Reliability analysis of elastic graphite packer in heat injection well during oil shale in-situ conversion

Heat injection well reaches temperatures above 400 ◦C during the process of heat injection, Heat injection is essential for oil shale in-situ conversion technology. The downhole of the and part of the high-temperature gas dissipates through the wellbore annulus. Consequently, in addition to causing energy loss, the dissipation causes thermal damage to the casing and wellhead. To avoid dissipation, components that are suitable for high-temperature environments should be sealed and used during heat injection while mining. Therefore, this study presents the design of a packer composed of elastic graphite rubber and a high-temperature-resistant material. The influence of numerous factors, such as downhole temperature, working load, and height of rubber, on the reliability of the packer was analyzed. Subsequently, the numerical simulation analysis of the packer reliability in in-situ conversion mining under high temperature and pressure environments was performed. The results indicate that when the operating temperature is stable, the operating load has the most obvious influence on the sealing reliability of the packer, whereas the change in the height of the rubber has the least significant effect on the maximum contact stress between the casing and rubber. The change in the operating temperature has the least significant effect on the overall sealing performance of the packer. Moreover, the rise of the temperature will increase the sealing reliability of the packer, and on the contrary, the drop in the temperature will decrease it.Cited as: Guo, W., Shui, H., Liu, Z., Wang, Y., Tu, J. Reliability analysis of elastic graphite packer in heat injection well during oil shale in-situ conversion. Advances in Geo-Energy Research, 2023, 7(1): 28-38. https://doi.org/10.46690/ager.2023.01.0

Scaling Behavior and Variable Hopping Conductivity in the Quantum Hall Plateau Transition

We have measured the temperature dependence of the longitudinal resistivity $$ of a two-dimensional electron system in the regime of the quantum Hall plateau transition. We extracted the quantitative form of scaling function for $\rho_{xx}$ and compared it with the results of ordinary scaling theory and variable range hopping based theory. We find that the two alternative theoretically proposed scaling functions are valid in different regions.Comment: 4 pages, 4 figure

Simultaneously suppressing the dendritic lithium growth and polysulfides migration by a polyethyleneimine grafted bacterial cellulose membrane in lithium-sulfur batteries

Owing to the ultrahigh theoretical energy density and low-cost, lithium-sulfur (Li-S) batteries hold broad prospects as one of the promising substitutes for commercial lithium-ion batteries. The polysulfides shuttling originated from sulfur cathode and the lithium dendrite growth from lithium anode are the main challenges that hinder the commercial survival of Li-S batteries. Herein, thermal stable bacterial cellulose (BC) separator is successfully fixed with polyethyleneimine (PEI) by a scalable chemical grafting. The hydroxyl groups and amino groups in PEI grafted BC (PEI@BC) separator can participate in the formation of Li2O and Li3N, respectively, contributing to robust solid electrolyte interface with high ionic conductivity. Therefore, the lithium deposition is well regulated, resulting in a spherical and dendrite-free Li deposit pattern. The Li/Li symmetrical cell assembled with PEI@BC separator exhibits excellent cyclic stability, which can continuously plate/stripe for more than 820 h with an overpotential of ∼ 40 mV at 2 mA cm−2. Meanwhile, the polar amino group can restrain the polysulfides migration via chemosorption. As a consequence of these merits, ultrahigh initial capacity (1402 mAh g−1 at 0.1C) and excellent rate performance (440.5 mAh g−1 at 2C) for Li-S full cell are achieved, presenting new insights into the fabrication of multifunctional separators for Li-S batteries

Corrigendum to “Simultaneously suppressing the dendritic lithium growth and polysulfides migration by a polyethyleneimine grafted bacterial cellulose membrane in lithium-sulfur batteries” [Appl. Surf. Sci. 597 (2022) 153683]

The authors regret the error in the first author's name and the correct author list is updated as above. The authors would like to apologise for any inconvenience caused.</p