bluuebunny/crossref_metadata_2025 huggingface dataset:
Prediction Method of Cutting Settling Velocity in Gas-Liquid Two-Phase Flow Based on Multi-Gene Genetic Programming
Authors: Zhu Zhaopeng , Song Xianzhi , Han Liang , Zhang Rui , Liu Wei , Fu Jiasheng , Hu Xiaoli , Li Dayu , Qin Furong , Yang Donghan
Published: October 2022

The cuttings settling process becomes erratic in the complex gas-liquid mixture under gas kick, it is very difficult to accurately describe the migration process of cuttings. Meanwhile, the traditional empirical formula based on fitting experimental data is difficult to accurately predict the complex cuttings settlement. Neural network and other intelligent models with high prediction accuracy are difficult to be popularized and applied due to their black box properties. Multi-gene genetic programming can accurately describe complex nonlinear problems and automatically optimize the structure and parameters of the mathematical model, so as to effectively reduce the complexity of the model. Based on the multi-gene genetic programming algorithm, this study used a variety of input parameters to predict the settling velocity, explored the relationship between the input variables and the result, and established an explicit mathematical model of settling velocity with RMSE of 0.0896 in test set and R2 of 0.9292, which breaks the accuracy limits of traditional empirical model and the inexplicability of neural network model. This new method for predicting cuttings settling velocity in gas-liquid mixture can provide theoretical guidance for efficient cuttings migration in wellbore during gas kick.

1. INTRODUCTION

The migration of bottom-hole cuttings during oil and gas well drilling and the migration of solid proppant in cracks during fracturing are examples of particle settling in the field of petroleum engineering (Xu et al, 2017). When the particles settle freely in the fluid, they will be affected by their own gravity, buoyancy and resistance (Nouri et al, 2014). When these three forces reach an equilibrium state, the particles will reach a stable settling velocity, which is called the particle terminal settling velocity (McCabe et al, 2004). Understanding the settling law and properties of solid particles in their fluid environment, such as rock cuttings and fracturing proppant, is critical for enhancing drill cleaning efficiency and fracturing design. Until now, Many industry specialists and academics have devoted a significant amount of time and effort to the study of particle settling velocity.
Influencing Factors of Acid Etching Fracture Conductivity of Tuff Reservoir in Northeastern Sichuan Block
Authors: Xie Jinyang , Zuo Luo , Hou Bing , Dai Yifan , Li Jiaxin , Zhuang Li , Elsworth Derek
Published: October 2022

With the continuous depth breakthrough of two ultra-deep exploration wells in northeastern Sichuan block, tuff reservoir was finally discovered at the depth of 6700-7300 m. It belongs to ultra-deep tight gas reservoir with low brittle mineral content and high clay content. Hydraulic fracturing is hard to be reformed this special reservoir, easy to appear hydration expansion and other problems. However, the research and development of such tight tuff reservoir with high temperature and high pressure are relatively low in the domestic and overseas until now. Therefore, it is of great significance to carry out experimental research on relevant reservoir reconstruction methods of such rocks and explore the factors of fracture conductivity here. In this study, the influence of acid type, sanding concentrations, proppant size was research by a new experimental installation. The factors of fracture conductivity are analyzed by experimental data and the reconstitution of fracture surface. The results show that before the abnormal point, the acid etching effect of crosslinked acid on tuff is better than that of gelling acid. At the condition of closure pressure is lower 30 MPa, the higher sanding concentrations, the higher fracture conductivity, then narrowed the gap among them. Meanwhile, the larger proppant size, the higher fracture conductivity in low closure pressure. With increasing closure pressure, fracture conductivity of smaller size proppant decreased slowly. In conclusion, it is also convenient for the field operation to choose the best acid and proppant parameters.

1. INTRODUCTION

As an important new field of exploration and development of oil and gas resources in the world, igneous reservoir have gradually received extensive attention from geological and petroleum researchers all over the world. The exploration and research on the igneous reservoir has a history of more than 130 years. Now, some igneous reservoir have been exploited in the United States, Indonesia, Japan, Brazil, Australia and other countries (Tang, et al. 2020). Its oil and gas mainly come from athrogenic rock reservoir. Athrogenic rock is a transitional type between magmatic rocks and sedimentary rocks, and it is also one of the important reservoir rock types. It has the advantages of thick pay information and large reserves (Li, et al. 2015). The tuff reservoir is very complex and special and has both lithologic characteristics in terms of petrophysics and diagenesis (ZHANG, et al. 2012). The low degree of development of original porosity and poor connectivity of pore throats indicate that such reservoir is tight reservoir (Zeng, et al. 2021). At present, the well known athrogenic rock reservoir in the world including East Anatolia Basin in Turkey (Gecer-Buyukutku, et al. 2005), Bohai Bay in China (Zhao, et al. 1996), Erlian (Guo, et al. 2013) and Hailar (Yu, et al. 2013) basins.
Comprehensive Stress Modeling Approach for High Topography-Complex Geological Structure of XGS Field
Authors: Luo Yu , Zhou Yuan , Peng Xian , Zhao Yichao , Li Longxin , Li Limin , Younessi Ahmadreza , Zhou Yongsheng
Published: October 2022

