AutoSCORES FAQ (last updated 4 October 2019)
Why would I use AutoSCORES?
AutoSCORES is a state-of-the-art tool to extract residual oil saturation, relative permeabilities and capillary pressure from SCAL production data. The impact of an AutoSCORES interpretation is large. As an example: residual oil saturation reported by AutoSCORES often is 10 to 15 saturation units lower than reported by conventional methods. This is likely to have an important impact on the prediction of production behaviour of mature fields and on scope for EOR.

Do I need training to use AutoSCORES?
No, AutoSCORES input screens are self-explanatory. However, for first-time users it is important to read this FAQ and to explore all technical hints marked on the web pages.

Where can I get help?
The PanTerra AutoSCORES Team can be contacted by phone or e-mail.
  • Phone : +31 715813505>
  • support@scores-panterra.nl>
What does AutoSCORES do?
AutoSCORES seeks to find the best choice for relative permeability for water and oil (or gas) and for capillary pressure that duplicates the production behaviour as measured in the laboratory. It starts from an initial estimate provided by you (preferably obtained from JBN, Hassler-Brunner, Forbes or other analytical methods). A Levenberg-Marquardt iterative procedure is conducted automatically to seek for the best match between simulated production data and the data observed in the laboratory. At each iteration, only the relative permeability and capillary pressure data are adjusted. At the end of the iterative process, the user will receive an Email with the best choice for relative permeability and capillary pressure.

What is the difference between SCORES and AutoSCORES?
SCORES has no automatic history matching, is FREE of charge, and can be used to DESIGN a laboratory experiment.
AutoSCORES is to be used when your laboratory experiment is completed, and you want to extract the true relative permeability, capillary pressure and Sor.

What is the recommended workflow to use AutoSCORES?
Conduct always first you own analysis of the SCAL production data with JBN, Hassler-Brunner, Forbes, etc. Only then, start-up AutoSCORES and fill out the forms from left to right. All screens are self-explanatory. If you feel lost at some point, do not hesitate to contact the AutoSCORES Team at PanTerra Geoconsultants on support@autoscores-panterra.nl.

Which laboratory experiments can be handled by AutoSCORES?
AutoSCORES manages automatic history matching of Steady-State, Unsteady-State (Welge), Centrifuge and Porous Plate experiments. Best results are obtained when a flooding experiment is combined with a multi-speed or porous-plate experiment. AutoSCORES will history match such experiments simultaneously.

I am a first time user of a flow simulator. How do I start my first AutoSCORES run?
We recommend that you start by opening the relevant page of the free SCORES suite and fill out the data of your experiment there. Once that you have been able to conduct your first simulation successfully, you will be in a good starting position to use AutoSCORES. AutoSCORES controls the SCORES simulator during automatic history matching and will require you to fill out similar pages for each experiment.

I have only one experiment to be history matched, so no combination of a flooding experiment with a centrifuge or porous plate experiment. Is that a problem?
The short answer is: Yes, that is a problem. Actually the problem is not so much that no match could be found by AutoSCORES, but rather that the quality is low for the result defining the best relative permeabilities and capillary pressure curves. The estimated standard deviation for residual oil and other parameters can easily be larger than 100%. This is still true if a saturation profile is available for the flooding experiment. In our experience, in practice, the saturation profile cannot sufficiently constrain the results of the history match although theoretically it should be possible. This has to do with noise levels in the saturation profile and with the finite positional resolution, particularly near the end flanges of the core holder.

I have conducted bump floods at the end of my Steady-State experiment. How can I handle that in AutoSCORES?
You want to choose the option “Steady-State Rates” on the Main Portal page.

Does AutoSCORES replace JBN, Hassler-Brunner, Forbes or other analytical procedures to calculate relative permeability or capillary pressure from SCAL laboratory measurements?
No, it does not. AutoSCORES is the next step in the modern data interpretation workflow. It works best when JBN, Hassler-Brunner, Forbes, etc. data are calculated first and then inserted into to the AutoSCORES input screens as indicated on the web site.

Why are the relative permeability and capillary tables locked on the pages for the individual experiments like Unsteady-State, Centrifuge?
You are specifying an initial estimate for relative permeability and capillary pressure on one of the opening AutoSCORES portal pages. AutoSCORES will use that information for all subsequent pages and fills out the tables for you.

