Browsing by Author "Wang, Xinglin"

Now showing 1 - 6 of 6
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    Application of magnetic nanoparticles as demulsifiers for surfactant-enhanced oil recovery
    (Wiley, 2023) Zhang, Leilei; Bai, Chutian; Zhang, Zhuqing; Wang, Xinglin; Nguyen, Thao Vy; Vavra, Eric; Puerto, Maura; Hirasaki, George J.; Biswal, Sibani Lisa
    Nonionic surfactants are increasingly being applied in oil recovery processes due to their stability and low adsorption onto mineral surfaces. However, these surfactants lead to the production of emulsified oil that is extremely stable and difficult to separate by conventional methods. This research characterizes the stability of crude oil mixed with a nonionic surfactant, L24–22, in a brine solution. When subjected to gravity separation, a middle oil-rich and bottom water-rich emulsion are generated for various water–oil ratios. Thermal treatments can effectively break oil-rich emulsions, but the bottom water layer remains contaminated with micron-sized crude oil droplets. A magnetic nanoparticle treatment is shown to demulsify the crude oil emulsions, dropping the total organic carbon (TOC) in the water layer from 1470 to 30 ppm.
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    Determination of fluid-phase-specific petrophysical properties of geological core for oil, water and gas phases
    (2024-03-05) Vinegar, Eva; Singer, Philip M.; Hirasaki, George J.; Chen, Zeliang; Wang, Xinglin; Vinegar, Harold J.; Rice University; Vinegar Technologies LLC; United States Patent and Trademark Office
    The following invention is used for determining the relative permeability of a fluid in a rock for three different phases: water, oil, and gas, in both conventional and unconventional formations. The permeability of a phase describes how much it can flow in porous media given a pressure gradient and is useful in evaluating reservoir quality and productivity. The following invention is a method to determine the three-phase relative permeabilities in both conventional and unconventional formations using NMR restricted diffusion measurements on core with NMR-active nuclei, combined with centrifugation of the core. In addition, the tortuosity, pore size (surface-to-volume ratio), fluid-filled porosity, and permeability is determined for each of the three phases in a rock.
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    Distinguishing the Effect of Rock Wettability from Residual Oil on Foam Generation and Propagation in Porous Media
    (American Chemical Society, 2021) Amirmoshiri, Mohammadreza; Wang, Xinglin; Bai, Chutian; Tewari, Raj Deo; Xie, Sheena Xina; Bahrim, Ridhwan Zhafri Kamarul; Singer, Philip M.; Farajzadeh, Rouhi; Biswal, Sibani Lisa; Hirasaki, George. J.
    One of the common challenges of applying foam for enhanced oil recovery is the foam instability in the presence of crude oil and nonwater-wet surfaces. In this experimental study, we systematically distinguish the effect of rock surface wettability from that of crude oil saturation on foam rheology under reservoir conditions. Neutral-wet Berea and reservoir sandstone cores are prepared by aging with crude oil, followed by the wettability index measurements. Transient foam generation and steady-state foam quality scans are conducted in neutral-wet cores, with/without water-flood residual oil. Nuclear magnetic resonance imaging is also utilized to measure the remaining oil saturation at the end of the foam-flood. It is shown that strong foam can be generated in a neutral-wet core with no residual oil because of the solubilization of the adsorbed crude oil components and the wettability alteration toward more water-wet conditions. However, in a neutral-wet core containing residual oil, foam generation is initially hindered. Foam generation occurs after injecting several pore volumes of surfactant solution and increasing the superficial velocity to overcome the minimum pressure gradient required for in situ foam generation. The findings from this study suggest that surface wettability in the presence of bulk oil saturation significantly affects transient foam generation. The final steady-state foam strength becomes comparable to the water-wet and oil-free case once the residual oil saturation is adequately reduced.
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    Method for determining the composition of natural gas liquids, mean pore-size and tortuosity in a subsurface formation using NMR
    (2021-08-24) Vinegar, Harold J.; Singer, Philip M.; Hirasaki, George J.; Chen, Zeliang; Wang, Xinglin; Rice University; Vinegar Technologies LLC; United States Patent and Trademark Office
    New methods for determining the volumetric composition and saturation of methane and NGLs (natural gas liquids: ethane, propane, butane, and pentane) in a petroleum reservoir combining NMR (nuclear magnetic resonance) logging and NMR core analysis and for determining the mean pore-size and tortuosity of the light hydrocarbon-filled porosity in a petroleum reservoir using NMR core analysis.
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    Method of estimating permeability using NMR diffusion measurements
    (2024-03-19) Vinegar, Harold J.; Singer, Philip M.; Hirasaki, George J.; Chen, Zeliang; Wang, Xinglin; Vinegar, Eva; Rice University; Vinegar Technologies LLC; United States Patent and Trademark Office
    This invention is useful for determining the permeability of a geological formation using 1H NMR diffusion measurements acquired in the laboratory and using downhole 1H NMR well logging. The current technology for obtaining formation permeability downhole using NMR is not adequate for low-permeability, unconventional source rock formations with high organic content. This new method uses laboratory 1H NMR diffusion measurements for creating continuous downhole well logs of the mobile-hydrocarbon permeability of the hydrocarbon-filled pore space of downhole geological formations.
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    NMR Core Analysis for Unconventional Formations
    (2022-12-02) Wang, Xinglin; Hirasaki, George J.; Chapman, Walter G.
    Unconventional oil and gas are playing a more and more important role in the global energy supply and clean energy future. Because of some unique features of unconventional formations like low permeability special pore structure and the existence of organic matter, more understanding of unconventional formations and core analysis methods are needed. This thesis focuses on how to apply Nuclear Magnetic Resonance (NMR) techniques to understand fluid properties in unconventional formations. NMR is a powerful nondestructive method to analyze the fluid in porous media. By applying different pulse sequences, various petrophysical properties can be derived like porosity, fluid distribution, relaxation times, and diffusivity. First, permeability estimation is crucial for formation evaluation and becoming a challenge in understanding low-permeability, unconventional formations. NMR well logging is often used to estimate formation permeability but in many unconventional formations, the current NMR methods are not adequate. To overcome the challenge, a new method is developed to estimate permeability. This method uses a modified Carman-Kozeny model with pore size, tortuosity, and porosity information inferred from NMR diffusion measurements. Another variant for the ultra-low permeability scenario is also developed using D2O diffusion measurements for the scenario where NMR diffusion measurements are limited in some ultra-low permeability shales. Second, to better understand the NMR relaxation mechanism in shale formations and interpret the porosity and saturation from logs, the correlations between relaxation times and oil/water saturation are investigated by NMR T_1-T_2 measurements on partially saturated samples. This methodology overcomes the challenges due to potential overlapping signals in unconventional formations between micropore water and bound hydrocarbon, and, macro-pore water and hydrocarbons. Last but not the least, NMR is used to investigate the relaxation mechanism of fluids in kerogen, which is one type of organic matter in formations. To better understand the fluid relaxation mechanisms, intergranular and intragranular fluids in kerogen isolate pellets are studied. Different frequencies are compared when analyzing fluid in kerogen. It is found that the maturity can have impacts on intragranular relaxation times and porosities. The effects of diffusive coupling are also investigated and discussed. This thesis focuses on applying NMR technique to understand and do core analysis for unconventional formations. Several new methods are proposed to estimate permeability, macro-pore saturation and analyze fluid in kerogen. In principle, these new methods and techniques can be used to better understand unconventional formations.