Production

Enhanced Oil Recovery with ASP Flooding 







  



	Using alkali-surfactant-polymer (ASP) flooding to retrieve oil reserves in mature wells gets a boost. 


	
	
by Greg Kriebel, Fluid Dynamics


	

	



	

	

	The debate of whether more onshore and offshore drilling for oil and gas within the U.S. should occur has become a political football game, with the respective sides unwilling to budge from their long-held positions.




	Currently, vast reserves of conventional oil deposits are below our feet and have only been partially tapped. These deposits may have been discovered as many as 50 years ago, but their wells were capped when reduced recovery rates no longer made them cost-efficient.




	Now, recent advances in oil production and oil recovery technology can make those old, supposedly played-out wells vibrant producers again. The challenge is finding and using the correct—and most cost-effective—technology to retrieve these previously hard-to-reach oil deposits.




	This article identifies a new method of enhanced oil recovery (EOR) that relies on the injection of a chemical concoction consisting of alkalis, surfactants and polymers into the well to help the trapped oil rise to the surface.




	Unrecovered Oil




	The most difficult parts of oil production are locating the deposit and drilling the wells. When wells are first drilled, the product is flowing freely. This is known as primary recovery. During this time, as little as 10 percent of the reservoir’s oil makes its way up the well bore. After a few years, the natural pressure of the reservoir is no longer enough to produce oil.




	In the past, significant deposits remain trapped underground, and the well was abandoned because of economic restraints on production. The company would then initiate secondary recovery. In this stage of production, water is injected into the reservoir where it displaces the oil, allowing it to flow to the well bore and up to the surface. This secondary recovery process can generally recover between 20 and 40 percent of a reservoir’s remaining oil.




	This means that anywhere from 50 to 70 percent of the reservoir’s recoverable product is still underground. At this point, the oil producer has two options:



    
	
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		Initiate one of many EOR operations (gas injection, chemical injection or thermal recovery)
	
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		If the cost of EOR is too prohibitive, cap the well and move on to the next
	
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	For years, many wells were abandoned because the cost of EOR operations outweighed the return that would be realized on the recovered oil. However, that has changed in recent years for two reasons:



	
	







			
	

  


  

    

          
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