bluuebunny/crossref_metadata_2025_split huggingface dataset:
Studying Factors to Optimize Flowback and Productivity of Mfhws in Shale Gas Formations
Authors: Jing Guicheng , Chen Zhangxin , Zhang Kai 
Published: May 2023

Abstract
Nowadays, the only economic and effective way to exploit shale reservoirs is multi-stage fracturing of horizontal wells. The backflow after fracturing affects the damage degree of a fracturing fluid to a formation and fracture conductivity, and directly influences a fracturing outcome. At present, the backflow control of the fracturing fluid mostly adopts empirical methods, lacking a reliable theoretical basis. Therefore, it is of positively practical significance to reasonably optimize a flowback process and control the flowback velocity and flowback process of a fracturing fluid. On the other hand, the previous research on the productivity of multi-stage fracturing horizontal wells after fracturing is limited, and an equation derivation process has been simplified and approximated to a certain extent, so its accuracy is significantly affected. Based on previous studies, this paper established a new mathematical model. This model optimizes the flowback velocity after fracturing by dynamically adjusting a choke size and analyzes and predicts the production performance after fracturing. To maximize fracture clean-up efficiency, this work builds the model for a dynamic adjustment of choke sizes as wellhead pressure changes over time. It uses a two-phase (gas and liquid) flow model along the horizontal, slanted and vertical sections. The forces acting on proppant particles, filtration loss of water, the compressibility of a fracturing fluid, wellbore friction, a gas slippage effect, water absorption and adsorption are simultaneously considered. With the theories of mass conservation, we build a mathematical model for predicting production performance from multi-fractured horizontal wells with a dynamic two-phase model considering dual-porosity, stress-sensitivity, wellbore friction, gas adsorption and desorption. In this model, the gas production mechanisms from stimulated reservoir volume and gas and water relative permeabilities are employed. Based on shale reservoir parameters, wellhead pressure, a choke size, a gas/liquid rate, cumulative gas/liquid production, cumulative filtration loss and a flowback rate are simulated. In the simulations, the influential factors, such as shut-in soak time of the fracturing fluid, forced flowback velocity, fracturing stages and fracture half-length after fracturing, are studied. It is found by comparison that in the block studied, when a well is shut in four days after fracturing, the dynamic choke size is adjusted with wellhead pressure changing over time, the fracturing stage is 11, and the fracture half-length is 350 meters, the fracture conductivity after flowback is the largest, and the productivity of the horizontal well is the highest.
An Answer to Ever-Challenging Question of Selecting the Right Test Method (Dispersion or Deposition) for Asphaltene Stability Determination
Authors: Punase Abhishek , Burnett Will , Wylde Jonathan 
Published: May 2023

Abstract
Changing thermodynamic and compositional conditions of producing fields can cause decreased asphaltene stability and initiate aggregation, subsequent precipitation, and eventual deposition within flowlines. Usage of asphaltene inhibitors that prevent aggregation and tackle the problem right at the inception is widely preferred. However, such chemistries were observed to be counter-productive and led to higher asphaltene deposition in many cases. Thus, raising the question of what approach works best for assessing asphaltene stability: Dispersion or Deposition?
The focus of this study is to explore the relationship between the underlying working mechanism of dispersion and deposition-based test methods. Multiple crude oil samples produced from different regions of the world were evaluated using asphaltene inhibitor chemistries with optical transmittance, thermoelectric, and flow loop methods. Optical transmittance method evaluates sedimentation rate and cluster size distribution of asphaltene cluster within the test fluid medium. Thermoelectric method describes the dispersion state of asphaltenes within native crude oil. Flow loop setup assesses total mass deposited when the oil (blank or dosed) and precipitant mixture is flown through capillary tubes.
The results from these tests indicated that a fine balance between the dispersion and deposition mechanisms must be maintained as these may not respond linearly or in direct relationship at all conditions. It was seen that dispersing the asphaltene clusters too small may lead to high diffusional rate within the low flow shear regime and build up more deposit in depositional dominant test methods. Variation in treatment concentration (especially overtreatment) of an effective asphaltene inhibitor can result in lowering of cluster size to a range which in effect can cause more deposition. The overall assessment suggests that not having a holistic overlook at these test methods and following the standard process of giving specific focus on a singular approach, can mislead the asphaltene stability and inhibitor performance evaluation.
The key role of asphaltene cluster size as a bridge relating the dispersion and deposition-based test method is revealed in this paper. It is seen that there exists an effective range of cluster size within which the results from different test methods correlate well. Therefore, it is imperative that the asphaltene inhibitor development philosophy must include test screening methods focusing on each instability stage (precipitation, aggregation, and deposition) individually and combine the learnings to come up with the best recommendation.
Effects of Nano-Particles on Foamy Oil of CO2-Heavy Oil System under Nonequilibrium Conditions
Authors: Shi Yu , Lv Wang , Zhang Yin , Zhu Guangya 
Published: May 2023

