This study presents a synergistic strategy to overcome the inherent activity limitations of graphene for the hydrogen evolution reaction (HER). We synthesized defect-rich N, P-co-doped graphene (NPG) via a one-step chemical vapor deposition process and subsequently fabricated the NPG/NF electrode by depositing the asprepared NPG onto 3D nickel foam. The catalyst exhibits exceptional alkaline HER performance with an ultralow overpotential of 51 mV at 10 mA cm- 2 and a small Tafel slope of 55.4 mV dec- 1, and showing highly competitive HER performance compared with representative catalysts reported for alkaline media. Comprehensive characterization (XPS, Raman, HRTEM) combined with DFT calculations suggest that the co-dopants and in-situ generated vacancies generate a synergistically modulated local electronic environment, in which pyridinic N, C-P species, and neighboring defect sites may together contribute to optimized hydrogen adsorption/ desorption kinetics.

Supercritical carbon dioxide (ScCO2), characterized by its high diffusivity, tunable density, and unique solvent properties, presents a novel opportunity to manipulate the local environment in electrocatalytic reactions. This study demonstrates the efficacy of ScCO2 as a reaction medium to dramatically enhance the selectivity of the electrocatalytic CO2 reduction reaction (ECO2RR) toward methane (CH4) on a Pd-decorated porous CuZn (CuZn@Pd) catalyst. Under optimized ScCO2 conditions (50 °C, 16 MPa, -1.2 V vs Pt), the Faradaic efficiency (FE) for CH4 reaches a remarkable 65%, a substantial increase from the 33% FE observed under ambient aqueous conditions. Concurrently, the competing hydrogen evolution reaction (HER) is effectively suppressed, with the H2 FE plummeting to only 3%. Comprehensive characterization and electrochemical analysis reveal that the ScCO2 medium enhances CO2 mass transport, increases its local concentration at the catalyst surface, and modifies the interfacial environment. Density functional theory (DFT) calculations provide atomic-level insight, showing that ScCO2 facilitates the key *CO to *COH step at Pd sites, reducing the reaction energy barrier and steering the pathway selectively toward CH4. This work establishes supercritical fluid medium engineering as a powerful strategy for controlling product selectivity in electrocatalysis.

Suppressing the hydrogen evolution reaction (HER) and controlling product selectivity remain critical challenges in the electrocatalytic CO 2 reduction reaction (eCO 2 RR).

Heavy oil is a crucial energy resource, and in-situ combustion (ISC) is regarded as one of the most efficient technologies for its recovery. Low temperature oxidation (LTO) is a critical process in enabling ISC technology. The Reactive Force Field (ReaxFF) method was employed to investigate the low-temperature oxidation (LTO) of heavy oil. The simulation results closely align with experimental data, validating the accuracy of the heavy oil model. The study reveals that LTO initiates with the decomposition of long carbon chains, resulting in the formation of alkylperoxy radicals, while CO2 is produced from the oxidation of smaller carbon fragments. The residual products of LTO include polycyclic aromatic hydrocarbons and aromatic compounds. These molecular-level insights into the LTO mechanisms offer valuable guidance for optimizing the process of in-situ combustion (ISC).

In situ combustion has already been applied in reservoirs which were adopted steam recovery. It is essential to investigate the effect of water on oxidation behaviors, especially in high water content. Simultaneous thermal analysis (STA) and accelerating rate calorimeter (ARC) were used to study the impacts of water on heavy oil oxidation characteristics at atmosphere pressure (0.1 MPa) and reservoir pressure (7.2 MPa). It was found from STA data at atmosphere pressure that water in a vapor state could promote the process of heavy crude oil oxidation. Besides, the exothermicity of low-temperature oxidation (LTO) would decrease due to evaporative heat absorption of liquid water at high water saturation, resulting in lower peak temperatures, peak pressures, and self-heating rate. It is indicated that water in a liquid state would inhibit the LTO reaction. High-pressure ARC curves suggested that self-ignition technology is not advisable under the reservoir pressure (7.2 MPa) and temperature (100 °C) after steam recovery. Subsequently, the iso-conversational methods were used to calculate the kinetic parameters. Steam could increase the oxidation activity of heavy oil evident in the decreased activation energy with elevated steam fraction. This work can assist the development and application of air injection in reservoirs after steam recovery and co-injection of steam and air technology.

