Factors, Mechanisms, and Kinetics of Spontaneous Emulsification for Heavy Oil-in-Water Emulsions.

In challenging reservoirs where thermal recovery falls short, cold or chemical oil recovery methods are crucial. Spontaneous emulsification (SE), triggered by gentle disturbance, significantly enhances oil recovery. In elucidating SE mechanisms and kinetics, SE processes via direct contact between oil and aqueous phases without stirring were conducted.

Modeling of Burial History, Source Rock Maturity, and Hydrocarbon Generation of Marine-Continental Transitional Shale of the Permian Shanxi Formation, Southeastern Ordos Basin.

The Ordos Basin is characterized by abundant natural gas resources, and the marine-continental transitional shale gas of the Permian Shanxi Formation has great exploration and development potential. However, few systematic studies have focused on the burial history, thermal maturity, and hydrocarbon generation of the shale, which limits the understanding of shale gas enrichment and resource evaluation. To reveal the shale gas resource potential, we focused on the Shanxi Formation shale in the southeastern Ordos Basin.

The preparation of gallic acid-grafted cationic chitosan as effective salt-tolerant flocculants.

In this work, gallic acid was successfully grafted onto quaternary aminated chitosan to prepare a high efficiency cationic flocculant. The mechanism of flocculation and different influencing factors were studied in detail. The prepared flocculant only needs 60 mg L to achieve a 98.

Study on the kinetics of formation process of emulsion of heavy oil and its functional group components.

Enhanced oil recovery (EOR) by in situ formation of oil-in-water emulsion in heavy oil cold production technology has received growing interest from the petroleum industry. We present an experimental study of emulsification of model oils prepared by heavy oil and its functional group compositions dissolved into toluene brought into contact with a surfactant solution. The effects of functional group composition, emulsifier concentration, temperature, pH and stirring speed on the emulsification rate of heavy oil was investigated.

Numerical Simulation of Proppant Transport in Major and Branching Fractures Based on CFD-DEM.

This research investigated the effect of branching fracture, proppant, and fracturing fluid on proppant transport based on the CFD-DEM coupling model. The obtained results show that the balance height of embankment in the major fracture decreases gradually with increasing angle between major and branching fractures, while it increases gradually in the branching fracture. This is because the additional resistance of fracturing fluid flow at the joint increases with increasing angle, leading to the decrease of the fracturing fluid velocity.

Dynamics of green economic development in countries joining the belt and road initiative: Is it driven by green investment transformation?

Green investment transformation is the main interval difference of the Belt and Road Initiative, however, its actual effects are still uncertain. Finding out its utility, mechanism and improvement on green economy may accelerate green development. In this paper, Slack Based Measure model is used to obtain original results, Super-Efficiency model is used to sort effective decision-making units for stronger efficient frontier and Minimum Distance to Strong Efficient Frontier model is used to narrow gaps between non-effective ones and real situations.

Modeling Permeability Using Advanced White-Box Machine Learning Technique: Application to a Heterogeneous Carbonate Reservoir.

From exploration to production, the permeability of reservoir rocks is essential for various stages of all types of hydrocarbon field development. In the absence of costly reservoir rock samples, having a reliable correlation to predict rock permeability in the zone(s) of interest is crucial. To predict permeability conventionally, petrophysical rock typing is done.

Organic Geochemical Characteristics and Organic Matter Enrichment of the Upper Permian Longtan Formation Black Shale in Southern Anhui Province, South China.

Although previous studies have yielded valuable insights into shale gas reservoirs, a comprehensive understanding of the organic geochemical characteristics and organic matter enrichment of marine-continental transitional shale has yet to be achieved. The Longtan Formation transitional shales were extensively deposited in Southern Anhui Province, South China, during the Late Permian. Our analysis of twenty-two rock samples from one core (Gangdi-1 well) and two outcrops (Daoshanchong outcrop and Changqiao outcrop) revealed that the Longtan Formation shale extracts exhibit a wide range of C-C-alkanes and acyclic isoprenoids, with unimodal, bimodal, and multimodal distributions.

Organic matter enrichment mechanism of Youganwo Formation oil shale in the Maoming Basin.

The Youganwo Formation oil shale located in the Maoming Basin represents a large commercially valuable lacustrine oil shale resource and a potential bio-shale gas reservoir in South China. With the aim of deepening the understanding of factors that influence organic matter enrichment, this research conducted a geochemical investigation to reconstruct the depositional paleoenvironment of bioproductivity, preservation and dilution. Youganwo Formation oil shale is mainly deposited in semi-deep to deep-lake environments with relatively warm and humid paleoclimate in the subtropical-temperate zone.

Molecular Insights into the Effect of Nitrogen Bubbles on the Formation of Tetrahydrofuran Hydrates.

In this work, a molecular dynamics simulation was conducted to study the microscopic mechanism of how nitrogen bubbles affect the formation of THF hydrates at the molecular level. The results obtained reveal that the nitrogen bubble can promote the formation of THF hydrates. In the system with a nitrogen bubble, more THF-filled cages were generated, and the crystal structure was more orderly.

Study on Pyrolysis-Mechanics-Seepage Behavior of Oil Shale in a Closed System Subject to Real-Time Temperature Variations.

In situ mining is a practical and feasible technology for extracting oil shale. However, the extracted oil shale is subject to formation stress. This study systematically investigates the pyrolysis-mechanics-seepage problems of oil shale exploitation, which are subject to thermomechanical coupling using a thermal simulation experimental device representing a closed system, high-temperature rock mechanics testing system, and high-temperature triaxial permeability testing device.

Performance demonstration of gas-assisted gravity drainage in a heterogeneous reservoir using a 3D scaled model.

