CO2 storage simulation with heterogeneous perm field fails to converge

Hi all,

I have a problem with building a geological CO2 storage model using the TOUGH2/ECO2N module. In this model, I considered a heterogeneous permeability field by using the PM-coefficients function. It worked correctly when all PM-coefficients were 1.0. But when the permeability heterogeneity (k = 2e-12 and 0.43<=KM<=9.8) was considered, the smulation failed to converge that it halted prematurely with the time step reducing from days to seconds.The error information is as follows:
( 139,  6) ST = 0.494715E+07 DT = 0.418099E+05 DX1= 0.355524E+06 DX2= -.215953E-06 T =  45.000 P = 59797233. S = 0.000000E+00
 +++++++++ REDUCE TIME STEP AT ( 140,  9) ++++++++++++++++   NEW DELT = 0.104525E+05
( 140,  3) ST = 0.495760E+07 DT = 0.104525E+05 DX1= 0.889802E+05 DX2= -.369786E-07 T =  45.000 P = 59889436. S = 0.000000E+00
 +++++++++ REDUCE TIME STEP AT ( 141,  9) ++++++++++++++++   NEW DELT = 0.522624E+04
( 141,  2) ST = 0.496283E+07 DT = 0.522624E+04 DX1= 0.444203E+05 DX2= 0.313006E-08 T =  45.000 P = 59955913. S = 0.138405E+00
 +++++++++ REDUCE TIME STEP AT ( 142,  9) ++++++++++++++++   NEW DELT = 0.261312E+04
 +++++++++ REDUCE TIME STEP AT ( 142,  9) ++++++++++++++++   NEW DELT = 0.653280E+03
 +++++++++ REDUCE TIME STEP AT ( 142,  9) ++++++++++++++++   NEW DELT = 0.163320E+03
 +++++++++ REDUCE TIME STEP AT ( 142,  9) ++++++++++++++++   NEW DELT = 0.408300E+02
 +++++++++ REDUCE TIME STEP AT ( 142,  9) ++++++++++++++++   NEW DELT = 0.102075E+02
 +++++++++ REDUCE TIME STEP AT ( 142,  9) ++++++++++++++++   NEW DELT = 0.255188E+01
( 142,  1) ST = 0.496283E+07 DT = 0.255188E+01 DX1= 0.000000E+00 DX2= 0.000000E+00 T =  45.000 P = 59931612. S = 0.000000E+00
 +++++++++ REDUCE TIME STEP AT ( 143,  9) ++++++++++++++++   NEW DELT = 0.127594E+01
( 143,  1) ST = 0.496283E+07 DT = 0.127594E+01 DX1= 0.000000E+00 DX2= 0.000000E+00 T =  45.000 P = 59931612. S = 0.000000E+00
( 144,  1) ST = 0.496283E+07 DT = 0.255188E+01 DX1= 0.000000E+00 DX2= 0.000000E+00 T =  45.000 P = 59931612. S = 0.000000E+00
 +++++++++ CONVERGENCE FAILURE ON TIME STEP # 145 WITH DT = 0.510375E+01 SECONDS, FOLLOWING TWO STEPS THAT CONVERGED ON ITER = 1
           STOP EXECUTION AFTER NEXT TIME STEP
 +++++++++ REDUCE TIME STEP AT ( 145,  9) ++++++++++++++++   NEW DELT = 0.127594E+01
( 145,  1) ST = 0.496284E+07 DT = 0.127594E+01 DX1= 0.000000E+00 DX2= 0.000000E+00 T =  45.000 P = 59931612. S = 0.000000E+00
 END OF TOUGH2 SIMULATION RUN --- ELAPSED TIME =   108.764 SEC-- CALCULATION TIME =   108.327 SEC-- DATA INPUT TIME =    0.437 SEC

Can someone help me? The model input and output files are attached. Thanks in advance.

Jim