With the theoretical and technological developments related to cratonic strike-slip faults,the Shuntuoguole Low Uplift in the Tarim Basin has attracted considerable attention recently.Affected by multi-stage tectonic ...With the theoretical and technological developments related to cratonic strike-slip faults,the Shuntuoguole Low Uplift in the Tarim Basin has attracted considerable attention recently.Affected by multi-stage tectonic movements,the strike-slip faults have controlled the distribution of hydrocarbon resources owing to the special fault characteristics and fault-related structures.In contrast,the kinematics and formation mechanism of strike-slip faults in buried sedimentary basins are difficult to investigate,limiting the discussion of these faults and hydrocarbon accumulation.In this study,we identified the characteristics of massive sigmoidal tension gashes(STGs)that formed in the Shunnan area of the Tarim Basin.High-resolution three-dimensional seismic data and attribute analyses were used to investigate their geometric and kinematic characteristics.Then,the stress state of each point of the STGs was calculated using seismic curvature attributes.Finally,the formation mechanism of the STGs and their roles in controlling hydrocarbon migration and accumulation were discussed.The results suggest that:(1)the STGs developed in the Shunnan area have a wide distribution,with a tensile fault arranged in an enéchelon pattern,showing an S-shaped bending.These STGs formed in multiple stages,and differential rotation occurred along the direction of strike-slip stress during formation.(2)Near the principal displacement zone of the strike-slip faults,the stress value of the STGs was higher,gradually decreasing at both ends.The shallow layer deformation was greater than the deep layer deformation.(3)STGs are critical for connecting source rocks,migrating oil and gas,sealing horizontally,and developing efficient reservoirs.This study not only provides seismic evidence for the formation and evolution of super large STGs,but also provides certain guidance for oil and gas exploration in this area.展开更多
Gear shaving is a gear finishing operation of high efficiency and high precision. After shaved by shaving cutter of true involute profile, there are the "mid-concave" phenomena around the pitch points of the...Gear shaving is a gear finishing operation of high efficiency and high precision. After shaved by shaving cutter of true involute profile, there are the "mid-concave" phenomena around the pitch points of the work gear tooth flanks inevitably. This problem severely affects the shaving accuracy and gear transmission quality, which hasn’t been resolved thoroughly for a long time. Aiming at the problem, based on shaving mechanism and the analysis on gear tooth profile mid-concave, a new-style shaving cutter with unequal depth gashes is designed and manufactured. As compared with common shaving cutter, its depth of gashes is zero on the pitch points of tooth profiles and gradually gets deeper to max. from pitch points to the tops of teeth or the roots. Because of no depth on the pitch points, there are no cutting edges, that is, no cutting action, so the work gear isn’t cutted around its pitch points and is only pressed during shaving operation. Therefore, the gear tooth errors are decreased greatly. And the experimentations have proved the shaved gear has better surface finish that achieves the expectant effect. In addition, this paper analyses the forming of gash on the basis of slotting principle, and proposes a design method of gash: gash bottom is formed by two involutes which intersect on the pitch point and are concentric with the base circle of involute profile of cutter. Furthermore, the equations of the two involutes are deduced and the solution is introduced. This paper analyses the forming of gash on the basis of slotting principle, and proposes a gash-designing method. And the experiment has proved that the shaved gear has better surface finish that achieves the anticipated effect.展开更多
基金Thanks to the Northwest Oilfield Branch,SINOPEC,for providing the seismic data.We thank Dr.Yi-Duo Liu of University of Houston,Ying-Chang Cao and Fang Hao of China University of Petroleum(East China)for their constructive suggestions of this manuscript.We also thank two anonymous reviewers for their comments that helped us to improve the manuscript.This research is jointly supported by the National Natural Science Foundation of China(No.42272155)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDA14010301)+1 种基金the Science Fund for Creative Research Groups of the National Natural Science Foundation of China(Grant No.41821002)National Natural Science Foundation of China(No.41702138).
文摘With the theoretical and technological developments related to cratonic strike-slip faults,the Shuntuoguole Low Uplift in the Tarim Basin has attracted considerable attention recently.Affected by multi-stage tectonic movements,the strike-slip faults have controlled the distribution of hydrocarbon resources owing to the special fault characteristics and fault-related structures.In contrast,the kinematics and formation mechanism of strike-slip faults in buried sedimentary basins are difficult to investigate,limiting the discussion of these faults and hydrocarbon accumulation.In this study,we identified the characteristics of massive sigmoidal tension gashes(STGs)that formed in the Shunnan area of the Tarim Basin.High-resolution three-dimensional seismic data and attribute analyses were used to investigate their geometric and kinematic characteristics.Then,the stress state of each point of the STGs was calculated using seismic curvature attributes.Finally,the formation mechanism of the STGs and their roles in controlling hydrocarbon migration and accumulation were discussed.The results suggest that:(1)the STGs developed in the Shunnan area have a wide distribution,with a tensile fault arranged in an enéchelon pattern,showing an S-shaped bending.These STGs formed in multiple stages,and differential rotation occurred along the direction of strike-slip stress during formation.(2)Near the principal displacement zone of the strike-slip faults,the stress value of the STGs was higher,gradually decreasing at both ends.The shallow layer deformation was greater than the deep layer deformation.(3)STGs are critical for connecting source rocks,migrating oil and gas,sealing horizontally,and developing efficient reservoirs.This study not only provides seismic evidence for the formation and evolution of super large STGs,but also provides certain guidance for oil and gas exploration in this area.
文摘Gear shaving is a gear finishing operation of high efficiency and high precision. After shaved by shaving cutter of true involute profile, there are the "mid-concave" phenomena around the pitch points of the work gear tooth flanks inevitably. This problem severely affects the shaving accuracy and gear transmission quality, which hasn’t been resolved thoroughly for a long time. Aiming at the problem, based on shaving mechanism and the analysis on gear tooth profile mid-concave, a new-style shaving cutter with unequal depth gashes is designed and manufactured. As compared with common shaving cutter, its depth of gashes is zero on the pitch points of tooth profiles and gradually gets deeper to max. from pitch points to the tops of teeth or the roots. Because of no depth on the pitch points, there are no cutting edges, that is, no cutting action, so the work gear isn’t cutted around its pitch points and is only pressed during shaving operation. Therefore, the gear tooth errors are decreased greatly. And the experimentations have proved the shaved gear has better surface finish that achieves the expectant effect. In addition, this paper analyses the forming of gash on the basis of slotting principle, and proposes a design method of gash: gash bottom is formed by two involutes which intersect on the pitch point and are concentric with the base circle of involute profile of cutter. Furthermore, the equations of the two involutes are deduced and the solution is introduced. This paper analyses the forming of gash on the basis of slotting principle, and proposes a gash-designing method. And the experiment has proved that the shaved gear has better surface finish that achieves the anticipated effect.