Abstract
In situ formation of foamy oil has been widely utilized to improve the heavy oil recovery, especially considering its cost efficiency. Therefore, the stability and strength of generated foam actually play a crucial role on the foamy oil recovery. In this work, the effects of nanoparticles (NPs), the additives in a CO2-heavy oil system, on the so-called NPs-stabilized foam of CO2-heavy oil systems are experimentally and mathematically assessed. Specifically, a visual high temperature high pressure (HTHP) foam generator is utilized to investigate the foam stability of NPs- CO2-heavy oil system. The effects of different NPs concentrations and NPs types on the foam stability is systematically observed and analyzed with measuring the relationship between the height of foam column and time under nonequilibrium conditions. Then, a mathematical model is proposed to quantify processes of NPs-stabilized foam generation and collapse according to the experimental results. The results show that NPs of SiO2 with a size of 20-30 nm can effectively improve the foam stability and generation of CO2-heavy oil system compared with pure CO2-heavy oil foam. The concentration of NPs impose impact on the foam properties to some degree. Also, different types of NPs, SiO2, Al2O3 and MgO, on the foam stability are experimentally probed mainly to unveil the difference between metallic NPs and non-metallic NPs. Finally, the exponential functions with parameters characterizing concentration and nonequilibrium conditions are developed to quantify the foam generation and stability under nonequilibrium conditions.
Quantification of Phase Behaviour and Physical Properties of n-Alkane Solvents/Water/Athabasca Bitumen Mixtures Under Reservoir Conditions
Authors: Huang Desheng , Li Yunlong , Dong Xiaomeng , Yang Daoyong 
Published: May 2023

Abstract
Experimental and theoretical techniques have been developed to quantify phase behaviour and physical properties in terms of phase boundaries, swelling factors, phase volumes, and phase compositions. Experimentally, five sets of PVT experiments of pentane, hexane, and heptane, respectively, mixed with bitumen have been conducted to measure phase behaviour data in the absence and presence of water by using a conventional PVT setup at elevated temperatures up to 438.2 K. Theoretically, the Athabasca bitumen is characterized as four pseudocomponents, while the binary interaction parameters (BIPs) are optimized by reproducing the measured saturation pressures. The original Peng-Robinson equation of state (PR EOS) has been advanced to perform flash calculations by incorporating a recently modified alpha function and an improved volume translation method together with the Huron-Vidal mixing rule, while the results have been compared with those obtained from CMG WinProp module incorporated with the original alpha function as well as default and optimized BIP correlations. It is from the experimental observation that the saturation pressures of n-alkane solvents/water/bitumen mixtures are decreased with carbon numbers at the same conditions. Also, the saturation pressures of n-alkane solvents/bitumen mixtures are increased with the addition of water because water molecules are evaporated into vapour phase at relatively low pressure and high temperature conditions. The BIPs of pure solvent/bitumen pairs, which are optimized through fitting the measured saturation pressures, work well for n-alkanes/bitumen mixtures in the absence and presence of water. Such an advanced PR EOS (APR EOS) model can accurately reproduce the experimentally obtained multiphase boundaries, swelling factors, phase volumes and compositions with an average absolute relative derivation (AARD) of 7.82%, 2.11%, 6.78%, and 4.38%, respectively, indicating that it can provide fundamental data for the design and optimization of the hybrid solvent-steam recovery method for bitumen resources.
Produced Water Treatment with Deoiling Hydrocyclones – Misconceptions & Corrections
Authors: Ditria John C. , Rawlins Charles H. 
Published: May 2023

Abstract
Deoiling hydrocyclones are a mature technology for oil removal from produced water. Since the introduction of this technology in the 1980s it has become ubiquitous in all oil producing regions. From its original intent – to treat water directly off the outlet leg of a production separator – many operators have tried to use deoilers for every water treating application. The lack understanding the operation and design of deoilers has led to misconceptions around their performance. Deoiling hydrocyclones can treat emulsions, high-pressure gas condensate water, high-turndown requirements, and work with pumps – however their fundamentals must still be adhered to for the system to work properly. Not all deoiler liners are the same and vendor experience is critical during evaluation of this technology.
The Sustained Casing Pressure: Periodical Annuli Pressure Survey Campaign Findings in Mature Offshore Oil Field
Authors: Alshammari Ahmad Ejaimi , Alsdeiri Saad A. , Alhamdan Mohammad Ahmad 
Published: May 2023

