zRT  pw2  2


 gxd 5   


Tofasestrøm/ Two phase flow
1  2
f v dx  0
2 d
2
   g x L 2 
 1   e zRT   m 2
 
 

dp  TP g x dx  0.5 f  m / d  v 2 dx  0
Fart-fraksjon/Velocities and fraction:
vg  vsg yg  vsg 1  yl 
Driftfluksrelasjon/Drift flux relationship: v g  Co vl  vo
TP   g y g  l yl
Tofasetetthet/two-phase density:
Strømningstetthet/ Flow-averaged density:  m   g g   l l
 TP cTP 
vk   dvsl dyl  v
Kritisk fart/Critical velocity:
1
v* 
Kinematisk/ Kinematic wave :
m
Innstrømningeskarakteristikk/ inflow performance
dP 
 v   v 2
Strømning i porøse media/ Flow in porous mediea: 
dr k
(P= hydraulisk potensial / P = hydraulic potential)
6 kh
PI horisontal brønn/PI horizontal well J H 
 D

h 
h
o Bo 
f a  3  ln
 S 
Lw  2 rw

 2 Lw
2
 1   Lw L 
Lw Lw 
L
L
Geometri/ Geometry factor: f a 
  0.53    1.15  0.164 

 0.45   Lw L 
L
L
D
D

ˆ
yˆ  y kh kv , k  kh kv
Skalering for anisotropi/ Anisotropy scaling :
Skintrykktap/ Skin pressure drop:
S H  p S
2 k
Lw
qo  o Bo
Innstrømningskarakteristikk m. friksjon/ IPR with flow friction along liner:
1
16 f  3
2
Pwt  PR 
qL  xo   jL
Qt
jL
3  2d 5
Med innstrømningskontroll/With ICD:
Pwt  PR 
1
Qt  pw
jL Lw
Trykktap i kompletteringsrøyr/ pressure drop in liner: pw 
Spes. prodindeks/ Spec. PI:
8

f 2 5 qL 2 Lw3
3  d
jL  JBo Lw
2
1  L  2
Trykkfall over ICD/Pressure drop accross ICD: pc    c  q L
2  nc Ac 
Gassløft/Gas lift
g x 2d 5 8 f m 
Optimal gassrate/Opt. Gas rate: Qˆ g 
Oljerate/ Oil rate:
Qo  Qg
pR  ps   g g x L  8 f m
8 fm
Pumping
Effekt /Power:
E  Q p p 
o
 d
2
5
LQg2 
g
LQg2
 2d 5
1
Qg   o g x L
JBo