bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparative analysis on the hydrodynamic characteristics of offshore floating photovoltaic systems based on membrane structures under different mooring configurations
Authors: Zhang Puyang , Ren Jianyu , Xiong Lichao , Le Conghuan , Ding Hongyan
Published: November 2024

In the context of rapidly increasing global energy demand, solar energy is considered one of the most promising alternatives due to its ubiquity and sustainability. Floating photovoltaics, which do not occupy land and offer higher power generation efficiency, are becoming increasingly popular. As a novel type of floating photovoltaic, membrane structures are drawing more attention due to their lightweight nature, easy installation, and cost-effectiveness. Based on the Ocean Sun's floating photovoltaic membrane prototype as a reference, this study designed and fabricated a 1:40 scale model for laboratory experiments. The research investigated the influence of different mooring configurations and lengths on the hydrodynamic characteristics of membrane structures. The conclusions indicate that structures with more anchor chains exhibit smaller amplitudes in various movements and mooring forces. As the mooring length decreases, the amplitudes of various structural movements decrease, but mooring forces increase. Compared to regular wave conditions, mooring has a more significant impact on structural motion responses under irregular waves. In practical engineering, a comprehensive consideration of structural safety and cost-effectiveness is necessary for design. The selection of appropriate mooring configurations and lengths plays a crucial role in ensuring the safe operation and sustainability of membrane structures.
All-fiber supercontinuum absorption spectroscopy for mid-infrared gas sensing
Authors: Bizot Rémi , Tiliouine Idris , Désévédavy Frédéric , Gadret Grégory , Strutynski Clément , Serrano Esteban , Mathey Pierre , Kibler Bertrand , Février Sébastien , Smektala Frédéric
Published: November 2024

The development of compact fiber-based light sources emitting over a wide wavelength range in the mid-infrared and their application to the detection of greenhouse gases and volatile organic compounds still remain of critical interest. In the present work, we make use of several dedicated infrared fibers for implementing a mid-infrared optical device pumped by a thulium doped-fiber laser around 1.965 μm that simultaneously enables a first nonlinear stage of frequency conversion and supercontinuum generation and a second linear stage of gas absorption spectroscopy. As a proof-of-principle, we carry out mid-infrared supercontinuum absorption spectroscopy of methane around 7.7 μm by means of a hollow-core fiber-based gas cell combined to a commercial Fourier-transform infrared spectrometer. Our all-fiber configuration operating in the femtosecond regime at megahertz repetition rate allows the detection of methane concentrations as low as 20 ppm.
A multiple linear regression model for predicting characteristic frequencies in biological tissues
Authors: Apon Imtiaz Ahamed , Hasan Md. Ratul , Zafur Abu , Wahid Md Ferdoush , Haque Mohammad Salman
Published: November 2024

This research introduces a novel mathematical methodology for identifying the distinctive frequency of human tissue. The model has been formulated using bioelectrical impedance analysis. The developed model can be utilized to detect a range of ailments, including those associated with the cardiovascular system, cancer, and dengue fever. A total of 3813 data points, including both males and females, were utilized. Data from a sample of both male and female individuals, including their age, height, bioelectrical impedance at frequencies ranging from 5 kHz to 1 MHz (for the Fc model), body mass index, and an impedance index of 2000, were utilized to create mathematical models. To validate the suggested models, data from a total of 1813 individuals (both male and female) were utilized. The statistical analysis of the proposed model (Fc) reveals a significant correlation (Pearson coefficient = 0.997, p < 0.001) between both male and female subjects, with a positive covariance. The model’s 95% limits of agreement, ranging from −1.28 to 1.98 L for both males and females, are sufficiently minimal. All errors fall within this limit. In addition, the suggested model has undergone validation in terms of various types of error analysis, such as bias and root mean square (RMSE). The bias and RMSE values, which are indicators of error, reach a maximum of 0.32 and 0.38 L (for both male and female), respectively. These values are within the predicted range and can be considered minimal.
Factors influencing the variability in performance of cattle grazing tropical pasture
Authors: Charmley E. , Bishop-Hurley G. J. , McSweeney C. S. , Takeuchi R. , Martinez-Fernandez G. , Denman S.
Published: November 2024

