Vertical Stress Models

digirock.FStressModel

Build a stress model for a rock using a user defined function.

The function func passed to the constructor should be of the form

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def stress_func(props = None, **kwargs) -> NDArrayOrFloat:
    return props.

where props contains constants or properties for each calculation point and returns an NDArray of the same size or a constant. The keys required by stress_func should be given to the keys argument of the constructor to enable property_checks at runtime.

Attributes:

Name	Type	Description
stress_func	callable	Stress function

__init__(self, func, name=None, keys=None) special

Parameters:

Name	Type	Description	Default
func		the vertical stress function	required
name	str	name of the model	None
keys	List[str]	A list of property keys that this function requires, e.g. 'depth'	None

get_summary(self)

Return a dictionary containing a summary of the fluid.

Returns:

Type	Description
dict	Summary of properties.

vertical_stress(self, props, **kwargs)

Returns the vertical stress using user defined function vertical_stress.

Returns:

Type	Description
Union[numpy.ndarray, float]	vertical stress (MPa)

digirock.LGStressModel

Build a stress model for a rock using a linear gradient (LG).

Attributes:

Name	Type	Description
grad	float	Stress overburden gradient
ref_pres	float	Pressure (MPa) at ref_depth
ref_depth	float	Reference depth (mTVDSS) for ref_pres.

__init__(self, grad, ref_pres, ref_depth=0, name=None) special

Background stress set using a linear gradient

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Sv = grad*(depth-ref_depth) + ref_pres

Parameters:

Name	Type	Description	Default
grad	float	The gradient of the background stress in MPa/m	required
ref_pres	float	The intercept of the stress gradient trend i.e. at ref_depth (MPa)	required
ref_depth	float	Depth at reference pressure (mTVDSS)	0

get_summary(self)

Return a dictionary containing a summary of the fluid.

Returns:

Type	Description
dict	Summary of properties.

vertical_stress(self, props, **kwargs)

Returns the vertical stress \(S_v\) for the class.

Parameters:

Name	Type	Description	Default
props	Dict[str, Union[numpy.ndarray, float, int]]	A dictionary of properties required	required
kwargs		ignored	{}