Method for evaluating near-well fractured crack through Gd neutron tracing yield imaging

The invention discloses a method for evaluating a near-well fractured crack through Gd neutron tracing yield imaging and particularly relates to the technical field of exploration and development of petroleum and natural gas. The method comprises the steps that a high heat capture cross section material Gd2O3 is added into a propping agent, by utilizing action of neutrons and Gd, Gd yields in different azimuths and the borehole macroscopic capture cross section are obtained through designed and combined array gamma imagers, and the near-well fractured crack is imaged; after a stratum is fractured, the propping agent with the Gd2O3 material with the high capture cross section is injected into the stratum; and mixed gamma energy spectrums in different azimuths are obtained through measuring of the azimuth gamma imagers, a crack imaging figure of the Gd yields on the periphery of a well is obtained after processing of the mixed gamma energy spectrums, and accordingly the azimuth, height, width and inclination of the crack are determined through the crack imaging figure. Compared with an existing evaluation technique of radioactive cracks, non-radioactive cracks and the like, the method has the characteristics that downhole crack recognition is visual, radioactive pollution is avoided, recognition of the azimuth, height, width and inclination of the crack are accurate, and sensitivity is high.