Context Whereas it is known that there is variation in liveweight gain (described as performance in this paper) within a group of grazing cattle, the causes of this variation are not well understood. Aim A 2-year grazing study in northern Queensland was conducted to understand the relative influence of diet selection, grazing behaviour and rumen fermentation on variation in performance of growing cattle. Methods Eighty-nine Bos taurus × B. indicus (~6 months old) growing steers were grazed as a group on mixed tropical pasture for 23 months. Pasture was characterised for biomass, species and nutrient composition. Cattle were ranked according to overall liveweight (LW) gain and the top (high performance, HP) 20 and bottom (low performance, LP) 20 head were compared for diet composition, rumen fermentation and grazing behaviours. Results Pasture biomass, and nutritive value of pasture and diet varied between seasons and years of study. The HP cattle achieved overall LW gains 20% greater than those of the LP cattle mainly due to higher rates of gain in the wet season. However, the nutritive value and rumen fermentation characteristics were similar for both LP and HP cattle, although there was evidence that crude protein and digestibility were modestly higher in diets of HP cattle, especially in the first wet season. Activity, measured as distance travelled, declined as pasture biomass declined, and cattle appeared to favour pasture with higher legume content. Conclusion It is concluded that divergence in performance of cattle on tropical pasture could not be fully explained by measurements taken in this study. Diet selection for plant components with improved nutritive value probably played a small role. Differences in initial LW between the LP and HP groups may have been a contributory factor. Implications Despite comprehensive measurements of factors that influence efficiency and performance on pasture, we were unable to identify definitive causes. Genetic variation in feed intake or efficiency of digestion needs to be investigated.
A rapid numerical method for nonlinear generalized time-fractional kawahara equations via domination polynomials of complete graph
Authors: Nirmala A N , Kumbinarasaiah S
Published: November 2024

The key objective of this study is to examine the nonlinear Time-fractional generalized Kawahara equation N-TF-GKE, a significant nonlinear equation that appears in a variety of physical domains, including ion-acoustic waves in plasmas, shallow water waves, and nonlinear acoustics. This Equation exhibits complex dynamic properties, most notably the appearance of shock waves, solitary waves, and chaotic solutions. We use a graph theoretic polynomial approach to obtain numerical solutions of the N-TF-GKE. We present the dominance polynomials of complete graphs (DPC), a new class of graph polynomials, to develop an efficient operational integration matrix to approximate the N-TF-GKE. The N-TF-GKE turns into a collection of nonlinear algebraic equations with the standard collocation points. We acquire the numerical solutions for the Domination polynomial using Newton's approach. We validate the efficiency and robustness of our method, the domination polynomial collocation method (

D
C
M

), with a set of numerical experiments and comparative analyses.
cosmocnc: A fast, flexible, and accurate framework for galaxy cluster number count likelihood computation
Authors: Zubeldia Íñigo , Bolliet Boris
Published: November 2024

We introduce cosmocnc, a new framework for computing the number count likelihood
of galaxy cluster catalogues in a fast, flexible and accurate way. cosmocnc offers three
types of likelihoods: an unbinned, a binned, and an extreme value likelihood. It also supports the
addition of stacked cluster data, which is modelled consistently with the cluster catalogue. The
unbinned likelihood, which is the main focus of the framework, can take an arbitrary number of
mass observables as input and deal with several complexities in the data, such as variations in
the properties of the cluster observable across the survey footprint, the possibility of different
clusters having measurements for different combinations of mass observables, redshift measurement
uncertainties, and the presence on unconfirmed detections in the catalogue. If there are more than
one mass observables, the unbinned likelihood is computed with a novel approach, the backward
convolutional approach. After introducing the framework in detail, we demonstrate its application
with synthetic Simons-Observatory-like catalogues, finding excellent agreement between their
properties and cosmocnc's predictions and obtaining constraints on cosmological and
scaling relation parameters featuring negligible biases. A Python implementation of the
cosmocnc framework is publicly available at
https://github.com/inigozubeldia/cosmocnc.
Rotational properties and blocking effects in N = 152 isotones 254No, 255Lr, and 256Rf*
Authors: Zhang 章 Jun 骏 , Zhang 张 Hai-Qian 海黔 , He 贺 Xiao-Tao 晓涛
Published: November 2024

The ground-state bands in the

isotones 254No, 255Lr, and 256Rf are investigated using the cranked shell model (CSM), with pairing correlations treated via the particle-number-conserving (PNC) method. The experimentally kinematic moments of inertia are reproduced well by the PNC-CSM calculations, and the contributions to

from neutrons exhibit remarkable similarities. Compared to 254No, the observed identity of

in 256Rf is a result of the negligible contribution to

from the two additional protons partially occupying the

,

, and

orbitals. The increase in

observed in the odd-A nucleus 255Lr, compared to those of the neighboring even-even isotones 254No and 256Rf, is attributed to the contribution of the proton

owing to the blocking of the nucleon on the proton

orbital. Compared to the case of the heavier isotones 255Lr and 256Rf, the different behavior of the

value above

MeV in 254No is predicted to be due to the level

crossing

.
Two-zero textures for Dirac neutrinos*
Authors: Lenis Yessica , Martinez-Ramirez R. , Peinado Eduardo , Ponce William A.
Published: November 2024

We review the two-zero mass matrix textures approach for Dirac neutrinos with the most recent global fit in the oscillation parameters. We found that three of the 15 possible textures are compatible with current experimental data, while the remaining two-zero textures were ruled out. Two textures are consistent with the normal hierarchy of neutrino masses and are CP-conserving, while the other is compatible with both mass orderings and allows for CP violation. We also present the correlations between the oscillation parameters for the allowed two-zero textures.
A Saturation Correction Method Based on Static and Dynamic Parameters
Authors: Xiao-jiao Qiu , Fan-xi Zhao , Tian-yu Deng , An-pei Sun
Published: November 2024

