Objective During the exploration and development of fractured-vuggy carbonate reservoirs, acoustic reflection imaging logging technology enables the detection of fractured-vuggy bodies around wells. However, this technology suffers from unclear response characteristics and a strong multiplicity of solutions. Focusing on the Tarim Oilfield, this study aims to establish a tailored interpretation method by integrating geological and geophysical characteristics. The purpose is to enhance the identification accuracy and reliability of fractured-vuggy bodies in these reservoirs.

Methods Based on the distribution characteristics of fractured-vuggy carbonate reservoirs in the Tarim Oilfield, this study established the numerical simulation models of three typical fractured-vuggy bodies: inter-breccia porous, fault-cavity, and tectonic-fracture types. Then, the imaging results of acoustic reflection imaging logging data were optimized using Hilbert transform-based envelope extraction and vertical constraint-based data reconstruction technique. Using the finite-difference numerical algorithm, this study simulated the theoretical reflection wavefields of various fractured-vuggy bodies. Then, using the optimized procedure for the imaging results of acoustic reflection imaging logging data, this study processed the migration imaging results of different types of fractured-vuggy bodies and summarized their typical characteristics. Based on typical theoretical response characteristics, the imaging results of acoustic reflection imaging logging data can be interpreted.

Results and Conclusions The imaging results of acoustic reflection imaging logging data, obtained using the optimized procedure, exhibited clearer features. Compared to the imaging response characteristics of forward modeling, the imaging results of acoustic reflection imaging logging data revealed the presence of three sets of reflectors in the target interval. These reflectors were characterized by clear and distinct imaging results, mutual independence, and the occurrence of arc-like pseudomorph caused by adjacent reflectors. These characteristics aligned with the imaging response characteristics of fault-cavity-type fractures, demonstrating that these extra-well reflectors at this well interval are of the fault-cavity type. The interpretation results corresponded well with conclusions from well tests, confirming the presence of high-productivity fault-cavity-type fractured-vuggy reservoirs at this interval. The processing results of actual data validated the reliability of the identification of fractured-vuggy carbonate bodies based on theoretical response characteristics. This method provides robust technical support for the precise identification and interpretation of near-well fractured-vuggy carbonate bodies in the Tarim Basin.