Parameter_data

 

Data Structure: Parameter_data

Description

Input/output files

Usage

Parameter_data     NUM=ival   where ival  is the data structure number

 

Description

Overview

The Parameter_data data structure defines the parameters (variables) and parameter ranges to be considered in the the inversion analysis.

 

The inversion parameters may be identified in the data files by either:

•Direct specification of the associated ParaGeo material or fluid data structure - The data structure type and number must be specified for each parameter using Variable_structure_name and Variable_structure_number.

•Replacing the parameter value with Parameter_name in the template data file, where ParameterName is an arbitrary name assigned to the parameter for inversion.

 

 

Click to expand/collapseName    Parameter names

Usage

Name

IDM=ival

 

 

Character Names

 

 

 

 

where

ival

Number of parameters to be evaluated in the inversion

Description

List of parameter names to be considered in the inversion analysis. If the parameters are identified in the template data file via Parameter_name then ParameterName can be arbitrarily defined here. For inversion using ParaGeo material parameters the lists of valid names are:

 

Elasticity

Name

Description

Young

Young's Modulus

Poiss

Poisson's ratio

 

Porosity

Name

Description

Porosity

Porosity

Porosity_gradient

Linear gradient of porosity with pore pressure

 

Permeability

Name

Description

Permeability

Isotropic permeability

Permeability_x

Orthotropic permeability in X-direction

Permeability_y

Orthotropic permeability in Y-direction

Permeability_z

Orthotropic permeability in Z-direction

Permeability_gradient

Isotropic permeability gradient with pore pressure

 

Tortuosity

Name

Description

Tortuosity

Tortuosity

Tortuosity_gradient

Linear gradient of tortuosity with pore pressure

 

For inversion of fluid properties valid parameters are:

 

Viscosity

Name

Description

Viscosity

Viscosity

Viscosity_gradient

Linear gradient of viscosity with pore pressure

 

Knudsen Diffusion

Name

Description

Klinkenberg_b

Klinkenberg b coefficient

Beskok_alpha

Constant alpha in Beskok and Karniadakis model

Beskok_a_con

Constant A in Beskok and Karniadakis model

Beskok_b_con

Constant B in Beskok and Karniadakis model

Beskok_b

Constant b in Beskok and Karniadakis model (different from Klinkenberg b)

 

For inversion of fracture properties valid parameters are:

 

Fracture Normal stiffness

Name

Description

Fracture_spacing

Fracture spacing

Norm_stiffness

Normal stiffness

Init_norm_stiff

Initial normal stiffness

Init_aperture

Initial aperture

Max_norm_stiff

Maximum normal stiffness

Fracture Shear Stiffness

Name

Description

Shear_stiffness

Shear stiffness

Shear_stiff_fact

Factor of normal stiffness defining shear stiffness

Max_shear_stiff

Maximum shear stiffness

Max_shear_stress

Maximum shear stress

Fracture Hydraulic fracture

Name

Description

Minimum_stress

Minimum stresss corresponding to hydrofracture initiation

Percent_pore

Percentage of pore pressure corresponding to hydrofracture initiation

Fracture Shear Strength

Name

Description

Cohesion

Cohesion

Frict_angle

Friction angle

Res_cohesion

Residual Cohesion

Res_shear_disp

Shear displacement at residual values

Fracture Reference Values

Name

Description

Ref_norm_stress

Reference Normal Stress

Ref_shear_xz

Reference Shear Stress-XZ

Ref_shear_yz

Reference Shear Stress-YZ

 

Click to expand/collapseType    List of flags (free/prescribed) for inversion parameters

Usage

Type

IDM=ival

 

 

Integer Values

 

 

 

 

where

ival

Number of parameters to be evaluated in the inversion

Description

Type defines a list of flags (free/prescribed) for all the inversion parameters specified in the Name keyword. Valid options are:

•0 - Free (to be evaluated in the inversion with valid range defined using the Minimum_value and Maximum_value keywords)

•1 - Prescribed (fixed value using the Value keyword)

 

Notes

•By default all inversion parameters are considered to be 'free' ( Type = 0). If all parameters are 'free', Type does not need to be defined.

 

 

Click to expand/collapseValue    List of prescribed parameter values

Usage

Value

IDM=ival

 

 

Real Values

 

 

 

 

where

ival

Number of parameters to be evaluated in the inversion

Description

Value is used to define the values for the prescribed parameters (i.e. those assigned Type = 1). If the Value keyword is defined, a value must be input for each of the parameters listed in Name, however, with the values for the 'free' parameters being ignored.

 

Notes

•If all parameters are 'free' then Value does not need to be defined.

 

 

Click to expand/collapseMinimum_value    List of minimum values for the 'free' parameters

Usage

Minimum_value

IDM=ival

 

 

Real Values

 

 

 

 

where

ival

Number of parameters to be evaluated in the inversion

Description

Minimum_value is used to define the minimum values allowed for the 'free' parameters (i.e. those defined with Type = 0) in the models generated during the inversion analysis. Minimum_value keyword must always be defined and a value must be input for each parameter listed in Name, however, with the values for the fixed/prescribed parameters being ignored.

 

 

Click to expand/collapseMaximum_value    List of maximum values for the 'free' parameters

Usage

Maximum_value

IDM=ival

 

 

Real Values

 

 

 

 

where

ival

Number of parameters to be evaluated in the inversion

Description

Maximum_value is used to define the maximum values allowed for the 'free' parameters (i.e. those defined with Type = 0) in the models generated during the inversion analysis. Maximum_value keyword must always be defined and a value must be input for each parameter listed in Name, however, with the values for the fixed/prescribed parameters being ignored.

 

 

Click to expand/collapseVariable_structure_name    Data structure name associated with each parameter

Usage

Variable_structure_name

IDM=ival

 

 

Character Names

 

 

 

 

where

ival

Number of parameters to be evaluated in the inversion

Description

Variable_structure_name is used to identify the ParaGeo data structure name containing each of the parameters listed in the Name keyword or alternatively, via usage of Parameter_name in the template data file, where ParameterName is the input in the Name keyword. Valid names are:

•"Material_data" - ParaGeo  Material_data data structure (see list of valid parameter names in Name)

•"Fluid_properties" - ParaGeo  Fluid_properties data structure (see list of valid parameter names in Name)

•"Fracture_data" - ParaGeo  Fracture_data data structure (see list of valid parameter names in Name)

•"Tag_name" - defined when Parameter_name is used in the template data file with associated user-defined ParameterName input in Name

 

Notes

•By default all variable structure names are assumed to be of type "Tag_name" and defined by Parameter_name in the template data file.

•If all variables are defined via "Tag_name", then Variable_structure_name need not be defined.

 

 

Click to expand/collapseVariable_structure_number    Data structure number associated with each parameter

Usage

Variable_structure_number

IDM=ival

 

 

Integer Values

 

 

 

 

where

ival

Number of parameters to be evaluated in the inversion

Description

Variable_structure_number is used to identify the ParaGeo data structure number for the Variable_structure_name containing the inversion parameter. If the inversion parameters are defined via Parameter_name in the template data file, then the Variable_structure_number for those parameters should be set to 0.

 

Notes

•Variable_structure_number must be defined for Variable_structure_name defined via ParaGeo data structure names.

•If all parameters are defined via Parameter_name in the template data file, then neither Variable_structure_name nor Variable_structure_number are required to be defined.