Hydrogen can be generated from crude oil by in situ gasification (ISG); pyrolysis gasification is one of the main methods used for hydrogen production. In this study, thermogravimetric analysis with mass spectrometry (TG-MS) was used to study hydrogen generation from crude oil through pyrolysis gasification and was combined with equivalent characteristic spectrum analysis (ECSA) to obtain the amount of hydrogen and hydrogen generation efficiency (HGE). The results of thermogravimetry (TG) and derivative thermogravimetry (DTG) from heavy oil (HO) and light oil (LO) can be divided into three stages: drying, pyrolysis, and coking. HO generated hydrogen in all stages, whereas LO produced hydrogen only during the pyrolysis and coking stages. The results of quantitative analysis indicated that hydrogen was mainly generated in pyrolysis stage, where temperature interval was 358-521 degrees C. The Friedman, Ozawa-Flynn-Wall (OFW), and Kissinger-Akahira-Sunose (KAS) methods were used to calculate the kinetic parameters. The results suggested a raising trend of activation energies with the tem-perature increase, and the range of activation energies of hydrogen generation from HO and LO are 80.40-258.84 kJ/mol and 130.35-285.16 kJ/mol, respectively. The hydrogen generation behavior and kinetics of crude oil by pyrolysis gasification can provide certain parameters for ISG technology and assist in under-standing the hydrogen generation process, which can promote the development of hydrogen generation through in-situ gasification.

Distinguishing between shallow-water delta and fluvial fan deposits in the subsurface of lacustrine basins is challenging due to their similar depositional characteristics and distribution patterns. This study focuses on the Middle Jurassic Shaximiao Formation in the central Sichuan Basin using core observations, seismic analyses, petrology analyses, zircon analyses, palaeoclimate indicators and palaeocurrent analyses to address this issue. Fifteen sedimentary lithofacies and eight lithofacies associations were established, corresponding to channelized fluvial deposits, non-channelized fluvial deposits and shallow-water delta deposits. Shallow-water deltas are dominated by channels and mouth-bar complexes with grey, red and green interbedded mudstone. Shingled seismic reflection, green mud clasts, small burrows and wave ripples are common with occasional palaeosols. Fluvial fans are dominated by channels and crevasse-splays with pink colour and accompanied by red coloured floodplain deposits. Bright spot seismic reflection, red mud clasts, big burrows, current ripples and palaeosols are common. The increased uplift of the Dabashan Mountains controls the palaeocurrent direction, promoting the evolution from a shallow-water delta in relatively humid environments to a fluvial fan in relatively arid environments. The channel widths in shallow-water deltas are wider than those in fluvial fans, whereas the opposite applies for the channel amalgamation rate. Highly frequent channel-width variations are controlled by short-cycle climate fluctuation, corresponding to chemical index of alteration value fluctuations in different sandstone groups. The channel width in the relatively humid environments is wider than that in arid environments for both shallow-water deltas and fluvial fans. It is likely that the sedimentary evolution from shallow-water deltas to fluvial fans is relatively common in lacustrine basins in relatively arid environments with wide and gentle slope landforms.

Pyrolysis is regarded as the primary reaction for heavy crude oil upgrading during ISC process, and gas compositions produced by this reaction is also gaining attention. It is critical to establish the kinetic model to predict all products. The kinetic of heavy oil upgrading was studied and all experiments were carried out in an autoclave at 350-450 degrees C, 0.5 MPa, and 1-10 h. An improved kinetic including SARA fractions, coke, and gas compositions was proposed be more detailed description of the reaction process. Smaller SSE and bigger coefficients of determination (>0.99) of parity plots suggested the accuracy of calculated parameters of the improved kinetic model. The sensitivity analysis results demonstrate that the obtained kinetic parameters represent the optimal values. Gas prediction, a neglected aspect in previous studies, was also addressed, further enhancing the model's utility.

