Sweep Efficiency of Heavy Oil Recovery by Chemical Methods

“…Thermal processes such as steam-assisted gravity drainage (SAGD), cyclic steam stimulation (CSS), steam flooding, and in situ combustion are normally applied during heavy oil recovery. However, the loss of heat to aquifers, overburden, and under burden makes their application noneconomic. , Nevertheless, the freshwater requirement for steam generation coupled with the emission of CO 2 , and higher wastewater treatment costs, makes the thermal recovery methods less appropriate for heavy oil recovery and calls for more nonthermal methods to produce heavy oil. , As such, emulsion formulation via chemical injection is a nonthermal recovery approach recently evidenced for heavy oil recovery …”

Section: Introductionmentioning

confidence: 99%

Formulation of Spontaneous In Situ Emulsification Using Sodium Lauryl Sulfate Grafted Nanopyroxene for Enhanced Heavy Oil Recovery in Sandstone Reservoirs

et al. 2023

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Heavy oil recovery presents enormous challenges during production, especially in thin reservoirs, where thermal recovery is inefficient. To overcome these challenges, chemically heavy oil recovery methods are extensively used. Herein, we formulated a new class of stable nanofluids from surfactant-coated nanomaterials to improve the microscopic displacement efficiency and recover a medium-viscosity heavy oil. Our nanofluid consists of an anionic surfactant, sodium lauryl sulfate (SLS), grafted on the surface of nanopyroxene to be used as an emulsifier that can instinctively emulsify heavy oil by minimal agitation designed for heavy oil enhanced oil recovery (EOR). Optimum screening of the designed emulsions was performed by interfacial tension (IFT) measurements and emulsion stability testing. The droplet size distribution and microscopic morphology of the created emulsions were observed by an optical microscope, dynamic light scattering testing, and magnetic resonance imaging. Afterward, the EOR mechanism of emulsions was investigated by core flooding studies with the aid of NMR and/or computer tomography (CT). The characterization results showed that our synthesized nanoparticles were successfully grafted with the anionic surfactant. Then, the grafted surfactant-nanopyroxene resulted in an ultralow IFT and hence stable oil/water emulsions (E1). Moreover, the synergy effect between nanopyroxene and SLS was further enhanced by adding 0.2 wt % NaOH, which greatly improved the capability of emulsification (E2). As a result, the designed formulation E1 and/or E2 emulsified heavy crude oil by applying a minimum force. Notably, crude oil in small pores was more effectively displaced by the E2 system than E1. Consequently, E2 exhibited a higher EOR efficiency than the E1, SLS, and SLS+NaOH systems. E2 recovered (34.4%) compared to E1 (18.5%), SLS (16.2%), and SLS +NaOH (1.2%). This work revealed the EOR mechanism of the surfactant grafted nanoparticle systems from the level of the pore structure using NMR and CT scan.

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“…The resulting mineral dissolution and precipitation can modify the porosity and permeability of the reservoirs and caprocks, affecting injectivity of the reservoirs and long-term storage security (Johnson et al, 2001(Johnson et al, , 2004Xu et al, 2011b). In EOR, low-salinity water is injected to the oil reservoir to improve sweeping efficiency by modifying wettability via surface complexation reactions (Zhang et al, 2006;Kumar et al, 2011). In the shallow subsurface, LNAPL contamination of groundwater is a widespread environmental problem.…”

Section: Introductionmentioning

confidence: 99%

The Effect of Pore-Scale Two-Phase Flow on Mineral Reaction Rates

Deng

Molins

2022

Front. Water

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In various natural and engineered systems, mineral–fluid interactions take place in the presence of multiple fluid phases. While there is evidence that the interplay between multiphase flow processes and reactions controls the evolution of these systems, investigation of the dynamics that shape this interplay at the pore scale has received little attention. Specifically, continuum scale models rarely consider the effect of multiphase flow parameters on mineral reaction rates or apply simple corrections as a function of the reactive surface area or saturation of the aqueous phase, without developing a mechanistic understanding of the pore-scale dynamics. In this study, we developed a framework that couples the two-phase flow simulator of OpenFOAM (open field operation and manipulation) with the geochemical reaction capability of CrunchTope to examine pore-scale dynamics of two phase flow and their impacts on mineral reaction rates. For our investigations, flat 2D channels and single sine wave channels were used to represent smooth and rough geometries. Calcite dissolution in these channels was quantified with single phase flow and two phase flow at a range of velocities. We observed that the bulk calcite dissolution rates were not only affected by the loss of reactive surface area as it becomes occupied by the non-reactive non-aqueous phase, but also largely influenced by the changes in local velocity profiles, e.g., recirculation zones, due to the presence of the non-aqueous phase. The extent of the changes in reaction rates in the two-phase systems compared to the corresponding single phase system is dependent on the flow rate (i.e., capillary number) and channel geometry, and follows a non-monotonic relationship with respect to aqueous saturation. The pore-scale simulation results highlight the importance of interfacial dynamics in controlling mineral reactions and can be used to better constrain reaction rate descriptions in multiphase continuum scale models. These results also emphasize the need for experimental studies that underpin the development of mechanistic models for multiphase flow in reactive systems.

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Sweep Efficiency of Heavy Oil Recovery by Chemical Methods

Cited by 10 publications

References 26 publications

Status of Alkaline-surfactant Flooding

Status of Alkaline-surfactant Flooding

Formulation of Spontaneous In Situ Emulsification Using Sodium Lauryl Sulfate Grafted Nanopyroxene for Enhanced Heavy Oil Recovery in Sandstone Reservoirs

The Effect of Pore-Scale Two-Phase Flow on Mineral Reaction Rates

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