The saturation analysis date of sealed coring wells can provide the most direct quantitative data for studying remaining oil distribution. However, the oil/water saturation values measured in laboratory test usually deviate form the true values of underground conditions due to multiple factors, and they must be corrected for exact data. Most existing calibration methods consider the changes in pressure and pore conditions during the coring process, ignoring the differences in the oil/water saturation values caused by lithology and electrical properties. In this paper, well J2-6-A145 is selected as the study object. Firstly, the lithology and oil water loss rate are determined as the main influencing factors of oil water saturation by using the Analytic Hierarchy Process. Then a classification statistical correction chart based on lithology and oil-water loss rate is established in sequence, with correlation coefficients ranging from 0.92 to 0.97. Finally, based on the Electrical Property Water Content Relationship Chart of mining production statistics, considered the differences in oil water volatilization under different content levels. The oil-water saturation under different Oiliness is corrected by combining production dynamics chart and permeability curve. A saturation correction method based on statistical regression is obtained by considering multiple factors such as lithology, oil-water loss rate, oiliness, permeability and production dynamics. This method improves correlation after segmented regression, better reflects the oil content of the formation by considering dynamic factors, and provides an accurate data foundation for understanding and evaluating the distribution pattern of remaining oil.
The application of PVC hollow fiber ultrafiltration membrane in ultra-low permeability oilfield
Authors: Li Ying
Published: November 2024

Oil containing wastewater produced from ultra-low permeability oil fields generally needs to be treated to meet the 5-1-1 standard before it can be reinjected. In order to meet the standards for treating oily wastewater in ultra-low permeability oil fields, PVC hollow fiber ultrafiltration membranes and pre-treatment processes for removing oil, suspended solids, sulfides, etc. before the membrane were selected. The application shows that the aeration air flotation flow sand filtration PVC hollow fiber ultrafiltration membrane process can treat oily wastewater, and the treated water can reach the “5-1-1” standard. In the pre-treatment process of PVC hollow fiber ultrafiltration membrane, the silicone rubber membrane aeration device has good oxidation effect, high efficiency in micro nano air flotation for oil removal and suspended solids, and easy management of sand flow filters. This process has economic feasibility and provides technical support for the treatment of oily wastewater in ultra-low permeability oil fields, with great promotional value.
Practice and Exploration of Ground Engineering for Pilot Testing of Offshore Gas Storage Facilities
Authors: Fan Jiaxi , Hao Dayong , Li Min , Wu Yingli , Wang Yong , Hu Caiyun
Published: November 2024

The N gas storage facility is an offshore gas storage facility for oil reservoir reconstruction. There is no successful experience to learn from in the construction and operation of surface engineering. Therefore, a pilot experiment centered on economic benefits and fully utilizing the existing facilities in the oilfield has been carried out. Unlike traditional underground gas storage facilities, the construction difficulties of offshore gas storage facilities are more prominent. By strengthening design management, procurement management, construction management, testing management, and HSE management, the construction of gas storage facilities is efficiently promoted and successfully put into operation, achieving the experimental goal. In the construction and operation practice, facing many difficulties such as the evaluation and governance of old systems, inconvenient maritime transportation, long procurement cycle of compressors, and unsuitable production and operation, we have explored management methods such as utilizing old and leasing compressors, reasonable coordination of sea transportation, and adjustment of production parameters. We have innovated technologies such as soaking cleaning+steel wire ball unblocking and cleaning, small pipe capacity short distance series injection, and rapid construction of gas lift liquid discharge warehouses, Provide reference significance for the construction of similar gas storage facilities.
Research and Experiment on Efficient Fracturing Technology of Tight Gas in Qaidam Basin
Authors: Feng Xinyuan , Liu Yong , Liu Huan , Fu Ying , Xiao Qian , Qiao Xingyu
Published: November 2024

The lithology of the Huangguamao block reservoir in the Qaidam Basin is complex and dense. The difference between gas and water is not obvious. The gas reservoir has the characteristics of low porosity, low permeability, low saturation, and coexistence of gas and water. The problem of water output after fracturing and short stable production period has put forward higher requirements for improving production and efficiency in tight gas horizontal wells. Based on successful cases of tight gas reservoir fracturing both domestically and internationally, as well as the experience of unconventional reservoir volume transformation in the Qaidam Basin, this study conducts a historical analysis of reservoir characteristics and measures transformation in the Huangguamao block, evaluates the difficulties of measures transformation, optimizes the formation of two process ideas: high viscosity liquid controlled sand lifting fracturing and reverse composite fracture network fracturing, and prepares fracturing programme for MP2 and MP3 wells. After on-site fracturing, two processes were evaluated and analyzed, and the results showed that the reverse composite fracturing process, which takes into account both crack length and complexity, can effectively increase the transformation volume, provide more sufficient formation energy, increase production, and have stronger adaptability.
Research on Perforation-Adding Tapping Strategies for Perforation-avoided Production Wells of Block A in Daqing Oilfield
Authors: Qin Yong
Published: November 2024

