Abstract: Taking Che-66 well area in Chezhen sag as an example, the horizontal direction of terrestrial stress is studied using electric imaging logs and dipole acoustic logs. The drilling-induced fractures given by the imaging logging interpretation are accordant with the maximum horizonta! stress orientation, while the minimum horizontal stress orientation is obtained by the hole collapse direction and macroaxis orientation. The fast S-wave orientation from anisotropic imaging map by dipole acoustic logs means the maximum horizontal stress azimuth. The orientation frequency diagram of maximum horizontal stress for drilling induced fractures, hole collapse and fast S-wave azimuth is presented according five wells' electric imaging logs and dipole acoustic logs. The major orientation indicates that the present maximum horizontal stress azimuth of Che-66 well area is the orientation of NWW --SEE, basically accordant with the strike of basin-dipping fractures adjacent to this well area, reflecting the hereditabilty of terrestrial stress field.

Key words: imaging logging, acoustic log, terrestrial stress, drilling, fracture