|
What is streamline based simulation?
The paths traced by movement of fluid particles subjected to a potential
gradient (or pressure gradient) are called streamlines. A tangent
drawn to a streamline at a certain point represents the total
velocity vector at that point. The streamline simulation is a
technique that predicts multi-fluid displacements along the
streamlines generated from numerical solutions to the diffusivity
equation. The technique decouples computation of saturation
variation from the computation of pressure variation in time and
space. Using a finite difference method, the initial steady state
pressure field is computed based on spatial variations in mobility,
and is updated in response to significant time-dependent changes in
mobility. The flow velocity field is then computed from the pressure
field, and streamlines are traced based on the underlying velocity
field. Streamlines originate at the injectors and culminate at
producers. Once the streamline paths are determined, displacement
processes are computed along the streamlines using 1-D, analytical
or numerical models. The details of the calculation procedure can be
found elsewhere (Thiele, 1994; Batycky, 1997). More Info
Why should I use streamlines instead of analytical or numerical simulation?
Streamline simulation is ideally suited for modeling large heterogeneous
multi-well systems dominated by convection. While FD methods can
account for convection terms this is the domain where FD methods
fail in practice. Conversely, the streamline method is not well
suited to complex physics displacements (high compressibility,
capillary effects, complicated phase behavior).
There is no one numerical method that can solve the governing equation for
all cases efficiently. Depending on which term(s) dominates,
different techniques should be used.
If heterogeneity is believed to have a first-order affect on field
performance (i.e. convection term dominates) then multiple fine
scale realizations are required. In this instance streamline
based simulation is the simulation method of choice because it is
fast, can simulate fine scale models, and can capture effects due to
heterogeneity.
When do I use streamlines based simulation?
Ranking of Geological Models - Streamline-based reservoir simulation is
ideal for ranking large geological models because of the efficiency
in modeling the transport equations regardless of the degree of
heterogeneity. For heterogeneous systems, ranking based on
incompressible waterflood can be a good indicator of ranking
behavior for more complex black-oil displacements.
Fine-Scale Reference Solutions - Streamline-based reservoir simulation can
provide fine-scale reference solutions of the original geological
model. This allows one to evaluate the effect of different
geostatistical algorithms for generating the geological model in the
first place and allows one to validate the up-scaled algorithms.
Novel Data - By construction, streamlines allow one to gather data
that is not possible to extract from finite-difference simulators.
Optimal Infill Drilling - The optimal location of infill well(s) is
dependent on a number of factors, including reservoir heterogeneity,
other well locations, and displacement mechanism. In all cases,
finding the optimal location requires the minimization of some
objective function based on dynamic response data and therefore
multiple forward simulations. These forward simulations can be run
efficiently using streamlines.
History Matching Fine Scale Models - History matching, particularly of
water breakthrough and oil production for larger models involves
many forward simulations. Additionally, streamlines give information
about which areas of the reservoir are seen by the
various wells and therefore allow to selectively modify
geological/flow parameters for history matching purposes.
Any Voidage Replacement Simulation - Streamline-based simulation is
likely to outperform finite-differences in voidage-replacement type
simulations, even if the system is compressible.
Grid Orientation - Problems in which finite-differences fail due to
grid orientation are good candidates for streamline-based
simulation. This is because streamline-based fluid transport does
not exhibit grid orientation effects.
Numerical Diffusion - As in the case of grid orientation,
finite-difference problems that are affected by numerical diffusion
are very good candidates for streamline-based simulation. Numerical
diffusion can become a problem when simulating strongly
heterogeneous systems that might force a small time step in
finite-difference models.
Sensitivity Studies - If the displacement is mainly convective dominated,
sensitivity studies are best done using streamlines due to the speed
of the method.
What is ResAssist™ + 3DSL®? Read Brochure
ResAssist™ is an easy-to-use PC based graphical user interface (GUI) developed
by Epic Consulting Services Ltd. that allows the user to interact
with StreamSim’s powerful 3DSL®
streamline simulator module in the familiar Windows™
environment thus eliminating the need to execute keyword commands
normally required to run 3DSL®. The combination of ResAssist™ and 3DSL®
is an affordable alternative to conventional finite difference
simulations when dealing with reservoirs that have
production/injection displacements. It gives the user fast and practical results which can be
used as is, or to initiate more in depth simulations using
streamline or conventional simulation.
What unique information does ResAssist™ provide?
Streamlines and well allocation factors
Streamline images provide the user with a unique glimpse of the flow
patterns that relate to injector/producer pairs. The
movement of fluids in a reservoir are often more complex
than anticipated. The streamline image can also
display allocation factors that illustrate the allocation
for a given producer relative to the injectors in the field
and vice versa (see side image). The streamline plot
coupled with the saturation plots give the user a good
indication regarding infill well placement.
Dynamic reservoir conditions change flow paths
 
Conditions in the reservoir can be quite dynamic with varying injection and
production offtakes. In the example shown on the left, note the
area of influence (orange) of the injector at the bottom. In the
image on the right, increased offtake by the producers
to the east result in the (orange) injection being diverted.
Water injection efficiency plots
ResAssist™ can also calculate and plot injection efficiency for a reservoir. The injectors are plotted according to their
efficiency with regards to oil production.
In this example, the green injectors effect
far more oil to be produced per unit of water
injected than the red injector.
The efficiency plot can be mapped aerially to provide an
indication of where the injection is most effective
(green) or where areas have been well swept (red).
Can I forecast?
ResAssist™ makes it easy to place new injector and producer infill
wells into an existing model. The yellow wells shown are new
injectors and producers that were inserted into the model
forecast. ResAssist™ generates saturation and
streamlines plots that include these new wells.
Why do you need ResAssist™ + 3DSL®?
Summary
3DSL is a state of the art streamline engine developed by StreamSim Technologies Ltd. For
more information on streamlines technology please visit the
StreamSim.
To receive a demo copy of ResAssist™ or for more information on ResAssist™, please contact us via phone at (403) 444-1400 or by email at ResAssist@epiccs.com. You can also visit our website at www.epiccs.com.
is POWERED by: 
| 
