| Abstract | There are several similarities between seismic refraction and acoustic logging. Therefore, seismic refraction solutions can be applied for investigation of the near wellbore effects on the acoustic logging responses. In this study, the 2-layer seismic refraction models with horizontal and dipping interface were applied to determine the effects of mud type, mud salinity, borehole deviation, and tool tilting. In addition, the 3-layer, 4-layer, and 5-layer seismic refraction models were used to study on the invasion effect for four types of formation, i.e., limestone (LS), dolostone (DS), sandstone (SS), and shale (SH). The study went further to consider corrections for the three major effects, i.e., borehole deviation, tool tilting, and invasion. For the borehole deviation and tool tilting effects, correction was done based on the 2-layer seismic refraction model with variable interfaces. The correction on travel time due to these effects of borehole deviation and tool tilting was found as()3.460.01cortαΔ=− Δ+, whereαΔis the difference between the tool tilting and borehole deviation angle. For correction of the invasion effect, a 3-layer seismic refraction model with horizontal interface was used. The invaded zone was converted into an equivalent layer. The corrections were performed for 4 types of formation rocks, i.e., limestone, dolostone, sandstone, and shale. The study also proposed a new parameter named Alteration Index (AI) for characterizing the near-wellbore formation. In addition, formation interpretation based on dynamic mechanical properties deduced from acoustic logging data was also done and compared with traditional well logging interpretation for the study site, located in Chumporn basin, Western gulf of Thailand. |