Capillary pressure imbibition curve problem

[qingqi-code]

Hi,

I have the same problem mentioned in #1477, the imbibition capillary curve is above the drainage curve which is not correct.

The yellow curve is the imbibition curve should be below the blue one which is the drainage curve and drainage residual saturation should be equal to the imbibition initial saturation.

Following Dr. Jeff suggestion, I have set all the boundary pores' diameter to zero but still get the wrong plot. Is something wrong about my code? Thank you so much!

import openpnm as op
import numpy as np
import matplotlib.pyplot as plt
import os
from pathlib import Path

pn = op.network.Cubic(shape=[10, 10, 10], spacing=0.0001)
geo = op.geometry.SpheresAndCylinders(network=pn, pores=pn.Ps, throats=pn.Ts)
print(pn)
print(geo)
pn['pore.diameter'][pn['pore.left']] = 0
pn['pore.diameter'][[pn['pore.right']]] = 0
pn['pore.diameter'][[pn['pore.surface']]] = 0
water = op.phases.Water(network=pn, name='water')
oil = op.phases.GenericPhase(network=pn, name='oil')

oil['pore.viscosity'] = 0.001
oil['pore.contact_angle'] = 120
water['pore.contact_angle'] = 60
oil['pore.surface_tension'] = 0.04
water["pore.surface_tension"] = 0.04
water["pore.temperature"] = 350
water.regenerate_models()
oil.regenerate_models()

phys_water = op.physics.GenericPhysics(network=pn, phase=water, geometry=pn)
phys_oil = op.physics.GenericPhysics(network=pn, phase=oil, geometry=pn)
mod = op.models.physics.capillary_pressure.washburn
water.add_model(propname='throat.entry_pressure', model=mod)
oil.add_model(propname='throat.entry_pressure', model=mod)

mod = op.models.physics.hydraulic_conductance.hagen_poiseuille
phys_water.add_model(propname='throat.hydraulic_conductance', model=mod)
phys_oil.add_model(propname='throat.hydraulic_conductance', model=mod)

IP_withdrawal = op.algorithms.MixedInvasionPercolation(network=pn)
IP_withdrawal.setup(phase=oil)
#IP_withdrawal.set_inlets(pores=pn.pores('inlets')[::4])
IP_withdrawal.set_inlets(pores=pn.pores('left'))
IP_withdrawal.run()
IP_withdrawal.set_outlets(pores=pn.pores('right'))
IP_withdrawal.apply_trapping()
injection_data = IP_withdrawal.get_intrusion_data()
# imbibition: water invade oil
IPw = op.algorithms.MixedInvasionPercolation(network=pn)
IPw.setup(phase=water)
# IPw.set_inlets(pores=pn.pores('inlets')[::4])
IPw.set_inlets(pores=pn.pores('left'))
IPw.set_residual(pores=IP_withdrawal['pore.invasion_sequence'] == -1)
IPw.run()
IPw.set_outlets(pores=pn.pores('right'))
IPw.apply_trapping()
injw = IPw.get_intrusion_data()

fig, ax = plt.subplots()
ax.plot(1-injection_data.S_tot, injection_data.Pcap)
ax.plot(injw.S_tot, -injw.Pcap)
ax.set_xlabel("Water Saturation")
ax.set_ylabel("Capillary pressure [Pa]") 

[jgostick]

I don't have a quick answer for this one, and I'm a bit more swamped that usual at the moment. We are currently working on OpenPNM V3, and a renovation of the OP/IP algorithms is planned. Once I start digging into that project I will be able to answer your question, and fix any bug if there is one (hopefully not!). This will happen in the next month, sorry for the wait.

[qingqi-code]

Thank you Dr. Gostick! Looking for the new version OpenPNM

[minzhangut]

Hello @qingqi-code, I am wondering whether you got an update on this drainage vs. imbibition Pc curve comparison. Thanks!