Organic matter accumulation under the Middle-Upper Ordovician tectonic transition on the western margin of the North China platform.

The tectonic of the Middle and Late Ordovician in the western margin of the north China Platform is complex, and the accumulation models of organic matter of the Wulalike Formation formed during this period are still unclear. Total organic carbon (TOC) content, mineral composition, organic carbon isotope composition, as well as the major and trace elements in the shale samples were all measured in this study. The Wulalike Formation was formed during a tectonic transition from a passive continental margin to an active continental margin.

Research on the timing for subsequent water flooding in Alkali-Surfactant-Polymer flooding in Daqing Oilfield based on automated machine learning.

Determining the optimal timing for subsequent water flooding in Alkali-Surfactant-Polymer (ASP) flooding is essential to maximizing both the technical and economic outcomes of oilfield blocks. This study identified eight critical parameters that influence the benefits of ASP flooding and established parameter ranges based on data from completed blocks and actual field measurements. The optimal timing for subsequent water flooding was determined by evaluating cumulative net profit variations throughout the ASP flooding lifecycle.

Determination and Application of Stress States Based on Finite Element Techniques: A Case Study of the Longmaxi Formation in the Luzhou Block, Sichuan Basin.

Knowledge of the present-day in situ stress field (PIS) has important theoretical and practical significance for shale gas exploration and development. The Wufeng-Longmaxi Formation in the Luzhou Block serves as the main reservoir of marine shale production in southern China. However, there is no clear understanding of PIS in the Luzhou area, which leads to a series of production problems.

Mechanisms of U enrichment and helium generation potential in marine black shales following U isotope-constrained Neoproterozoic Oxidation Event.

Following the NOE, the early Cambrian witnessed the global deposition of marine black shales with high U concentrations. This study analyzes the Lower Cambrian Yuertusi Formation in the Tarim Basin, China, focusing on U isotopes to elucidate U enrichment mechanisms in black shales and their potential for helium generation. In wells XK-1, LT-1, and LT-3, the average U concentrations in the Yuertusi Formation black shale are 41.

CO Utilization and Sequestration in Organic and Inorganic Nanopores During Depressurization and Huff-n-Puff Process.

CO injection in shale reservoirs is more suitable than the conventional recovering methods due to its easier injectivity and higher sweep efficiency. In this work, Grand Canonical Monte Carlo (GCMC) simulation is employed to investigate the adsorption/desorption behavior of CH-CH and CH-CH-CO mixtures in organic and inorganic nanopores during pressure drawdown and CO huff and puff processes. The huff and puff process involves injecting CO into the micro- and mesopores, where the system pressure is increased during the huffing process and decreased during the puffing process.

Pore Structure and Fractal Analysis of Low-Resistivity Longmaxi Shale in the Southern Sichuan Basin Combining SEM, Gas Adsorption, and NMR.

Pore structure can affect the reservoir property, petrophysics, and fluid migration/adsorption, which is critical for shale evaluation and development. In this paper, the pore structure, fractal characteristics, and their influencing factors on low-resistivity shale (LRS) from the Longmaxi Formation in the Southern Sichuan Basin were analyzed by combining geochemistry experiments, physical property analysis, X-ray diffraction, scanning electron microscopy (SEM), N/CO gas adsorption experiments, and nuclear magnetic resonance (NMR). The results indicate that in LRS, the layered clay mineral/pyrite distribution and more developed pores with a larger size and better connectivity can build a complex and superior conductive network.

Coal-straw co-digestion-induced biogenic methane production: perspectives on microbial communities and associated metabolic pathways.

This study assessed the impacts of wheat straw as a cosubstrate on coal biocoverion into methane and the associated mechanism within methane metabolic pathways. Co-digestion of coal with varying wheat straw concentrations resulted in a remarkable (1246.05%) increase in methane yield compared to that of the control (CK).

Study on the Suppression of Vitrinite Reflectance: A Thermal Simulation Experiment.

Vitrinite reflectance is the most widely used parameter for reconstructing the thermal history of sedimentary basins and evaluating the maturation of source rocks. However, suppression of vitrinite reflectance has also been reported, which could affect the accuracy of evaluating the degree of thermal evolution. In this article, the influence of hydrocarbon generation on vitrinite reflectance during thermal evolution is studied based on thermal simulation experiments in a closed system.

