Nano-fluid viscosity screening and study of in situ foam pressure buildup at high-temperature high-pressure conditions

Abstract

In this study, an industrial-based surfactant known as MFomax surfactant has been modified with unfunctionalized and silanefunctionalized silica nanoparticles (NPs) to select the high viscous nano-fluid (NF) for generation of in situ foam to assess the differential pressure buildup (∆p) behavior in the porous media. Different weight concentrations of NPs and MFomax from 0.1 to 0.5% were studied using Design Expert Software to generate full matrix design of NF formulations. The viscosity data were analyzed with the aid of response surface analytical tool to investigate the response of NPs loading on the NF viscosity for optimization. The microstructural properties of the NFs were characterized using spectroscopic equipment. Subsequently, the high viscous NF was selected to generate in situ foam in comparison with the precursor MFomax foam for ∆p buildup assessment at 110 °C and 2023 psi in the native reservoir core. Results have shown that both the silica NPs could significantly improve the MFomax viscosity; however, the silane-functionalized silica NPs have more effect to improve the viscosity and other microstructural properties than the unfunctionalized NPs, and thus, they were selected for further experimental studies. The coreflood ∆p buildup assessment shows that NF foam built more ∆p having average value of 46 psi against 25 psi observed in the case of the precursor MFomax foam. Thus, this study demonstrates that functionalized silica NPs could improve the MFomax viscosity and eventually generates high ∆p buildup at high-temperature high-pressure conditions.

Study on Screening and Evaluation of Foam Drainage Agents for Gas Wells with High Temperature and High Pressure

“…The relationship of initial foaming volume, half-life, and comprehensive index with pressure is shown in Figures – , respectively. It could be seen from the figures that with the increase of pressure, the initial foaming volume of FDAs increased except for UT-11C, and the half-life became longer, indicating that the high pressure would strengthen the foamability and foam stability, which was consistent with the classical foam theory . The classical foam theory held that the higher the pressure, the smaller the diameter of a single foam, and the more uniform the foam size .…”

“…It could be seen from the figures that with the increase of pressure, the initial foaming volume of FDAs increased except for UT-11C, and the half-life became longer, indicating that the high pressure would strengthen the foamability and foam stability, which was consistent with the classical foam theory. 28 The classical foam theory held that the higher the pressure, the smaller the diameter of a single foam, and the more uniform the foam size. 29 At the same time, the internal friction of the liquid phase increased with the increase of pressure; so, the viscosity of the liquid phase also increased, making the liquid on the foam liquid film difficult to flow and weakening the drainage effect, and thus the foamability and foam stability were enhanced.…”

The Effect of Pushing Rate on Foam Stability in the Tessari Method

“…Szabries and colleagues 18 showed that higher pressure increases foam stability while Tiuman and colleagues 19 demonstrated that higher pressure promotes foam stability by generating smaller bubbles, minimizing Plateau borders, and slowing down Ostwald ripening. Hamza and colleagues 20 observed and explained a similar phenomenon.…”

Distinguishing the Effect of Rock Wettability from Residual Oil on Foam Generation and Propagation in Porous Media

“…Two types of surfactants were tested in this study: first, C 14–16 alpha olefin sulfonate (AOS 1416 ), a commercial anionic surfactant from Stepan; second, a proprietary blend of AOS 1416 , cocamidopropyl hydroxysultaine, and cocoamidopropyl betaine, provided by PETRONAS Research Sdn, Bhd. − The tested surfactants will be referred as AOS and SB, respectively. The surfactant samples were tested as received with no treatments.…”