Fault formation and evolution in the presence of multiple pre-existing weaknesses has not been investigated extensively in rift basins. The fault systems of Weixinan Sag, Beibuwan Basin of China, which is fully covere...Fault formation and evolution in the presence of multiple pre-existing weaknesses has not been investigated extensively in rift basins. The fault systems of Weixinan Sag, Beibuwan Basin of China, which is fully covered with high-precision 3-D seismic data and is rich in oil-gas resources, have been successfully reproduced by sandbox modeling in this study with inclusion of multiple pre-existing weaknesses in the experimental model. The basic characteristics of fault formation and evolution revealed by sandbox modeling are as follows. 1） Weakness-reactivation faults and weakness-related faults are formed much earlier than the distant-weakness faults （faults far away from and with little or no relationship to the weakness）. 2） Weakness-reactivation faults and weakness-related faults develop mainly along or parallel to a pre-existing weakness, while distant-weakness faults develop nearly perpendicular to the extension direction. A complicated fault system can be formed in a fixed direction of extension with the existence of multiple pre-existing weaknesses, and the complicated fault system in the Weixinan Sag formed gradually in a nearly N-S direction with multiple pre-existing weaknesses. 3） The increase in the length and number of faults is closely tied to the nature of pre-existing weaknesses. The sandbox model may provide a new clue to detailed fault system research for oil and gas exploration in rift basins.展开更多
Three series of sandbox modeling experiments were performed to study the fault-increment pattern in extensional basins. Experimental results showed that the tectonic action mode of boundaries and the shape of major bo...Three series of sandbox modeling experiments were performed to study the fault-increment pattern in extensional basins. Experimental results showed that the tectonic action mode of boundaries and the shape of major boundary faults control the formation and evolution of faults in extensional basins. In the process of extensional deformation, the increase in the number and length of faults was episodic, and every ＇episode＇ experienced three periods, strain-accumulation period, quick fault-increment period and strain-adjustment period. The more complex the shape of the boundary fault, the higher the strain increment each ＇episode＇ experienced. Different extensional modes resulted in different fault-increment patterns. The horizontal detachment extensional mode has the ＇linear＇ style of fault-increment pattern, while the extensional mode controlled by a listric fault has the ＇stepwise＇ style of fault-increment pattern, and the extensional mode controlled by a ramp-flat boundary fault has the ＇stepwise-linear＇ style of fault-increment pattern. These fault-increment patterns given above could provide a theoretical method of fault interpretation and fracture prediction in extensional basins.展开更多
A sandbox experiment model was designed to simulate how differences in rock strength and gravity between two blocks can influence the formation characteristics of thrusts. In the experiment the compression was from on...A sandbox experiment model was designed to simulate how differences in rock strength and gravity between two blocks can influence the formation characteristics of thrusts. In the experiment the compression was from one direction with basement shortening and the initial surfaces of the model were oblique. The results show that if the initial surface was horizontal or the slope angle was smaller than 7°, the compression induced two groups of thrusts with opposite dip orientations. If the slope angle of the initial surface was greater than 7°, the compression induced only one group of thrusts with a dip orientation contrary to the original compression direction. This result is similar to the actual section of a collision zone between two continental blocks. By applying stress analysis, rock strength is shown to be an important factor in deformation. As other boundary conditions are changeless, it is the change of gravitational potential energy that leads to different deformation styles.展开更多
Ransomware is a type of malicious software that blocks access to a computer by encrypting user’s files until a ransom is paid to the attacker.There have been several reported high-profile ransomware attacks including...Ransomware is a type of malicious software that blocks access to a computer by encrypting user’s files until a ransom is paid to the attacker.There have been several reported high-profile ransomware attacks including WannaCry,Petya,and Bad Rabbit resulting in losses of over a billion dollars to various individuals and businesses in the world.The analysis of ransomware is often carried out via sandbox environments;however,the initial setup and configuration of such environments is a challenging task.Also,it is difficult for an ordinary computer user to correctly interpret the complex results presented in the reports generated by such environments and analysis tools.In this research work,we aim to develop a user-friendly model to understand the taxonomy and analysis of ransomware attacks.Also,we aim to present the results of analysis in the form of summarized reports that can easily be understood by an ordinary computer user.Our model is built on top of the well-known Cuckoo sandbox environment for identification of the ransomware as well as generation of the summarized reports.In addition,for evaluating the usability and accessibility of our proposed model,we conduct a comprehensive user survey consisting of participants from various fields,e.g.,professional developers from software houses,people from academia(professors,students).Our evaluation results demonstrate a positive feedback of approximately 92%on the usability of our proposed model.展开更多