The magnitude and orientation of the in-situ stresses are greatly impacted in areas where the ground elevation changes dramatically within the field boundaries. The stress model for XGS field, located in onshore China, is constrained using a comprehensive workflow starting from analyzing the wellbore scaled data to a full field finite element numerical model. The well data from 14 offset wells are used to constrain the magnitude and orientation of the principal stresses in the XGS field. Because of the significant difference in the ground elevation of the offset wells, the calculated in-situ stresses are associated with some level of errors in the 1D models. This is corrected to some extend by calculating the stresses using a 3D modeling approach. Subsequently, a 4D finite element numerical model is used to capture the impact of the complexities in geological structure and high topography changes in XGS field. The findings from the 4D model show that the state of stresses in the shallow sections within the high topography structure tend to be under normal stress regime which gradually changes to strike-slip stress regime in the deeper section.

1. INTRODUCTION

The XGS underground gas storage facility currently operates in a depleted gas reservoir located in the Sichuan province, Southwest China. The facilities are constructed during the second half of 2011 and cushion gas injection started in June 2013. Located in a high topography and high tectonic stress region, the geological setting of the XGS field is structurally complex and highly faulted (Li et al., 2021).

Because the field is located under a high topography structure (Fig 1), the magnitude and orientation of the in-situ stresses are greatly impacted. A comprehensive approach was used to capture the complexities in the stress model withing the XGS field. For this purpose, first the stress magnitudes and orientations are modeled using the wellbore scaled events from 14 main offset wells. These 1D well-centric models are then upscaled to the entire field using 3D static modeling approaches. Subsequently, a 4D numerical model is used to initialize the stresses to capture the impact of the complexities in geological structure and high topography changes in XGS field. Similar workflows were used to conduct 4D models by Fang et al. (2014) and Younessi et al. (2018).
Laboratory Evaluation of Micro-Proppants on Enhancement of Microfracture Conductivity
Authors: Yuan Shuai , Zhou Fujian , Tian Yakai , Liang Tianbo , Liang Xingyuan
Published: October 2022

The complex fracture network generated from hydraulic fracturing is of great importance for well productivity in unconventional reservoirs. However, numerous natural or induced microfractures are closed without proppant placement after hydraulic fracturing is completed. Micro-proppants have small enough particle sizes and longer transport distances, which can access microfractures and keep them open. The objective of this work is to investigate the particle size distribution, crushing rate as well as microfracture conductivity by micro-proppants from fly ash. Microproppants have a large range of particle size from 1 μm to 300 μm, and the average particle diameters are 22.84 μm and 51.13 μm. The crushing rates of micro-proppants are related to the particle size distributions and mineral contents. More concentrated distribution of particle sizes and higher contents of high-hardness minerals lead to a lower crushing rate of micro-proppants. The fracture conductivity is exponentially decreased with closure stress, and it is controlled by average particle sizes and crushing rates of micro-proppants. The results demonstrate micro-proppants from fly ash are sufficient to the requirements of hydraulic fracturing and improve hydrocarbon production of unconventional reservoirs.

1. INTRODUCTION

Hydraulic fracturing is considered the most effective stimulation method for unconventional reservoirs to improve well productivity. The complex fracture networks are created by pumping a large number of fracturing fluids during hydraulic fracturing, which consists of primary fractures, secondary fractures, and induced microfractures. The induced microfractures have small openness of less than 0.1 mm (Danso et al., 2021). For unconventional reservoirs with extremely low permeability like shales, induced microfractures have a large contribution to the conductivity of the fracture network (Sharma & Manchanda, 2015; Grieser et al., 2016; Keshavarz et al., 2016). The 20/40 mesh proppants are usually used to support the primary fracture for high fracture conductivity. The 100-mesh proppants in recent use cannot reach the induced microfractures. Therefore, micro-proppants with particle diameters less than 150 μm (100-mesh) are selected to reach the induced microfractures (Nguyen et al., 2013; Dahl, Calvin, et al., 2015; Calvin et al., 2017a; Tian et al., 2022). The micro-proppants are generally added to the pad fluid before placing the conventional proppant in primary fractures. Field trials have indicated that micro-proppants can improve well productivity up to 50% in unconventional reservoirs such as Wolfcamp, Woodford SCOOP, and Barnett Shale formations (Calvin et al., 2017b; Dahl, Nguyen, et al., 2015; Lau et al., 2019; Radu et al., 2020).
Heat Propagation Through Fractures During Hydraulic Stimulation in Crystalline Rock
Authors: Wenning Q. C. , Gholizadeh Doonechaly N. , Shakas A. , Hertrich M. , Maurer H. , Giardini D. , Team Bedretto , Serbeto F. , Bethmann F. , Dyer B. , Castilla R. , Meier P. , Wiemer S.
Published: October 2022