To avoid inefficient and ineffective circulation and improve the producing degree of low water-cut layers, ultra-high water-cut layers of new wells were not perforated before putting into production. In order to fully tap remaining oil in perforation-avoided layers, this paper studied on perforation-adding tapping strategies for perforation-avoided production wells of block A in Daqing oilfield according to dynamic and static characteristics of injection and production wells, logging curves and numerical simulation. The research results show that the whole layer and the top of the layer without perforation are preferred to selected to add perforation. Injection parameters optimization, separate-layer adjustment and hydraulic fracturing can slow down the decline of injection and production capacity. Meanwhile, plane adjustment in perforation-adding area can further improve the development effect. Based on perforation-adding effect and numerical model prediction results, the optimal perforation-adding time of classified wells is different. The best perforation-adding effect of wells with class I and class II channels perforating avoided was achieved in the middle and late water cut rising period while achieved in the middle and late low water-cut stage in wells with class III and class IV channels perforating avoided.
Two-Dimensional Physical Model Experimental Study on Sweep Efficiency of Offshore Heavy Oil Hot Water Flooding
Authors: Liu Dong , Cai Hui , Chen Jianbo , Tian Cong , Liao Hui
Published: November 2024

The conventional water flooding approach for the development of ordinary heavy oil faces challenges such as high injection-production mobility, rapid increase in water cut, and low final recovery. By using the temperature-sensitive properties of heavy oil, the viscosity can be effectively reduced, and the flow capacity within porous media can be enhanced by increasing the temperature of injected water. Onshore hot water flooding is primarily used to exploit the remaining oil potential during the later stages of steam stimulation, while offshore is used to enhance efficiency during the mid to late stages of water flooding. The key to the success of hot water flooding technology lies in the improvement of the sweep coefficient. Firstly, a two-dimensional physical experiment model is designed in accordance with the geological and reservoir characteristics of the target oilfield, based on the principle of similarity. Secondly, parameters that quantitatively characterize the development law of the plane temperature field, such as the effective sweep coefficient, regular factor, and plane expansion speed of the high-temperature region, are studied. Then, through two-dimensional experiments, the effects of injection medium, formation rhythm, and timing of hot water injection on sweep efficiency and temperature field development were discussed. Finally, on the basis of two-dimensional experiments, the effects of heat injection temperature, timing of heat injection, hot water injection speed, and high permeability strip on the improvement of sweep efficiency were quantitatively analyzed by numerical simulation. The results show that compared with hot water flooding, hot water composite flooding can increase the effective sweep coefficient from 15.05 % to 28.71 %. The anti-rhythm is helpful to the upward expansion of the high temperature zone, which can increase the oil displacement efficiency by 1.5 %. Water channeling can be effectively controlled by injecting hot water with low water cut. The increase of heat injection temperature is helpful to increase the proportion of high temperature heating area. The higher the injection speed, the greater the expansion speed of the heating chamber. The research results provide a direction for the development of heavy oil conventional water flooding to improve oil recovery in offshore heavy oil.
Research on Production Behavior of A Fractured Well in Gas Hydrate Reservoirs Considering Multilayer
Authors: Dang Chenyue , Li Xuan , Li Honghong , Zhang Yaohui , Fu Jiyou , Nie Shuaishuai
Published: November 2024

Natural gas hydrates are internationally recognized as a new clean energy source with high prospects for commercial development. However, the vast majority of hydrates are hosted in oceanic clayey silty sediments, which are inefficient to exploit due to the extremely low effective permeability. In this paper, a novel development mode, that is, multilayer commingled production with a hydraulically fractured well, is proposed for the multilayered reservoir where hydrate and free gas coexist, to enhance productivity. Especially, the co-production behavior was numerically investigated, with the multilayered reservoir containing a hydrate-bearing layer, a three-phase layer, and a free gas layer located in the Shenhu Area as the geological background. The results indicated that the fracture provided flow channels for gas production in the multilayer, as well as greatly increasing the pressure drop spreading zone and changing the hydrate decomposition mode from around the wellbore to along the fracture surface. Compared with improving the fracture conductivity, increasing the fracture length is more effective for improving hydrate decomposition efficiency and co-production capacity. Specifically, when the fracture half-length was 30 m and the fracture conductivity was 100 D·cm, the cumulative gas production reached 949×104 m3 at 3600 days, which was 3.28 times that of the unfractured scenario. Additionally, fracturing the free gas layer hardly affects productivity as the free gas can be well-recovered by the wellbore. Overall, the proposed mode is promising for multilayered gas hydrate reservoirs, provides references for the co-production plan design, and contributes to the scale mining of hydrates.
Research and Application of Deformation Detection Technology for Vertical Storage Tanks Based on Three-dimensional Laser Scanning
Authors: Wang Yangchao , Liu WenCai
Published: November 2024

