High Angle Research Articles

ANISOTROPY ESTIMATION FROM DEVIATED WELLS: UNCERTAINTIES AND THEIR IMPLICATIONS — A CASE STUDY

The Vertical Transverse Isotropy of a sequence of Lower Coastal Plain sediments undergoing mechanical compaction has been estimated from a group of wells drilled at a range of inclinations relative to the geologic bedding. Estimates of Thomsen’s anisotropy parameters have been made as a function of the volume of clay. Anisotropy increases with clay content. In shales the Thomsen parameters ϵ and γ are greater than 0.25 but δ is strongly negative. There are significant uncertainties in estimating all parameters, especially for rocks with low clay content due to the paucity and variable quality of the available data and the requirement to make many assumptions. The positive correlation between contrasts in ϵ and contrasts in acoustic impedance, Vp/Vs, and density results in the enhancement of the Amplitude Variation with Offset (AVO) response of reservoir sands below shales, especially at high angles. The negative δ suppresses changes in AVO below 30°. The delineation of gas in reservoir sands through prestack simultaneous inversion is not impacted by ignoring the anisotropy in this case study. Acoustic impedance plays a key role in the detection of gas in these reservoirs and is unaffected by ignoring anisotropy. Errors in predicting Vp/Vs can be minimized by estimating wavelets whilst assuming isotropy. Errors in predicting density, however, can be significant. It is not expected that ignoring anisotropy will be suitable for all geologic scenarios and forward modelling is recommended to understand the full implications.

Drone-Based Adaptive Hybrid Techniques for Improving Face Detection and Recognition

With the rapid development of Unmanned Aerial Vehicle (UAV) related technologies, Drones gained the opportunity to search locations that are dangerous or difficult for humans to reach. In this regard, Drones technology has been widely used to detect and recognize humans on the ground. In order to identify their potential role in counter-terrorism operations, the aim of this research study is to design and develop a reliable aerial system capable of identifying people with a high detection rate. Furthermore, it presents a solution to all challenges that degrade the resolution when query images are taken from high altitudes, different angles, and long distances. In the context of improving the accuracy of facial detection and recognition, two adaptive techniques are proposed: The first approach is to adaptively adjust the Drone’s altitude, speed, and attitude based on two parameters: Ground sampling distance (GSD), and confidence level of the recognized face. The second approach is to adaptively adjust the resolution of images captured by drone based on the size of the detected facial area. Face detection and recognition are done using the Haar Cascade classifier and Local Binary Pattern Histogram (LBPH) algorithm. The entire system was developed, implemented, and tested using a Hexacopter Drone and onboard vision system. The testing results corroborate the system's practicality and demonstrate that the prototype may be simply implemented to track dangerous people with criminal records.

Research on Minimum Unstick Speed Flight Test Method for Civil Aircraft

The minimum unstick speed (VMU) is defined as the calibrated airspeed at which an aircraft can safely lift off and continue its takeoff without any difficulties. The VMU flight test, characterized by low-speed and high angle of attack under the influence of ground effect, poses significant challenges and high risks, making it one of the most hazardous flight test subjects in civil aircraft flight test. The research on VMU flight test methods for civil aircraft is of utmost importance in strengthening the foundation of flight test technology, improving flight test efficiency, and ensuring flight test safety.

Varying the holding time to modify microstructure and improve forming angle precision of AZ31 magnesium sheet

An effective method to precisely control sheet metal forming is proposed by varying the holding time. To clarify the differences in forming angles under different holding times, this study conducted 90° precision forming experiments on AZ31 magnesium sheets using two methods: a holding time of 5 seconds ( HT5S) and a holding time of 1 hour ( HT1H). The grain size and recrystallization, twinning and texture, Schmidt factor on the tension and compression sides of the bending fillet were all investigated using an optical microscope and EBSD technology, and the mechanism causing the difference in forming angle was defined. The results show: on both sides of tension and compression, grain size and recrystallized structure, high or low angle grain boundaries, the proportion of different types of twins, texture strength and Schmidt factor all changed in order to coordinate plastic deformation. When the forming method is switched from HT5S to HT1H, the forming angle is close to the target value, and the average value decreases by 2.734 %. But it also raises the risk of failure. Among them, after the proportion of {10−12} twins and the Schmidt factor of the {0001} basal slip system decrease, more twins and slip systems need to be activated to coordinate plastic forming. The activation of twins and slip systems requires greater stress, which can easily lead to uncoordinated plastic deformation and failure.