Large-scale hydrocarbon accumulations have rarely been found in volcanic reservoirs around the world. This study documents large gas accumulations in Permian reservoirs in two areas of the Sichuan Basin, southwestern China, that include the deepest ( >5000 m) volcanic reservoirs yet identi fied worldwide. Petroleum system elements differ in these deep volcanic accumulations between the Jianyang and Zhougongshan areas within the basin. In the Jianyang area, natural gas was derived mainly by the cracking of oil from Cambrian source rocks. Accumulations are overpressured strati graphic traps spatially controlled by the distribution of a welded tuff reservoir with high porosity and high permeability. In contrast, low porosity and low -permeability welded lapilli tuff and welded breccia reservoirs have lower gas saturations and are not productive. In the shallower Zhougongshan area, gas was generated by the cracking of kerogen in middle Permian source rocks. Regional tectonism formed normally pressured structural traps in fractured basaltic reservoirs. Multistage tectonism likely breached seals and allowed oil and gas to escape, reducing the scale of the accumulations in this area. Key factors in fluencing the large-scale accumulation and preservation of natural gas in the study area include development and preservation of adequate reservoir quality as well as tectonic history favorable to maintain seal integrity in brittle rocks. Our results provide guidance for the exploration for similar reservoirs in other areas.

In-situ gasification (ISG) was considered as a promising technology for hydrogen generation and aquathermolysis is one of significant reactions during the prolonged gasification process. Therefore, it is critical to establish the kinetic model and analyze reaction routes for understanding reaction mechanisms. The aquathermolysis experiments were carried out in a closed reactor under the condition of different temperatures (200 degrees C, 240 degrees C, 280 degrees C) and different reaction times (12h, 24h, 48h, 72h). Then a comprehensive kinetic model involving five gas components and four liquid components was proposed to be more detailed description of the reaction process. The kinetic parameters were obtained by fitting experimental data based on Levenberg Marquardt algorithm and Runge-Kutta method, followed by calculating the activation energies by the Arrhenius equation. The rate constants were used to estimate the gases generation rates for analyzing reaction routes. The model presented a great fit suggested by the parity plot and smaller objective function values (SSE). The results showed that methane and HMWG were main from the evaporation of saturates, and asphaltenes gasification were major source of hydrogen, carbon dioxide, and hydrogen sulfide. Besides, methane and HMWG from cracking primarily came from asphaltenes. The kinetic model and its corresponding kinetic parameters could be used to predict the mass fraction of liquid and gas components in aquathermolysis in numerical simulation method, which can assist promoting the development of ISG technology.(c) 2023 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Air injection has been widely considered as a technology to enhanced heavy oil recovery on account of the heavy oil upgrading caused by high temperature oxidation during this process. This paper aims at exploring the effects of oxidation thermal processing in a porous media at high temperature from 500 to 540℃ which is the high temperature oxidation range of heavy oil known from TG results, and reaction time from 8 to 16 hours for heavy oil upgrading. It was suggested that the viscosity decreased with the temperature and retention time increased due to getting less ring structure seen from IR Spectrum results. It was observed that the viscosity of heavy oil was reduced 1 to 2 orders of magnitude. Besides, the kinetics of heavy oil upgrading were analysed using five pseudo components including HO (C 35+ ), MO (C 15 ~ C 35 ), LO (C 5 ~ C 14 ), coke, G (gas products) and successfully predicted the products results with an error of 4.34%, and great correlation to Arrhenius equation. The activation energies obtained are in the range of 44 ~ 215 kJ/mol. This work has great value in revealing the mechanisms of high temperature oxidation heavy oil upgrading and assisting heavy oil production.

PreviousNext No Access2nd SEG Rock Physics Workshop: Challenges in Deep and Unconventional Oil/Gas Exploration, Qingdao, China, 25–27 October 2019Radial resistivity measurements in shale and sandstone samplesAuthors: Jiahuan He*Keming ZhouLi ZengMin LiNong LiYu YangJiahuan He*PetroChina Southwest Oil and Gas Field CompanySouthwest Petroleum UniversityShale Gas Evaluation and Exploitation Key Laboratory of Sichuan ProvinceSearch for more papers by this author, Keming ZhouPetroChina Southwest Oil and Gas Field CompanySearch for more papers by this author, Li ZengPetroChina Southwest Oil and Gas Field CompanySearch for more papers by this author, Min LiSouthwest Petroleum UniversitySearch for more papers by this author, Nong LiPetroChina Southwest Oil and Gas Field CompanySearch for more papers by this author, and Yu YangPetroChina Southwest Oil and Gas Field CompanySearch for more papers by this authorhttps://doi.org/10.1190/rpwk2019-025.1 SectionsAboutPDF/ePub ToolsAdd to favoritesDownload CitationsTrack CitationsPermissions ShareFacebookTwitterLinked InRedditEmail Abstract In order to characterize the effect of the anisotropy on resisitivity in rocks, we developed a core holder and proposed the radial resistivity measurement method. Then, the radial resistivity of 6 shales and 2 sandstones were measured, and the results showed that the radial resisitivities in the different radial directions were different. Besides, we established the mathematical model of the radial resistivity. In the end, we found the experimental values of the radial resistivity agreed with the theoretical ones. Keywords: resistivity, shale, sandstone, anisotropy, isotropicPermalink: https://doi.org/10.1190/rpwk2019-025.1FiguresReferencesRelatedDetails 2nd SEG Rock Physics Workshop: Challenges in Deep and Unconventional Oil/Gas Exploration, Qingdao, China, 25–27 October 2019ISSN (online):2159-6832Copyright: 2020 Pages: 58 publication data© 2019 Published in electronic format with permission by the Society of Exploration Geophysicists, China University of Petroleum (East China), Hohai UniversityPublisher:Society of Exploration Geophysicists HistoryPublished Online: 14 Apr 2020 CITATION INFORMATION Jiahuan He*, Keming Zhou, Li Zeng, Min Li, Nong Li, and Yu Yang, (2020), "Radial resistivity measurements in shale and sandstone samples," SEG Global Meeting Abstracts : 32-32. https://doi.org/10.1190/rpwk2019-025.1 Plain-Language Summary KeywordsresistivityshalesandstoneanisotropyisotropicPDF DownloadLoading ...

