What Is It?
It’s a term applied to methods used for recovering oil from a petroleum reservoir beyond that recoverable by primary and secondary methods.
Stages Of Production:
Primary recovery :occurs when a well is initially put into production and the oil flows to surface naturally.
-Secondary recovery :occurs after the reservoir pressure declines and the well no longer flows oil to surface.
-as we take the oil out of the ground, so the pressure in the oil reduces, and the flow slows down.
-Tertiary recovery: involves more technically developed methods such as the injection of steam, chemicals, gases, microbes or heat.
Techniques Involved:
EOR includes five methods
Water flooding.
thermal recovery.
.gas miscible recovery
chemical flooding .
microbial flooding
-The thermal recovery methods are steam flooding, cyclic steam stimulation and in situ combustion.
-The gas miscible recovery methods are carbon dioxide flooding, cyclic carbon dioxide stimulation, nitrogen flooding and nitrogen-CO2 flooding.
-The chemical flooding methods are polymer flooding (including polymer gels), micellar-polymer flooding, and alkaline flooding.
-Microbial EOR methods include microbial flooding and cyclic microbial recovery.
to be contiued