History Matching process in 3 steps - my view

This is my view about HM process. I do not have extensive experience so all comments are welcome.

Let’s assume that you have a model successfully initialized.
We run it on reservoir volume as matching parameter and notice that observed volumes cannot be produced.
In this case I will multiply reservoir permeability until volumes are produced than I will check for reservoir pressure match.

[B]1. PRESSURE MATCH[/B]
For matching the pressure I can play with:
- Reservoir boundaries
- Aquifer size and PI
- Rock compressibility
- Reservoir permeability
- Porosity
- Res thickness
- Contacts
- Residual Oil saturation and Connate water saturation
It is important to understand what are the ranges for each parameter can vary. For example OWC can vary in a range of 50 m but Residual oil and Connate water have reliable values while SCAL data is available. Also is important to assess the impact each parameter have inside of his determined range.

[B]2. SATURATION MATCH[/B]

In this step I will try to match WOR and GOR and I will play with:
- Vertical and horizontal permeability. It is important in case we have layers with different permeability to understand their individual contribution to flow.
- Aquifer parameters. It is important here what type of Aquifer you have (from bottom, from edge), size, strength.
- Relative permeability curves. Even if SCAL data is present if you have a heterogeneous reservoir RelPerm need to be adjusted in my opinion. Also here is important if you have a good facies model and you can create different rock types, each having his own RelPerm table.
- Contacts are important in water , gas breakthrough time
- Well completion is not too much object of changing but there are cases when data is wrong and in reality well is perforated 2-3 meters higher or lower

Could be the case that working at this point than general pressure match from point 1 will be affected, so will be a back and forth until saturation and pressure are acceptable matched.

[B]3. BHP / PI match[/B]

The last step in my opinion will be to match well productivity index. Could be the case that you successfully matched first 2 points but your well have in reality an average drawdown of 60 bars but in your model the fluids are produces with a drawdown of 10 bars.
For solving this problem you can change

- Horizontal and vertical permeability around the well
- Well PI
- Well skin
Again changes here could affect your WOR, GOR matching and again you need to move through this iterative process.

Thank you for reading.
[FONT=Arial Black]Please comment...[/FONT]

Hi Catapam,

This sort of posts are really welcome. As you may know there is no single, standard procedure for History Matching a model, that's why some call this process an art more than a science, but you summarized well the overall process. Step number #3 is indeed important.

Best regards,

Well , the HM can be divided in to 3 major steps
1. Perfomance of the reservoir
2. Perfomance of wells
3. marrying wells and reservoir
But you mentioned very good point