Field Test of an Aqueous Surfactant System For Oil Recovery, Benton Field, Illinois

Abstract

French, M.S., SPE-AIME, Shell Oil Co. Keys, G.W., SPE-AIME, Shell Oil Co. Stegemeier, G.L., SPE-AIME, Shell Oil Co. Ueber, R.C., SPE-AIME, Shell Oil Co. Abrams, A., SPE-AIME, Shell Development Co. Hill, H.J., SPE-AIME, Shell Development Co. In this pilot study, which involved drilling five process wells, three observation wells, and four evaluation core holes, there were four injection phases:a preflood,a slug of chemical solution,a drive solution, anda fresh-water flood. Although the oil cut in the pilot increased appreciably, the chemical system would have to be modified pilot increased appreciably, the chemical system would have to be modified for commercial application of the process. Introduction A tertiary process for recovering oil left by conventional waterflooding has been applied in a 1-acre pilot in the Benton field, Franklin County, III. The pilot was a five-spot pattern with three observation wells drilled around one injection well to provide data for early evaluation of the process (see Fig. 1). The process tested in the pilot consisted of four injection phases:a preflood of low-salinity water to displace the high-salinity formation water from the vicinity of the injection wells;a slug of chemical solution that contained a surfactanta controlled-mobility drive solutionan ordinary waterflood with fresh water. The chemical slug used in Phase 2 was based upon work by Hill et al., carried out in the Shell Development Co. Bellaire Research Center. Adsorption and mobility experiments in small Benton cores provided the technological design requirements for the chemical system. However, both technological and economic factors were considered in arriving at the final design. During the operation of the pilot, one of the injectors experienced poor receptivity and was abandoned before significant chemical was injected. After the four phases had been injected, four core holes were cored through the objective zones and swab-produced to provide data on reservoir conditions. Reservoir Characteristics The Tar Springs sandstone in the Benton flood unit is a northwest-southeast trending distributary channel bordered on both sides by delta fringe deposits. The 1-acre pilot site was located in the fringe portion in the southern part of the field (see Fig. 2). Only the upper 20-ft sand interval was included in the chemical pilot, with impermeable layers separating this interval pilot, with impermeable layers separating this interval from the remaining sand, This site was selected because of suitable sand thickness, low-permeability layers above and below the sand representing layering in much of the field, and sand quality representative of most of the field. Restriction of the test to the 20-ft interval reduced the cost of the project and the time required to complete the test. The interval selected for the pilot can be sub-divided into three zones on the basis of sedimentary features, average permeability, and frequency distribution of permeability. The upper zone (Zone A) averages 8 ft in thickness and consists of ripple-bedded, very fine-grained sandstones; the middle zone (Zone B) averages approximately 4 ft in thickness and consists of medium-scale, cross-bedded, fine-grained sandstone; the lower zone (Zone C) averages 10 ft in thickness and is similar in appearance to Zone A. These three zones appear in the same order in all wells at the pilot site. Porosity averages about 17 percent. Pore volume in Zone B was 4,970 bbl. JPT P. 195

Laboratory and Field Studies on Gravitational Effect in Low-Tension Waterflooding

“…Laboratory result on residual oil saturation distribution after low-tension waterflooding published by T~r~k and Gesztesi [6], reported analyses of cores drilled after surfactant flooding for the Benton and Loudon tests by French et al . [10] and Reppen et al . [11] support these ideas .…”

Essentials of Upscaling Surfactants for EOR Field Projects

“…Surfactants, or surface active agents, have a long history in the detergent consumer industry and in oilfield applications. The application of surfactants for chemical enhanced oil recovery (cEOR) started in the late 1960s [1] and early 1970s [2][3][4] and further developed during the 1980s [5,6] and included field scale evaluations [7][8][9][10]. The co-surfactant-enhanced alkali flooding process [5] that was evaluated in a trial at White Castle [9] can be considered the predecessor of alkali surfactant polymer (ASP) flooding.…”

Wettability Alteration in Carbonate Rocks by Implementing New Derived Natural Surfactant: Enhanced Oil Recovery Applications

“…Their infrared that their proposed natural surfactant has high performance in producing oil from carbonate oil reservoirs by means of interfacial tension reduction and mobility control approach Shadizadeh 2012, 2013a, b;Zendehboudi et al 2013). The practical possibility of oil recovery with the aim of surfactant flooding was illustrated in early field projects by various experts in upstream (Gogarty and Surkalo 1972;Earlougher et al 1976;Hill et al 1973;French et al 1973;Pursley et al 1973;Pursley and Graham 1975;Lake and Pope 1979) once, massive investigations contributing the bulk oil recovery characterization of surfactant floods have been dabbled in. The majority of these researches have carried out the effects of phase behavior (Lake and Pope 1979), wettability (Sheng 2010), interfacial tension (Ravari et al 2011;Shen et al 2010;Zhang et al 2010;Yu et al 2010;Babadagli 2006), water mobility (Zhang et al 2010), and foaming performance ) on the performance and robustness of oil recovery utilizing surfactant floods, although there are gigantic investigations on chemical EOR with the aim of surfactant floods at the large scale (Pope 1980;Hirasaki and Zhang 2004;Liu et al 2007;Hirasaki et al 2011).…”