Page 184 - Formulas and Calculations for Petroleum Engineering

Well test analysis formulas and calculations Chapter 3 177

Formula(s)

q
J ¼
P P
wf

r
ln e 0:75
r w
k ¼ 141:2 J B m
j
h
!
k r e
s ¼ 1 ln 0:75
k r
j w
Reference: Lee, J., Rollins, J. B., & Spivey, J. P. (2003). Pressure Transient Testing (Vol. 9). Richardson, Texas: Society of
Petroleum Engineers, Page: 16.

3.5 Analysis of DST flow data with Ramey type curves

Input(s)
p i : Initial Pressure (psi)
p wf : Well Flowing Pressure (psi)
p o : Pressure at Time T ¼ 0 (psi)
Ø: Porosity (dimensionless)
c t : Total Compressibility (1/psi)
h: Formation Thickness (ft)
C: Wellbore Storage Coefficient (bbl/psi)
r w : Radius of Wellbore (ft)
m: Viscosity (cP)
t c : Dimensionless Parameter from Curve Fitting as T d (dimensionless)
c d
t: Time (h)
CES: Match Point for Dimensionless Well Bore Coefficient from Curve as (Cd E^(2 s))_(mp) (dimensionless)

Output(s)

p DR : Dimensionless Pressure (dimensionless)
q DR : Dimensionless Flow Rate (dimensionless)
C D : Dimensionless Well Bore Storage Coefficient (dimensionless)
k: Permeability (mD)
s: Skin Factor (dimensionless)

Formula(s)

ð
p p Þ tðÞ
i
wf
p ¼
DR
p p o
i
q ¼ 1 p
DR DR
C
C ¼ 0:8936
D
Ø h c r
2
t w
C
t

c
k ¼ 3390 m
h t
CES

s ¼ 0:5 ln
C D
Reference: Lee, J., Rollins, J. B., & Spivey, J. P. (2003). Pressure Transient Testing (Vol. 9). Richardson, Texas: Society of
Petroleum Engineers, Page: 155.