Hydrocarbon production method comprising a productivity index of the wells subject to thermal effect
The present invention relates to a production method for hydrocarbons contained in an underground formation penetrated by at least one well. The method is based on the determination of at least one productivity index IP dependent on the temperature and pressure.
1. A method for hydrocarbon production from an underground formation penetrated by at least one well, comprising:
constructing a numerical model including permeabilities of the underground formation with a computer with the model comprising meshes which account for at least petrophysical data applied to the meshes, and characteristics of at least one well which penetrates through the underground formation;
determining a function of pressure and temperature dependency of permeabilities accounted for in the model;
determining a model of productivity index as a function of the permeabilities of the meshes;
determining for at least one mesh of the model, a pressure and temperature dependent productivity index, by accounting for the functions of pressure and temperature dependency of the permeabilities, and the model of productivity index;
exploiting the underground formation as a function of the productivity index; and
determining of the productivity index is performed according to a relationship:
IP
(
K
eff
)
=
2
π
K
eff
x
K
eff
y
h
ln
(
r
0
r
w
)
+
s
wherein thickness is perpendicular to flow h, well radius r w , drainage radius r 0 and skin factor s.
2. The hydrocarbon production method as claimed in claim 1 , wherein the functions of pressure and temperature dependency of the permeabilities which are accounted for in the numerical model comprise permeability multipliers.
3. The hydrocarbon production method as claimed in claim 2 , wherein the multipliers are determined by using modifications of porosity as a function of temperature and pressure.
4. The hydrocarbon production method as claimed in claim 1 , comprising exploiting the underground formation by performing thermal drainage.
5. The hydrocarbon production method as claimed in claim 2 , comprising exploiting the underground formation by performing thermal drainage.
6. The hydrocarbon production method as claimed in claim 3 , comprising exploiting the underground formation by performing thermal drainage.
7. The hydrocarbon production method as claimed in claim 1 , comprising determining the productivity index for the meshes of the numerical model which are affected by the well.
8. The hydrocarbon production method as claimed in claim 2 , comprising determining the productivity index for the meshes of the numerical model which are affected by the well.
9. The hydrocarbon production method as claimed in claim 3 , comprising determining the productivity index for the meshes of the numerical model which are affected by the well.
10. The hydrocarbon production method as claimed in claim 4 , comprising determining the productivity index for the meshes of the numerical model which are affected by the well.
11. The hydrocarbon production method as claimed in claim 5 , comprising determining the productivity index for the meshes of the numerical model which are affected by the well.
12. A computer program product that non transiently stores on a computer-readable medium comprising program code instructions for implementing a method preformed on a computer used as part of exploitation of the underground formation comprising the steps of:
constructing a numerical model including permeabilities of the underground formation with a computer with the model comprising meshes which account for at least petrophysical data applied to the meshes, and characteristics of at least one well which penetrates through the underground formation;
determining a function of pressure and temperature dependency of permeabilities accounted for in the model;
determining a model of productivity index as a function of the permeabilities of the meshes;
determining for at least one mesh of the model, a pressure and temperature dependent productivity index, by accounting for the functions of pressure and temperature dependency of the permeabilities, and the model of productivity index; wherein
determining the productivity index is performed according to a relationship:
IP
(
K
eff
)
=
2
π
K
eff
x
K
eff
y
h
ln
(
r
0
r
w
)
+
s
wherein thickness is perpendicular to flow h, well radius r w , drainage radius r 0 and skin factor s; and exploiting the underground formation as a function of the productivity index.