Seismogenic model of the 2023 MW5.5 Pingyuan earthquake in North China Plain and its tectonic implications

The 6 August 2023 MW5.5 Pingyuan earthquake is the largest earthquake in the central North China Plain (NCP) over the past two decades. Due to the thick sedimentary cover, no corresponding active faults have been reported yet in the epicenter area. Thus, this earthquake presents a unique opportunity to delve into the buried active faults beneath the NCP. By integrating strong ground motion records, high-precision aftershock sequence relocation, and focal mechanism solutions, we gain insights into the seismotectonics of the Pingyuan earthquake. The aftershocks are clustered at depths ranging from 15 to 20 km and delineate a NE-SW trend, consistent with the distribution of ground motion records. A NE-SW nodal plane (226°) of the focal mechanism solutions is also derived from regional waveform inversion, suggesting that the mainshock was dominated by strike-slip motion with minor normal faulting component. Integrating regional geological data, we propose that an unrecognized fault between the NE-SW trending Gaotang and Lingxian-Yangxin faults is the seismogenic fault of this event. Based on the S-wave velocity structure beneath the NCP, this fault probably extends into the lower crust with a high angle. Considering the tectonic regime and stress state, we speculate that the interplay of shear strain between the Amurian and South China blocks and the hot upwelling magma from the subducted paleo Pacific flat slab significantly contributed to the generation of the Pingyuan earthquake.

Preparation and properties of Ni-SiO2 superhydrophobic coating by brush plating on inner wall of pipeline

Coal is easy to stay on the inner wall of the pipeline during transportation. In order to solve this problem, it is usually necessary to improve the hydrophobicity of the inner wall of the pipeline. In this study, 45 # steel, which is wear-resistant and has good machinability, is used as the matrix for coal pipeline. Ni-SiO2 composite coatings were prepared on the inner surface of 45 # steel pipelines using a novel brush plating tool, and the hydrophobicity of the coatings were evaluated. Firstly, a series of four-factor and three-level orthogonal tests were conducted to investigate the impact of brush plating working voltage (12V, 14V, 16V), nanoparticle concentration (1g/L, 2g/L, 3g/L), brush plating duration (2min, 3.5min, 5min), and bath temperature (25 ℃, 35 ℃, 45 ℃) on the hydrophobicity of the composite coating. Subsequently, optimum process parameters were determined. Then 1H, 1H, 2H, 2H- perfluorodecyltrimethoxysilane was used to modify the coating surface in order to further improve its hydrophobicity. Scanning electron microscope (SEM), energy spectrum analyzer (EDS), optical contact angle measuring instrument, white light interferometer, Vickers hardness tester, scratch tester, friction and wear meter and electrochemical workstation were used to evaluate the coating's related properties. The experimental results show that the Ni-SiO2 nano-composite coating has a higher angle (135°) when the operational voltage of brush plating is 14V, the amount of nanoparticles is 3g/L, the brush plating time is 2min, and the bath temperature is 35 ℃. The concentration of nanoparticles is the biggest factor affecting the hydrophobicity through orthogonal test analysis, so the control variable method is used to further study the influence of the concentration of nanoparticles on the comprehensive performance of the coating. It was found that with the increase of nanoparticle concentration, surface quality and comprehensive performance of the coating showed a trend of increasing first and then decreasing, and the surface of the coating was rougher when the nanoparticles were added at 4g/L, and the maximum porosity was 31.34%. At this time, the contact angle of the super hydrophobic coating has reached 150.1°, which has reached the super hydrophobicity, and the coating has good hardness, wear resistance and corrosion resistance.

Observations of Uranus at High Phase Angle as Seen by New Horizons

We present flux measurements of Uranus observed at phase angles of 43.°9, 44.°0, and 52.°4 by the Multispectral Visible Imaging Camera on the New Horizons spacecraft during 2023, 2010, and 2019, respectively. New Horizons imaged Uranus at a distance of about 24–70 au (2023) in four color filters, with bandpasses of 400–550 nm, 540–700 nm, 780–975 nm, and 860–910 nm. High-phase-angle observations are of interest for studying the energy balance of Uranus, constraining the atmospheric scattering behavior, and understanding the planet as an analog for ice giant exoplanets. The new observations from New Horizons provide access to a wider wavelength range and different season compared with previous observations from the Voyager spacecraft. We performed aperture photometry on the New Horizons observations of Uranus to obtain its brightness in each photometric band. The photometry suggests that Uranus may be darker than predicted by a Lambertian phase curve in the blue and red filters. Comparison to simultaneous low-phase Hubble WFC3 and ground-based community-led observations indicates a lack of large-scale features at full phase that would introduce variation in the rotational light curve. The New Horizons reflectance in the blue (492 nm) and red (624 nm) filters does not exhibit statistically significant variation and is consistent with the expected error bars. These results place new constraints on the atmospheric model of Uranus and its reflectivity. The observations are analogous to those from future exoplanet direct-imaging missions, which will capture unresolved images of exoplanets at partial phases. These results will serve as a “ground truth” with which to interpret exo-ice-giant data.