Abstract
Sustained pressure in oil and gas wells remains a serious challenge that directly impacts the well integrity. This phenomenon commonly appears in aged wells. Well completion elements provide the required isolation to protect the well. Cement prohibits fluid movement between the subsurface formations. Additionally, mechanical isolation packers are employed to alleviate the probability of tubing/annulus communication. In the Arabian Gulf, it is attributable to the presence of a shallow-depth aquifer that contains corrosive water, carbon dioxide, and hydrogen sulfide gases.
Surveillance campaigns are performed to ensure the safety and healthiness of well completion components in addition to the reservoir management requirements. The Annuli Pressure Survey (APS) is deemed to be important to identify well integrity problems, especially the sustained casing/casing annulus (CCA) or tubing/casing annulus (TCA) pressure. Wells with sustain pressure are recommended for bleed-off/buildup test to check the communication between the casing sections.
The annuli pressure survey campaign is run periodically in a Middle Eastern Mature Offshore Oil Field. Oil producers and water injection wells are surveyed at least twice per year. The most recent campaign for 229 wells revealed that 8.3% of the surveyed wells exhibit sustain casing pressure (SCP), and most of these wells age +20 years.
This paper aims to illustrate the findings of the APS on this field. It includes the identification of the attributable factors that might lead to the SCP. It also provides a best practice to monitor the casing strings pressures and ensure well integrity in addition to diagnostic test should be followed to confirm the SCP.
Missing link in control of Tuberculosis transmission to human: Evidence from quantitative survey of livestock community resource persons of Tamil Nadu, India
Authors: Duraisamy Thirunavukkarasu , M Jothilakshmi , Kannan Porteen , Romney Dannie 
Published: May 2023

Abstract

Dairy farming in India is considered one of the pathways to moving out of poverty for more than 80 million marginalized rural households. However, there are challenges in productivity and production due to disease and other factors. In addition to these challenges the intensification in smallholder dairying likely to increase the incidence of bovine Tuberculosis (bTB) and paves way for potential public health risks due its zoonotic potential. Currently information is available with regard to knowledge, perception and adoption of practices associated with control of bTB transmission from among farmers and there is absence of information regarding the understanding bTB among livestock community resource persons. This demands an understanding of the knowledge and perception of community-level livestock resource persons who are engaged in livestock extension services for farmers, regarding bovine tuberculosis and consequence of knowledge and perception of community resource persons on their operational areas. Currently India has 42913 women community level livestockresource persons as a part of National Rural Livelihood Mission. In this study, knowledge, perceptions and practices associated with tuberculosis were studied and analyzed among 149 community level workers. The results showed above workers had limited knowledge (2.20%) on Bovine tuberculosis. Added they had poor perception with factors associated with control of bovine tuberculosis. Further adoption of risk-prone practices such as drinking of un-pasteurized milk, poor sanitization practices after handling animal among cattle owning community resources persons and also in their operational areas of which may increase the risk of transmission to the common public, including farmers. The contact with livestock extension system has not improved the knowledge on zoonotic potential and perception of zoonotic control associated practices of btB as similar to human health system which is revealed in the past studies. Thus there is imperative need to integrate both human and livestock system in communication strategies on btB. Furthermore caste, education, contact with extension agency and farming experience of community level workers influences on perception and adoption of zoonotic control practices. This needs to be considered during communication programmes / technology transfer activities which has potential to influence perception and on zoonotic control practices associated with bTB.
What is affecting the improvement of green innovation efficiency in the old industrial base: Evidence from Northeast China
Authors: Guo Fuyou , De ligeer , zhou mingxi , li rui , zhang yu 
Published: May 2023

