Emulsion

[ELgharib]

Hi all,

Please, I need your help to understand what's going in one of our well. We have 4 ESP wells producing from the same reservoir. Intake pressure are respectiveley 14, 14, 22 and 28 bars.

The ESP with a PIP of 22 bars is limited due to high motor temp while the one with 28 bars is producing an emulsion oil. (emulsion of water and oil)
The reservoir is pressure supported with water injection, and the reservoir is not compartmentalized which mean the fluid should be the same. The WCT is around 45% for all the 4 wells.

When you collect sample of the fluid from the wells, the emulsion will not breakout after days.

I would like to understand why only one well is producing this emulsion. What could be the reason behind?

I am planning to analyse the fluids, but before that my boss would ask me what do I think about the reasons behind that to justify the fluid analysis.

Thanks in advance

[vinomarky]

I assume from this that you are dealing with low API oils, probably asphaltenic and possibly even with high TAN numbers?

I don't have a whole lot of experience in this area. I've only ever looked at a field with these characteristics for possible acquisition - which we declined to bid on - so my experience is limited to quite superficial, but for what it's worth my thoughts below;

Heavy oils are often 'heavy' due to microbial activity, which can be quite localized in behaviour - wells either side of a field can exhibit different oil properties. What you are seeing could well be due to slightly different oil properties in your problem well

Another possibility is that in the 20-50% watercut range, these emulsions that can be formed have radically changing (increasing) viscosities - what you are seeing in one well could be what is very soon in store for you from the other wells

Another possibility - the emulsion tendency is quite dependant upon the amount of shear in your system. I'm assuming all your downhole pumps/jewelry are identical in these wells? If not, that could be a cause. Are all the pumps running at the same rpm? Otherwise, perhaps your perfs are not as well connected to the formation in the problem well, causing some additional shear?

Just a couple thoughts - sorry could not offer anything definitive