Tuning pores and mechanical properties for the heterogeneous interface of laser directed energy deposited IN718/316L laminate via in-situ laser surface remelting

In the past decades, laser directed energy deposition (L-DED) of multi-material attracts much attention for the integration of structure and performance. However, interfacial pores and limited mechanical properties are still bottlenecks. The present study introduces the in-situ laser surface remelting (LSR) treatment to L-DED of IN718/316 L laminate. During the LSR process, the continuous-wave (CW) near-infrared fiber printing laser rescans the whole surface after completely depositing the bottom material. When the bottom material was selected as 316 L and IN718, the pores around the heterogeneous interface were obviously eliminated and the proportion of high angle grain boundaries (HAGBs) was respectively lifted by 85.1 % and 149.1 % with slightly reduced average grain diameter after LSR treatment. Eventually, 8.5 % and 58.9 % increase in the elongation were respectively achieved. According to the numerical investigation, the “pinch-off” of bubble is observed during LSR process for the first time and the necking is enhanced with increased remelting laser power when the bottom material is IN718. Furthermore, the pore below the molten pool is prone to enlarge with stress concentration. This work can provide a novel guidance for the defect-free AM-built laminate.

Dynamic covalent bonds enabled robust and self-healing superhydrophobic coatings with multifunctions

Inspired by plants and animals in nature, durable superhydrophobic surfaces have been successfully developed in the past decades. However, the practical application of these superhydrophobic surfaces suffers from poor mechanical and chemical stability after damage or longtime usage. Thus, effective silicone-based polymers are developed to prepare the intelligent self-healing and durable superhydrophobic coatings with multifunctions. The superhydrophobic coatings are composed of dynamic silicone polymers and silica nanoparticles, which can be applicable in various substrates with enhanced water repellency. The abundant hydrogen bonds and reversible B-O covalent bonds in the dynamic silicone polymers enable a strong binding force with the substrate and self-healing nature. Thus, the superhydrophobic coatings exhibit a high contact angle up to 159.3°, and a low sliding angle of 6.9°. Meanwhile, it displays mechanical stability against washing and abrasion damage, and chemical stability in acid and alkaline environment. Especially, it is capable of repairing the superhydrophobicity after damage due to the reversible association/dissociation of dynamic B-O covalent bonds in silicone polymers. In addition, the superhydrophobic cotton fabric shows excellent anti-fouling, self-cleaning, antibacterial property, and can be applied in oil–water separation with high efficiency. This robust and versatile superhydrophobic coatings without containing perfluoro-compounds are promising in commercial textile fishing treatment with low cost.

Different Behavior of Density Perturbations Between Dayside and Nightside in the Martian Thermosphere and the Ionosphere Associated With Atmospheric Gravity Waves.

To investigate the excitation mechanism of ionospheric perturbations on Mars by the Neutral Gas and Ion Mass Spectrometer (NGIMS) onboard Mars Atmosphere and Volatile EvolutioN (MAVEN), we categorize ionospheric perturbations into three cases: (a) the ion-neutral coupling cases where ion and neutral perturbations are well coupled, (b) the ion-specific cases where ion perturbations move independently from neutrals, and (c) the coronal mass ejection cases associated with solar wind extreme events. A representative number of cases from total profiles are compared with a numerical model to determine the fraction that can be explained by an atmospheric gravity waves (GW). The neutral perturbations on the dayside at 170-190km altitudes are in excellent agreement with the GW. Whereas, contrary to previous thoughts, neutral perturbations are not necessarily explained by the GW especially on the nightside at 190-210km. Ion perturbations on the dayside at 170-190km also show a good agreement with the GW. The agreement becomes extremely low on the nightside at 190-210km, reaching the limit of strong ion-neutral coupling around 190km. Further investigation found that the behavior of the ion perturbations explicitly depends on the dayside and nightside. Its dominant driver potentially differs clearly between dayside and nightside. Statistics of relative perturbations demonstrate a clear effect associated with species scale height in neutrals. Whereas, the correlation between ions and neutrals breaks down at high solar zenith angle near southern dusk. We see currently unexplained behavior that cannot be fully interpreted by GW both at night and near southern dusk.

