Logging evaluation on mechanical-damage characteristics of the vicinity of the wellbore in tight reservoirs

Abstract The rock mechanical behavior and damage characteristic is of great importance for in situ stress evaluation, wellbore stability analysis hydraulic fracturing design. velocities elastic waves are usually reduced the presence damage, it may be used determining progressive rock. Therefore, this paper aims to investigate characteristics transversely isotropic tight sand formation, parameters vicinity were calculated using acoustic logging data. results indicated that Poisson's ratio decrease with increasing radial distance, while modulus Thomsen’s coefficients increase. At same position, vertical smaller than horizontal, degree anisotropy P-wave greater S-wave, horizontal parameter vertical, which micro-cracks near mainly occur direction. changes parameters, rapidly changed range 1.0–1.8 times borehole radius. variations mudstone obviously sandstone, due induced between rocks drilling fluid much higher sandstone.