How are relative permeabilities normalised?
SCORES considers relative permeability to be normalised to single phase (“absolute”) permeability. You are free to set the end point of the oil relative permeability kro(Swc) equal to unity, but you should then use the effective permeability to oil as measured in the laboratory at Swc as input for the Permeability input field on the pages for Unsteady-State, Steady-State, etc. Note that SCORES will not accept relative permeability end points to be larger than unity.

What is the meaning of the “Permeability” input field on the Unsteady-State, Steady-State etc. pages? Is this absolute brine permeability, Klinkenberg corrected permeability or what?
SCORES uses the “Permeability” value as absolute permeability to which relative permeabilities have been normalised. Note that SCORES will not accept relative permeability end points to be larger than unity.

I am only interested in the relative permeabilities and residual oil saturation. Why do I need to input a capillary pressure curve?
The measurement of relative permeability and residual oil saturation are impacted by capillary end effects. Even “bump-floods”, in our experience, will not be able to correct for that. Because capillary pressure is always acting, the simulator needs to include that into the flow calculations.

How are capillary pressure curves restricted in SCORES or AutoSCORES?
The capillary pressure curve needs to be input as a table of exactly 11 points. The first and last point are directly linked to the numbers you input for the Corey parameters Swc and Sor. The capillary pressure curve must be monotonically declining; in other words the capillary curve cannot have a “hump”. A hump will prompt an error message asking you to ensure monotonicity of this curve. Finally, the values in the Sw column must be strictly increasing.

What is the format for the saturation profile that I can submit as extra information for history matching?
SCORES accepts a table showing saturation data as measured in the laboratory as a function of position along the core plug. SCORES measures the position starting at the OUTFLOW end of the core plug. This means that on the plot, injection runs from RIGHT to LEFT. SCORES assumes that this saturation profile is measured at the very end of the experiment only. Presently, no saturation profiles can be introduced at intermediate times in the experiment. Detailed formatting instructions are shown in the pop-up screens on the upload pages.

I do not have an X-ray saturation profile. Is this a problem?
To interpret a Steady-State experiment in isolation this would be a problem because information on the capillary pressure curve would then be missing. This renders the results of the history matching process ambiguous and the error bar on the value of e.g. the residual oil saturation will be large. If the flooding experiment would be accompanied by a multi-speed centrifuge run on a “sister” plug, sufficient information on the capillary pressure curve would be available and put to use in a combined history match of the flooding experiment and the centrifuge experiment.

How do I fill out the flow rate or RPM tables?
These tables are used by AutoSCORES to duplicate the timing of the flow and RPM’s used in your experiment. Each line should show the time at which a flow or RPM was started. The first line therefore needs to have t=0 filled out for the time setting. A single-speed centrifuge run or an Unsteady-State experiment without a bump flood will have only one line. The last line of the table indicates the last change made in flow or RPM in the laboratory. AutoSCORES needs to know when the experiment was halted and this information is input in a separate field marked as “end of experiment”.

How reliable are the results from AutoSCORES?
The Email sent to the user at the end of the iterative process contains estimates of the standard deviations for the found values for residual oil saturation and other data.

I consider the reported standard deviations to be too large. What can I do?
The best results are obtained when a combination of experiments are input into AutoSCORES. A recommended approach is to combine data from a flow experiment like the Unsteady-State with a multi-speed centrifuge experiment. For a better control on the “tail-end” of the imbibition oil relative permeability a single-speed centrifuge run can be included into the AutoSCORES analysis as an extra option.

Does the iterative scheme of AutoSCORES always finish successfully?
No history matching scheme can be guaranteed to finish successfully. In our experience, there are two options to exploit in case of a non-converged AutoSCORES run:
  1. Review and adjust your initial estimates for relative permeabilities and capillary pressure;
  2. Reduce the accuracy level that you require from AutoSCORES. Both options are accessible in one of the AutoSCORES opening screens.
Will I be charged for a non-converged AutoSCORES run?
No, there is no charge in that case. Even better: in the event of non-convergence, the AutoSCORES Team receives automatically an Email with diagnostic information on your case. You are welcome to contact the Team at PanTerra Geoconsultants for assistance on support@scores-panterra.nl. If you do, please specify the date of the run that did not converge.

How can I pay for the AutoSCORES service?
On the main page there is an easy subscription table, where you can choose from. Payment can be done by invoice or credit card. If you cannot pay by credit card, but still want to use, you can contact AutoSCORES Team, and ask to send a regular invoice to your company.

What happens to my data after I do the upload?
PanTerra Geoconsultants will strictly adhere to the European laws on digital data management, to be fully compliant with GDPR. You can contact the AutoSCORES Team, if you want your own data to be permanently deleted.