声波测井井下数据压缩算法压缩效果测试  

Effect Test on Compression Algorithms of Acoustic Logging Downhole Data

作　　者：贾安学[1,2] 乔文孝[1,2] 鞠晓东[1,2] 车小花[1,2] 陆蓉[1,2] 王瑞甲[1,2] 

机构地区：[1]中国石油大学油气资源与探测国家重点实验室,北京102249 [2]北京市地球探测与信息技术重点实验室,北京102249

出　　处：《测井技术》2011年第3期288-291,共4页Well Logging Technology

基　　金：国家自然科学基金面上项目(批准号:40874097);国家科技重大专项(课题编号:2011ZX05020-009)

摘　　要：由于电缆传输带宽有限,大量声波测井全波列数据从井下传送至井上存储和处理时井孔信息丢失,因此需要采用数据压缩技术在井下对声波数据进行实时压缩。介绍了算术编码、预测编码、FLAC(Free Lossless AudioCodec)和APE等无损压缩算法和有损压缩算法,并将无损压缩算法应用于正交多极子声波测井仪MPAL专家模式井下数据,并从压缩率和失真度2个方面测试了压缩效果。结果表明,FLAC和APE压缩算法具有较好的压缩率,特别是APE算法达到50%左右的压缩率,并且压缩率较稳定。在对小信号质量要求不高时,可以采用有损压缩算法。Due to limitations of cable bandwidth, when a large number of acoustic logging data are transported to the ground from the downhole for storage and process, well information is of- ten lost, so, acoustic log data need to be compressed in real-time in the downhole by data com- pression technology. Introduced are lossless compression algorithms, such as, arithmetic coding, predictive coding, free lossless audio codec （FLAC） and APE, and lossy compression algorithm. The lossless compression algorithms are used to the downhole log data of MPAL expert mode, and the compression effect is investigated about the compression ratio and the distortion, the re- sults from which show that FLAC algorithm and APE algorithm can obtain a better compression ratio, and the compression ratio of APE algorithm is about 50% and stability is better. When there＇s less demand on the small signal quality, lossy compression algorithms may be used.

关 键 词：声波测井 数据压缩 算术编码 预测编码 无损音频压缩解码(FLAC) APE 压缩率 

分 类 号：P631.84[天文地球—地质矿产勘探]