Boosting Acidic Hydrogen Evolution Kinetics Induced by Weak Strain Effect in PdPt Alloy for Proton Exchange Membrane Water Electrolyzers.

Strain engineering is an effective strategy for manipulating the electronic structure of active sites and altering the binding strength toward adsorbates during the hydrogen evolution reaction (HER). However, the effects of weak and strong strain engineering on the HER catalytic activity have not been fully explored. Herein, the core-shell PdPt alloys with two-layer Pt shells (PdPt) and multi-layer Pt shells (PdPt) is constructed, which exhibit distinct lattice strains.

Synthesis, Surface Activity, Emulsifiability and Bactericidal Performance of Zwitterionic Tetrameric Surfactants.

In this paper, a series of tetrameric surfactants (4CSAZs, = 12, 14, 16) endowed with zwitterionic characteristic were synthesized by a simple and convenient method and their structures were characterized by FT-IR, H NMR and elemental analysis. Their physicochemical properties were studied using the Wilhelmy plate method, fluorescence spectra and dynamic light scattering technique. 4CSAZs have higher surface activities and tend to adsorb at the air/water surface rather than self-assembling in aqueous solution.

In Situ Efficient End Functionalization of Polyisoprene by Epoxide Compounds via Neodymium-Mediated Coordinative Chain Transfer Polymerization.

The Nd-mediated coordinative chain transfer polymerization (CCTP) of dienes represents one of the state-of-the-art techniques in the current synthetic rubber field. Besides having well-controlled polymerization behaviors as well as high atom economies, it also allows for the generation of highly reactive Al-capped polydienyl chain-ends, which hold great potential, yet much less explored up to date, in achieving end functionalization to mimic the structure of natural rubber. In this study, we demonstrate an efficient in situ method to realize end-functionalizing polyisoprene by introducing epoxide compounds into a CCTP system.

Generation Potential and Kinetics of Gaseous Hydrocarbons from Upper Paleozoic Carboniferous Benxi Formation Mudstone in Ordos Basin, China.

Industrial quantities of tight gas from the Carboniferous Benxi Formation have been found in the southern Ordos Basin. The source and contributions from mudstone and coal in the Benxi Formation to the tight gas are still unclear, and the hydrocarbon generation potential and kinetics of the Benxi Formation mudstone have rarely been reported, which has halted resource evaluation of tight gas. Confined pyrolysis experiments were performed to determine the yields and kinetic parameters for gaseous hydrocarbon formation for a representative sample of a Benxi Formation mudstone from the Ordos Basin, with a hydrogen index (HI) of 137 mg/g TOC and of 434 °C.

Productivity Prediction Model for Horizontal Wells of Shale under Cyclic Conflagration Compression Fracturing Percussion.

A multiscale complex fracture and matrix damage coupled productivity prediction model under cyclic percussion of horizontal wells is established, according to the evolution of matrix permeability and the characteristics of complex fracture seepage after cyclic conflagration compression fracturing. The effects of the conflagration loading rate, cyclic percussion times, horizontal in situ stress difference, seepage interference, and wellbore pressure drop on horizontal well productivity are analyzed. The results show that the loading rate and percussion times are positively correlated with the production growth rate, but the growth through percussion has a threshold.

Characterization of Pore Structure and Fluid Mobility of Shale Reservoirs.

Accompanying the commercial exploitation of shale oil and gas in North America, shale oil has gradually become an important resource, sparking great interest among countries around the world in recent years. In this study, focusing on the Paleogene Shahejie Formation in Bohai Bay (Eastern China), techniques such as CT, nitrogen adsorption, mercury injection capillary pressure (MICP), and nuclear magnetic resonance (NMR) were used to characterize the pore structure and mobility of the shale reservoir. Based on the X-ray CT data, the pore radius of the shale reservoir is in the range 0.

Research on the Erosion Law and Protective Measures of L360N Steel for Surface Pipelines Used in Shale Gas Extraction.

The erosion of surface pipelines induced by proppant flowback during shale gas production is significant. The surface pipelines in a shale gas field in the Sichuan Basin experienced perforation failures after only five months of service. To investigate the erosion features of L360N, coatings, and ceramics and optimize the selection of two protective materials, a gas-solid two-phase flow jet erosion experimental device was used to explore the erosion resistance of L360N, coatings, and ceramics under different impact velocities (15 m/s, 20 m/s, and 30 m/s).

