Application:
Type
curve can be used for:
•
Thermal
projects: SAGD, CSS
•
Water
floods
•
Multi
stage frac unconventional plays
•
Individual Wells
•
For
predicting future estimation of production.
•
Estimating
the recovery.
•
Finding
reservoir parameters
such as skin, permeability, , fracture , porosity parameters
•
for buildup test design and
interpretation
Figure 1
A
Gringarten type curve is the most practically usable type curve in oil
industry. In Gringarten type
curve, pD is plotted vs. the time function tD/CD,
with a parameter CDe2s as shown
in below figure:
Figure 2
Procedure:
The main procedure that used in type curve
analysis of declining rate- time data are as follows
1-
Plot
measured pressure drop ?p versus ?t data in any convenient units on log-log
tracing paper of the same cycle size as the type curve to be used.
2-
Put
the tracing paper data curve over the type curve that has been plotted. The
paper has to be kept parallel and shifting in a position to make the best fit
of the data of type curve and till the match point will be achieved.
3-
To
gain the reservoir variable a match point selected anywhere on the overlapping
portion of the curve where the measured points match; they correspond to value
of CDe2s
4-
Select
the value of CDe2s that
best matches the field data.
5-
Pick
a match point, M, whose coordinates can be read in both the type curve system
of axes (p D, t D/C D) as well as in the field data system (?p, ?t), The point
M can be chosen anywhere on the plot, not necessarily on the curve.
6-
Calculate permeability from the
pressure match-point ratio, then calculate S skin factor and CD by the
following Equation:
The procedure is clearly shown by
the following graph:
Figure 3
Figure 4
Figure 5
Figure 6
Figure 7
References:
Petrowiki.org.
(2018). Type curves -. online Available at: http://petrowiki.org/Type_curves
Accessed 25 Jan. 2018.
Fetkovich,
M. (1980). Decline Curve Analysis Using Type Curves. Journal of Petroleum
Technology, 32(06), pp.1065-1077.
Bourdet,
D., Ayoub, J. A., & Pirard, Y. M. (1989, June 1). Use of Pressure
Derivative in Well Test Interpretation. Society of Petroleum Engineers.
doi:10.2118/12777-PA
Landman.ca.
(2018). online Available at:
http://landman.ca/wp/wp-content/uploads/2014/07/Sept-18-2015-Sproule.pdf
Accessed 26 Jan. 2018.