Vertical storage tank is one of the most important storage equipment in the petroleum industry, which is widely used in the petroleum and petrochemical industry. Once a deformation accident occurs in a vertical storage tank, it will generate extremely high danger and cause great harm effects. Therefore, foreign experts have been focusing on research on deformation detection of vertical storage tanks. In this paper, Vertical storage tanks are subjected to deformation assessment using 3D laser scanning technology, which focuses on solving the problem of missing point cloud repair in the application of three-dimensional laser scanning. Our research represents a BP neural network point cloud repair calculation method based on interpolation, which is based on the conventional interpolation method for horizontal point cloud repair. Compared with interpolation method, the BP neural network point cloud repair calculation method based on interpolation method has faster speed and higher accuracy. These findings provide essential technical support for further research on vertical tank deformation detection technology which based on three-dimensional laser scanning in the future.
Application of Seismic Sedimentology in Identifying Submarine Fan Bodies
Authors: Li Yanjie , Chen Xuehai , Qiao Wei , Liu Yang , Peng Jianliang , Zhang Xiangjuan , Fan Zhang , Xu Lixian , Zhang Fan
Published: November 2024

The research area is located in the Yenisai Hatanga Basin of Russia, which is a transitional facies sedimentary rock between sea and land. Oil and gas are mostly concentrated in turbidite sand bodies of the low level domain submarine fans of Lower hutt formation in the Lower Cretaceous, and locally developed in the slope fan sand bodies of the high postion domain. which is good oil and gas reservoir, however, due to limitations of geological research conditions and data, the sedimentary characteristics and planar distribution of the submarine fan sand bodies are not clear in research area. This article conducts research on the identification and plane distribution prediction of submarine fan bodies using seismic sedimentology methods, By combining sequence stratigraphy, seismic profile, and RGB fusion technology, the sand bodies of submarine fans are analyzed. Through the correlation analysis of seismic profiles and seismic facies, corresponding relationship between sedimentary microfacies and typical seismic wave patterns is established. The study shows that the study area mainly develops continental shelf slope facies, submarine fans, and shallow to semi deep marine facies. Sediments formed a turbidite submarine fan composed of sandstone siltstone mudstone in the ancient trough. There are 5 sand groups developed in the Hutt Formation under the main target layer in the study area. Among them, the IV oil group is the main oil-bearing layer. The 0, Ⅰ, and Ⅱ sand groups have limited distribution and poor sand body connectivity. The Ⅲ sand group is mainly developed in the study area. In the north, it is distributed in the middle of the study area on the plane. The IV sand group is widely developed and distributed in the middle of the study area on the plane. Seismic sedimentology can provide technical support for prediction research of reservoirs.
Application of Supervised Pattern Fault Identification Technology In Y Reservoir
Authors: Wei Luo , Bo Zhao , Ning Yin , Xiaochuan Yang , Jun Zhu , Yongshou Zhang
Published: November 2024

The Y reservoir in the Tarim Basin is a fault-controlled buried hill reservoir. Affected by factors such as deep embedding depth and high degree of stratum fragmentation, the signal-to-noise ratio of is low and the imaging effect of faults is poor. Therefore, it is very difficult to identify faults accurately. The conventional geometric attribute plane is extremely messy, the interference information is serious, and the fault information is difficult to be effectively identified, which cannot solve the problem of fine identification of buried hill reservoir faults. Aiming at the demand of fault characterization in reservoir area, combined with the artificial intelligence analysis method of big data, a fault identification technology under supervised pattern is proposed. Firstly, through cascade denoising and fault space imaging enhancement processing, the signal-to-noise ratio of seismic data and the fault imaging effect is improved. Secondly, the fault types are divided according to the discontinuous characteristics of the seismic axis, and different types of faults are characterized by multi-type sensitive attributes. Finally, the training samples are established according to the fault type. Through the iterative constraint training method, the fault identification work under the supervised pattern is carried out, and the fine characterization of different types of faults in Y reservoir is completed. Relying on the artificial intelligence big data analysis method, this technology has the innovation of full-type fault information utilization and supervised constraint training, which plays an important guiding role in the fine identification of faults in low signal-to-noise ratio areas.
Study on reservoir heterogeneity of Chang 8 reservoir in Hongde Oilfield, western margin of Ordos Basin and knowledge of fine stratification development practice
Authors: Yang Chen , Wang xiqiang , Li Ling , chun Zhaohu
Published: November 2024

