Method for optimizing the working of a deposit of fluid by taking into account a geological and transitory exchange term between matrix blocks and fractures

Patent metadata

Field	Value
Publication number	US-10712469-B2
Application number	US-201414298997-A
Country	US
Kind code	B2
Filing date	Jun 9, 2014
Priority date	Jun 13, 2013
Publication date	Jul 14, 2020
Grant date	Jul 14, 2020

Abstract

The invention is a method for optimizing working (EXP) of a deposit of fluid traversed by a network of fractures that involves determining the transitory exchange terms between matrix blocks and fractures (FFA, FFN), for any type of available information (INFO) concerning the network of fractures, regardless of the level of knowledge of the fractured environment.

First claim

The invention claimed is:

1. A method for optimizing working of a deposit of fluid represented in a model of a reservoir which is traversed by a network of fractures, in which the deposit is discretized into a set of meshes by using known information characterizing the network of fractures allowing defining of porous blocks and fractures within the set of meshes, comprising:
a) determining a stream of transitory exchanges between the porous blocks and the fractures in each mesh by using software executed on a computer to perform the steps of:
i) determining a geological and transitory shape function I v determined by using information characterizing the network of fractures, wherein the information being used for determination of the transitory shape function I v is by rules which include:

the information type for each mesh involves dimensions (a, b and c) of at least one equivalent block and the shape function I v is determined by performing the steps of:
formulating an invasion function V(x) as a function of the block dimensions of at least one equivalent block,
calculating S(x) which is a total surface of an exchange front calculated by the formula:
S ( x )=∂ V ( x )/∂ x

calculating analytically the shape function I v by a relationship

I
V

⁡

(
X
)

=

1

Δ
⁢

⁢
A
⁢

⁢
Δ
⁢

⁢
B
⁢

⁢
Δ
⁢

⁢
C

⁢

1

∫
0
X

⁢

⁢

d
⁢

⁢
x

S
⁡

(
x
)

in order to obtain a relationship I V (X)=f(a,b,c,X), where X is a distance of advance of the exchange front within the porous blocks; and
ii) calculating the stream of transitory exchanges f p by using the shape function I v and the stream of transitory exchanges f p being calculated by a relationship: f p =CP mp ΔΦ p , with C being a geometric coefficient defined by C=ΔA·ΔB·ΔC·I V (X), ΔA, ΔB, ΔC are dimensions of the meshes, ΔΦ p is a potential difference and P mp is a property relating to fluids and to an environment of a matrix;
b) simulating flows of fluids and the stream of transitory exchanges between the porous blocks and fractures based on the geological and transitory shape function I v determined at step a) as two continuous exchanges of fluids in the deposit with a flow simulator implemented by software executed on a computer; and
c) working the deposit by using the flow simulation carried out at step b) of the flows of fluids by the flow simulator to produce fluids from the deposit including choosing configurations for working the reservoir including choosing at least one of location of at least one of production and injection wells, type of tools that are used, fluids that are used and determining production forecasts, production patterns, and maximum production profit; and
the known information for each mesh corresponds to dimensions (a, b and c in three directions) of a single equivalent block and the shape function I v is determined by:
the at least one equivalent block is of anisotropic permeability k x , k y and k z along axes of the at least one equivalent block, dimensions of an equivalent isotropic block a′, b′ and, c′ of permeability k′ that is equivalent to the anisotropic block in terms of streams of exchanges by a unit of volume of the matrix are determined from the permeabilities k x , k y and k z and the dimensions a, b and c, and the shape function is determined from the dimensions a′, b′ and c′, and I V (X)=f(a,b,c,X) or I V (X)=f(a′,b′,c′,X), with a, b and c being the dimensions of the equivalent block, and X corresponds to a distance of advance for the exchange front within the porous block and for fixed mesh dimensions ΔA, ΔB and ΔC, the formula of I v (X) is a function of a, b, and c or a′, b′ and c′ with a derivative for the invaded volume S(x)=V′(x) being expressed as a polynomial function of x.

2. A method for optimizing working of a deposit of fluid represented in a model of in a reservoir which is traversed by a network of fractures, in which the deposit is discretized into a set of meshes of using known information characterizing the network of fractures allowing defining of porous blocks and fractures within the set of meshes, comprising:
a) determining a stream of transitory exchanges between the porous blocks and the fractures in each mesh by using software executed on a computer to perform the steps of:
i) determining a geological and transitory shape function I v determined by using information characterizing the network of fractures, wherein the shape function I v accounts for information type and the information being used for determination of the transitory shape function I v including:

information for each mesh of the reservoir model involves dimensions (a i , b i and c i ) of equivalent blocks relating to meshes i of dimensions (ΔA i , ΔB i and ΔC i ) in a more finely meshed model, an invasion function V(x) is determined analytically by a formula:

V
⁡

(
x
)

=

∑
i

⁢

(

Δ
⁢

⁢

A
i

)

⁢

(

Assignees

• Ifp Energies Now

Inventors

• Bourbiaux Bernard
• Bauer Daniela

Classifications

• E21B43/00 Primary

  Methods or apparatus for obtaining oil, gas, water, soluble or meltable materials or a slurry of minerals from wells (applicable only to water E03B) · CPC title

• G01V9/007 Primary

  by detecting gases or particles representative of underground layers at or near the surface (analysing earth materials G01N33/24; analysing gases per se G01N) · CPC title

• G01V99/005

  Physics · mapped topic

• G01V20/00

  Geomodelling in general · CPC title