Abstract
Green innovation is an important driving force for high-quality development and is vital for reinvigorating the old industrial bases in Northeast China. As such, this study investigates the spatial-temporal evolution characteristics and factors influencing green innovation efficiency (GIE) in Northeast China from 2005 to 2020, using the super-efficient EBM-Malmquist model, kernel density estimation, and random forest model. The results show the following. 1) The "growth effect" of technological change is the main force driving GIE improvement; the "horizontal effect" of pure technical efficiency change has started to play an important role; and the club convergence characteristics of GIE in Northeast China have started to be optimized. 2) GIE in Northeast China shows significant spatial differentiation. The urban agglomeration of Mid-southern Liaoning and Harbin-Changchun has had high values for GIE, indicating that green innovation has a cyclic cumulative effect and the spatial pattern of green innovation needs to be further optimized. 3) The random forest model is more accurate and provides more trustworthy results compared with the traditional multiple linear regression model. The results of random forest model measurement illustrate that the number of digital economy enterprises, public finance expenditure, GDP per capita, and vegetation coverage play a positive role in promoting GIE. The proportion of the non-farm population and industrial agglomeration plays a negative role in GIE. In the same period, the contribution of the number of digital economy enterprises ≥ 0.41, public expenditure ≥ 0.47, GDP per capita ≥ 0.39, and vegetation coverage ≥ 0.36 to GIE reach maximum values and then remain unchanged.
New Consideration of the Skin Effect in Electrodynamics
Authors: Maslov Sergey , Maslov Iurii , Maslov Dmitry 
Published: May 2023

Abstract
The article proposes an approach to solving the normal skin effect problem based on integral equations derived directly
from Ampère's circuital law, Faraday's law of induction and Kirchhoff's circuit laws, in contrast to modern solutions
based on Maxwell's equations of electrodynamics in differential form. It is shown that the skin effect is mainly due
to the electromotive force of the wire self-induction, which depends on the distance to the surface, and the influence of
eddy currents is either very small or absent. New equations, their solutions and formulas for the total current and impedance are proposed for various technically significant cases immediately taking into account the inductance of the
external space and in two versions: taking into account only the self-induction of the conductor; taking into account
both self-induction and eddy currents. On the example of a solid cylinder, it is shown that, in accordance with the formulas of the existing approach itself, the current density on the surface of the wire does not increase with increasing
frequency, as it is stated in words. It is shown that, in fact, the solutions of the existing concept are based not on eddy
currents, but on the uneven distribution of elementary self-induction currents over depth and are completely equivalent
to the variant of the presented solutions, taking into account only self-induction. Power balances were obtained without
the introduction of a frequency-dependent active resistance to alternating current in two versions: based on the total
current, voltage and average electromotive force of induction; based on the integration of the balance of specific powers
over the entire volume of the wire. The physical meaning of the visual increase of the active resistance with increasing
frequency is revealed, but certainly not on the basis of a decrease in the effective cross section of the wire. Based on the
symmetry of the distribution of eddy currents, the assumption is made that they are absent in galvanically closed wires,
but present in open wires such as antennas. An experiment was carried out with a negative result on the detection of the
alleged thermal separation in the wire, an explanation for this was proposed.
Observation of Robust Interlayer Biexcitons in Twisted Homobilayer Superlattices
Authors: Zheng Haihong , Xie Xing , Li Shaofei , Chen Shula , He Jun , Liu Zongwen , Wang Chang-Tian , Wang Jian-Tao , Duan Xidong , Lu Yuerui , Pan Anlian , LIU Yanping 
Published: May 2023

Abstract
Moiré superlattices are formed by stacking 2D materials with a twist angle and have recently gained attention as a platform for investigating the interactions and correlations of moiré-trapped interlayer excitons (IXs). However, understanding these excitons remains challenging, as theoretical predictions suggest the existence of both parallel and antiparallel dipole-dipole interactions, while only repulsive interactions with a parallel configuration have been experimentally observed. Here, we investigate the localization of strain-induced moiré interlayer excitons in twisted transition metal dichalcogenide (TMDC) superlattices. Our results reveal that modulating the moiré trap in strain-engineered homobilayers leads to a higher density and emission efficiency of IXs, while also enhancing dipole-dipole interactions. In particular, we observe a transition in the nature of the moiré interlayer exciton-dipole interaction from repulsion to attraction in a twist-angle homostructure, resulting in a stable interlayer biexciton (IXX) phase with an antiparallel configuration, which had only been theoretically predicted before. Moreover, the moiré trap in homobilayers can be modulated by adjusting the spacing of the Au nanoarrays, which enabled us to achieve IXX emission up to 150 K, the highest temperature reported to date. This breakthrough is expected to pave the way for the observation of a Bose-Einstein condensate at room temperature. Our findings provide new opportunities for studying correlated many-body systems and have implications for developing novel optoelectronic devices and controllable nonlinear optics.