Predicting relative permeability

[gxw-ll]

I modeled the predicted relative permeability using the code in the documentation, which is https://github.com/PMEAL/OpenPNM/blob/dev/examples/applications/relative _ permeability.ipynb. I used the SNOW2 algorithm for the pore network to extract it, but running the code produced KeyError: ' throat. [Volume']

, Here's my code：
`import porespy as ps
import matplotlib.pyplot as plt
import numpy as np
import openpnm as op
op.visualization.set_mpl_style()
np.random.seed(0)
np.set_printoptions(precision=5)
op.Workspace().settings.loglevel = 40

def sat_occ_update(network, nwp, wp, ip, i):
pore_mask = ip['pore.invasion_sequence'] < i
throat_mask = ip['throat.invasion_sequence'] < i
sat_p = np.sum(network['pore.volume'][pore_mask])
sat_t = np.sum(network['throat.volume'][throat_mask])
sat1 = sat_p + sat_t
bulk = network['pore.volume'].sum() + network['throat.volume'].sum()
sat = sat1/bulk
nwp['pore.occupancy'] = pore_mask
nwp['throat.occupancy'] = throat_mask
wp['throat.occupancy'] = 1-throat_mask
wp['pore.occupancy'] = 1-pore_mask
return sat

def Rate_calc(network, phase, inlet, outlet, conductance):
phase.regenerate_models()
St_p = op.algorithms.StokesFlow(network=network, phase=phase)
St_p.settings._update({'conductance' : conductance})
St_p.set_value_BC(pores=inlet, values=1)
St_p.set_value_BC(pores=outlet, values=0)
St_p.run()
val = np.abs(St_p.rate(pores=inlet, mode='group'))
return val

if name == "main":
shape = [30, 30, 30]
im = ps.generators.blobs(shape=shape, porosity = 0.4, blobiness = 1)

net = ps.networks.snow2(phases = im, voxel_size=1e-3)
pn = op.io.network_from_porespy(net.network)

pn.add_model(propname='pore.cluster_number', model=op.models.network.cluster_number)
pn.add_model(propname='pore.cluster_size', model=op.models.network.cluster_size)
print(pn)

Ps = pn['pore.cluster_size'] < 92
op.topotools.trim(network=pn, pores=Ps)
ax = op.visualization.plot_tutorial(pn, font_size=8)
ax = op.visualization.plot_connections(pn, linewidth=1)
ax = op.visualization.plot_coordinates(pn, ax=ax, markersize=10)

pn["throat.diameter"] = pn["throat.equivalent_diameter"]
pn["pore.diameter"] = pn["pore.equivalent_diameter"]
air = op.phase.Air(network=pn,name='air')
air['pore.surface_tension'] = 0.072
air['pore.contact_angle'] = 180.0
f = op.models.physics.capillary_pressure.washburn
air.add_model(propname='throat.entry_pressure',
          model=f, 
          surface_tension='throat.surface_tension',
          contact_angle='throat.contact_angle',
          diameter='throat.diameter')
air.add_model_collection(op.models.collections.phase.air)
air.add_model_collection(op.models.collections.physics.basic)
air.regenerate_models()
water = op.phase.Water(network=pn,name='water')
water.add_model_collection(op.models.collections.phase.water)
water.add_model_collection(op.models.collections.physics.basic)
water.regenerate_models()
ip = op.algorithms.InvasionPercolation(network=pn, phase=air)
Finlets_init = pn.pores('xmin')
Finlets=([Finlets_init[x] for x in range(0, len(Finlets_init), 2)])
ip.set_inlet_BC(pores=Finlets)
ip.run()



flow_in = pn.pores('xmin')
flow_out = pn.pores('xmax')

model_mp_cond = op.models.physics.multiphase.conduit_conductance
air.add_model(model=model_mp_cond, propname='throat.conduit_hydraulic_conductance',
          throat_conductance='throat.hydraulic_conductance', mode='medium', regen_mode='deferred')
water.add_model(model=model_mp_cond, propname='throat.conduit_hydraulic_conductance',
          throat_conductance='throat.hydraulic_conductance', mode='medium', regen_mode='deferred')

Snwp_num=20
max_seq = np.max([np.max(ip['pore.invasion_sequence']),
      np.max(ip['throat.invasion_sequence'])])
start = max_seq//Snwp_num
stop = max_seq
step = max_seq//Snwp_num
Snwparr = []
relperm_nwp = []
relperm_wp = []

for i in range(start, stop, step):
    air.regenerate_models();
    water.regenerate_models();
    sat = sat_occ_update(network=pn, nwp=air, wp=water, ip=ip, i=i)
    Snwparr.append(sat)
    Rate_abs_nwp = Rate_calc(pn, air, flow_in, flow_out, conductance = 'throat.hydraulic_conductance')
    Rate_abs_wp = Rate_calc(pn, water, flow_in, flow_out, conductance = 'throat.hydraulic_conductance')
    Rate_enwp = Rate_calc(pn, air, flow_in, flow_out, conductance = 'throat.conduit_hydraulic_conductance')
    Rate_ewp = Rate_calc(pn, water, flow_in, flow_out, conductance = 'throat.conduit_hydraulic_conductance')
    relperm_nwp.append(Rate_enwp/Rate_abs_nwp)
    relperm_wp.append(Rate_ewp/Rate_abs_wp)`