Comparative Study of Using Nanoparticles for Enhanced Oil Recovery: Wettability Alteration of Carbonate Rocks

Abstract

Nanofluids have been recently proposed as new chemical agents for enhanced oil recovery from oil reservoirs. Various nanofluids have been studied in that regard and reported in the literature, verifying the capability of nanostructured materials in enhancing the oil recovery through alteration of rock wettability. In this study, the impacts of different nanofluids of zirconium dioxide (ZrO 2 ), calcium carbonate (CaCO 3 ), titanium dioxide (TiO 2 ), silicon dioxide (SiO 2 ), magnesium oxide (MgO), aluminum oxide (Al 2 O 3 ), cerium oxide (CeO 2 ), and carbon nanotube (CNT) on the wettability of carbonate rocks were investigated. A series of preliminary contact angle evaluations were performed to screen the nanoparticles. The performances of the selected nanofluids were evaluated by spontaneous imbibition and core flooding experiments. Results of spontaneous imbibition tests and coreflooding experiments confirm the active roles of CaCO 3 and SiO 2 nanoparticles for enhancing oil recovery. In addition, the effect of nanofluid injection on rock surface wettability was examined by drainage capillary pressure measurement. It is shown that the irreducible water saturation and the entry capillary pressure were both increased after treatment by CaCO 3 nanaofluid. Moreover, the structural disjoining pressure gradient is proposed to be the responsible mechanism for changing wettability. Both experiments and theoretical calculations prove that disjoining pressure of the nanoparticles layer near the contact point can be high enough to remove oil from the surface.

Review on enhanced oil recovery by nanofluids

“…Many types of nanoparticles utilized for EOR are made of materials, for example, silica (Nazari Moghaddam et al, 2015) or graphene (Luo et al, 2016). These materials usually do not react chemically or physically with the in-situ fluids (oil, formation water, etc.)…”

“…They did not present any change of IFT by the addition of nanoparticles. Nazari Moghaddam et al (2015) investigated the performances of eight different nanoparticles for wettability alteration from oil-to water-wetness in carbonate rocks. The core flooding results showed an increase, about 8-9%, in oil recovery by injecting the nanofluids with CaCO 3 and SiO 2 nanoparticles of 35-40 nm.…”

Effect of Silica Nanoparticles on Fluid/Rock Interactions during Low Salinity Water Flooding of Chalk Reservoirs

“…Few investigations have addressed the applicability of NPs to carbonate reservoirs [20][21][22][23][24]. Nazari Moghaddam, et al [25] compared the performance of different types of NPs in altering the wettability of carbonate reservoirs. Al-Anssari, et al [26] reported that silica NPs adhere to the calcite surface irreversibly and can alter the wettability of oil/mixed-wet to water-wet state.…”

Improved rheological properties and stability of multiwalled carbon nanotubes/polymer in harsh environment

“…In the last decade, nanoparticle (NP) dispersions have attracted great attention in oil industries due to the significant different properties of NPs compared to the same fine or bulk molecules. 1,2 One of the current state of the art techniques for increasing the amount of crude oil from an oil field [known as enhanced oil recovery (EOR)] involves improvement of polymer characteristics such as rheological behavior with the help of NPs. [3][4][5] Polymer flooding is a robust chemical flooding method with more than 40 years' precedent.…”