US2015053398A1PendingUtilityA1
Method for determining an inflow profile of multilayer reservoir fluids in a wellbore
Assignee: SCHLUMBERGER TECHNOLOGY CORPPriority: Aug 23, 2013Filed: Aug 22, 2014Published: Feb 26, 2015
Est. expiryAug 23, 2033(~7.1 yrs left)· nominal 20-yr term from priority
Inventors:Valery Vasilievich ShakoVyacheslav Pavlovich PimenovBertrand TheuvenyMaria Viktorovna Sidorova
E21B 47/103E21B 36/001E21B 47/0003
38
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Claims
Abstract
Methods for determining an inflow profile of multilayer reservoir fluids in a wellbore are described herein. A bottom-hole zone is cooled before well perforation. Then, the wellbore is perforated, and a flow temperature is measured in the wellbore above each perforation zone. A production rate of each productive layer is determined taking into account thicknesses of the perforation zones and using results of temperature measurements acquired in a period between an end of an initial production stage characterized by strong impact of a volume of the wellbore and quick flow temperature changes in the wellbore, and a time when the bottom-hole zone cooling effect on the temperature measurements becomes insignificant.
Claims
exact text as granted — not AI-modified1 . A method for determining an inflow profile of multilayer reservoir fluids in a wellbore comprising:
cooling of a bottom-hole zone, perforating the wellbore, measuring flow temperature in the wellbore above each perforation zone, and determining a production rate of each productive layer taking into account thicknesses of the perforation zones and using results of temperature measurements acquired between (i) an end of an initial production stage and (ii) a time starting from which the bottom-hole zone cooling effect on the temperature measurements becomes insignificant.
2 . The method of claim 1 , wherein the bottom-hole zone is cooled by drilling.
3 . The method of claim 1 , wherein the bottom-hole zone is cooled by well circulation.
4 . The method of claim 1 , wherein the flow temperature in the wellbore is measured by sensors installed on a tubing string used for perforation above the each perforation zone.
5 . The method of claim 1 , wherein for determining the production rates of the productive layers, temperature measurement results are used, which are acquired within an interval of 1 to 10 hours after the start of production.
6 . The method of claim 1 , wherein starting from a second perforation zone relative production rates of perforation zones Y n , n=2, 3, . . . m are calculated successively upward by means of minimization according to:
S
(
Y
n
)
=
∑
i
F
(
Y
n
,
t
i
)
2
⇒
min
where
Y
n
=
Q
n
Q
1
+
Q
2
+
…
+
Q
n
,
(n=2, 3, . . . m) is the production rate of each perforation zone,
F
(
Y
n
,
t
)
=
Y
n
-
T
n
-
1
,
a
(
t
)
-
T
n
,
a
(
t
)
T
n
-
1
,
a
(
t
)
-
T
1
a
[
a
n
·
t
]
a
n
=
q
n
q
1
=
h
1
h
n
·
Y
n
(
1
-
Y
2
)
·
(
1
-
Y
3
)
·
…
·
(
1
-
Y
n
)
,
h n (n=1, 2, . . . m) is a thickness of a n perforation zone, T n,a (t) is a flow temperature measured in the wellbore above the n perforation zone, t i is time moments equally distributed within the interval t 1 <t<t 2 , where t 1 is the end time of the initial production stage, t 2 is the time starting from which the bottom-hole zone cooling effect on the temperature measurements becomes insignificant, a number of the time moments in the interval t 1 <t<t 2 is equal to a number of temperature measurements, and the production rates Q n (n=2, 3, . . . m) of the perforation zones are determined formulas according to:
Q
1
=
Q
1
+
Y
2
1
-
Y
2
+
Y
3
(
1
-
Y
2
)
·
(
1
-
Y
3
)
+
…
+
Y
m
(
1
-
Y
2
)
·
(
1
-
Y
3
)
·
…
·
(
1
-
Y
m
)
Q
2
=
Q
1
·
Y
2
1
-
Y
2
Q
3
=
Q
1
·
Y
3
(
1
-
Y
2
)
·
(
1
-
Y
3
)
Q
n
=
Q
1
·
Y
n
(
1
-
Y
2
)
·
(
1
-
Y
3
)
·
…
·
(
1
-
Y
n
)
where Q is a total volumetric wellbore production rate.
7 . The method of claim 1 , wherein wellbore flow temperature is additionally measured under each perforation zone, and F(Y n , t) is determined according to:
F
(
Y
n
,
t
)
=
Y
n
-
T
n
,
b
(
t
)
-
T
n
,
a
(
t
)
T
n
,
b
(
t
)
-
T
1
,
a
[
a
n
·
t
]
where T n,b (t) and T n,a (t) are temperatures measured in the wellbore below and above the n perforation zone.
8 . The method of claim 1 , wherein pressure is additionally measured in the wellbore below all perforation zones and an inverse task is solved using a numerical simulation with such numerical model parameters selected which ensure matching of measured and calculated temperature-time dependencies, and the measured wellbore pressure is applied as a boundary condition for simulation of pressure and temperature fields in the production layers.Cited by (0)
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