Sticking is the most serious cause of failure in complex drilling operations.In the present work a novel“early warning”method based on an artificial intelligence algorithm is proposed to overcome some of the known pr...Sticking is the most serious cause of failure in complex drilling operations.In the present work a novel“early warning”method based on an artificial intelligence algorithm is proposed to overcome some of the known pro-blems associated with existing sticking-identification technologies.The method is tested against a practical case study(Southern Sichuan shale gas drilling operations).It is shown that the twelve sets of sticking fault diagnostic results obtained from a simulation are all consistent with the actual downhole state;furthermore,the results from four groups of verification samples are also consistent with the actual downhole state.This shows that the pro-posed training-based model can effectively be applied to practical situations.展开更多
Through the collection of oriented samples,consolidation of undisturbed samples,and systematic microscopy of thin sections,the deformation products from the Daqingshan piedmont active fault zone have been studied.The ...Through the collection of oriented samples,consolidation of undisturbed samples,and systematic microscopy of thin sections,the deformation products from the Daqingshan piedmont active fault zone have been studied.The obtained results have been analyzed in combination with those of rock fracture experiments and macroscopic surveys.Based on the above,the present article summarizes the microscopic indicators of stick-slip and creep-slip,which reflect the characteristics of fault movement,and has given some suggestion on relevant problems.展开更多
Based on fault geometric features,composite pattern,faulting land-forms and seismic data,this paper discussed the activity behavior along the northern segment of the Anninghe fault(from Xichang to Shimian)since the La...Based on fault geometric features,composite pattern,faulting land-forms and seismic data,this paper discussed the activity behavior along the northern segment of the Anninghe fault(from Xichang to Shimian)since the Late Pleistocene.The fault can be divided into three active segments by discrepancies of their activity:the segment from Xichang to Mianning,the segment from Mianning to Zimakua,and the segment from Zimakua to Tianwan.The southern segment has the background of occurrence of great earthquakes,but the middle and the northern segments can generate strong and moderate events respectively.According to the features of quartz from fault gouges by scanning electron microscopy(SEM),this paper discussed the movement features along the fault and indicated the stick-slipping feature on the segment from Xichang to Zimakua,the creeping feature on the segment from Jiziping to Tianwan and the transitional feature on the segment in between.展开更多
The comparative study of the geologic and seismic dislocations often major active faults,such as the Aikin fault etc.,on China mainland,has shown that the ratio between the seismic slip rate(Vs)and geologic slip rate(...The comparative study of the geologic and seismic dislocations often major active faults,such as the Aikin fault etc.,on China mainland,has shown that the ratio between the seismic slip rate(Vs)and geologic slip rate(Vg),i.e.,Q=Vs/Vg,for most of the active faults ranges between 0.5-0.8,indicating that most of the active faults are characterized by stick slip movement.According to the magnitude of the Q value,the slip mode of the faults can further be classified into four types:strong stick-slip(Q≥0.75),mainly stick-slip(0.5≤Q【0.75),mainly creep-slip(0.5】0≥0.25),and strong creep-slip(Q【0.25).The authors have also analyzed the constraint of the determination of Q value,as well as the prospect of the application of Q value to the determination of slip mode of major active faults.展开更多
基金The project is supported by CNPC Key Core Technology Research Projects(2022ZG06)received by Qing Wangproject funded by China Postdoctoral Science Foundation(2021M693508)received by Qing Wang.Basic Research and Strategic Reserve Technology Research Fund Project of Institutes directly under CNPC received by Qing Wang.
文摘Sticking is the most serious cause of failure in complex drilling operations.In the present work a novel“early warning”method based on an artificial intelligence algorithm is proposed to overcome some of the known pro-blems associated with existing sticking-identification technologies.The method is tested against a practical case study(Southern Sichuan shale gas drilling operations).It is shown that the twelve sets of sticking fault diagnostic results obtained from a simulation are all consistent with the actual downhole state;furthermore,the results from four groups of verification samples are also consistent with the actual downhole state.This shows that the pro-posed training-based model can effectively be applied to practical situations.
基金This project was sponsored by the Joint Earthquake Science Foundation (95133),China.
文摘Through the collection of oriented samples,consolidation of undisturbed samples,and systematic microscopy of thin sections,the deformation products from the Daqingshan piedmont active fault zone have been studied.The obtained results have been analyzed in combination with those of rock fracture experiments and macroscopic surveys.Based on the above,the present article summarizes the microscopic indicators of stick-slip and creep-slip,which reflect the characteristics of fault movement,and has given some suggestion on relevant problems.
文摘Based on fault geometric features,composite pattern,faulting land-forms and seismic data,this paper discussed the activity behavior along the northern segment of the Anninghe fault(from Xichang to Shimian)since the Late Pleistocene.The fault can be divided into three active segments by discrepancies of their activity:the segment from Xichang to Mianning,the segment from Mianning to Zimakua,and the segment from Zimakua to Tianwan.The southern segment has the background of occurrence of great earthquakes,but the middle and the northern segments can generate strong and moderate events respectively.According to the features of quartz from fault gouges by scanning electron microscopy(SEM),this paper discussed the movement features along the fault and indicated the stick-slipping feature on the segment from Xichang to Zimakua,the creeping feature on the segment from Jiziping to Tianwan and the transitional feature on the segment in between.
基金This pronject was sponsored by the Joint Earthquake Science Foundation,China.
文摘The comparative study of the geologic and seismic dislocations often major active faults,such as the Aikin fault etc.,on China mainland,has shown that the ratio between the seismic slip rate(Vs)and geologic slip rate(Vg),i.e.,Q=Vs/Vg,for most of the active faults ranges between 0.5-0.8,indicating that most of the active faults are characterized by stick slip movement.According to the magnitude of the Q value,the slip mode of the faults can further be classified into four types:strong stick-slip(Q≥0.75),mainly stick-slip(0.5≤Q【0.75),mainly creep-slip(0.5】0≥0.25),and strong creep-slip(Q【0.25).The authors have also analyzed the constraint of the determination of Q value,as well as the prospect of the application of Q value to the determination of slip mode of major active faults.