Theoretical study of the synergistic effect between glyceryl monooleate lubricant and carboxymethylcellulose in reducing the coefficient of friction of water-based drilling fluids.

Drilling fluids must reduce the coefficient of friction between the drilling equipment and the drilled rock or well casing. Friction forces become particularly relevant in drilling with a high angle gain, in which cases oil-based fluids are generally used. The latter are highly lubricating, but harmful to the environment. For environmental and economic reasons, there is great interest in the development of new additives that enable the use of water-based drilling fluids in all phases of well drilling. Preliminary experimental results show that there is a synergistic effect between glyceryl monooleate (GMO), normally used as lubricant additive, and carboxymethyl cellulose (CMC), a polysaccharide normally used in water-based drilling fluids as a rheological modifier, resulting in extremely low friction coefficients. This work aimed to clarify, through theoretical calculations, the interaction between CMC and GMO, as well as their role in reducing the coefficient of friction between the drilling equipment and the drilled rock when added to water-based fluids. Calculations based on density functional theory (DFT) were used to predict which, CMC or GMO, preferentially binds to the metal surface. The interactions between the polysaccharide and the surfactant were studied through a combination of classical molecular dynamics and DFT calculations. Finally, dynamic calculations were carried out involving fragments of the polysaccharide, the surfactant and hematite (Fe2O3) representing the metal surface, since in the experimental conditions the metal surface will be covered by a primary oxide layer. The results pointed to the preferential binding of CMC to hematite. Regarding the interaction between polymer and surfactant, it was found that the polar part of the GMO interacts with the CMC through hydrogen bonds while the nonpolar carbon chain remains close to the polymer due to hydrophobic interactions. Molecular dynamics calculations showed that GMO increases the binding energy of CMC to hematite and also that this increase in the binding energy is highly influenced by electrostatic interactions.

Light control using a double-stacked liquid crystal cell with enhanced viewing angle–blocking performance

In the future, there will be technological challenges between providing entertainment to passengers and eliminating driver distractions to ensure safety. Viewing angle control technologies for automotive display panels depending on each mode are required to integrate and provide both entertainment and advanced driver assistance system functions because watching videos while driving is regulated in most countries. In automotive display panels, unique electro-optical characteristics are required to control blocking or transmission only from the driver's direction while always being well observed from the passenger's direction. In this study, we developed a viewing angle control technology using double-stacked twisted nematic liquid crystal (TN-LC) films with excellent light-blocking performance only in the driver's direction over wide polar angle ranges in the privacy mode. By configuring the two TN-LC films in ordinary-ray mode and the other in the extraordinary-ray mode, the light could be completely blocked in the privacy mode, whereas it remained well transmitted in the normal mode in a specific left direction. Moreover, using double-stacked TN-LC films, light leakage at high polar angles in the privacy mode can be completely eliminated even without an optical compensation film, which is typically used to eliminate light leakage at high polar angles. Electro-optical films based on polarization optics are potential candidates for accelerating the growth of infotainment in self-driving cars.

A new understanding of phase transformation in vacuum electron beam welding of NS163 Co-based superalloy and AISI 410L stainless steel: Based on in situ observation and variant selection

This study establishes a link between crystallographic variants and mechanical properties at both the edge and center regions of NS163 Co-based superalloy wires and AISI 410L stainless steel plates welded joints. The thermal cycle of vacuum electron beam welding was simulated using in situ laser confocal microscopy to clarify the martensitic transformation process. Results indicate that martensite preferentially nucleates at grain boundaries, maintaining the Kurdjumov-Sachs orientation relationship with the parent austenite. Most variant boundaries in these regions correspond to variants within the same crystal packet, with V1/V3&V5 emerging as dominant pairs. At the edge, the increased cooling rate and temperature gradient amplify the driving force for martensitic transformation, fostering the generation of diverse variants. Conversely, lower cooling rate at the center raises the martensitic transformation temperature and expands variant selection. The study notes significant dislocation slip during micropillar compression, with the edge of weld exhibiting finer martensite laths and dense dislocations, which enhances strength (∼1279 MPa) compared to the center (∼1040 MPa), aligning with the results obtained via nanoindentation. The observed "size effect" results in a twice strength as measured by micropillar compression compared to nanoindentation. Additionally, staggered Bain groups at the edge include a greater number of high angle grain boundaries, indirectly improving toughness. This research aligns with recent literature and aids in the development of compositional design and machining techniques for heterogeneous welds.

