一种基于井下硬件平台的反演方法

井下地层流体核磁分析模块是地层测试器的重要组成部分，受到数据传输带宽的限制，无法将大量回波数据上传到地面进行实时分析，需要在井下硬件平台上完成T2谱反演。以DSP为主要处理芯片的井下硬件平台，无法在规定时间内完成SVD（奇异值分解）反演算法。根据反演算法的特点，通过在地面提前求解不同核心矩阵A的逆矩阵、把多个逆矩阵保存在井下非易失性存储芯片中，使DSP的运算时间能够从10 s减小到1.33 s，在6.6 s内完成反演算法。在井下地层流体模块硬件平台上进行实验，结果表明，该方法能够有效缩短运算时间，在规定时间内完成反演算法。

Inversion method based on hardware platform

The down hole fluid NMR analysis module is an important part of formation tester measures too large echo data which is constrained by data transmission bandwidth so that it is necessary to complete the inversion of T2 spectrum on the hardware platform. The SVD (singular value decomposition) inversion algorithm can not be completed within the specified time, which is based on DSP as the main processing chip. According to the characteristics of inversion method, solving the inverse matrix of different matrix A in advance and storing the results in the downhole nonvolatile memory chip make DSP operation time be reduced from 10 s to 1.33 s, in the 6.6 s time to complete the inversion algorithm. The results show that the proposed method can effectively shorten the computation time and complete the inversion algorithm within the specified time on the hardware platform of downhole fluid module.