Abstract. Creating increasingly realistic groundwater models involves the
inclusion of additional geological and geophysical data in the
hydrostratigraphic modeling procedure. Using multiple-point statistics (MPS)
for stochastic hydrostratigraphic modeling provides a degree of flexibility
that allows the incorporation of elaborate datasets and provides a framework
for stochastic hydrostratigraphic modeling. This paper focuses on comparing
three MPS methods: snesim, DS and iqsim. The MPS methods are tested and
compared on a real-world hydrogeophysical survey from Kasted in Denmark,
which covers an area of 45 km2. A controlled test environment, similar
to a synthetic test case, is constructed from the Kasted survey and is used
to compare the modeling results of the three aforementioned MPS methods. The
comparison of the stochastic hydrostratigraphic MPS models is carried out in
an elaborate scheme of visual inspection, mathematical similarity and
consistency with boreholes. Using the Kasted survey data, an example for
modeling new survey areas is presented. A cognitive hydrostratigraphic model
of one area is used as a training image (TI) to create a suite of stochastic
hydrostratigraphic models in a new survey area. The advantage of stochastic
modeling is that detailed multiple point information from one area can be
easily transferred to another area considering uncertainty. The presented MPS methods each have their own set of advantages and
disadvantages. The DS method had average computation times of 6–7 h, which
is large, compared to iqsim with average computation times of 10–12 min.
However, iqsim generally did not properly constrain the near-surface part of
the spatially dense soft data variable. The computation time of 2–3 h for
snesim was in between DS and iqsim. The snesim implementation used here is
part of the Stanford Geostatistical Modeling Software, or SGeMS. The snesim
setup was not trivial, with numerous parameter settings, usage of multiple
grids and a search-tree database. However, once the parameters had been set
it yielded comparable results to the other methods. Both iqsim and DS are
easy to script and run in parallel on a server, which is not the case for
the snesim implementation in SGeMS.
A location-based multiple point statistics method: modelling the reservoir with non-stationary characteristics
