Method for the hydrodynamic characterization of multi-reservoir wells
The preferred embodiments are directed to the oil-producing industry and can be used in operating multi-reservoir wells. A method for the determination of hydrodynamic parameters for each flowing reservoir that includes reaching at least one well operating mode with fluid flow through both the wellbore and one or more reservoirs, measuring at least one parameter that characterises fluid flow, recording its acoustic noise logging data, calculating noise power using reservoir fluid flow noise logging data, and subsequent multi-phase hydrodynamic modelling to determine hydrodynamic parameters for each identified reservoir.
1. A method for the determination of hydrodynamic parameters for each flowing reservoir in a wellbore through multiple reservoirs, including:
reaching at least one well operating mode with fluid flow through both the wellbore and one or more reservoirs;
measuring at least one parameter that characterises fluid flow and recording acoustic noise generated by fluid flow in the one or more reservoirs;
performing a noise power calculation using the recorded acoustic noise data for the one or more reservoirs and subsequently performing multi-phase hydrodynamic modelling to determine hydrodynamic parameters for each of the one or more reservoirs to determine the reservoir pressure and the piezoconductivity coefficient on the supply loop and the skin factor separately for each identified reservoir, calculated using the equation:
{
P
1
=
P
n
π
-
(
N
1
~
a
·
(
P
n
π
-
P
1
)
)
·
∑
i
=
1
n
p
u
(
t
1
-
t
1
0
,
θ
)
…
P
n
=
P
n
π
-
(
N
1
~
a
·
(
P
n
π
-
P
1
)
-
N
~
n
-
1
a
·
(
P
n
π
-
P
n
-
1
)
)
·
∑
i
=
1
n
p
u
(
t
n
-
t
n
0
,
θ
)
where P nπ is the reservoir pressure;
, , . . . is the formation noise power calculated from the acoustic noise logging data;
θ is the vector of reservoir parameters (including piezoconductivity coefficient and skin factor);
t n is the measurement time at the n-th operation modes of the well;
t n 0 is the time of switching to the n-th well operation mode;
a is the proportionality coefficient constant for a specific tool and a specific formation;
P 1 , P 2 . . . P n is the pressure in the wellbore opposite the identified formation at the 1st, 2nd and nth well operation modes, respectively;
p u (t n −t n 0 , θ) is one of the analytical solutions of the piezoconductivity equation.
2. A method according to claim 1 in which fluid flow is characterised by measuring at least wellbore pressure.