In view of the problems of reservoir heterogeneity and unclear understanding of main control factors in Chang8 reservoir of Hongde Oilfield in the middle part of Tianhuan, Ordos Basin, efficient development and stable production are restricted by a large number of drilling, core data and log comparative analysis, using core observation, microscopic rock slice identification, scanning electron microscopy, mercury injection and phase infiltration experiments, etc. Based on the understanding of sedimentary facies and diagenesis, the quantitative analysis of Chang 8 in the study area is carried out from the macro intra-layer, interlayer, plane heterogeneity and microscopic heterogeneity. Finally, it is concluded that Chang 8 reservoir in Hongde Oilfield presents strong heterogeneity, and sedimentary microfacies, different clastic components of sandstone, diagenesis and other main factors affecting its strong heterogeneity. At the same time, in the development practice of De 5 area of Hongde Oilfield, the multi-stage sedimentary cycle division and step production and development were taken as a breakthrough, and the differential reservoir seepage theory was innovatively used to reduce the section/plane contradiction caused by reservoir heterogeneity, and a technical system such as regional fine stratified production, differentiated reservoir fracturing and reconstruction, single sand body fine injection and production control and stratified water injection was formed. The high efficiency development and utilization of strong heterogeneous reservoir is realized.
Determination of Fracturing Risk-Units base on seismic and micro-seismic
Authors: Jin Qi-hu , Yu Xue-meng , Liang Xue-li , He Hui , Xu Gang , Yao Zheng-xin
Published: November 2024

During hydraulic fracturing, unconventional oil and gas reservoirs often encounter risks, such as fracturing casing deformation, which affects the efficiency and effectiveness of fracturing. We can accurately identify the location of fracturing risks by using logging data and seismic data. However, we cannot avoid the occurrence of risks, and the location of deformation may be in the un-fractured stage, which is relatively far from the already fractured stage. In severe cases, it is necessary to merge or discard the un-fractured stage of the casing deformation, which will inevitably affect the fracturing effect and production. Therefore, it is particularly important to effectively divide risk units, optimize the sequence of fracturing in the stage, and reduce the impact of risk occurrence. In order to reduce the impact, the author proposes a method to determine risk-units. Firstly, before hydraulic fracturing, seismic data is used to interpret faults and determine risk-units based on the connectivity of faults. Then, during hydraulic fracturing, micro-seismic events are applied to explain artificial faults, optimize the connectivity of faults, and determine risk-units. Finally, based on the risk-units, determine the sequence of fracturing, the stage within the same risk-units should be subjected to hydraulic fracturing as the same batch, after all stages within the same risk-units are fractured, the stages of next risk-units can be carried out. The method proposed by this paper has been applied in zipper fracturing, which can effectively reduce the impact of casing deformation. After the application of this method, the deformation only occurs in the fractured stage or near the un-fractured stage, thus significantly reducing the impact on the un-fractured stage. However, due to the complexity of geological structure and stress transmission, the stages may also have mutual influence, located within different risk-units. Therefore, how to optimize the sequence of fracturing based on risk-units is a topic that needs further-deepening research. This paper innovatively proposes a method for determining fracturing risk-units based on seismic and micro-seismic data to optimize the sequence of fracturing in zipper fracturing, this is of great significance for improving fracturing efficiency, improving fracturing effectiveness, and increasing single well oil and gas production.
Optimization of Velocity String Drainage and Gas Recovery Process for Sour Gas Wells in Jingbian Gas Field
Authors: Gao Wei , Liu Yang , Liu Liping , Miao Muyang , Chen Hu , Gong Xiaoliang
Published: November 2024

In view of the gradual attenuation of gas well energy during the development of Jingbian gas field, the liquid carrying effect of some gas wells with small gas production becomes worse, the drainage effect of 60 % gas wells is not ideal, and the H2S content of the lower paleo-sulfur gas wells is high, the salinity is high, there is a certain corrosion, and most of the drainage measures cannot be implemented. The optimization of sulfur-resistant velocity string was carried out from the aspects of velocity string size and pipe material, and the appropriate pipe diameter and pipe material were selected. A new type of broken disc speed string plug was developed, which successfully solved the problem that the existing plug could not be broken or returned after construction. The field application results show that compared with the 27/8 “ string, the liquid carrying flow rate is reduced by 82 %. After 2.5 years of service, the anti-corrosion performance of the pipe is good. The cumulative increase of the well is 445.4 thousand cubic meters, and the effective rate of the measures is 97.45 %. The stable and continuous liquid carrying of the gas well is realized, which has a good application effect. It has certain reference significance for the implementation of the drainage gas recovery technology of the velocity string in the lower ancient sulfur gas well.
A New Productivity Prediction Model for Multi-fractured Horizontal Wells in Tight Oil Reservoirs
Authors: Gang Rui , Gao Han , Li Bo , Zhang Ming , Lv Weiyuan , Tao Liang , Li Lingduo
Published: November 2024