Hyaluronic acid-based hydrogels as codelivery systems: The effect of intermolecular interactions investigated by HR-MAS and solid-state NMR Spectroscopy

Hydrogels based on hyaluronic acid and agarose-carbomer, due to their peculiar 3D architecture and biocompatibility, are promising candidates for pharmaceutical strategies based on the codelivery of drugs targeting different diseases. The successful development of these applications requires a precise understanding of drug-drug interactions and their effects on transport and release mechanisms. In this study, such an investigation is carried out on hydrogels loaded with ethosuximide and sodium salicylate at different concentrations. Intermolecular interactions and transport properties are characterized by means of High Resolution Magic Angle Spinning and solid-state Magic Angle Spinning NMR Spectroscopy.At variance with our previous findings on single-drug formulations, the two drugs exhibit closely similar diffusion patterns when co-loaded in the HA-based hydrogels, plausibly due to drug-drug intermolecular interactions. At the highest drug concentrations, where superdiffusion comes into play, we find a fraction of molecules with time-varying diffusion coefficients. A trapping-release mechanism is proposed to explain this observation, which also accounts for the role of drug-hydrogel interactions in drug diffusion motion. The effects of drug-drug interactions on release profiles are finally assessed by means of in vitro release experiments.

A continuous plane of polarization rotator and detector based on the liquid crystal Θ-cell

Modulation of the polarization state of optical beams is crucial in advanced optical applications such as polarization microscopy, polarization rotation, and medical imaging. We demonstrate a continuous polarization rotator (PR) by utilizing the liquid crystals (LC) in Θ-cell configuration comprising of circular and parallel alignment of LC on two aligning glass substrates. A rotation of plane of polarization (PoP) up to ∼ 160˚ is observed using Stokes polarimetry. This is further substantiated by the mathematical analysis using Mueller matrix formalism. Further, the device is demonstrated as a PoP detector with high precision detection angle. The PoP is analyzed through single-shot imaging of the intensity distribution of transmitted light through the LC Θ-cell.

In-situ thermally induced formation of an ultra-glossy hydrophilic surface for oil fouling prevention in TiO2@MXene membranes

Oil droplets are inevitably deposited on the surface of membranes, resulting in membrane contamination during oily sewage separation. To effectively prevent oil fouling, a TiO2@MXene membrane with an ultra-glossy hydrophilic surface was designed via in-situ thermal induction to regulate the membrane surface structure and properties. Through high temperature-induced evolving the Ti valence and the functional groups of Ti3C2Tx, uniform TiO2 nanoparticles were generated in-situ on the Ti3C2Tx surface while altering the surface structure and properties, which considerably improved the hydrophilicity, underwater oleophobic properties, and surface finish of the membrane. Specifically, the TiO2@MXene membrane (MT600) exhibited a low water contact angle of 7.5° and a high underwater oil contact angle of 133.3°. Notably, the oil adhesion force of the membrane was as low as 0.0013 μN, outperforming most oil water separation membranes. Thus, the unique structure and surface properties endowed MT600 membrane with excellent oil retention (TOC removal efficiency of > 95 %) and antipollution ability (permeance decay rates of < 10 %) for oil-in-water emulsion separation. This is because the ultra-glossy hydrophilic and oleophobic surface prompted the formation of a continuous and stable hydration layer on the membrane surface and prevented oil droplets from falling into the membrane grooves. Benefiting from the robust, ultra-glossy surface, the MT600 membrane exhibited excellent long-term durability and reusability (emulsion permeance recovery of > 90 %) in high-salt, highly acidic, and highly alkaline environments. This study opens pathways to realize ultra-glossy membrane surface for the efficient demulsification of small size emulsions and long-lasting, stable oil water separation.

