During drilling the horizontal section of a shale gas well

oil-based drilling fluid is commonly used in China in order to ensure downhole safety

especially to solve the problems of lost circulation and well collapse. Based on the study of chemical solidification plugging technology and the XRD（X-ray diffraction） analysis of Longmaxi shale samples in Chongqing area

the nano micron size plugging materials are selected to explore a new technology for plugging and collapse prevention of shale gas wells. Field application of chemical solidification technology effectively solves the lost circulation problem of a well in Jiaoye

and meet the requirements of subsequent construction. In the process of drilling

the polysilicon fiber and micro-nano plugging agent selected in the laboratory not only completely control the collapse and block falling

but also reduce the daily average drilling fluid consumption by 1/3

so as to achieve the purpose of anti-seepage and anti-collapse. It is proved that chemical solidification and micro-nano plugging are effective methods to solve the plugging and collapse prevention of shale gas wells

which play a positive role in the development of shale gas wells in Chongqing area.