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Technical Papers

Understanding EOR & IOR Concepts

By 20 de January de 2022January 26th, 2022No Comments

In the last decade it has had valuable and controversial discussions about the difference between EOR and IOR  concepts, this issue has been reinforced by the launching of emerging technologies in order to increase production from mature fields in a cost – efficient manner. The basic understanding of these concepts can help you to maximize the value of the asset in terms of production recovery and  economical feasibility. The society of petroleum engineers (SPE) has been guiding the oil and gas industry by establishing some standars from the technical point of view. In this case,  according to SPE, the Improved Oil Recovery Concept (IOR) is “any of various methods, chiefly reservoir drive mechanisms and  enhanced recover(y) techniques, designed to improve the flow of  hydrocarbons from the reservoir to the wellbore or to recover  more oil after the primary and secondary methods (water- and  gas floods) are uneconomic”.  

Enhanced Oil Recovery (EOR), is “one or more of a variety of  processes that seek to improve the recovery of hydrocarbon  from a reservoir after the primary production phase.” Several  authors has established their criteria, for example Thomas  (2008) quoted that EOR “implies a reduction in oil saturation  below residual oil saturation (Sor)“. This last definition seems  to be in accordance with the basic phenomenum of EOR  in the micro and macro scale affecting the capillary forces  and viscous forces, causing a decrease in the residual oil  saturation. Consequently, well placement optimization,  

artificial lift improvements, conformance, well stimulation  and changing in operating conditions for example, might be  considered as IOR rather than EOR.  

However the EOR and IOR concepts are subjected after  the primary production phase without pressure injection  support, they might turn ambiguous. We have discussed  earlier that the implementation of and IOR or EOR process  can be linked to the beginning of the production phase of any  reservoir based on their physical characteristics and fluid  properties. Others practical perspectives suggests than  IOR techniques are aligned to EOR process, since IOR only  consider an improve in the flow of hydrocarbons. 

Finally, it can be concluded that any process which attempt  to affect the residual oil saturation (Sor) will increase  oil production and recovery factor as well, thus can be  considered as an Enhanced Oil Recovery (EOR) process.

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