Assessing Productivity Impairment of Surfactant-Polymer EOR Using Laboratory and Field Data

Abstract

Surfactant-polymer (SP) flooding is an enhanced oil recovery (EOR) technique used to mobilize residual oil by lowering the oil-water interfacial tension, micellar solubilization, and lowering the displacing phase mobility to improve sweep efficiency. Surfactant-polymer flooding, also known as micellar flooding, has been studied both in the laboratory and field pilot tests for several decades. Surfactant polymer flooding is believed to be a major enhanced oil recovery technique based on laboratory experiments; however, its applications to field has not met the expectations of laboratory results. Successful field applications of SP flooding have been limited because of a number of obstacles, which include the large number of laboratory experiments required to design an appropriate SP system, high sensitivity to reservoir rock and fluid characteristics, complexity of reservoirs, infrastructure required for field implementation, and lack of reliable statistics on successes of field applications. In other words, there are many variables that affect reservoir performance. Traditionally, in SP flooding, a tapered polymer solution follows the injected surfactant slug. However, in recent years co-injection of surfactant and a relatively high concentration of polymer solution have been used in several field trials. Despite significant increase in oil recovery at early times in several surfactant-polymer floods, the increase in oil production period has had short duration followed by significant reduction in oil production. Thus, this research primarily relied on field test data to understand the problem, hoping that an improved solution strategy can be developed for new field applications. Second, current numerical models do not correctly predict the performance of surfactant-polymer floods and tend to over predict. Thus the second objective of this research was to develop a methodology to use combined field and laboratory data in commercial simulators to improve their predictive capability. iv TABLE OF CONTENTS

Historical and recent observations in polymer floods: An update review

“…During the single phase, experiment polymer was injected in a water-saturated core (in absence of oil). Results of this experiment did not suggest any adverse polymer-rock interaction and the residual resistance factor reported (RRF = 2.5) can be considered reasonable compared to those documented in the literature (Izadi, 2015;Martin, Donaruma & Hatch, 1982). However, polymer injection in tertiary mode did show a significant pressure increase (80 psi) and a poor incremental oil recovery (≈ 3% of the OOIP) after the injection (at 0.15 cc/min) of approximately 3 PV and 2 PV of polymer and brine with lower salinity (TDS = 35,000 ppm), respectively.…”

“…Izadi, M., Kazemi, H., Manrique, E., Kazempour, M., & Rohilla, N., (2014) and Izadi (2015) recently reported the abnormal pressure response observed during a tertiary polymer flood experiment ( Figure 5). In this research, a polymer solution was injected in 1 ft. Berea core plugs in a single phase (Figure 5a) and at irreducible oil saturation to water (Figure 5b).…”

Optimization and comparison between polymer, surfactant-polymer and water flooding recoveries in a pre-salt carbonate reservoir considering uncertainties.

“…From this total, only 3 of the 33 projects on the U.S were performed on carbonate reservoirs, according to Manrique et al (2007). Additionally, two more recent projects can be added to this list, the Illinois pilot (IZADI et al, 2018), and the Middle East pilot performed by Total S.A on an offshore carbonate reservoir (MOREL et al, 2016) summing up 44 projects.…”

“…From these projects mentioned previously, Sheng (2011), Zhu et al (2012) and Manrique (2007) describe 12 of these projects, and they can be defined as the projects more documented in the literature. From this, it can be concluded: Source: MANRIQUE; MUCI; GURFINKEL, 2007;MOREL et al, 2008;SHENG, 2011;ZHU et al, 2012;CHAUHAN, 2014;IZADI et al, 2018; Next, will be introduced some field implementations, laboratory applications and simulation research relevant to this study as a guide for the work developed.…”

“…Despite the challenges and risks, it was categorized as a success as safety was maintained during all the project, a significant oil desaturation was achieved, the tracer injection was a success as it helps evaluate the uncertainties on porosity channels, residual oil saturation, and reservoir dispersity. It was reporting a reduction of oil saturation of approximately 4 units of saturation within 1 meter around the well Izadi et al (2018). reported a technically successful SP injection on a pilot scale on the Illinois basin.…”