CO2 Foam Stability Improvement Using Polyelectrolyte Complex Nanoparticles Prepared in Produced Water

Abstract

Abstract:Despite the increasing interest in CO 2 foam flooding for enhanced oil recovery applications, it is challenging to have a successful field operation as the performance of the surfactant is often affected by the presence of crude oil and salinity of the water. It is also challenging to dispose of huge amounts of water associated with the field operation. Due to the incompatibility of the produced water with chemicals used in the foam system, the produced water cannot be used as an injecting fluid. The objective of this project is to design a chemical system compatible with produced water which may fully utilize the oil field produced water as an injecting fluid and make the foam injection economically viable and environmentally friendly. In this study, we investigate the performance of a foam system with a surfactant and the addition of polyelectrolyte and polyelectrolyte complex nanoparticles (PECNP) in various salinities of produced water. A recipe is developed to prepare a nanoparticle solution that is sustainable in high salinity produced water. The rheological property of the foam, the stability, and durability of the foam with and without the presence of crude oil are measured and compared as the water salinity is changed. It is found that foam stability and durability deteriorated when water salinity increased. However, by the addition of polyelectrolyte and PECNP in the system, the foam stability and durability was improved even in high salinity water with or without the presence of crude oil.

A Novel Approach to Stabilize Foam Using Fluorinated Surfactants

“…Selection of surfactants for foaming application in EOR, CO 2 sequestration, hydraulic fracturing, and other upstream applications is a challenging task [17][18][19][20][21][22][23][24][25]. A surfactant for foaming applications should be generally thermally stable, compatible with reservoir brine and other chemicals, have lower adsorption on reservoir rock, have high foamability and foam stability, and should be economically viable [26][27][28][29][30].…”

Experimental and Mechanistic Study of Stabilized Dry CO2 Foam Using Polyelectrolyte Complex Nanoparticles Compatible with Produced Water To Improve Hydraulic Fracturing Performance

“…The surfactant was dissolved in 33.3 and 66.7 kppm brines to form 1 w/w % reference solutions. Polyelectrolyte complex nanoparticles (PECNP) were prepared according to the procedure developed by Barati and co-workers. ,, Branched polyethylenimine (PEI) was obtained from Sigma-Aldrich with an average molecular weight of 25 000 g/mol, 1.03 g/mL density at 25 °C, and corresponding viscosity ranging between 13 000 and 18 000 cP at 50 °C. DS was provided from Sigma-Aldrich with 500 000 g/mol molecular weight.…”

“…The mixing ratio of PEI to DS to the diluting brine solution (PEI:DS:brine) was chosen to be 3:1:0.1 to make positively charged nanoparticles. This ratio was developed based on previous observations with zeta potential and particle size measurements. , The nanoparticle solution was mixed with surfactant solutions (1 w/w %) in both 33.3 kppm and 66.7 kppm brine systems for 20 min to form the PECNP/surfactant complexation with different mixing ratios of PECNP:surfactant (1:9, 2:8, 3:7, and 4:6). The concentration of the surfactant remains constant in mixing with nanoparticles (1 w/w %).…”

“…To understand the underlying mechanism of synergistic electrostatistic complexation between surfactant and polymer in the bulk lamella mixture, Raman spectroscopy was employed. In order to tailor ionic activity of surfactants and to decrease the rate of lamellae drainage, polyelectrolyte complex nanoparticles were developed by our group for both enhanced oil recovery (EOR), reservoir treatment, and hydraulic fracturing applications. ,− Interactions between the polyelectrolytes and oppositely charged sites on the surfactant create a variety of different colloidal systems with liquid crystalline-like mesostructured and long-range order on nanometer scale. The supercharged and stable nano aggregates in high-salinity produced water are capable of stabilizing the CO 2 –water interface to resist against the shear around the wellbore, to carry the proppants to the fracture, and to reduce leak-off in tight formations.…”

A micro-scale rheometer to study foam texture and flow resistance in planar fractures

“…One option, to improve the fluid transport efficiency through fractures and increase the recovery of non-aqueous phase liquids for aquifer remediation, is to reduce the gas mobility by foaming the injectant. [5][6][7][8][9][10][11][12][13] Foam provides mobility control in fractures and systems featuring large permeability contrasts. [14][15][16][17] Accurate and detailed understanding of foam physics contributes to successful use of foam for aquifer remediation, improved hydrocarbon recovery efficiency, and hydraulic fracturing.…”