The Effect of Polymer Additives on Oil Recovery In Conventional Waterflooding
Authors: Clay Terry D. , Menzie Donald E. 
Published: December 2007

This paper was prepared for the SPE Four Corners Regional Meeting to be held in Farmington, N. M., Sept. 9–10, 1966. Permission to copy is restricted to an abstract of not more than 300 words. Illustrations may not be copied. The abstract should contain conspicuous acknowledgment of where and by whom the paper is presented. Publication elsewhere after publication in the JOURNAL OF PETROLEUM TECHNOLOGY or the SOCIETY OF PETROLEUM ENGINEERS JOURNAL is usually granted upon requested to the Editor of the appropriate journal, provided agreement to give proper credit is made.

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This paper discusses the results of laboratory investigation utilizing water soluble polymer additives in conventional waterflooding. The investigation of polymer-flooding was performed while a student at The University of Oklahoma. A conventional waterflood was conducted through each core utilizing a 50,000 ppm brine solution as the displacing medium. Also, a polymer-flood was conducted through each core utilizing a 0.05 percent polymer solution as the displacing medium. The results of this investigation indicate that oil recovery at breakthrough and that ultimate oil recovery was increased when polymer solution was used as the displacing medium. Expressed as a percent of the original oil in place, the recovery at breakthrough ranged from 7.60 to 10.76 percent higher when compared with a conventional waterflood. Increased oil recovery after 2.5 pore volumes of fluid were injected ranged from 3.3 to 10.0 percent It was concluded from this investigation that increased oil recovery was a result of the viscosity effect of the polymer additive.

Introduction

It has been known for some time that certain water-soluble polymers thicken, or increase the viscosity of water. Also, it is known in petroleum research that conventional waterflooding is often times not successful or very efficient, because the displacing medium, water, has a much lower viscosity than the displaced medium, - oil. Therefore, water tends to seek a path of least resistance in the reservoir rock and bypasses large quantities of oil. If the viscosity of the displacing medium can be increased to some value approaching that of the oil, less bypassing or channeling of the flood water could be expected. That is, the mobility of the flood water would be decreased and a more piston-like displacement of the flood front could be anticipated.

In this investigation, a comparison of the following properties are made:

The viscosities of various polymer solutions. The mobility ratio or water-oil ratio of the flowing fluids in a conventional water-flood and a polymer-flood. The ultimate recovery in a conventional waterflood and a polymer-flood. The absolute permeability to water and to oil prior to and after a polymer-flood.