Gas-assisted gravity drainage (GAGD) is an effective method for oil recovery. Gravity increases the stability of the Gas-Oil Contact (GOC), thus delaying gas breakthrough and promoting crude oil production. Studying the effects of fluid and reservoir parameters on the stability of GOC could help understand the mechanism of GAGD.

Calculating the Eroded Thickness Corresponding to a Short-Term Tectonic Uplift with Milankovitch Theory: A Case Study of the Middle Permian Maokou Formation in Southeastern Sichuan Basin, Southwest China.

The Middle Permian Maokou Formation in the southeastern Sichuan Basin is a typical carbonate karst reservoir. At the end of the Middle Permian, a short-term tectonic uplift (Tungwu movement) occurred in the upper Yangtze region, causing the formation of dissolved fissures and holes. To determine the location of the high-quality reservoir, this paper calculated the eroded thickness using the Milankovitch theory.

Solid-Acid Catalytic Conversion of Oil Shale: Effects of Sulfonic Acid Grafting on Oil Yield Enhancing and Quality Improvement.

Oil shale is a promising unconventional resource and in situ upgrading technology has been a practical approach for enhancing oil and gas recovery. Mineral-based clin/SBA-15 has been prepared and subsequently functionalized to get SOH-SBA-15 catalysts. Compared with the noncatalytic conversion of oil shale under subcritical water, sulfonic acid grafted catalysts have played a predominant role in enhancing the oil yield by 3-16% and improving oil qualities.

Effects of aqueous phase circulation and catalysts on hydrothermal liquefaction (HTL) of penicillin residue (PR): Characteristics of the aqueous phase, solid residue and bio oil.

Hydrothermal liquefaction (HTL) is a promising thermochemical technology for the treatment of hazardous wastes such as penicillin residue (PR). For the treatment of aqueous waste produced by PR in the HTL process, aqueous phase circulation is an attractive solution, both environmentally and economically. The present study shows that aqueous phase circulation can promote the transfer of organic matter from the aqueous phase to bio-oil.

Catalytic upgrading of penicillin fermentation residue bio-oil by metal-supported HZSM-5.

Antibiotic fermentation residue (AR) is composed of hazardous organic waste produced by the pharmaceutical industry. AR can be effectively converted into bio-oil by fast pyrolysis, but its high nitrogen content limits the prospect of bio-oil as a fuel resource. In order to further reduce the nitrogen content of AR bio-oil, we have examined the catalytic removal of N and O from penicillin fermentation residue (PR) bio-oil under fast pyrolysis conditions.

Preparation of bio-oils by hydrothermal liquefaction (HTL) of penicillin fermentation residue (PR): Optimization of conditions and mechanistic studies.

Response surface methodology (RSM) was used to investigate factors influencing the yield of bio-oil from the hydrothermal liquefaction (HTL) process of penicillin fermentation residue (PR). The reaction mechanism of the HTL was also studied. The hydrolysis of organic compounds in PR was enhanced, and the bio-oil yield increased with an increase of temperature.

Nanoscale Pore Fractal Characteristics of Permian Shale and Its Impact on Methane-Bearing Capacity: A Case Study from Southern North China Basin, Central China.

Fractal dimension is closely related to the nanoscale pore structure of shale, and it also has an important influence on the gas content of shale. To investigate the correlation between the fractal dimension and the methane (CH₄) bearing features of shale, seven Permian shale samples were analyzed with field emission scanning electron microscopy (FE-SEM), low temperature nitrogen (N₂), carbon dioxide (CO₂) and CH₄ adsorption and on-site gas desorption experiments. Based on the N₂ adsorption and desorption data, we proposed a new method to better determine the gas adsorption stage at different relative pressure (/) points in the multilayer adsorption or capillary condensation stage.

Evolution of pore structure and fractal characteristics of marine shale during electromagnetic radiation.

Electromagnetic radiation has been proposed to non-aqueously stimulate shale formations, which can generate fractures and enhance the porosity of the matrix. The proposed method consumes electricity and thereby possesses significant advantages for sustainable and environmental hydrocarbon production. In this study, we investigate the pore structure variations of marine shale during electromagnetic radiation.

Fracture Characterization Using Flowback Water Transients from Hydraulically Fractured Shale Gas Wells.

Fracture characterization is necessary to evaluate fracturing operations and forecast well performance. However, it is challenging to quantitatively characterize the complex fracture network in shale gas reservoirs because of the unknown density and reactivation of natural fractures. The flowback water transients can provide useful information about the complexity of the fracture network after the fracturing operations.

Subthreshold depression among diabetes patients in Beijing: Cross-sectional associations among sociodemographic, clinical, and behavior factors.

Background: This study explores the prevalence of subthreshold depression (SubD) and its association with factors in type 2 diabetes mellitus (T2DM) patients.

Methods: This cross-sectional study involved 808 outpatients with T2DM from ten hospitals in Beijing between September 2015 and January 2016. All participants completed the Patient Health Questionnaire 9-item (PHQ-9) to evaluate depressive status, with scores between 5 and 14 considered SubD.

Heterogenous oceanic redox conditions through the Ediacaran-Cambrian boundary limited the metazoan zonation.

Recent studies have enhanced our understanding of the linkage of oxygenation and metazoan evolution in Early Cambrian time. However, little of this work has addressed the apparent lag of animal diversification and atmospheric oxygenation during this critical period of Earth history. This study utilizes the geochemical proxy and N isotope record of the Ediacaran-Cambrian boundary preserved in intra-shelf basin, slope, and slope basin deposits of the Yangtze Sea to assess the ocean redox state during the Early Cambrian metazoan radiation.