Validation of Jutul against existing reservoir simulators

This example contains validation of Jutul against MRST. In general, minor differences are observed. These can be traced back to a combination of different internal timestepping done by the simulators and that JutulDarcy by default uses a multisegment well formulation while MRST uses a standard instantaneous equilibrium model without well bore storage terms. These differences are most evident when simulators start up.

These cases have been exported using the MRST jutul module which can export MRST or Eclipse-type of cases to a JutulDarcy-compatible input format. They can then be simulated using simulate_mrst_case.

using JutulDarcy, Jutul
using GLMakie

Define a few utilities for plotting the MRST results

We are going to compare well responses against pre-computed results stored inside the JutulDarcy module.

function mrst_case_path(name)
    base_path, = splitdir(pathof(JutulDarcy))
    joinpath(base_path, "..", "test", "mrst", "$(name).mat")
end

function mrst_solution(result)
    return result.extra[:mrst]["extra"][1]["mrst_solution"]
end

function mrst_well_index(mrst_result, k)
    return findfirst(isequal("$k"), vec(mrst_result["names"]))
end

function get_mrst_comparison(wdata, ref, wname, t = :bhp)
    yscale = "m³/s"
    if t == :bhp
        tname = :bhp
        mname = "bhp"
        yscale = "Pa"
    elseif t == :qos
        tname = :orat
        mname = "qOs"
    elseif t == :qws
        tname = :wrat
        mname = "qWs"
    elseif t == :qgs
        tname = :grat
        mname = "qGs"
    else
        error("Not supported: $t")
    end
    jutul = wdata[tname]
    mrst = ref[mname][:, mrst_well_index(ref, wname)]

    return (jutul, mrst, tname, yscale)
end

function plot_comparison(wsol, ref, rep_t, t, wells_keys = keys(wsol.wells))
    fig = Figure()
    ax = Axis(fig[1, 1], xlabel = "time (days)")
    l = ""
    yscale = ""
    T = rep_t./(3600*24.0)
    for (w, d) in wsol.wells
        if !(w in wells_keys)
            continue
        end
        jutul, mrst, l, yscale = get_mrst_comparison(d, ref, w, t)
        lines!(ax, T, abs.(jutul), label = "$w")
        scatter!(ax, T, abs.(mrst), markersize = 8)
    end
    axislegend()
    ax.ylabel[] = "$l ($yscale)"
    fig
end

plot_comparison (generic function with 2 methods)

The Egg model (oil-water compressible)

A two-phase model that is taken from the first member of the EGG ensemble. For more details, see the paper where the ensemble is introduced:

Jansen, Jan-Dirk, et al. "The egg model–a geological ensemble for reservoir simulation." Geoscience Data Journal 1.2 (2014): 192-195.

Simulate model

egg = simulate_mrst_case(mrst_case_path("egg"), info_level = -1)
wells = egg.wells
rep_t = egg.time
ref = mrst_solution(egg);

MRST model: Reading input file /home/runner/work/JutulDarcy.jl/JutulDarcy.jl/src/../test/mrst/egg.mat.
[ Info: This is the first call to simulate_mrst_case. Compilation may take some time...
MRST model: Starting simulation of immiscible system with 18553 cells and 2 phases and 2 components.
MRST model: Model was successfully simulated.

Compare well responses

injectors = [:INJECT1, :INJECT2, :INJECT3, :INJECT4, :INJECT5, :INJECT6, :INJECT7]
producers = [:PROD1, :PROD2, :PROD3, :PROD4]

4-element Vector{Symbol}:
 :PROD1
 :PROD2
 :PROD3
 :PROD4

Bottom hole pressures

plot_comparison(wells, ref, rep_t, :bhp, injectors)

Oil rates

plot_comparison(wells, ref, rep_t, :qos, producers)

Water rates

plot_comparison(wells, ref, rep_t, :qws, producers)

SPE1 (black oil, disgas)

A shortened version of the SPE1 benchmark case.