The Bedretto Underground Laboratory for Geosciences and Geoenergies (BULGG) is located in central Switzerland and serves as a test bed for geothermal energy research. Several boreholes were drilled from the laboratory section (ca. 1.1 km overburden) to serve as injection boreholes for stimulation and geophysical monitoring boreholes. During a hydraulic stimulation injection in winter 2020 into injection borehole ST2 interval ranging from 313 to 320 m, we observe a thermal perturbation using distributed fiber optic temperature sensing in a neighboring open borehole (MB1) at a depth of 275 m to 295 m. Prior to injection, there is a thermal anomaly in MB1 at about 289 m due to natural fracture fluid flow. Below this depth the temperature is approximately 1.5 °C higher than above. During injection there is a gradual upward movement of the thermal anomaly to ca. 278 m depth. After injection is stopped, the thermal signal gradually recovers to the original depth. The cause for such a temperature change is potentially due to increased warm water flow reaching the base of MB1 from deeper ST2 or poro-elastic fracture closure of the cold-water conducting fractures at 278 and 289 m depth in MB1 during stimulation.

1. INTRODUCTION

Geothermal energy is considered a sustainable form of power generation. While the earth generates over three times the total yearly human energy consumption (Pollack et al., 1993; Davies and Davies, 2010), the use of geothermal energy for power generation at the industrial scale has been limited, largely in part due to the need to engineer and stimulate reservoirs at significant depth to tap into the heat sources.

Such ‘enhanced’ or ‘engineered’ geothermal systems (EGS) require hydraulic stimulation or fracturing to achieve economic heat extraction, adding to economic impact of drilling and completing a well, as well as creating additional difficulties like induced seismicity. To date, there are just a few examples from across the world which have had success in producing heat from EGS reservoirs (Brown, 1995; Albright and Pearson, 1982; Moore et al., 2018; Link et al., 2020; Genter et al., 2010).
On Averaging of Toughness Heterogeneity When Modelling Hydraulic Fracture Evolution
Authors: Da Fies G. , Peck D. , Dutko M. , Mishuris G.
Published: October 2022

In this paper we describe various approaches used to capture heterogeneity within the reservoir undergoing hydraulic fracturing treatment and their implication on modelling of fracture propagation. In highly laminated reservoirs with soft and/or weak layers, capturing heterogeneity at an appropriate resolution is the key for successful prediction fracture growth and other crucial treatment parameters.

Our focus is on studying several strategies to average fracture toughness and assess their suitability for use in advanced computational methods such as FE/BEM. In practice the well log and petrophysical data deduced from various measurements and observations are upscaled and/or homogenized to the spatial approximation size. The fracture toughness is one of the most delicate physical parameters and application of the homogenization techniques are rather uncertain, hence any proposed averaging will depend on process conditions and the toughness distribution.

We propose and analyse a notion of an average toughness and show that it is a process dependent variable and provide some recommendations how to implement the defined measure into the numerical modelling. As an example, we use periodic distributions and consider model without leak off that allows us straightforward handling different regimes (toughness/viscosity).

1. INTRODUCTION

Typically, when using computational methods such as Finite Element Method, the well log and petrophysical data obtained from various measurements and observations are upscaled and/or "homogenized" to the element size. From all in-situ parameters, toughness is one of the most delicate physical parameters to handle, as application of the homogenization techniques are rather questionable here as commented on by Caiulo and Kachanov (2010) and Kachanos (1994). Compared to other types of fracture evolution, hydraulic fracturing is probably the most stable crack propagation process and thus, fortunately, some estimates can be provided here.

We estimate errors introduced by various strategies to incorporate heterogeneous fracture toughness into numerical modelling (Dontsov and Suarez-Rivera (2021), Da Fies et al. (2021)). We use periodic distributions and consider model without leak off that allows us straightforward handling different regimes (toughness/viscosity). For the simulations, we use an extremely effective in house-built time – space adaptive solver utilizing main ideas from those reported by Wrobel and Mishuris (2015). The solver is capable to compute rather arbitrary distribution of the toughness.
Numerical Simulation of Triaxial Experimental Results on Sandstone Using Critical State Mechanics
Authors: Reppas N. , Davie C. , Wetenhall B. , Gui Y. L. , Ma J
Published: October 2022

In carbon capture and storage schemes, the carbon dioxide (CO2) can be injected at high pressures and low temperatures for permanent storage in deep reservoirs. In the North Sea, the storage sites will be predominantly sandstone. Triaxial tests on sandstone were conducted until failure using representative in-situ stresses to estimate the mechanical properties of the rock. A theoretical constitutive model, using Finite Element Modelling (FEM), describing the stress-strain behavior and damage evolution of rock during triaxial testing, is presented alongside the results of the tests. The model reproduced the experimental outcomes satisfactorily and was used to estimate the critical state mechanic parameters. Lower temperature indicated higher strength on sandstone, a decrease in the Poisson’s ratio and, consequently, damage increase.

1. INTRODUCTION

Potential Carbon Capture and Storage (CCS) schemes include injecting liquid carbon dioxide (CO2) from ships into subsea formations for permanent storage. CO2 on a ship is stored at a temperature close to the triple point of CO2 at around -50°C~-57°C and exposed to almost 0.6~0.7 MPa pressure in order to keep the containment of the CO2 mixture in liquid form (Reppas et al., 2021, Wetenhall et al., 2014). The difference between the injected CO2 from a ship and the temperature of the wellbore wall, which is increasing by 30°C/km, is causing temperature fluctuations and external stresses. These loadings and their mechanical effects on the wellbore wall can be described by triaxial tests.