A corrugated edge tapered slot dual polarized MIMO antenna for phased array systems

ABSTRACT In this paper, a corrugated-edged slot antenna with dual linear polarisation properties is presented. The antenna incorporates corrugations along the outer edges between the elements to control the complex mutual coupling effect at high scan angles, resulting in nearly linear polarised waves in the two principal E and H planes. The dual-polarised antenna structure is accomplished by incorporating two orthogonal tapered slot Vivaldi antennas in a cross-shaped configuration, ensuring there is no galvanic contact between them. The proposed four-element antenna is compact in size and has a low profile of L × W × h = 30 × 25.5 × 1 mm3. The antenna optimised dimensions have been determined through meticulous parametric studies, ensuring its suitability for operation within the desired frequency band. The proposed antenna diversity performance characteristics are analysed with regard to parameters such as envelope correlation coefficient (ECC), diversity gain (DG), mean effective gain (MEG), total active reflection coefficient (TARC) and channel capacity loss (CCL). The corresponding values obtained are 0.02, 9.97 dB, ±3 dB, −6 dB and 0.09 bits/s/Hz, respectively. To validate the design, a prototype of the four-element antenna model is fabricated and measured. The results demonstrate that the return losses (S11) are lower than −10 dB across the operational frequency band. The isolation (S21) between the antenna ports is better than -30 dB and achieved a maximum measured gain of 7.1 dB at 18 GHz.

Magnetically responsive superhydrophobic surface: Reversible switching for water repellency and active/passive anti-icing

This research aims to address the negative impact of global climate change on equipment stability, with a particular focus on the occurrence of icing on working surfaces at low temperature. To this end, we have developed a novel magnetically responsive superhydrophobic surface to enhance anti-icing properties and adapt to environmental changes. We prepared magnetically responsive micro-cilia arrays (MRMAs) with good flexibility and magnetostriction through a facile spray gun coating technique. By adjusting the application mode and distance of the magnetic field, three different morphologies can be achieved: vertical, curved and crossed, thus optimizing water repellency, active anti-icing and passive anti-icing performance. Experimental data show that vertical MRMAs exhibit extremely high contact angles and low droplet adhesion, which facilitates rapid water droplet removal, while curved MRMAs exhibit the lowest ice adhesion strength, which effectively reduces the likelihood of ice formation. In addition, the crossed MRMAs excelled in delaying icing, significantly prolonging the time before water droplets begin to freeze. This research not only provides a novel anti-icing strategy, but also offers new ideas for designing multifunctional surfaces that can adapt to complex environmental conditions.

Effect of temperature and capillary number on wettability and contact angle hysteresis of various materials. Modeling taking into account porosity

The effect of surface temperature and laser texturing on the wettability and contact angle hysteresis of Cu, Cu/G, AlMg3, Cu-SiC was considered. Modeling using molecular dynamics qualitatively confirms the experimental results: 1) an increase in the contact angle hysteresis on a textured surface; 2) influence of the surface wettability on contact angle hysteresis; 3) influence of the contact line velocity on contact angle hysteresis. Heating the sample of different composite materials can lead to either an increase in the contact angle or a decrease. It was shown that after laser texturing, a system of nano-micro pores was formed in the surface layer of the material, which leads to an abnormally high contact angle hysteresis on the Cu-SiC composite. A new model is proposed that explains the different qualitative behavior of the contact angle hysteresis in different studies with increasing capillary number (Ca), as well as with increasing sample temperature.

Gas–Water–Sand Inflow Patterns and Completion Optimization in Hydrate Wells with Different Sand Control Completions

Sand production poses a significant problem for marine natural gas hydrate efficient production. However, the bottom hole gas–water–sand inflow pattern remains unclear, hindering the design of standalone screen and gravel packing sand control completions. Therefore, gas–water–sand inflow patterns were studied in horizontal and vertical wells with the two completions. The experimental results showed that gas–water stratification occurred in horizontal and vertical standalone screen wells. The gas–water interface changed dynamically, leading to an uneven screen plugging, with severe plugging at the bottom and high permeability at the top. The high sand production rate and low well deviation angle exacerbated screen plugging, resulting in a faster rising rate of the gas–water interface. The screen plugging degree initially decreased and then increased as the gas–water ratio increased, resulting in the corresponding variation in the gas–water interface rising rate. Conversely, gas–water stratification did not occur in the gravel packing well because of the pore throat formed between the packing gravels. However, the impact of gas and water led to gravel rearrangement and the formation of erosion holes, causing sand control failure. A higher gas–water ratio and lower packing degree could result in more severe destabilization. Therefore, for the standalone screen completion, sand control accuracy should be designed at different levels according to the uneven plugging degree of the screen. For the gravel packing completion, increase the gravel density without destabilizing the hydrate reservoir, and use the coated gravel with a cementing effect to improve the gravel layer stability. In addition, the screen sand control accuracy inside the gravel packing layer should be designed according to the sand size to keep long-term stable hydrate production.