Noise reduction plays a pivotal role in enhancing the signal-to-noise ratio (SNR) of microseismic data during the preprocessing stage. However, due to the heterogeneous nature and high complexity of noise sources, conventional model-driven denoising methods frequently exhibit suboptimal performance, thereby compromising the fidelity and reliability of downstream microseismic processing tasks. Moreover, while deep learning-based approaches have shown promise for microseismic noise suppression, the resulting models often exhibit limited generalization capability and insufficient preservation of physically meaningful signal features. To address these challenges, this study introduces RD-SAUNet—a novel U-Net–based architecture incorporating hybrid dilation convolutions and a residual spatial attention mechanism. Built upon the foundational U-type convolutional neural network (U-Net) framework, RD-SAUNet integrates three key innovations: (i) residual connections to facilitate gradient flow and accelerate training convergence; (ii) a spatial attention mechanism (SAM) that adaptively emphasizes discriminative signal features while suppressing spurious noise; and (iii) hybrid dilation convolutions that expand the receptive field to capture broader contextual information without significantly increasing computational overhead. Collectively, these design choices enhance both model generalizability and signal fidelity. The proposed method is rigorously evaluated on both synthetic and field-collected microseismic datasets and benchmarked against state-of-the-art denoising techniques. Experimental results confirm that RD-SAUNet achieves robust suppression of random noise, yields substantial SNR improvement, and faithfully preserves the intrinsic temporal-spectral characteristics essential for accurate microseismic event detection and characterization.



