Browsing by Author "Xingguang Xu"
Now showing 1 - 3 of 3
Results Per Page
Sort Options
Item A comprehensive review on CO2 thickeners for CO2 mobility control in enhanced oil recovery: Recent advances and future outlook(Journal of Industrial and Engineering Chemistry, 2023-06-16) Emanuel X. Ricky; Grant Charles Mwakipunda; Edwin E. Nyakilla; Naswibu A. Kasimu; Chao Wang; Xingguang XuCarbon dioxide (CO2) has been utilized to recover the residual oil from the geological reservoirs through enhanced oil recovery (EOR) methods for over 50 years. Despite its long history of success as an EOR technique, CO2 flooding recovers only about 20–40% of the original oil in place (OOIP) from the geological reservoirs. The small amount of oil recovered by CO2 flooding is associated with the low viscosity of CO2 injected into the reservoir, resulting in CO2 viscous fingering, CO2 gravity override and unfavourable mobility. To address these problems, the CO2 viscosity needs to be enhanced considerably using CO2 thickeners or viscosifiers. Despite more than five decades of intensive research work in formulating and identifying effective CO2 thickeners such as polymers, surfactants, small molecules and nanoparticles; as yet none of these chemicals can be regarded as effective CO2 thickeners for EOR field applications. Thus, CO2 thickener is an interesting research topic for future studies to come up with effective and affordable CO2 thickeners for EOR field applications. This article presents the recent developments in CO2 thickening technologies in EOR. Furthermore, the CO2 thickening mechanisms, screening criteria, field scale applications, challenges and future research directions on CO2 thickeners are evaluated.Item Modified Corn Starch as an Environmentally Friendly Rheology Enhancer and Fluid Loss Reducer for Water-Based Drilling Mud(Society of Petroleum Engineers, 2022-01-07) Emanuel Xwaymay Ricky; Musa Mpelwa; Chao Wang; Bahati Adnan Hamad; Xingguang XuDrilling fluid rheology and fluid loss property are fundamental parameters that dictate the effectiveness and easiness of a drilling operation. Maintaining these parameters under high temperatures is technically challenging and has been an exciting research area for the drilling industry. Nonetheless, the use of drilling mud additives, particularly synthetic polymers threatening the ecological environments. Herein, modified corn starch (MCS) was synthesized, characterized, and investigated as an environmentally friendly rheology enhancer and filtration loss controlling agent for water-based mud (WBM) at high temperatures. The experimental results indicated that MCS exhibits better performance in improving rheological properties and fluid loss controlling ability for WBM than the commonly used mud additives. With the addition of an optimal concentration (0.3 wt%), MCS improved the rheology and fluid loss behaviour of WBM formulation at harsh ageing temperature (220 °C) practically 4 times and 1.7 times, respectively. The MCS was revealed to perform superbly over polyanionic cellulose (PAC) addition at all investigated temperatures. The better performance of the MCS was ascribed to the improved entanglements in the mud system due to the additional hydroxyl (OH) groups. Besides, the Herschel–Bulkley model was found to be a constitutive model that described the rheological properties of the investigated muds satisfactorily. Moreover, the MCS was found to exhibit acceptable biodegradability properties.Item Nanoparticle-Assisted Surfactant/Polymer Formulations for Enhanced Oil Recovery in Sandstone Reservoirs: From Molecular Interaction to Field Application(American Chemical Society, 2023-10-29) Athumani Omari Mmbuji; Ruibo Cao; Yang Li; Xingguang Xu; Emanuel Xwaymay RickyThere has been some success with polymer and surfactant injections into depleted sandstone reservoirs for reducing residual oil saturation and improving oil recovery. However, their microemulsion stability is compromised in the harsh conditions of high temperature and salinity. Nanoparticle addition to the polymers and surfactant has resulted in a nanofluid with more stability, improved rheological behaviors, reduced adsorption loss, and much more as a result of the synergistic effects of their components. In this work, the performance of polymeric and surfactant nanofluids and the factors that impair their efficacy were highlighted. Numerous surfactant adsorption mechanisms, such as ion pairing, ion exchange, hydrogen bonds, dipole interactions, and hydrophobic interactions, on the rock surface were illustrated. Synergistic interactions of ternary phases of surfactant, polymer, and nanoparticles to the interfacial tension reduction, wettability alteration, adsorption reduction, rheological enhancement, and nanofluid stability for enhanced oil recovery were also presented. Additionally, the prevailing challenges and their plausible interventions have been highlighted in this review. The summarized results from published papers based on experimental evidence and theoretical deductions presented in this review will uplift the understanding of the screening, designing, and formulation of nanofluids.