The productivity of Multi-fractured horizontal wells (MFHWs) in the tight oil reservoirs is the key index to evaluate the effect of volume fracturing. In this study, to find a solution for this problem, firstly, the big data affecting the productivity of MFHWs were collected, and then a multi-level evaluation system was built by using the analytic hierarchy process(AHP). Secondly, the gray theory was used to calculate the correlation coefficients between different parameters and production capacity to screen out the key parameters affecting the production capacity. Finally, a new horizontal well productivity prediction model by coupling key geological and engineering parameters was established, to calculate the similarity coefficient and realize quantitative prediction of single well productivity. The results show that the length of horizontal section, formation pressure, fracturing fluid volume, number of stages, net pay thickness and permeability are the key parameters affecting productivity of MFHWs. The new productivity prediction model has been successfully applied to 175 wells in China’s typical tight oil fields, with prediction errors less than 5%. It can be used in productivity prediction of horizontal wells after volume fracturing in similar unconventional tight oil reservoirs, has broad application prospects, and can guide the efficient development of and fracturing scheme selection for tight oil reservoirs effectively.
Data-driven Performance Indicators for SAGD Process of Oil Sands Using Support Vector Regression Machine with Parameter Optimization Algorithm
Authors: Yu Yang , Liu Yang , Bao Yu , Geng Xiaoyan , Luo Qiang , Sun Hao
Published: November 2024

The rapid and accurate forecasting of performance in the Steam-Assisted Gravity Drainage (SAGD) process for oil sands is crucial for the reasonable design of the development plan. This study aims to address this need by presenting novel data-driven performance indicators based on support vector regression (SVR), a machine learning method that complements the traditional physics-driven approach. During the SAGD process, steam is injected into the reservoir to heat the bitumen, reducing its viscosity, and allowing it to flow towards a lower well where it can be collected. The performance of the SAGD process depends on various factors such as steam injection rate, reservoir heterogeneity, and operating conditions. Accurately forecasting the performance of the SAGD process can help optimize these parameters and improve the overall efficiency of oil sands recovery. The data-driven performance indicators proposed in this study utilize the SVR method to establish a relationship between input parameters and the desired performance outputs. In the constructing process, some parameter optimization algorithms, like grid search method, particle swarm optimization algorithm and genetic algorithm, are used to identify the optimal SVR model structure. The validation results show that the design meets the desired objectives. All in all, through proposed data-driven performance indicators, the performance of SAGD process in candidate oil sands projects could be rapidly and easily obtained.
Voltaire FRS: His career as a scientist
Authors: Cronk Nicholas
Published: November 2024

Voltaire is remembered as one of the leading thinkers of the European Enlightenment, often quoted today for his views on free speech and religious toleration. In his lifetime he also enjoyed a reputation as a scientific thinker. His Éléments de la philosophie de Newton, published in 1738, did much to further understanding of Isaac Newton in Europe and led to Voltaire’s election as a Fellow of the Royal Society. He even tried his hand at experimental research and briefly entertained an ambition to become the Permanent Secretary of the French Académie des sciences. The plan came to nothing, but Voltaire’s presentation and promotion of Newtonian physics was enormously influential and has continued to this day to influence our understanding of Enlightenment scientific thinking.
Frederick Lindemann and the renaissance of physics in Oxford
Authors: Farmelo Graham
Published: November 2024

Frederick Lindemann was the most controversial of all leaders in the history of physics at the University of Oxford. This paper reviews his development as a physicist and his ascent to an Oxford Chair and through his friendship with Winston Churchill, his role as an influential operator in Westminster. It is argued that although Lindemann was a widely unpopular figure - and had undeniable weakness and character flaws - his achievements have been under-rated.
Ptolemaic astronomy and its dissemination in the Islamic world, Europe, and Asia
Authors: van Dalen Benno
Published: November 2024

The geometrical planetary models that the 2nd century Greek scholar Ptolemy introduced in his major astronomical work, the Almagest were highly influential for more than a millennium. This paper briefly describes the characteristics of these models and the way in which astronomical activities in the Islamic world developed on the basis of Ptolemy’s work. It then discusses three cases of transmission of Islamic astronomy to surrounding parts of the world, namely to China under the Mongolian Yuan dynasty (13th and 14th century), to India during the Mughal empire (c. 1730), where it was used together with the latest European astronomical tables and to Europe, where a mixture of early Indian and Ptolemaic astronomy that had reached the western Islamic world in the 10th century remained influential until the beginning of the Renaissance.
From SMART1 and recent probes towards Artemis and a human/robotic Moon Village
Authors: Foing Bernard
Published: November 2024

This paper describes highlights of some of the European Space Agency (ESA) missions to the Moon, such as the 2003 ESA SMART-1 Mission to the Moon and the fleet of orbital missions from 2007 that changed our views of the Moon. It discusses the International Lunar Exploration Working Group (ILEWG) MoonVillage roadmap towards a series of landers or a robotic village, and then a Moon Village with human and robotic permanent presence. The paper shows some technical developments as well as laboratory and habitat simulations, and EuroMoonMars Field campaigns developed to prepare for Artemis, future lunar research stations and the MoonVillage. The new initiatives MVA, ArtMoonMars, EMMPOL, EuroSpaceHub are also described.
Space travel across the decades and beyond: A brief history of NASA’s space programme
Authors: Green James L.
Published: November 2024

