A Pilot Test of Surfactant Flooding in the Big Muddy Field
Authors: Gilliland Harold E. , Conley Francis R. 
Published: December 2007

American Institute of Mining, Metallurgical, and Petroleum Engineers, Inc.
This paper was prepared for the Improved Oil Recovery Symposium of the Society of Petroleum Engineers of AIME, to be held in Tulsa, Okla., March 22–24, 1976. 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 paper is presented. Publication elsewhere after publication in the JOURNAL OF PETROLEUM TECHNOLOGY or the SOCIETY OF PETROLEUM ENGINEERS JOURNAL is usually granted upon request to the Editor of the appropriate journal provided agreement to give proper credit is made. provided agreement to give proper credit is made. Discussion of this paper is invited. Three copies of any discussion should be sent to the Society of Petroleum Engineers office. Such discussion may be presented at the above meeting and with the paper, may be considered for publication in one of the two SPE magazines.

Abstract
Early response and a high oil displacement efficiency are occurring in a pilot surfactant field test currently underway in Wyoming. The watered out reservoir was selected after an intensive screening program and extensive laboratory testing of surfactant systems.
Peak oil production rate from the 1.2-acre Peak oil production rate from the 1.2-acre 5-spot was 38 bopd at an oil cut of 19%. Current oil production rate is 15 bopd at an 8% oil cut. Test completion is projected for the latter half of 1977.

Introduction
Over the years, numerous methods have been tried to bolster declining oil production rates and to increase ultimate recovery from petroleum reservoirs. In the United States, petroleum reservoirs. In the United States, the most successful processes have been waterflooding and low pressure gas injection. Unfortunately, even the best of these so-called secondary recovery methods typically leaves about 50 percent of the original oil in place in the ground. Intensive research efforts to develop other "tertiary" methods for recovery of additional oil from existing reservoirs have been underway since the early 1950's and continue to present. Of the suggested tertiary recovery methods, chemical flooding has the potential for the widest application in the United States.
What is a chemical flood? While many types of chemical floods have been described in the literature, there are really only three processes receiving much attention today processes receiving much attention today surfactant waterflooding, caustic flooding (which is a special type of surfactant flood), and mobility controlled polymer waterflooding. Surfactant waterflooding is the most important of the three chemical flooding processes. To understand the purpose of a surfactant flood, it is instructive to look at waterflooding in a little more detail. The amount of oil that will be recovered during a waterflood is a function of three efficiency factors.
The areal sweep efficiency is the fractional area of the reservoir that can be swept by injected fluids and depends on three parameters - the type of injection pattern, the parameters - the type of injection pattern, the economic life of the flood, and very importantly the ratio of the mobility of the injected fluid to that of the produced fluid.