Laboratory tests were undertaken to determine how the mechanical properties of sandstone elastic modulus E, Poisson’s ratio n, the shear modulus G and bulk modulus K of rock— are influenced by the different confining pressures and temperatures. As sandstone is found in the sub-sea basins, it has high porosity and can be a likely storage medium for CCS, it was selected as the type of rock for the triaxial testing. Three different temperatures 15°C, -5°C and -10°C were experimentally examined. The three temperatures represent a different injection scenario of CO2. Confining pressures of 12.5 MPa and 24 MPa were used to represent rock conditions at 500m depth and 1000 m depth under the North Sea, respectively.
Coarse-Graining Methods for the Modified JKR Contact Model on a Triaxial Compression Test
Authors: Kazidenov Daniyar , Khamitov Furkhat , Amanbek Yerlan
Published: October 2022

The Discrete Element Method (DEM) modeled by coarse-graining approaches has been gaining importance in many applications including a triaxial compression test that represents the key micromechanical behaviors of deformable solids. In this work, the triaxial compression test has been investigated using a realistic particle-size distribution sample that replicates the weak cemented sandstone in Kazakhstan. The simulation was performed by the modified Johnson-Kendall-Roberts (JKR)-based DEM model with cohesive contact forces. According to the model, bonds between particles are broken at the maximum value of the normal contact force, and no new bonds are formed after the breakage. In this research, we implemented the coarse-graining methods for the modified JKR model. A scaling law was developed for each material parameter in the model such as density, surface energy density, Young’s modulus, Poisson’s ratio, friction and restitution coefficients . In addition, those approaches were combined with the same statistic weight (SSW) and same size parcel (SSP) scaling methods in order to scale the polydisperse particles. These combined methods are based on the conservation of mass and momentum by applying statistic weights to the particle diameters. First, the original particle simulation with the modified JKR settings was validated with the experimental data. Then, the stress-strain response and bonding behavior were compared between the original particle system and coarse-grained simulations. There is a good agreement between the results obtained from the original particle system and coarse-grained particle models. Moreover, the speedup of the coarse-grained simulations in parallel computing is achieved approximately 15 times faster than the original particle system with the same number of cores.

1. INTRODUCTION

Sand production negatively affects the operation in the oil and gas industry. It usually occurs with weak unconsolidated sandstone reservoirs where the stress on the formation exceeds the mechanical strength of the rock, which leads to its failure. The produced sand blocks the flow line, destroys the equipment by erosion, and prevents access to the wellbore. As a result, the operational cost increases due to production limitations. The prediction of sand production optimizes the best strategy for sand control management to minimize those limitations.
Effect of Disturbance Factor Distribution Function on Stability of an Open Pit Mine
Authors: Ma T. , Cami B. , Javankhoshdel S. , Yacoub T. , Corkum B. , Curran J.
Published: October 2022

The disturbance factor (D) is a parameter in the Generalized Hoek-Brown failure criterion for rock slopes in slope stability. It represents the subsurface damage to the rock material properties resulting from blasting and stress relaxation during excavations. Within the region of assumed damage, a number between zero (undisturbed) and unity (very disturbed) is prescribed as the value of the disturbance factor. Most commonly a uniform value of D is assumed within the entire region of damage, but little research has been done to study the impact of the variation in the D parameter on stability. Through use of an example, this paper examines the effect of various distribution functions of D through the damaged region, such namely, as constant, linearly varying, and exponentially varying. The failure surfaces and factors of safety for the slope as determined via limit equilibrium are also compared with finite element analyses. Varying the distribution of the damage function was found to significantly affect the failure surface and factor of safety. It is recommended that practitioners adopt care to select an appropriate distribution for slope stability analysis.

1. BACKGROUND

The Generalized Hoek-Brown method (Hoek and Brown 2018) is widely used for determining rock mass strength in rock mechanics. One application of this method is in the design of open pits in rock masses which requires the evaluation of factor of safety against overall sliding. During excavation, subsurface damage can occur to the surrounding rock masses and cause fracturing. The damage can be caused by two sources: (a) blasting and (b) stress relaxation (Hoek et al. 2002), and can be quantified in the form of a disturbance factor, D, which ranges from a zero (undisturbed) to unity (disturbed) within the rock masses. For slope stability, the shear strength of the rock activated along the slip surface can be obtained by solving Eq. (1) to Eq. (4) (Hoek et al. 2018).
Stratigraphic Analysis of Microseismic Signatures During Hydraulic Stimulation
Authors: Welch N. J. , Huang L. , Gross M. R. , Glubokovskikh S.
Published: October 2022

This paper presents a novel workflow to enhance the interpretation of microseismic events by comparing the temporal evolution of the microseismic cloud between adjacent stages from two different wells. The stratigraphic properties of identified rock layers along with changes within the local stress field distribution may determine the propagation path and aperture of the hydraulic fracture. Hydraulic fractures however are largely aseismic, and thus microseismic signatures surrounding the hydraulic fracture may indicate important damage-zone fracture formation. A comparison of each microseismic event with the local rock stratigraphy of the hypocenter determined regions where rock composition and larger formation layers influenced the microseismic signals of events. This analysis allowed for classification of microseismic events by formation layers and can elicit different in-situ stress states during hydraulic stimulation. Principal Component Analysis of each formation microseismic cloud can quickly show dominating stresses in the microseismic signals. The changes in the microseismic cloud between the first and second stimulated wells during a zipper fracture stimulation shows the significant changes in formation stress from one well to another in a multi-well system.