Odeh, A.S. 1981. Comparison of Solutions to a Three-Dimensional Black-Oil Reservoir Simulation Problem. J Pet Technol 33 (1): 13–25. SPE-9723-PA

For comparison against other simulators, see the equivialent JutulSPE1 example in the Jutul module for MRST

Simulate model

spe1 = simulate_mrst_case(mrst_case_path("spe1"), info_level = -1)
wells = spe1.wells
rep_t = spe1.time
ref = mrst_solution(spe1);

MRST model: Reading input file /home/runner/work/JutulDarcy.jl/JutulDarcy.jl/src/../test/mrst/spe1.mat.
[ Info: This is the first call to simulate_mrst_case. Compilation may take some time...
MRST model: Starting simulation of black-oil system with 300 cells and 3 phases and 3 components.
MRST model: Model was successfully simulated.

Compare well responses

Bottom hole pressures

plot_comparison(wells, ref, rep_t, :bhp)

Gas rates

plot_comparison(wells, ref, rep_t, :qgs, [:PRODUCER])

SPE3 (black oil, vapoil)

A black-oil variant of the SPE3 benchmark case.

Kenyon, D. "Third SPE comparative solution project: gas cycling of retrograde condensate reservoirs." Journal of Petroleum Technology 39.08 (1987): 981-997

Simulate model

spe3 = simulate_mrst_case(mrst_case_path("spe3"), info_level = -1)
wells = spe3.wells
rep_t = spe3.time
ref = mrst_solution(spe3);

MRST model: Reading input file /home/runner/work/JutulDarcy.jl/JutulDarcy.jl/src/../test/mrst/spe3.mat.
[ Info: This is the first call to simulate_mrst_case. Compilation may take some time...
MRST model: Starting simulation of black-oil system with 324 cells and 3 phases and 3 components.
PRODUCER: Approaching zero rate, disabling producer for current step
PRODUCER: Approaching zero rate, disabling producer for current step
MRST model: Model was successfully simulated.

Compare well responses

Bottom hole pressures

plot_comparison(wells, ref, rep_t, :bhp, [:PRODUCER])

Gas rates

plot_comparison(wells, ref, rep_t, :qgs, [:PRODUCER])

Oil rates

plot_comparison(wells, ref, rep_t, :qos, [:PRODUCER])

SPE9 (black oil, disgas)

Example of the SPE9 model exported from MRST running in JutulDarcy.

Killough, J. E. 1995. Ninth SPE comparative solution project: A reexamination of black-oil simulation. In SPE Reservoir Simulation Symposium, 12-15 February 1995, San Antonio, Texas. SPE 29110-MS

For comparison against other simulators, see the equivialent JutulSPE9 example in the Jutul module for MRST

Simulate model

spe9 = simulate_mrst_case(mrst_case_path("spe9"), info_level = -1)
wells = spe9.wells
rep_t = spe9.time
ref = mrst_solution(spe9);

MRST model: Reading input file /home/runner/work/JutulDarcy.jl/JutulDarcy.jl/src/../test/mrst/spe9.mat.
[ Info: This is the first call to simulate_mrst_case. Compilation may take some time...
PVT: Fixing table for low pressure conditions.
MRST model: Starting simulation of black-oil system with 9000 cells and 3 phases and 3 components.
MRST model: Model was successfully simulated.

Compare well responses

injectors = [:INJE1]
producers = [Symbol("PROD$i") for i in 1:25]

25-element Vector{Symbol}:
 :PROD1
 :PROD2
 :PROD3
 :PROD4
 :PROD5
 :PROD6
 :PROD7
 :PROD8
 :PROD9
 :PROD10
 ⋮
 :PROD17
 :PROD18
 :PROD19
 :PROD20
 :PROD21
 :PROD22
 :PROD23
 :PROD24
 :PROD25

Injector water rate

plot_comparison(wells, ref, rep_t, :qws, injectors)

Oil rates

plot_comparison(wells, ref, rep_t, :qos, producers)

Water rates

plot_comparison(wells, ref, rep_t, :qws, producers)

Bottom hole pressures

plot_comparison(wells, ref, rep_t, :bhp, producers)

Example on GitHub

If you would like to run this example yourself, it can be downloaded from the JutulDarcy.jl GitHub repository as a script, or as a Jupyter Notebook

---

This page was generated using Literate.jl.