1646060694268.pdf INTRODUCCION A WELL TESTING

PETROLEOS

1. Introduction to Well Testing
Wathik M. Alhashimi. P.Eng.

2. Introduction to Well Testing
Instructional Objectives
1.List 4 objectives of well testing.
2.Define testing variables.
3.Compute compressibility of reservoir
systems.

3. Introduction To Well Testing
Outline
•Applications and objectives of well
testing
•Development of the diffusivity equation
•Definitions and sources for data used
in well testing

4. What Is A Well Test?
•A tool for reservoir evaluation and
characterization
–Investigates a much larger volume of
the reservoir than cores or logs
–Provides estimate of permeability
under in-situ conditions
–Provides estimates of near-wellbore
condition
–Provides estimates of distances to
boundaries

5. How Is A Well Test Conducted?
qq = 0
t
q
t
p

6. Well Test Applications
•Exploration
•Reservoir engineering
•Production engineering

7. Well Test Objectives
•Define reservoir limits
•Estimate average drainage area
pressure
•Characterize reservoir
•Diagnose productivity problems
•Evaluate stimulation treatment
effectiveness

8. Types of Well Tests
q
Single-Well Multi-Well

9. Development of the
Diffusivity Equation

10. The Diffusivity Equation
•Describes the flow of
–A slightly compressible fluid
–Having constant viscosity
–In a porous medium
–At constant temperature

11. The Continuity Equation()()
21
vAvAm −=
(Av)
1 (Av)
2

12. Equation of State for a Slightly
Compressible Liquid( )
o
ppc
oe
−
=

13. Flow Equation -Darcy’s Law
or, in differential form,L
pkA
q


= x
pk
u
x
x



−=

14. The Diffusivity Equationt
p
k
c
r
p
r
rr
1
t


=










15. Data Used in Well Testing

16. Formation Volume Factorsurf
res
o
V
V
B=

17. Viscosity
dy
v
v + dvdy
dv
A
F


18. Fluid Compressibility()
p
Vln
p
V
V
1
c
oo
o
o


−=


−

19. Porosity

20. PermeabilitypA
Lq
k


=

21. Pore Compressibility()
p
ln
p
1
c
f


=





22. Net Pay Thickness
h = h
1+ h
2+ h
3
Shale
Sand
h
3
h
2
h
1

23. Net Pay Thickness
Case 1 Case 3
Case 4Case 2

24. Saturations
H
2O

25. Wellbore Radius
r
w

26. Total Compressibilityggwwooft
cScScScc +++=