rockphypy

About

This Python 3.8+ package implements most of the rock physics models introduced in the Rock Physics Handbook. The package provides a bunch of usefel classes, i.e. Anisotropy, AVO, BW (Batzle&Wang), EM(Effective medium), Empirical, Fluid, GM(Granular Medium), Permeability and utils. An exhaust list of methods in different classes are given in the API Documentation.

Citation

Want to cite rockphypy in your work? Please cite as "Yu, Jiaxin and Mukerji, Tapan and Avseth, Per Ã…ge, Rockphypy: An Extensive Python Library for Rock Physics Modeling. Available at SSRN: https://ssrn.com/abstract=4486364 or http://dx.doi.org/10.2139/ssrn.4486364".

Installation

rockphypy is available through [PyPI] and may be installed using pip:

pip install rockphypy

Example code and documentation

Below is an simple example showing the comparison between critical porosity model and elastic bounds computed by Hashin-Strikmann bounds. See the documentation for more examples.

from rockphypy import EM
from rockphypy import Fluid

# specify model parameters
phi=np.linspace(0,1,100,endpoint=True) # solid volume fraction = 1-phi
K0, G0= 37,44 # moduli of grain material
Kw, Gw= 2.2,0 # moduli of water 
# VRH bounds
volumes= np.vstack((1-phi,phi)).T
M= np.array([K0,Kw])
K_v,K_r,K_h=EM.VRH(volumes,M)
# Hashin-Strikmann bound 
K_UHS,G_UHS= EM.HS(1-phi, K0, Kw,G0,Gw, bound='upper')
# Critical porosity model
phic=0.4 # Critical porosity
phi_=np.linspace(0.001,phic,100,endpoint=True) # solid volume fraction = 1-phi
K_dry, G_dry= EM.cripor(K0, G0, phi_, phic)# Compute dry-rock moduli
Ksat, Gsat = Fluid.Gassmann(K_dry,G_dry,K0,Kw,phi_)# saturate rock with water

# plot
plt.figure(figsize=(6,6))
plt.xlabel('Porosity')
plt.ylabel('Bulk modulus [GPa]')
plt.title('V, R, VRH, HS bounds')
plt.plot(phi, K_v,label='K Voigt')
plt.plot(phi, K_r,label='K Reuss = K HS-')
plt.plot(phi, K_h,label='K VRH')
plt.plot(phi, K_UHS,label='K HS+')
plt.plot(phi_, Ksat,label='K CriPor')
plt.legend(loc='best')
plt.grid(ls='--')

Issues and contributing

Issues

If you are having trouble using the package, please let me know by creating an [Issue on GitHub] and I'll get back to you.

Contributing

Whatever your mathematical and Python background is, you are very welcome to contribute to rockphypy. To contribute, fork the project, create a branch and submit and Pull Request. Please follow these guidelines:

• Import as few external dependencies as possible.
• Use test driven development, have tests and docs for every method.
• Cite literature and implement recent methods.
• Unless it's a bottleneck computation, readability trumps speed.
• Employ object orientation, but resist the temptation to implement many methods -- stick to the basics.
• Follow PEP8.

Timeline