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The application of ant-tracking in seismic interpretation shows its advantages in fault characterization.However, this technology is limited by the quality of seismic data, the selection of ant-tracking input data, and multi-solution caused by single attribute.Thus, how to improve the accuracy of ant-tracking has been the hot issue and hard nut to crack in the industry.This paper takes well-block 1 in Shunbei area of Tarim Basin as the research object, and analyses the differences and application potential of chaos, variance, and the maximum positive curvature theories in fault detection.Besides, based on generalized S transform spectral decomposition, we compare discontinuity detection effects of chaos, variance and the maximum positive curvature attributes in different frequencies.Next, the data is processed after discontinuity detection with ant-tracking and optimize the best date for each frequency.Finally, RGB fusion is carried out after occurrence control.Results show that chaos in low frequency, variance in medium frequency and the maximum positive curvature in high frequency respond well with big, medium and small faults.The ant-tracking aided with multi-frequency domain and different fault detections can display multi-scale fracture distribution and enrich the underground geological information.

The quality of microseismic data greatly affects the accuracy of the source location results, especially in surface microseismic data where the first arrivals of P waves and S waves are not obvious or the low signal-to-noise ratio signals are difficult to identify.Secondly, due to the different focal mechanisms that induce microseismic, the signal characteristics received by different geophones are not the same.All of these factors have a certain impact on the accurate location of microseismic events.This paper proposes a method for selecting microseismic data based on cluster analysis to improve the imaging quality of microseismic event amplitude superposition locating.First, the Euclidean distance between the trace channels is calculated by cluster analysis, and the trace channels with larger and smaller distances are removed through the clustering graph, that is, trace channels with insignificant signal characteristics or severe noise interference are removed.Second, the cross-correlation calculation is performed on the signals of each channel, the trace channels with strong signal characteristic correlation being extracted, and those with unobvious P wave characteristics removed.Finally, the screened trace channels are superimposed and located with amplitude superposition.The comparison of the locating results with the original trace channels shows that the locating effect of the microseismic cluster analysis is more focused, the location of the focal point is clearer, and the locating results are significantly improved.

Hydraulic fracturing in shale gas production can induce felt earthquakes, making it crucial to understand and mitigate induced earthquakes. The Cen'gong shale gas block in South China offers extensive data—3D seismic, geological structure, microseismic data, and detailed stimulation operations—allowing a comprehensive investigation into induced earthquakes by hydraulic fracturing. Using a dense temporary seismic array and deep‐learning workflows, we build a high precision earthquake catalog and determine their focal mechanisms. Pre‐existing fractures are identified through the Ant Tracking attribute derived from the 3D seismic data. We analyze the distribution, frequency, magnitude, and focal mechanisms of induced earthquakes, compare them spatially with the distribution of the pre‐existing fractures, and track their temporal changes during and after hydraulic fracturing. Most induced earthquakes occurred along pre‐existing fractures, exhibiting relatively larger magnitudes and persistent trailing seismicity. The number of trailing seismicity is proportional to the response time of stimulation earthquakes. The focal mechanism solutions suggest that the rupture mechanism of the trailing seismicity remained unchanged. By analyzing four clusters of earthquakes, we found that in two of these clusters, the induced earthquakes initiated from the far side of the fractures, then linearly migrated along the pre‐existing fractures. This directional migration pattern is explained by stress rotation along the fractures. Our analysis suggests that both pre‐existing fractures and stimulation operations significantly influence induced earthquake occurrences. Therefore, this work may enhance our understanding of pre‐existing fractures, and optimizing stimulation operations can mitigate earthquake hazards in shale gas production. Plain Language Summary: Felt hydraulic fracturing‐induced earthquakes have been reported worldwide. Understanding the triggering mechanisms of induced earthquakes is essential to mitigate earthquake hazards. This study utilizes extensive data recorded in the Cen'gong shale gas block in South China to comprehensively investigate and understand the spatial and temporal distribution, magnitudes, focal mechanisms, initiation, and migration of induced earthquakes. Our results suggest that both pre‐existing fractures and stimulation operations significantly influence induced earthquakes. Thus, induced earthquakes can be mitigated by understanding the interaction of the pre‐existing fractures and the stimulation operations. Key Points: We construct an earthquake catalog and determine focal mechanisms for the Cen'gong hydraulic fracturing through machine‐learning seamless workflowsThe distribution and intensity of induced earthquakes are influenced by both pre‐existing fractures and stimulation operationsThe linear directional migration of induced earthquakes is observed and attributed to stress rotation along the fracture [ABSTRACT FROM AUTHOR]