1. INTRODUCTION

The Hydraulic Fracture Test Site (HFTS-1) is a Public-Private partnership funded by the United States Department of Energy (DOE) with various industry and academic partners to expand our knowledge of the hydraulic stimulation of unconventional reservoirs. In the project 11 horizontal wells were drilled with over 400 stimulation stages completed with advanced monitoring deployed in multiple wells. The test site is located in the West Texas Permian (Midland) Basin targeting the upper and middle Wolfcamp formations. A total of 183 m (600 ft.) of core was recovered from a slanted investigation well drilled after stimulation to determine the extent of fracture propagation and proppant transport (Ciezobka et al., 2018; Courtier et al., 2017).
Simulation-Based Economical Modeling of Hydraulic Fracturing for Enhanced Geothermal System
Authors: Porlles J. W. , Jabbari H.
Published: October 2022

Hydraulic fracturing is applied to extract fluids (oil, gas, and water) from very low permeability rocks. This type of stimulation could develop hot and dry rock geothermal resources. Habitually, those reservoirs are located in the depth of 2.7 Km to 5.5 Km; and at more than 180 °C. This study designs a hydraulic fracturing model in horizontal wells to extract hot water economically, creating high permeable artificial fractures. We aim to investigate the effects of varying fracture-cluster lengths, proppant, and frac fluid types, on hydraulic fracturing treatments using 2D and 3D simulation models. Some parameters such as type of proppant, fracture fluids, number of stages, fracture length, and fracture width are evaluated considering the reservoir’s high temperature and high pressure. Finally, different scenarios are evaluated to know if the hydraulic model is economically feasible to generate electricity with the current price of electricity price, drilling, and completion cost.

1. INTRODUCTION

We perform an analysis to evaluate the feasibility of developing an enhanced geothermal system (EGS) project, considering the evaluation and modeling of a horizontal well stimulated by hydraulic fracturing, including fracture fluids and types of proppants that could be used in a frac job. The assessment covers a conceptual representation of a granitoid reservoir, considering a complete economic analysis including NPV, discount rate, reservoir temperature, number of horizontal wells, depth, and electricity sale price.

The Department of Energy (DOE) generated an important report called "Geovision, Harnessing the Heat Beneath our feet". This report explains some scenarios concerning the geothermal industry and how will be the forecast for the next 30 years (DOE, 2019). Figure 1 presents the three scenarios explained in the report. The business-as-usual scenario (BAU) explains current and anticipated future trends if the geothermal industry continues on the exact forecast of 2015 conditions. Next, the Improved Regulatory Timeline (IRT) scenario estimates the impacts of reduced geothermal project development timelines and increased discovery rate of geothermal resources due to streamlined regulatory and permitting processes. Finally, the Technology Improvement (TI) scenario assesses the impacts of advanced technology developed aggressivity and the reduction of the cost of some technologies such as drilling, stimulation, logging, and power plants.
Dynamic Characterization of Water Blockage During Water-Gas Alternated Flooding in the Underground Gas Storage
Authors: Zhang Mengchuan , Duan Yanwen , He Jiajun , Meng Leifeng , Liang Tianbo , Bai Hao , Zhou Fujian
Published: October 2022

As the main type of underground gas storage, the depleted gas reservoir is susceptible to the formation water. Limited by the current in-situ characterization methods, it remains unknown how relative permeabilities and distribution of water and gas change during different injection-production cycles at the non-Darcy-flow condition. In this paper, an unsteady-state water-gas relative permeability measurement method is established based on the in-situ CT scans and modified JBN calculation method. The water-gas distribution and water-gas relative permeability variation under the influence of different injection-production schemes are systematically revealed. The coreholder is improved to meet the measurement requirements of at least 30cm long core. The gasdisplacing-water coreflood is carried out under CT scans to obtain the water saturation of each scanning section at different displacement times. The axial distribution of water fractional flow in the core at different displacement times is calculated according to the improved water phase partial flow calculation method, and then the water-gas relative permeability curve is obtained according to the improved unsteady water-gas relative permeability calculation method. Then, multiple cycles of water-gas alternate injection are carried out on the same core to understand the change of water-gas relative permeability and residual phase distributions under different injection and production cycles. Compared with the conventional method, the influence of capillary effects can be effectively reduced, and the measurement accuracy is improved by 30%.. With the increase of injection production cycles, the gas-phase relative permeability decreases and the water-phase relative permeability increases, meanwhile, reduced efficiency of gas-displacing-water in the co-permeability area, and the gas is easier to break through, resulting in a residual water saturation increase 6%.

