EOR – Enhanced Oil Recovery

Have you considered wettability alteration as part of your EOR strategy?

 

Reservoirs have an optimum wettability that maximizes oil production, but this rarely is the natural state.  Reservoirs can be oil wet to the point that oil is not mobile even under waterflood.  When the rock is water wet, pore throats shrink the effective diameter as the capillary force of water clinging to the rock resists oil movement through the throat and snaps off the oil phase stranding mobile oil.  This optimum state is neutral wettability or the condition where oil and water move equally well through the porous medium.

Employ separately or as part of your existing EOR strategy

Can be employed with chemical, thermal and CO2 flooding to further improve results!

You are already using water. Why not use the right water to get more oil?

The change in injected water chemistry may improve injectivity, eliminate souring, reduce corrosion and scale formation and may even dissolve scales – all improving your wells’ performance. No expensive searching for sweet spots or development of new methodology.

Have More Questions?

Do we understand the mechanism for increasing recovery and how it works?

There is much debate even today about the mechanisms, but the emerging consensus is changing salinity alters the wettability of the reservoir system to increase recovery (see our reference page for more information).  At ESal our question is do we have enough practical understanding to make it work in the field. The answer is yes, we do.  This knowledge is incorporated into our screening tool and our design process to provide you with the best chance of success.  Our step-wise process of screening, lab testing, design and field deployment allows the client to de-risk the process saving time and money.  

My field is already water-wet. Why do I need to change my wettability?

The common misunderstanding is that more water-wet is good for oil recovery.  This is not correct. The most recovery (drainage) occurs when the reservoir is near neutral wettability not water-wet.  ESal’s aim is to shift your reservoir wettability to near neutral and get maximum recovery. If your field is already water-wet, we shift it towards more oil-wet to reach that middle ground.  If you are oil-wet, we shift the wettability to more water-wet but are still aiming at neutral wettability where the best recovery occurs. (See our reference page for more information)

How do I find out if this will work in my field?

Traditionally, the answer is several years and millions of dollars of lab work and reservoir modeling.  At ESal we have developed a screening tool to use your data on the rock, water and oil composition together with basic data on your field that gives you a numerical score within a few weeks (see our reference page for more information).  This procedure provides a fast and reliable answer and identifies which factors are the most sensitive for your field. We can screen one or more fields quickly and provided you with the critical information at the speed of business.

How much extra oil can I expect to recover?

Our screening tool and lab tests provide our clients with good estimates of potential benefits.  Depending on the type of reservoir (shale, carbonate, clastic) and the stage of deployment the benefit will vary. However, in general both field and lab testing has shown the benefits are from 5-15% OOIP (original oil in place) in both carbonate and sandstone reservoirs and 2-5% in shale (see our reference page for more information).  Avoiding expensive projects that provide little or no return is why you want ESal in your corner.

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