Although perovskite solar cells have achieved excellent photoelectric conversion efficiencies, there are still some shortcomings, such as defects inside and at the interface as well as energy level dislocation, which may lead to non-radiative recombination and reduce stability. Therefore, in this study, a double electron transport layer (ETL) structure of FTO/TiO2/ZnO/(FAPbI3)0.85(MAPbBr3)0.15/Spiro-OMeTAD is investigated and compared with single ETL structures of FTO/TiO2/(FAPbI3)0.85(MAPbBr3)0.15/Spiro-OMeTAD and FTO/ZnO/(FAPbI3)0.85(MAPbBr3)0.15/Spiro-OMeTAD using the SCAPS-1D simulation software, with special attention paid to the defect density in the perovskite active layer, defect density at the interface between the ETL and the perovskite active layer, and temperature. Simulation results reveal that the proposed double ETL structure could effectively reduce the energy level dislocation and inhibit the non-radiative recombination. The increases in the defect density in the perovskite active layer, the defect density at the interface between the ETL and the perovskite active layer, and the temperature all facilitate carrier recombination. Compared with the single ETL structure, the double ETL structure has a higher tolerance for defect density and temperature. The simulation outcomes also confirm the possibility of preparing a stable perovskite solar cell. [ABSTRACT FROM AUTHOR]

CO2 geological storage projects are an essential tool for China to achieve the double carbon target of energy savings and emission reductions. In order to safely and effectively control the implementation of injection projects and monitor the dynamics of CO2 injection, multi-dimensional and multi-disciplinary monitoring tools are required. Among them, microseismic monitoring is a key technology for predicting reservoir dynamics and reflecting reservoir geomechanical behavior. Such monitoring has been carried out previously for reservoirs in other countries, but experimental projects are also gradually being developed in China. In this paper, we focus on the research and analysis results of microseismic monitoring of carbon storage projects in various work areas. For different reservoir conditions, we explore combinations of the monitoring implementation methods in China, comparing the differences in each work area. We propose a joint well and ground microseismic monitoring method and a multi-spatial and multi-physical field coupling research system for use in the implementation of domestic demo projects for the future research and development of microseismic monitoring of carbon storage projects. The monitoring program can meet the requirements for certain periodic repeated or continuous observations and can intelligently assess the risk and handle the alert behavior. The foundation is laid for the development of the future microseismic monitoring technology to achieve the goal of developing cost-controllable, permanent, and real-time monitoring equipment. The application of the monitoring system in China has been effective, and this experience can contribute to the development of injection engineering in the future. [ABSTRACT FROM AUTHOR]

To broaden the absorption spectrum of cells, enhance the cell stability, and avoid high costs, a novel perovskite solar cell (PSC) with the structure of fluorine-doped tin oxide (FTO)/ZnO/CsPbI3/FAPbI3/CuSCN/Au is designed using the solar cell capacitance simulator (SCAPS) software. The simulation results indicate that the CsPbI3/FAPbI3 heterojunction PSC has higher quantum efficiency (QE) characteristics than the single-junction CsPbI3-based PSC, and it outputs a higher short-circuit current density (Jsc) and power conversion efficiency (PCE). In order to optimize the device performance, several critical device parameters, including the thickness and defect density of both the CsPbI3 and FAPbI3 layers, the work function of the contact electrodes, and the operating temperature are systematically investigated. Through the optimum analysis, the thicknesses of CsPbI3 and FAPbI3 are optimized to be 100 and 700 nm, respectively, so that the cell could absorb photons more sufficiently without an excessively high recombination rate, and the cell achieved the highest PCE. The defect densities of CsPbI3 and FAPbI3 are set to 1012 cm−3 to effectively avoid the excessive carrier recombination centering on the cell to increase the carrier lifetime. Additionally, we found that when the work function of the metal back electrode is greater than 4.8 eV and FTO with a work function of 4.4 eV is selected as the front electrode, the excessively high Schottky barrier could be avoided and the collection of photogenerated carriers could be promoted. In addition, the operating temperature is proportional to the carrier recombination rate, and an excessively high temperature could inhibit Voc. After implementing the optimized parameters, the cell performance of the studied solar cell was improved. Its PCE reaches 28.75%, which is higher than most of existing solar cells. Moreover, the open circuit voltage (Voc), Jsc, and PCE are increased by 17%, 9.5%, and 25.1%, respectively. The results of this paper provide a methodology and approach for the construction of high-efficiency heterojunction PSCs. [ABSTRACT FROM AUTHOR]