1. INTRODUCTION

Underground gas storage is the most important and irreplaceable means of natural gas storage and peaking, with the advantages of large storage capacity, wide peaking range, low gas storage cost and high safety factor (Ding et al., 2006). The relative permeability curve describes the relationship between the relative permeability of each phase of fluid and its phase saturation, which is a key parameter for multiphase porous flow calculation and dynamic analysis of oil and gas reservoirs. At the same time, it is also an important basis for capacity prediction of underground gas storage and optimization of cyclic injection and extraction system.
Assessing the Performance of Various Initial Support Systems for Tunneling in Swelling Clay – a Case Study from the Manikin Diversion Tunnel in Indonesia
Authors: Prassetyo S. H. , Zheng Stephen , Wattimena R. K. , Baskara A.
Published: October 2022

This paper describes the swelling phenomenon that occurs in the Manikin tunnel, an ongoing diversion tunnel for the Manikin Dam Project in Kupang, Indonesia, driven through swelling clay underlain by the Bobonaro Formation. The Manikin tunnel experiences significant large deformation, resulting in substantial damage to its initial supporting structures. Three initial support systems are assessed through numerical simulation using the 2-D finite element method, namely: (1) the original design, (2) larger steel-rib + invert beam, and (3) the original design with forepoling + invert beam. To represent the swelling phenomenon, a zone of ground strength reduction is developed in the area surrounding the tunnel, and swelling pressure is exerted on the initial lining. This method is able to match the results of convergence monitoring. Numerical simulations show that the original initial support design results in large convergence up to 89 cm or 11.4% strain and thickness of plastic zone up to 3 m, but the proposed alternative support systems are able to control the convergence much better. For the initial support with larger steel rib + invert beam, the convergence is only 14 cm or 1.8% strain, and for the original support with forepoling + invert beam, the convergence is only 9 cm or 1.2% strain. This paper points out that the original support design with forepoling + invert beam yields the best supporting method as it results in the smallest horizontal and diagonal convergences.

1. INTRODUCTION

Tunneling through swelling clay always poses a challenge in soft ground tunneling. The driven ground containing clay minerals tends to increase in volume when it comes into contact with water. The increase in volume, which is time-dependent, leads to inward movement of the tunnel perimeter. Large deformation, heaving of the tunnel floor, cracking of the sprayed shotcrete and poured concrete lining, and bending of the installed steel ribs are some of the many common manifestations of the swelling phenomenon. If remediating support measures are not performed effectively and in a timely manner, deformation may continue to increase with time, resulting in a complete collapse of the cavity.
Hydrogen Fuel Cell Vehicles Current Status
Authors: Sarkar B. K. , Singh Reena
Published: October 2022

Abstract: The hazardous effects of pollutants from conventional fuel vehicles have caused the scientific world to move towards environmentally friendly energy sources. Though we have various renewable energy sources, the perfect one to use as an energy source for vehicles is hydrogen. Like electricity, hydrogen is an energy carrier that has the ability to deliver incredible amounts of energy. On-board hydrogen storage in vehicles is an important factor that should be considered when designing fuel cell vehicles. In this study, a recent development in hydrogen fuel cell engines is reviewed to scrutinize the feasibility of using hydrogen as a major fuel in transportation systems. A fuel cell is an electrochemical device that can produce electricity by allowing chemical gases and oxidants as reactants. With anodes and electrolytes, the fuel cell splits the cation and the anion in the reactant to produce electricity. Fuel cells use reactants, which are not harmful to the environment and produce water as a product of the chemical reaction. As hydrogen is one of the most efficient energy carriers, the fuel cell can produce direct current (DC) power to run the electric car. By integrating a hydrogen fuel cell with batteries and the control system with strategies, one can produce a sustainable hybrid car.
New and interesting records of Lepidoptera in the Ural Mountains (Russia) (Lepidoptera: Papilionoidea, Noctuoidea)
Authors: Rybalkin S. A. , Yakovlev R. V. , Benedek B.
Published: October 2022

We report new findings of rare and little studied Macrolepidoptera species of the Ural Mountains. The new localities of the rare species are revealed: Euchloe ausonia (Hübner, [1804[), Boloria aquilonaris (Stichel, 1908), Oeneis jutta (Hübner, [1806]), Xestia lorezi (Staudinger, 1891), X. sincera (Herrich-Schäffer, 1851), and Coenophyla subrosea (Stephens, 1829). For the first time, the following species are reported from the Urals: Apamea schildei (Staudinger, 1901), Coranarta cordigera (Thunberg, 1778), Cardepia irrisoria (Erschoff, 1874), Polia vesperugo (Eversmann, 1856), Hadena corrupta (Herz, 1898), and Pseudohermonassa melancholica (Lederer,1853).
Relationship between vegetation characteristics and Lepidoptera diversity in the Hyrcanian forest, Iran (Insecta: Lepidoptera)
Authors: Hajizadeh G. , Jalilvand H. , Kavosi M. R. , Varandi H. B.
Published: October 2022