Morphology and Emulsification of Poly(-2-(methacryloyloxy) ethyl pyrrolidone)--poly(benzyl methacrylate) Assemblies by Polymerization-Induced Self-Assembly.

In this work, a series of amphiphilic diblock copolymers poly(-2-(methacryloyloxy) ethyl pyrrolidone)--poly(benzyl methacrylate) (PNMP --PBzMA ) were developed by the dispersion polymerization method in ethanol. The polymerization-induced self-assembly (PISA) behaviors were studied systematically, and a comprehensive structure-property relationship was also established. Two distinct PISA tendencies were observed, which was mainly depended on the polymerization degree of PNMP segment.

Quantitative classification evaluation model for tight sandstone reservoirs based on machine learning.

Tight sandstone reservoirs are a primary focus of research on the geological exploration of petroleum. However, many reservoir classification criteria are of limited applicability due to the inherent strong heterogeneity and complex micropore structure of tight sandstone reservoirs. This investigation focused on the Chang 8 tight reservoir situated in the Jiyuan region of the Ordos Basin.

Host-guest strategy improves rheological properties, conformational stability and oil displacement efficiency of xanthan gum.

The low cost and environmental advantages of Xanthan gum make its production and application scale exceed that of other polysaccharides. However, the temperature resistance of Xanthan gum limits its application. In this study, polysaccharide supramolecular Xanthan gum network (XG-β-CD/AD) based on β-cyclodextrin and adamantane was prepared for enhanced oil recovery.

Organic Matter Enrichment in Jurassic Hydrocarbon Source Rocks from the Turpan-Hami Basin: Insights from Organic and Elemental Geochemistry.

Petroleum can be generated by thermal cracking of organic matter within sediments, and the organic matter within sediments plays the dominant role in determining oil and gas generation. Organic matter within sediments is characterized by various sources, such as sapropelic organic matter from algal, microbial, and planktonic organisms and humic organic matter from higher plants. Paleo-productivity, terrestrial influx, and depositional environments could obviously influence the enrichment processes of the organic matter within sediments.

Multifractal Characteristics of Low-Field Nuclear Magnetic Resonance of Different Rank Coals and Its Permeability Predicting Method.

The permeability of methane in coal is a crucial factor in the production of coal-bed methane (CBM), which is dependent on the pore size distribution (PSD) of coal. The transverse relaxation time cutoff value () is a crucial parameter in nuclear magnetic resonance (NMR) techniques for converting NMR data into an absolute PSD. To investigate an appropriate approach for predicting the and permeability of different rank coals, this study first revealed, through centrifuge experiments with a centrifugal force of 1.

Chemical-Assisted CO Water-Alternating-Gas Injection for Enhanced Sweep Efficiency in CO-EOR.

CO-enhanced oil recovery (CO-EOR) is a crucial method for CO utilization and sequestration, representing an important zero-carbon or even negative-carbon emission reduction technology. However, the low viscosity of CO and reservoir heterogeneity often result in early gas breakthrough, significantly reducing CO utilization and sequestration efficiency. A water-alternating-gas (WAG) injection is a technique for mitigating gas breakthrough and viscous fingering in CO-EOR.

A study on the accumulation model of the Santos basin in Brazil utilizing the source-reservoir dynamic evaluation method.

The exploration potential within deep-water petroliferous basins holds great promise for oil and gas resources. However, the dearth of geochemical and isotopic data poses a formidable challenge in comprehending the intricate hydrocarbon charging processes, thereby impeding the comprehensive understanding of hydrocarbon accumulation mechanisms and models. Consequently, the establishment of robust source-reservoir relationships in deep-water petroliferous basins represents a pivotal challenge that significantly influences the exploration strategies and the comprehension of hydrocarbon enrichment dynamics within such basins.

Research on CO-WAG in Thick Reservoirs: Geological Influencing Factors and Random Forest Importance Evaluation.

In the development process of thick reservoirs, the impact of various geological factors on the effectiveness of the CO water alternating gas (CO-WAG) flooding technology remains unclear. This paper establishes multiple CO-WAG flooding models for thick reservoirs to study the effects of sedimentary rhythm, dip angle, matrix permeability, high-permeability streaks (HPS), and barrier layers on the effectiveness of CO-WAG flooding and then uses the random forest algorithm to rank the importance of these geological factors. The results show that different geological factors have varying degrees of impact on the distribution of water and gas migration and recovery rates during the CO-WAG flooding process.