Numerical Simulation Method and Application of High-Performance Acoustic Remote Detection Imaging in Fractured Reservoirs

Imaging of fracture morphology and orientation through acoustic remote detection technology is crucial for the efficient exploration and development of fractured reservoirs. The 2-D elastic wave time-domain staggered-grid finite-difference method has been widely applied in acoustic remote detection simulations. However, the substantial computational requirements and poor efficiency of the 3-D elastic wave time-domain simulation method have limited its widespread application in acoustic remote detection imaging. This study introduces a high-performance technique for 3-D elastic wave simulation, which employs a synchronous CPU+GPU heterogeneous parallelism architecture. The technique features a highly parallelized computational approach using 3-D staggered grids, thereby enabling the simulation of large-scale models with fractured stratigraphy. An optimized dimensionality reduction strategy has been adopted, significantly improving the computational efficiency for 3-D simulations. The method’s stability and precision were verified by conducting numerical simulations on a fractured reservoir model, capturing the 3-D wavefield evolution to facilitate the analysis of acoustic source propagation within a 3-D space. Simulations of fractured reservoir models at various distances from the borehole revealed that the amplitudes of reflected waves display an exponential decrease as the distance between fractures and the borehole increases. The optimal detection range for monopole acoustic far-detection imaging with an 8-kHz frequency source has been identified. Furthermore, beamforming and migration imaging techniques were employed to achieve precise imaging of fracture morphology and precise orientation identification. This study lays the groundwork for employing acoustic remote detection imaging techniques to ascertain fracture morphology and orientation within 3-D space, thereby facilitating the effective assessment of fractured reservoirs.