Drivers of Wettability Alteration for Oil/Brine/Kaolinite System: Implications for Hydraulic Fracturing Fluids Uptake in Shale Rocks
MetadataShow full item record
Hydraulic fracturing technique is of vital importance to effectively develop unconventional shale resources. However, the low recovery of hydraulic fracturing fluids appears to be the main challenge from both technical and environmental perspectives in the last decade. While capillary forces account for the low recovery of hydraulic fracturing fluids, the controlling factor(s) of contact angle, thus wettability, has yet to be clearly defined. We hypothesized that the interaction of oil/brine and brine/rock interfaces governs the wettability of system, which can be interpreted using Derjaguin–Landau–Verwey–Overbeek (DLVO) and surface complexation modelling. To test our hypothesis, we measured a suit of zeta potential of oil/brines and brine/minerals, and tested the effect of ion type (NaCl, MgCl2 and CaCl2) and concentrations (0.1, 1, and 5 wt %). Moreover, we calculated the disjoining pressure of the oil/brine/mineral systems and compared with geochemical modelling predictions. Our results show that cation type and salinity governed oil/brine/minerals wettability. Divalent cations (Ca2+ and Mg2+) compressed the electrical double layer, and electrostatically linked oil and clays, thus increasing the adhesion between oil and minerals, triggering an oil-wet system. Increasing salinity also compressed the double layer, and increased the site density of oppositely charged surface species which made oil and clay link more strongly. Our results suggest that increasing salinity and divalent cations concentration likely decrease water uptake in shale oil reservoirs, thus de-risking the hydraulic fracturing induced formation damage. Combining DLVO and surface complexation modelling can delineate the interaction of oil/brine/minerals, thus wettability. Therefore, the relative contribution of capillary forces with respect to water uptake into shale reservoirs, and the possible impairment of hydrocarbon production from conventional reservoirs can be quantified.
Showing items related by title, author, creator and subject.
A review on the influence of CO2/shale interaction on shale properties: Implications of CCS in shalesFatah, Ahmed ; Bennour, Ziad ; Ben Mahmud, Hisham ; Gholami, Raoof ; Hossain, Mofazzal (2020)© 2020 by the authors. Carbon capture and storage (CCS) is a developed technology to minimize CO2 emissions and reduce global climate change. Currently, shale gas formations are considered as a suitable target for CO2 ...
Pan, B.; Li, Y.; Wang, H.; Jones, Franca; Iglauer, Stefan (2018)CO 2 and CH 4 wettabilities of organic-rich shale are important physicochemical parameters that significantly influence CO 2 sequestration and CH 4 production. However, there is a serious lack of understanding of these ...
CO2 Wettability of Shales and Coals as a Function of Pressure, Temperature and Rank: Implications for CO2 Sequestration and Enhanced Methane RecoveryArif, M.; Barifcani, Ahmed; Zubair, T.; Lebedev, Maxim; Iglauer, Stefan (2016)The underground geological CO 2 storage into oil and gas reservoirs and/or saline aquifers is a promosing technique to reduce anthropogenic greenhouse gas emissions which thus ensures clean environment. CO 2 can also be ...