Physicochemical properties of nano-enhanced colloidal gas aphron (NCGA)-based fluids

Abstract

Colloidal gas aphrons (CGAs) are progressive operational fluids used in different areas such as engineering fields due to their unique characteristics. In between, the application of nanoparticle in several fields of engineering has received considerable attention in recent years. However, little or no information is available regarding the application of nanoparticle in CGA suspensions. In this study, the size distribution of bubbles, stability, API filtrate and rheology of a new type of these fluids called nanoparticle-enhanced colloidal gas aphron (NCGA)-based fluids are investigated. NCGAs’ stability is studied by measuring drainage rate tests. Also, for the investigation of fluid flow behavior, six rheological models are exerted, and their applicability is studied. The results of this study show that CGA system along with nanoparticles can be a successful combination for efficient system stability, improved filter loss, and better rheological behavior. It showed that NCGA fluid with the composition of (% w/v): xanthan gum (XG): 0.571, starch: 4.286, surfactant: 0.857, NaCl: 0, and nanoparticles: 0.428, has the best efficiency in improving the NCGA fluid properties.

Appendix A: Rheological models

1.1 Bingham plastic

$$ \tau = \tau_{0} + \eta \gamma $$

(A.1)

Parameters constraints: $\tau_{0}$ ≥ 0 and $\eta > 0$.

1.2 Power Law

$$ \tau = k\gamma^{n} $$

(A.2)

Parameters constraints: k > 0 and 0 < n < 1.

1.3 Herschel–Bulkley

$$ \tau = \tau_{0} + k\gamma^{n} $$

(A.3)

Parameters constraints: $\tau_{0}$ ≥ 0, k > 0 and 0 < n < 1.

1.4 Casson

$$ \tau^{0.5} = \tau_{0} + k\gamma^{0.5} $$

(A.4)

Parameters constrains: $\tau_{0}$ ≥ 0 and k > 0.

1.5 Robertson–Stiff

$$ \tau = k(\gamma_{0} + \gamma )^{n} $$

(A.5)

Parameters constraints: $\gamma_{0}$ ≥ 0, k > 0 and 0 < n < 1.

1.6 Mizhari–Berk

$$ \tau^{0.5} = \tau_{0} + k\gamma^{n} $$

(A.6)

Parameters constrains: $\tau_{0}$ ≥ 0, k > 0 and 0 < n < 1.