Method and system for stacking fracture prediction

Patent metadata

Field	Value
Publication number	US-10846447-B2
Application number	US-201715496859-A
Country	US
Kind code	B2
Filing date	Apr 25, 2017
Priority date	Apr 29, 2016
Publication date	Nov 24, 2020
Grant date	Nov 24, 2020

Abstract

Methods and systems for modeling and predicting fractures within the subsurface region are provided. The methods and systems use multi-layer models to represent stacks of layered rocks, which are used to evaluate shear tractions caused by the relatively higher lateral strains in a more compliant overlying or underlying adjacent layers. As the lateral strains can induce tensional stresses in the brittle layers that can exceed the rocks tensile strength and fail, the formation of natural fractures may be modeled. Accordingly, the method and system model fractures due to stacking using mechanical rock property information from well logs and simulating the farfield loading conditions using basin history.

First claim

What is claimed is:

1. A method of predicting natural fractures in a subsurface region, the method comprising:
creating a multi-layer model of the subsurface region;
populating the multi-layer model with mechanical rock properties;
iteratively for two or more time steps:
(a) applying a plurality of loads to the multi-layer model at each time step, wherein applying the plurality of loads at each time step comprises changing loads over the previous time step to reflect interpretation of actual geologic loads based on a burial and deformation history;
(b) determining a stress in each layer of the multi-layer model at each time step for each of the plurality of loads;
(c) determining a tensile failure at each layer in the multi-layer model at each time step for each of the plurality of loads to create one or more natural fractures in the multi-layer model; and
(d) updating the mechanical rock properties in the multi-layer model, wherein the mechanical rock properties are updated to reflect changes in mechanical compaction and chemical induced changes to the rocks at each time step;

determining one or more fracture characteristics associated with the one or more natural fractures for each layer in the multi-layer model based on the tensile failures; and
performing hydrocarbon management for the subsurface region based on the one or more fracture characteristics.

2. The method of claim 1 , further comprising determining one or more numerical results associated with natural fractures for each layer in the multi-layer model based on the tensile failures.

3. The method of claim 2 , further comprising creating a representation of the subsurface region with one or more tensile failures, one or more fracture characteristics, numerical results, and any combination thereof.

4. The method of claim 2 , further comprising creating a representation of the subsurface region based on the one or more fracture characteristics and the numerical results.

5. The method of claim 1 , wherein the one or more fracture characteristics comprise one of fracture stacking potential; normalized fracture stacking potential; multi-scale fracture stacking potential; total fracture stacking potential, and any combination thereof.

6. The method of claim 1 , wherein the method further comprises obtaining measurements from one or more of wireline logs and core data for the subsurface region and using the obtained measurements to create the multi-layer model of the subsurface region, and wherein determining the one or more fracture characteristics comprises calculating a multi-scale fracture stacking potential by solving:

MSP
=

∑

n
=
1

£
⁢

⁢
of
⁢

⁢
samples

⁢

Independent
⁢

⁢
Peak
⁢

⁢
Amplitude

(

Reference
⁢

⁢
F
⁢

⁢
P
*

(

Zone
⁢

⁢
Length

2

-
1

)

)

where n is an integer for the number of samples where the number of samples is the number of measurements; Independent Peak Amplitude is the highest value for a continuous non-zero section of the fracture potential response for a zone of interest; Reference FP is highest value for the multi-scale fracture stacking potential over all of the samples; and Zone Length is length of the zone of interest.

7. The method of claim 1 , wherein the method further comprising obtaining measurements from one or more of wireline logs and core data for the subsurface region; and using the obtained measurements to create the multi-layer model of the subsurface region, and wherein determining the one or more fracture characteristics comprises calculating a total fracture stacking potential by solving:

TSP
=

∑

n
=
1

#
⁢

⁢
Zones

⁢

⁢

(

MSP
n

+

FP
n

C
*

(

L

zone
n

)

)

*

L

zone
n

L
interval

,

where n is number of zones; MSP n is the multi-scale fracture stacking potential for the

Assignees

• Myers Rodrick
• Gomez Torres Leonel A
• Huang Hao
• Becker Gauthier D
• Exxonmobil Upstream Res Co

Inventors

• Myers Rodrick
• Gomez Torres Leonel A
• Huang Hao
• Becker Gauthier D

Classifications

• G06F30/23 Primary

  using finite element methods [FEM] or finite difference methods [FDM] · CPC title

• G06G7/48

  Analogue computers for specific processes, systems or devices, e.g. simulators · CPC title

• G01V2210/646

  Fractures · CPC title

• G01V99/005

  Physics · mapped topic

• G01V20/00 Primary

  Geomodelling in general · CPC title