基金supported by China National Major Project of Oil and Gas (2011ZX05023-004-012, 2011ZX05006-006-02-01)China Natural Science Foundation (Grant No. 40772086)
文摘Fault formation and evolution in the presence of multiple pre-existing weaknesses has not been investigated extensively in rift basins. The fault systems of Weixinan Sag, Beibuwan Basin of China, which is fully covered with high-precision 3-D seismic data and is rich in oil-gas resources, have been successfully reproduced by sandbox modeling in this study with inclusion of multiple pre-existing weaknesses in the experimental model. The basic characteristics of fault formation and evolution revealed by sandbox modeling are as follows. 1） Weakness-reactivation faults and weakness-related faults are formed much earlier than the distant-weakness faults （faults far away from and with little or no relationship to the weakness）. 2） Weakness-reactivation faults and weakness-related faults develop mainly along or parallel to a pre-existing weakness, while distant-weakness faults develop nearly perpendicular to the extension direction. A complicated fault system can be formed in a fixed direction of extension with the existence of multiple pre-existing weaknesses, and the complicated fault system in the Weixinan Sag formed gradually in a nearly N-S direction with multiple pre-existing weaknesses. 3） The increase in the length and number of faults is closely tied to the nature of pre-existing weaknesses. The sandbox model may provide a new clue to detailed fault system research for oil and gas exploration in rift basins.
文摘Three series of sandbox modeling experiments were performed to study the fault-increment pattern in extensional basins. Experimental results showed that the tectonic action mode of boundaries and the shape of major boundary faults control the formation and evolution of faults in extensional basins. In the process of extensional deformation, the increase in the number and length of faults was episodic, and every ＇episode＇ experienced three periods, strain-accumulation period, quick fault-increment period and strain-adjustment period. The more complex the shape of the boundary fault, the higher the strain increment each ＇episode＇ experienced. Different extensional modes resulted in different fault-increment patterns. The horizontal detachment extensional mode has the ＇linear＇ style of fault-increment pattern, while the extensional mode controlled by a listric fault has the ＇stepwise＇ style of fault-increment pattern, and the extensional mode controlled by a ramp-flat boundary fault has the ＇stepwise-linear＇ style of fault-increment pattern. These fault-increment patterns given above could provide a theoretical method of fault interpretation and fracture prediction in extensional basins.
基金This paper is supported by the project IGCP411(3-3-02-24) .
文摘A sandbox experiment model was designed to simulate how differences in rock strength and gravity between two blocks can influence the formation characteristics of thrusts. In the experiment the compression was from one direction with basement shortening and the initial surfaces of the model were oblique. The results show that if the initial surface was horizontal or the slope angle was smaller than 7°, the compression induced two groups of thrusts with opposite dip orientations. If the slope angle of the initial surface was greater than 7°, the compression induced only one group of thrusts with a dip orientation contrary to the original compression direction. This result is similar to the actual section of a collision zone between two continental blocks. By applying stress analysis, rock strength is shown to be an important factor in deformation. As other boundary conditions are changeless, it is the change of gravitational potential energy that leads to different deformation styles.
基金support of Security Testing-Innovative Secured Systems Lab(ISSL)established at University of Engineering&Technology,Peshawar,Pakistan under the Higher Education Commission initiative of National Center for Cyber Security(Grant No.2(1078)/HEC/M&E/2018/707).
文摘Ransomware is a type of malicious software that blocks access to a computer by encrypting user’s files until a ransom is paid to the attacker.There have been several reported high-profile ransomware attacks including WannaCry,Petya,and Bad Rabbit resulting in losses of over a billion dollars to various individuals and businesses in the world.The analysis of ransomware is often carried out via sandbox environments;however,the initial setup and configuration of such environments is a challenging task.Also,it is difficult for an ordinary computer user to correctly interpret the complex results presented in the reports generated by such environments and analysis tools.In this research work,we aim to develop a user-friendly model to understand the taxonomy and analysis of ransomware attacks.Also,we aim to present the results of analysis in the form of summarized reports that can easily be understood by an ordinary computer user.Our model is built on top of the well-known Cuckoo sandbox environment for identification of the ransomware as well as generation of the summarized reports.In addition,for evaluating the usability and accessibility of our proposed model,we conduct a comprehensive user survey consisting of participants from various fields,e.g.,professional developers from software houses,people from academia(professors,students).Our evaluation results demonstrate a positive feedback of approximately 92%on the usability of our proposed model.
