Configuration file
Note
The configuration files allow to set the integrated studies (generation of regional and site models, in addition to set the different boundary projection approaches). To use expreccs in any given two OPM Flow geological models to dynamically project pressures, this can be achieve without a configuration file, but setting the parameters via command lines (see the Overview or run pycopm -h for the definition of the argument options, as well as the example in Via OPM Flow decks).
We consider the configuration file (input.txt) available in the examples folder. The parameters are chosen to show the functionality and capabilities of the expreccs framework regarding generation of corner-point grids (cpg), heterogeinities (e.g., different rock properties, faults), adding wells, and defining schedules for the operations. See the example1.txt for a simpler configuration file.
The first input parameter in the configuration file is:
1"""Set the full path to the flow executable and flags"""
2flow --enable-opm-rst-file=true --enable-tuning=true
If flow is not in your path, then write the full path to the executable (e.g., /Users/dmar/expreccs/build/opm-simulators/bin/flow). We also add in the same line as many flags as required (see the OPM Flow documentation here).
Note
If you have installed flow with MPI support, then you can run the simulations in parallel by adding mpirun -np N flow … where N is the number of cpus.
Reservoir-related parameters
The following input lines are:
4"""Set the model parameters"""
545000 15000 81 #Reginonal aquifer length, width, and depth [m]
63,5,5 #Variable array of x-refinment (Regional)
75,5,5 #Variable array of y-refinment (Regional)
81,1,1 #Variable array of z-refinment (Regional)
91,1,1,5,5,15,15,15,15,15,5,5,5,5,5 #Variable array of x-refinment (Reference)
1025,25,25 #Variable array of y-refinment (Reference)
116,5,5,5,3,3,3,3,3 #Variable array of z-refinment (Reference)
1218000 5000 27000 10000 #Site xi, yi, xf, and yf box positions [m]
13free #Use free/closed/porv for the Regional aquifer (if porv, enter the bottom, right, top, and left values (e.g, porv 1e8 1e7 1e6 1e5))
14free #Use free/closed/porv/porvproj/flux/pres/pres2p/wells for the BC site (if porv; bottom, right, top, and left values (e.g, porv 1e4 1e3 1e2 1e1)); for pres/flux, add 'interp' to use linear interpolation in time
1510000 11000 0.01 10 22.5 #Regional fault x, and y positions [m], x and y multipliers for the trans, and height of the fault jump [m]
1621583 5710 24081 8233 0.0 0.0 #Site fault x, and y positions [m] (initial and final) and x and y multipliers for the trans
179,9,9,9,9,9,9,9,9 #Thicknes of the layers
182E7 60 50 6.11423e-10 #Pressure on the reservoir top [Pa], top and bottom temperatures [C], and rock compressibility [1/Pa]
1920000 8000 0 #Sensor position x, y, and z to assess the error over time w.r.t the reference solution [m]
20(20-20*mt.sin((2*mt.pi*(x+y)/10000))) #The function for the reservoir surface
211 2.92 #Add hysteresis (1/0) and salinity (value [1E-3 kg-M/kg])
220 #Number of interations for back-coupling.
Here we first set the dimensions of the regional model and the grid size for the discretization, where the origen is located in the left bottom corner. Then the site model is defined by giving the coordinates of the box. On lines 13 and 14 we define the BC for the regional and site models, where flux/press in the site model projects the fluxes/pressures from the regional simulations, porvproj adds copmputed pore volumes from the regional reservoir, and wells add 4 injectors and 4 producers on the middle points on the site boundaries. The following line defines a fault along the z-direction in the regional model. Similarly it is possible to define a fault in the site model, which extends from the given initial location and continues in zig-zag until the given final location. Finally, we set the thicknes of the layers along the z direction, which allows to consider different rock and saturation function properties, as well as the reservoir conditions (pressure, temperature, and rock compressibility), the location of a point of interest to compare results, and the z position of the tops cells as a function of the (x,y) location. The hysteresis option activates the Killough hysteresis model on the gas relative permeability.
Note
The functionality for back-coupling in line 22 is under development, see the Back-coupling (under development) if you are curious.
The site location in the regional model (upper left), the fault in the site model (upper right), the number of rock for the different properties in the regional (lower left) and reference (lower right) models. We observe that for the regional model the closest rock properties are kept in the coarser cell.
Well-related parameters
Now we proceed to define the location of the wells:
62"""Wells position"""
63"""x, y, zi, and zf positions [m]"""
6421180 7068 0 81 #Well 0
6524200 7800 15 65 #Well 1
6621718 7122 45 81 #Well 2
6714518 11377 0 50 #Well 3
6831679 8883 0 30 #Well 4
6928477 2732 0 81 #Well 5
The implementation allows to add as many wells as desired in the site and regional model.
The location of the wells in the regional, site, and reference models. We observe that for the regional model wells 0 and 2 share the same cells along the z-direction.
The injection rates are given in the following entries:
71"""Define the injection values"""
72"""injection time [d], time step size to write results regional [d], time step size to write results site/reference [d], maximum time step [d], fluid (0 wetting, 1 non-wetting) well 0, injection rates [kg/day] well 0, fluid ... well n, injection, ...well n, (if 'wells' for BC in site (Line 14); bottom, right, top, and left values (0(prod)/1(inj), pressure [Pa]))"""
73365. 73. 73. 73. 1 3e5 1 3e5 1 3e5 1 5e6 1 5e6 0 1e7
74365. 73. 73. 73. 1 3e5 1 3e5 1 3e5 1 5e6 1 0 0 1e7
Since we defined six wells (three of them inside the site model), then each row of the schedule has 16 entries, corresponding to the first three defining the injection time, number of restart files in the solution for the regional, number of restart files in the solution for the site/reference, and maximum solver time step, and 2*6 additional entries to define injected fluid (0 water, 1 CO2) and the injection rates from well 0 to well 5 respectively. If in line 14 the wells option is activated, then at the end of each row we add the values from the wells (BHP control) on the boundaries in the order of bottom, right, top, and left with two values respectively (0 for producers and 1 for injectors, and the BHP in Pascals, see example1_wells.txt).
Warning
Keep the linebreak between the sections in the whole configuration file and do not add linebreaks inside the sections (in the current implementation this is used for the reading of the parameters).
Simulation results
Since the configuration file’s name is input.txt, then it can be run by the following command:
expreccs
the following is a screenshot using ResInsight to visualize the pressure and gas saturation at the end of the simulation:
Then the approach is to project the fluxes/presures on the site boundaries from the regional simulations instead of using free flow as in this example.
See the examples section for further examples of configuration files and argument options for expreccs.