The pore structure characteristic parameters of vuggy carbonate reservoirs were extracted, and matrix resistivity of vuggy reservoir was calculated by the percolation network simulation. A segmented cross-scale resistivity calculation method was established, in which the finite element method was used to simulate the resistivity of vuggy reservoirs. The mathematical models of vug porosity and water saturation with rock resistivity in vuggy carbonate reservoir were established, and the relationships between them were obtained. Experimental results verified the reliability of the simulation results. The method presented provides new technical means and research method for the resistivity log interpretation of vuggy carbonate reservoirs. The matrix porosity, vug porosity and matrix pore water saturation are the key factors determining the resistivity of reservoir rocks.

The aim of this paper is to study the effect of sodium dodecyl sulfate (SDS) foam on methane formation nuclei process. The experimental data were compared with SDS solution in the absence of foam. Repeat experiments proved that the nucleation rate in the presence of SDS foam was 1.15 x 10(-1) min(-1), which was notably faster than 1.18 x 10(-2) min(-1) in the absence SDS foam. It indicated that the SDS foam can significantly accelerate nuclei process, which thus made the nuclei process instantaneous. The foam surface area, the interior gas pressure of the bubble and foam film were investigated to find out the reasons behind promoting nuclei process by SDS foam. The larger interface area of gas liquid provides more nucleation sites, whereas the effect of interior gas pressure on the nuclei process is not significant due to the negligible pressure variation. The result can be used to prevent the pipeline plugging during the gas well production or the gas transmission. (C) 2017 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

The large gas province of platform margin reefs and shoals of the Permian-Triassic ChangxingFormation-Feixianguan Formation in the Sichuan Basin is studied as an example to describe the forming conditions and geological characteristics of large strip-like gas provinces of platform margin reefs and shoals. The Sichuan Basin experienced cratonic rifting and basement faulting during the Late Permian. Within a widespread regional ramp, a paleogeomorphology pattern of “three highs and three depressions” were formed. The three negative relieves are, respectively, Chengkou-E'xi trough, Kaijiang-Liangping trough, and Nanchong-Mianyang intraplatform depression, and the three topographic highs are Fengjie-Zhenba platform flat, Shizhu-Yilong platform flat, and Suining-Moxi platform flat. In the transitional areas between platform flats and troughs, large-scale platform margin reef-shoal complexes were developed under high energy environment. Diagenetic processes, such as early stage dissolution, seepage-reflux dolomitization and burial dissolution, contributed to porosity improvement in high-quality dolomite reservoirs along platform margins. High mature source rocks and faults developed within the platform margin reef-shoal complexes, forming better hydrocarbon accumulation conditions than those of intraplatform reefs and shoals. Therefore, the distribution of platform margins controlled that of gas accumulation zones. Paleogeography background of large platform, extensive dolomitization and solution in reef-shoal reservoirs, good underlying and lateral adjacent source rocks, strip assemblages of lithological, structural, and litho-structural oil and gas traps are the four basic elements that determine the formation and distribution of large strip-like gas provinces. The configuration of the four elements in the studied area shows promising exploration prospects of large platform margin oil and gas provinces.