The patterns of diversity of Lepidoptera and its relationship with environmental characteristics in the Hyrcanian forests of northern Iran have not been investigated so far, while such studies are extremely effective in restoring forest biodiversity. This study aimed to assess the relationships between vegetation characteristics and the abundance and diversity of Lepidoptera in Darabkola forest, Sari district (Mazandaran province, northern Iran). Light trapping yielded a total of 474 exemplars representing 84 species and belonging to 16 families. 31 plant species belonged to 28 genera and 23 families were recorded of three distinct forests in the region. The total number of plant species and Fisher’s α showed the significant difference. The regression analysis indicated that the Lepidoptera abundance was correlated with basal area, diameter at breast height and tree density, although a significant relationship was not observed between plant characteristics and Fisher’s α of Lepidoptera. The lack of a significant relationship between plant diversity and the abundance and diversity of Lepidoptera represents the weak role of plant diversity in creating diversity patterns in forest ecosystems.
La sécurité, une affaire de professionnels? Intégrer la sécurité aux compétences professionnelles
Authors: Kamaté Caroline
Published: October 2022

Ce document présente de manière synthétique les résultats de l’analyse stratégique «Professionnalisation et sécurité industrielle», menée par la Foncsi entre 2015 et 2017. Sa rédaction a été coordonnée par Caroline Kamaté (Foncsi). Les opinions qui y sont exprimées sont celles du Groupe scientifique d’analyse stratégique de la Foncsi (GSAS).
The Effect of Lactation Management Training on Cadre Attitudes During Assistance for Breastfeeding Mothers
Authors: Meilinawati S.B. Elies , Khusniyati Etik , Purwati Heni
Published: October 2022

The success of exclusive breastfeeding is very dependent on the stages of lactation management, so all stages must be prepared properly so that exclusive breastfeeding runs successfully. The existence of new information about something will provide a new cognitive foundation for the formation of a person's attitude. Affective messages that are strong enough will provide an affective basis in assessing something so that a certain attitude direction will be formed. Posyandu cadres are at the forefront of direct contact with pregnant women, mothers giving birth and postpartum mothers through various posyandu activities and maternal classes. Posyandu cadres must be able to convey information, assist and motivate pregnant women, mothers giving birth and postpartum mothers to get proper health care. The purpose of this study was to determine the effect of cadre training on cadres' attitudes when carrying out mentoring for breastfeeding mothers. This research is a Pre-Experimental Design with One Group Pre Test and Post Test Design. The sample in this study amounted to 25 people obtained from purposive sampling technique. The results of the study based on the Paired sample t-Test, the results obtained a score of -value = 0.002 (ρ-value <0.05), which means that cadre training affects the attitude of cadres in mentoring breastfeeding mothers.
The Relationship of Mother's Pregnancy at A Young Age with The Emotional Development of Children Aged 3-5 Years Old in The Kebomas Health Center
Authors: Farihatin Yuyun , Ernawati  , Nur Fajaroh Eka
Published: October 2022

Background: The percentage of emotional and behavioral disorders in preschool age children is quite high, namely 34.10%. One of the factors that affect the emotional development of children is the age of the mother when she was pregnant. Results and Methods: This study aims to determine the relationship between pregnancy at a young age and the emotional development of children aged 3-5 years. This study uses a historical cohort design. The research subjects were all pregnant women who were pregnant in 2017-2018 in the working area of ​​the Kebomas Health Center. The sample of this study amounted to 74 respondents. The independent variable, namely the emotional development of children, was measured using a questionnaire. The dependent variable, namely maternal age was measured using a questionnaire. External variables, namely the number of children, gender, mother and father's education, parenting, and income were measured using a questionnaire. The analysis used is chi square and multiple logistic regression. Conclusion: The results show that there is a relationship between pregnancy at a young age and the emotional development of children aged 3-5 years. Children aged 3-5 years who are born to mothers who are pregnant at a young age and have an 80% chance of experiencing emotional development disorders compared to adult mothers. Suggestions for adolescents, families, and health workers to pay attention to age during pregnancy so that they can avoid emotional disturbances for children aged 3-5 years by making a pregnancy program after 20-35 years.
The Effectiveness of Increasing Parental Competence in Assisting Children Accessing Gadgets in The Covid-19 Pandemic Era Before and After Being Given Counseling
Authors: Mardiyana Rina
Published: October 2022

Parents are people who play a role and are fully responsible for their children. During the COVID-19 pandemic, all activities and daily habits have changed, especially in education. For this reason, parental assistance in accessing gadgets during the COVID-19 pandemic is very necessary. The role of parents in assisting children's success while studying at home is central to that. One of the challenges of parents in this modern era is the magnitude of the existence of technology in children's lives, so that it is almost inseparable from the activities of daily life, and one of them is gadgets as a form of modernity. Gadget is a term that comes from English, which means a small electronic device that has a special function. One thing distinguishing gadget from other electronic devices is the element of "novelty". Every day, gadgets always appear by presenting the latest technology that makes human life more practical. Gadget is one of the multifunctional technological devices, and its development is very fast. Gadget users are not only adults. Even children are very familiar with gadgets. The purpose of this study was that respondents, especially parents, can be more competent in accompanying their children when accessing gadgets and increasing parental competence in assisting children accessing gadgets was one solution to increase children's learning motivation. The type of this study used is quantitative with a pre-experimental design. The population of this study were all mothers of Muslimat NU 6 Kindergarten children. While the sampling technique in this study was Total sampling, the sample was all mothers of Muslimat NU 6 Kindergarten children. The results of this study used cross-tabulation, there was an effect of increasing parental competence in accompanying children accessing gadgets with the motivation of learning for Muslimat NU 6 Kindergarten children.
Immersive Learning Research from SVR Publications: A Re-conduction of the Systematic Mapping Study
Authors: Fernandes Filipe , Castro Diego , Werner Cláudia
Published: October 2022

