Foamflooding subterranean enhanced oil recovery

During the enhanced recovery using the core rock, 0.45 g of oil was collected and the produced water phase was still cloudy with the presence of the surfactant. For the oil specific gravity of 0.83, 1 pore volume corresponds to 8.3 0.8 g of oil. For a total recovery of 10.45 g of oil, this means that the surfactant was able to recover the last remaining oil in the core holder additional volume of recovered oil came from the fiow lines which amounted to 2 ml (1.9 g) at most. Also, from this example run, the multifunctional multipolymeric surfactant was capable of delivering about three times the amount of oil compared to that of tertiary recovery waterflooding. 

multifunctional multipolymeric surfactant-thickener mixtures generated from the FRRPP process are proposed to be used in the recovery of oil from subterranean sources from waterflooding operations. The idea is to simply add the surfactant into the water in the injection well and enhanced production of oil (at least three times the rate compared to waterflooding) can be realized in the production wells. Surfactant-thickener mixtures can also be recycled and can function as demulsifiers, which add to the viability of the oil recovery operation. 

In this section, we present the potential of using VA7AA-based copolymers from the FRRPP process as foaming surfactants in the recovery of crude oil that is trapped in various rock formations. Aside from the widely positive oil recovery performance characteristics of VA/AA copolymers that will be described below, a review of the raw material cost structure also points to its possibility of being commercially available in the future as shown its relatively simple projected manufacturing operation depicted in Fig. 5.2.1 (Caneba and Axland, 2002). 

The atmospheric static foam test method (Borchardt et al., 1988) was used in order to determine comparative performance of the neutralized VA/AA surfactant. In a 25-ml graduated cylinder, 10 ml of 0.5wt% surfactant in brine (1.5X, which contained 15.57 wt% NaCl and 1.14 wt% CaCl2), and 3 ml crude oil were mixed by vertical shaking, and the foam volume measured vs time. Two kinds of crude oil were used a heavy one and a light one. 

Emulsions from VA/AA copolymers in distilled water were viewed using an optical microscope (Zeiss Axioplan 2 from Zeiss, Thornwood, NY) at lOOX and 400X magnifications. A drop of emulsion was placed between glass slides. Frames of i were captured using the Scion ImagePC computer software and stored onto disks as an image files. 

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