Hao Xiaolong, Hu Yangtao, Yan Bingnan, Hui Hang, Chen Yunxia, Zhang Bingqi
Downhole Measurement and Control Laboratory of National Engineering Laboratory of Oil and Gas Drilling Technology, Xi'an 710065, China.
School of Electronic Engineering, Xi'an Shiyou University, Xi'an 710065, China.
Sensors (Basel). 2025 Jul 21;25(14):4512. doi: 10.3390/s25144512.
The substantial volume of data acquired through remote-detection acoustic logging poses a remarkable challenge because of the limited real-time upload speed of the cable, which severely impedes its further application. To address this issue, a two-stage data compression method that was implemented at the acquisition node was proposed in this study. This approach includes a field programmable gate array (FPGA)-based hardware system and a two-stage downhole data compression algorithm combining wavelet transform and adaptive differential pulse-code modulation paired with ground decompression software. Finally, the proposed compression method was evaluated using actual logging data. The test results revealed that the overall compression rate of the two-stage compression method was 25.1%. The reconstructed waveforms highly retained the overall shape of the original waveforms, and the severe relative distortion of individual data points did not affect the extraction of the sliding longitudinal, sliding transverse and reflected waveforms. The FPGA compressed 2048 16-bit waveforms in approximately 100 μs with low resource utilization and workload. It considerably outperformed DSP-based pre-transmission compression. Herein, the data compression method at the acquisition node helped in reducing the workload on the master control node and increasing the effective speed of the cable transmission up to 400%, thereby enhancing the remote-detection acoustic logging.
通过遥测声波测井获取的大量数据带来了巨大挑战，因为电缆的实时上传速度有限，这严重阻碍了其进一步应用。为解决这一问题，本研究提出了一种在采集节点实施的两阶段数据压缩方法。该方法包括一个基于现场可编程门阵列（FPGA）的硬件系统以及一种将小波变换与自适应差分脉冲编码调制相结合的两阶段井下数据压缩算法，并配有地面解压软件。最后，使用实际测井数据对所提出的压缩方法进行了评估。测试结果表明，两阶段压缩方法的总体压缩率为25.1%。重建波形高度保留了原始波形的整体形状，个别数据点的严重相对失真并不影响滑动纵波、滑动横波和反射波形的提取。FPGA在大约100微秒内压缩了2048个16位波形，资源利用率和工作量较低。它大大优于基于DSP的传输前压缩。在此，采集节点的数据压缩方法有助于减轻主控制节点的工作量，并将电缆传输的有效速度提高多达400%，从而增强遥测声波测井效果。