The National Aeronautics and Space Administration’s (NASA) journey into the cosmos is a captivating tapestry of milestones that have revolutionised our understanding of space. The intense competition in the early part of the Space Race between the US and Soviet space programmes fuelled rapid advancements in spacecraft technology, space science and interplanetary exploration strategies as both countries tried to be the first to put humans on the Moon. For NASA, human exploration began with the Mercury missions, followed by the Gemini missions proving humans could travel and work in space. The early pinnacle of NASA’s human space explorations came with the Apollo programme, which triumphantly made six historic lunar landings bringing back 382 kg of lunar material and leaving many important instruments on the Moon. Following the human Moon landings, NASA embraced space station missions with the marvel of engineering known as the Space Shuttle. This led to the assembly and maintenance of the International Space Station (ISS), a colossal orbiting laboratory hosting countless scientific experiments in microgravity. Now, NASA’s future human space exploration sets its sights on going back to the Moon, then onto Mars, aiming to establish a long-term human presence in the Solar System. Additionally, NASA’s science missions encompass Astrophysics, Earth Science, Heliophysics, Planetary Science, and Biological and Physical Sciences, yielding groundbreaking discoveries about our Sun, climate change, the Solar System and the Universe beyond and how life survives in the harshness of space. NASA’s extraordinary odyssey has left an indelible mark on human history, unlocking the secrets of the cosmos and igniting the dreams for past and future generations to come.
What is a clock?
Authors: Barbour Julian
Published: November 2024

Without differences between what we experience in different instants, we could never have a notion of time and its passage. The hands of a clock must move if it is to tell time and measure duration. As regards the direction of time, evidence from the Newtonian theory of gravitating point particles suggests that time’s arrow is not, on the scale of the Universe, determined by the statistical growth of entropy and a very special initial condition but has a direct dynamical origin manifested as the growth of structure. This paper also draws attention to the fact, first revealed by geologists, that a single static structure contains information about both its own age and even the age of the whole Universe.
Is time travel possible?
Authors: Heavens Alan
Published: November 2024

Time travel is a staple of popular fiction and culture, and as with many ideas that make their way into popular culture, there is some basis in real physics, but is it a fanciful extrapolation or a feasible possibility? This paper explores some notions of time and time travel from a physicist’s perspective.
Electric paradigms from Volta to Maxwell
Authors: James Frank A.J.L.
Published: November 2024

The paper argues that the ideas of scientific revolutions, normal science, paradigms and their shifts proposed by Thomas Kuhn in 1962 do not help with the understanding of the construction of electrical knowledge in the nineteenth century. That probably explains why many of the key figures in developing that extraordinarily important science, such as Humphry Davy and Michael Faraday, were not discussed by Kuhn. It also illustrates the neglect by historians and philosophers until the 1980s of the power of experiment.
Relativity and quantum theory: Under the spell of today’s paradigms
Authors: Weigert Stefan
Published: November 2024

Thomas S. Kuhn described the development of the (natural) sciences as a specific dynamical process. Periods of piecemeal growth of knowledge based on widely accepted paradigms are interrupted by bursts of revolutionary changes which lead to new paradigms incommensurate with the earlier ones. This process is briefly illustrated by recalling the changes to classical physics brought about by Albert Einstein’s theory of relativity on the one hand and by quantum theory on the other. Both theories represent fundamental paradigms of contemporary physics. They appear unshakeable to the working physicist but according to Kuhn their paradigmatic status is of a temporary nature only. Does Kuhn’s framework help to identify potential future revolutions?
The life and entangled adventures of Schrödinger’s cat
Authors: Sudbery Anthony
Published: November 2024

This paper, intended for a general audience, contains a description of Erwin Schrödinger’s thought experiment which was designed to show the strange results of extending the formalism of quantum theory, particularly the idea of superposition, beyond the subatomic regime. A way of understanding superposition in the terms of formal logic is outlined. The development of Schrödinger’s ideas after this thought experiment is traced along with a brief description of some work which realises it in actual experiments, as well as proposals for taking it further.
Einstein and Wittgenstein’s mental experiments: on the similarity between Wittgenstein and relativity theory
Authors: Penco Carlo
Published: November 2024

This summary paper will begin with historical and exegetical evidence of the connections between Wittgenstein and Einstein, including the impact Einstein had on the Vienna Circle and Wittgenstein’s continuous references to Einstein throughout his intellectual career after the Tractatus. It will then focus on the idea that Wittgenstein considered concepts analogous to measuring tools in relativity theory. This starts from using the term ‘reference system’, frequently used in Wittgenstein’s work and evoked notions in physics (Wittgenstein also occasionally used ‘coordinate system’). A development and expansion of the concept of reference system in the concept of the language game may be seen. The rest of the paper will be devoted to considering how Wittgenstein’s mental experiments with alien cultures could be analysed as an attempt to realise in philosophy the kind of approach developed in relativity theory, also making reference to anthropological cases.