Immersive Learning (iL) is known as a recent area of research that uses three-dimensional virtual environments and multi-sensory devices, also known as immersive technologies, to support the improvement of learning outcomes. This work aims to obtain evidence of theoretical and technological aspects of iL from the Symposium on Virtual and Augmented Reality (SVR) publications. A Systematic Literature Mapping protocol was developed and executed in order to select the primary studies to perform the analysis and data extraction. 76 primary studies helped to answer the research questions. A large part of the contributions by the SVR community are virtual environments that support education in the health area. In addition, some gaps and research opportunities were identified: virtual environments that serve audiences with special needs; development frameworks that consider pedagogical aspects; the use of biometric measures to support the validation of improved learning outcomes and more flexible tools that support educators in the development of immersive virtual environments that do not require specific knowledge in coding or 3D modeling.
Systematic mapping of technologies for supporting choreographic composition
Authors: Dornelas Iago Felicio , Seabra Rodrigo Duarte , De Souza Adler Diniz
Published: October 2022

Technology has increasingly occupied other areas of sciences and humanities, including art and dance. Over the years, initiatives to use technological applications in artistic performances have been observed and this research is developed regarding this context and the challenge of using technology to support the artist’s imagined creations. The systematic mapping of the literature carried out is part of a broad search for studies that portray the interdisciplinarity of these two universes, aiming to find technologies that support the choreographic composition process, focusing on tools that work together with the choreographer’s activities. The methodology consisted of using search terms in research repositories, which initially returned 635 publications, which were filtered by inclusion and exclusion criteria, to undergo further analysis. Eighteen tools were identified and explored in which the main applicability was the simulation of movements through graphic animation. From the operating mode of these applications, the challenges of the existing relationship between technology and the creation of dance were discussed. This study only incorporates technologies that act as a support tool by sharing the compositional effort, which creates the opportunity for future investigations into other ways of using technology in dance creation. The main contribution of this paper is identifying and classifying the main integration strategies of technology and dance composition, as well as summarizing the data and discussing its implications, been the identification of the lack of involvement of artists (end users) in the early stages of the development process the most relevant finding.
Darnus vystymasis
Authors: Balžekienė Aistė , Budrytė Paulina , Dagilienė Lina , Gurauskienė Inga , Gražulevičiūtė-Vileniškė Indrė , Jurkevičienė Jurgita , Kliučininkas Linas , Ramanauskaitė Joana , Stankevičiūtė Živilė , Stasiulaitienė Inga , Šeduikytė Lina , Telešienė Audronė , Urniežaitė Inga , Valušytė Rūta , Varžinskas Visvaldas
Published: October 2022

Vis dažniau iškylantys ekologijos ir gamtos saugojimo iššūkiai skatina mąstyti apie darnų vystymąsi. Vadovėlį parengę mokslininkai teigia, kad pagrindinė darnaus vystymosi idėja – suvokti, kaip žmonija turi gyventi tenkindama savuosius poreikius ir turėdama itin ribotus išteklius. Leidinio autoriai – skirtingų mokslo krypčių atstovai, todėl darnaus vystymosi ir šiai sričiai artimų temų problematika apžvelgiama iš skirtingų socialinių, ekonominių, inžinerinių ir kitų mokslo sričių perspektyvų. Leidinyje plačiai aptariamas išteklių valdymas, jų analizė, keliamas svarbiausias klausimas – kaip žmonės turėtų prisitaikyti prie šios planetos išteklių ribotumo? Išsamioje teorinėje vadovėlio dalyje skaitytojas supažindinamas su darniu vystymusi, šios šakos raida ir svarbiausiais komponentais. Kituose skyriuose darnaus vystymosi komponentai nagrinėjami detaliau: aptariamas socialinės gerovės ir laimės suvokimas, žiedinės ekonomikos pavyzdžiai ir svarba, klimato kaita, skaitmeninės kultūros įtaka. Skyrių pabaigoje pateikti klausimai leis įtvirtinti sukauptas žinias ir ugdytis esmines darnaus vystymosi kompetencijas: sisteminį mąstymą, numatymą, normatyvinę kompetenciją, strateginę kompetenciją, bendradarbiavimą, kritinį mąstymą, savivoką ir integruotą problemų sprendimo kompetenciją. Vadovėlis skirtas plačiam skaitytojų ratui, siekiančiam įgyti globalų, kritišką ir refleksyvų sąmoningumą, socialinio, ekonominio, kultūrinio ir aplinkos konteksto suvokimą, etinę poziciją, paremtą darnaus vystymosi principais.