Den 14. aug. 2013 kl. 09:03 skrev Alf Birger Rustad:

Dear developers,

We have done a terrific effort improving the OPM codes the last year, we all 
deserve a tap on the shoulder. On the reservoir simulation part it seems like 
we are ready to take on the next big challenge. Namely, demonstrating that we 
can replace an industry reservoir simulator on one full field model 
effectively. The Norne case seems most relevant for many reasons. The most 
prominent being: it is available to academia, several of us are already 
familiar with it, it converges relatively easily and simulation time is low, it 
is about as standard as it gets (i.e., few perks and hacks).

I believe we should have the following design goals (please add if you miss 
some):
-All physics  present in the full field model should be accounted for (e.g., 
fully implicit black oil and well models with relevant input accounted for in 
the simulations)
-We need to be able to parse the data and include files, and feed them to the 
simulator without user intervention
-We need to produce relevant grid and summary output for 3D visualization and 
2D production data without user intervention
-We need to be within striking distance performance wise. I believe three times 
slower than relevant industry simulator is acceptable here.

You will find pointers to the Norne model here: 
http://www.ipt.ntnu.no/~norne/wiki/doku.php?id=start

What do you guys think, is this something we can achieve by Christmas?

I think this may be doable, and agree that it makes for a good target case, due 
to its openness. To your second point, I must caution that I do not know what 
tricks and special features are used in the data-as-given that could give us 
trouble. In order to support this point, the opm-parser module will be needed 
in a usable state. We can and should start working on the case before that is 
available, but probably with a somewhat modified input deck.

Moving forward, there are a few points I'd like to focus on:

1. I think that the current effort in testing and validating the 
sim_fibo_bo.cpp simulator program using simpler cases is essential, to ensure 
that we can trust the simulator when moving to more complex cases, such as 
Norne.

2. The above mentioned simulator does not handle switching of well targets, 
which is needed for a real case. We have done this in other (operator 
splitting) simulators, and for fully implicit simulation we have done it in 
MRST.

3. The simulator and autodiff library has not been optimized. Although the 
autodiff library has been written in such a way that it should be possible to 
get good performance, very little profiling has been done (preliminary results 
indicate that quite some time is spent in the Eigen::SparseMatrix matrix 
multiply operation). I think we should be able to make the linear solver the 
bottleneck.

4. The Norne case is just large enough to be unfeasible with a direct solver 
(at least if we want some performance). So work needs to be done on 
preconditioning strategy etc. Again, much experimentation has been done in 
MRST, so it should be doable.

Atgeirr
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