Application Of Well Logging In The Detection Of Hidden Active Faults In Sanhe

Active fault on the growing of human existence urban detection work is also gradually expand the active fault exploration project.The main detection methods in urban active fault detection is given priority to seismic exploration,finding the approximate location of fault.Further the formation was united drilling borehole core description,finding fault on breakpoints.This is the most common detection methods.On this basis,this study using geophysical geophysical logging to determine the four physical parameters of geotechnical layer,including spontaneous potential,natural gamma,shear wave velocity and magnetization.The core description of the combined drilling was used to classify the quaternary system and judge the location of the northeast end branch of the xia pad fault and a newly discovered beiwu fault.In this study,three shallow seismic exploration lines were work,and geophysical logging areas were set up in the four translated faults,with 35 well logs.Through the three methods,the following conclusions are drawn,The quaternary system was divided by combined drilling and the northeast branch of xiadian fault and the location of a newly discovered beiwu fault were determined.1)The Quaternary is widely distributed in the study area,with little change in lateral thickness,and rapid lateral change in seismic reflection characteristics and good continuity.The strata can be divided and active faults can be found by well logging and core description.2)The 10-hole geophysical logging in liuxinzhuang area revealed the active structure of the late pleistocene,with the upper breakpoint buried about 4.7m,indicating the xiadian fault.3)Ten geophysical well logs were set up in xiwugezhuang area,and 2 faults were found.The active age was in late pleistocene,and the upper breakpoint was buried about 32 m deep in the south.The buried depth of the northern breakpoint is about 40 m.There are 7 geophysical well logs in xiaxingzhuang work area.The fault is trending NW There are weak signs of activity since late pleistocene,and the upper breakpoint is buried about 23 m deep.The two faults are jointly named beiwu fault.4)There are 8 geophysical well logs in xiquitou work area,which active age is earlier than the late pleistocene,and has no activity since the late Pleistocene.5)In this study,the results of spontaneous potential and susceptibility logging in the classification of quaternary system are good,which has obvious guiding significance in the classification of quaternary system,and being more economical and economical than drilling,saving manpower and material resources and time.It is expected to be widely used as a new detection method in active fault detection.