Wettability Alteration of Heavy-Oil-Bitumen-Containing Carbonates by Use of Solvents, High-pH Solutions, and Nano/Ionic Liquids

Abstract

Summary Capillary imbibition tests are commonly applied to measure wettability-alteration potential of chemicals. However, these tests are exhaustive, time-consuming, and expensive, and the underlying physics of the alteration process from a surface-chemistry point of view is often limited and/or unexplained. Contact-angle measurement is a quicker and more-feasible screening tool to assess the emerging wettability modifiers. It also provides visual data on the mechanics of the wettability-alteration process. This paper focuses on contact-angle measurements as a means to evaluate the wettability alteration on mineral plates and porous-rock samples. Imidazolium ionic liquids were tested at different concentrations. To study the effect of pH on the wettability, sodium chloride and sodium borate were used at different concentrations. The composition of divalent ions was varied because of their possible use with low-/high-salinity water as wettability-alteration agents. Unmodified and surface-modified silica, zirconium, and alumina nanoparticles were also tested. Contact-angle measurements were performed initially on mica, marble, and calcite plates. Experiments were repeated on polished surfaces of Berea sandstone, Indiana limestone, and cleaned Grosmont carbonate cores. Oils (pure and solvent-mixed crude oils) with different viscosities and densities were used to test the effect of oil type on the process. The images were obtained by an single-lens reflex (SLR) camera at different temperatures ranging from 25 to 80°C. By testing with different concentrations, the optimum chemicals were found for different mineral-plate/porous-rock systems. Then, the results were cross checked with the imbibition tests performed on the same samples to validate the contact-angle-measurement observations. Thermal-stability tests were also performed in case of their use during or after a thermal method. For the thermal-stability tests, contact-angle experiments were conducted in a high-pressure and high-temperature (up to 200°C) cell. It was shown that certain ionic liquids and nanofluids are stable at high temperatures and can be efficiently used at low concentrations.

Reconsideration of Steam Additives to Improve Heavy-Oil Recovery Efficiency: Can New Generation Chemicals Be a Solution for Steam-Induced Unfavorable Wettability Alteration?

“…Maghzi et al, 28 through a micromodel experimental study, concluded that dispersed silica nanoparticles could improve the wettability state from originally oil-wet to a strongly water-wet state, yielding to incremental oil recovery. Similar behavior of this wettability alteration, in a high-temperature condition, was also observed by Cao et al, 29 Wei and Babadagli, 7 and Mohammed and Babadagli. 30 The use of zirconium oxide was also reported to be effective in altering the wettability of the rocks; Karimi et al 31 and Nwidee et al 32 concluded that zirconia nanofluids could alter the wettability of the carbonates to a more waterwet state.…”

“…To summarize, the ZrO 2 nanofluid presented a more favorable performance compared to the SiO 2 nanofluid in terms of wettability alterationparticularly on a quartz surface and interfacial tension reduction. Cao et al also confirmed through their research in nanofluids that the ZrO 2 nanofluid performed more favorably than the SiO 2 nanofluid in altering the wettability at elevated temperatures but not at steam conditions.…”

Experimental Pore-Scale Study of a Novel Functionalized Iron-Carbon Nanohybrid for Enhanced Oil Recovery (EOR)

“…Major EOR mechanisms of nanofluid flooding including wettability alteration to more water-wet, interfacial tension (IFT) reduction, the decrease of the oleic phase viscosity, disjoining pressure, and preventing asphaltene precipitation have already been investigated in the literatures. The general mechanism of wettability alteration has been well studied and reported by recent studies [ 1 , 3 ]. The IFT reduction between oil and injected fluid is one the main effective mechanisms relevant to enhanced oil recovery.…”

Direct Pore-Level Visualization and Verification of In Situ Oil-in-Water Pickering Emulsification during Polymeric Nanogel Flooding for EOR in a Transparent Three-Dimensional Micromodel

“…It also appears to be an alternative for improving different engineering processes in the oil and gas industry, including reservoir characterization, reservoir management, drilling, , and completion process . Besides, the injection of NPs in the form of nanodispersions has also attracted the attention of being used as a potential EOR method due to its small size (1–100 nm) and many other promising interfacial properties. − Currently, it is widely accepted that the NPs could adsorb onto the interface of two immiscible fluids, − and this process helps recover more oil by reducing interfacial tension (IFT), ,,, altering wettability, − modifying disjoining pressure, , and stabilizing Pickering emulsions. − However, the mechanisms of NPs for extra oil recovery are still not well understood so that field applications are not widely applied and relevant research mostly is based on laboratory core flooding experiments. − …”