声波测井数据压缩算法的嵌入式开发与实现

发布时间：2018-01-07 13:13

本文关键词：声波测井数据压缩算法的嵌入式开发与实现　出处：《西安科技大学》2015年硕士论文　论文类型：学位论文

【摘要】：测井是石油勘探和开发过程中评估油藏的一种重要的方法,而声波测井已成为当前主流的一种测井技术。由于声波测井会产生庞大的数据量,当其要求的数据传输率过高而无法实时传输时,可采用存储式仪器对这些数据进行井下存储。为了减小仪器的存储压力,需要对数据进行压缩处理。为此本文设计了一种基于Lempel-Ziv-Welch(LZW)的声波测井数据压缩算法,并进行了嵌入式开发与实现。首先,通过对常用的各种数据压缩算法的优缺点比较分析,并结合系统实际设计要求,选择LZW算法作为核心算法,并针对LZW算法编码时采用固定的码长进行压缩编码的方式以及字典的存储容量有限等方面的缺点,对LZW算法进行了改进。为了提高压缩效率,本文提出了将Median Edge Detector(MED)模型与LZW融合的一种压缩算法。通过MED模型对原始的声波数据预测,并将其预测误差作为数据压缩的对象,再经过改进的LZW算法压缩,进一步提高了压缩效率。其次,根据嵌入式系统开发的流程,在对系统需求分析的基础上,确定了系统的硬件和操作系统构成,选择OK6410微处理器作为系统处理核心及Linux作为嵌入式开发的操作系统,在此基础上确定了系统硬件和软件概要设计,随后逐步说明了数据压缩、传输过程中需要解决的关键技术。最后将开发板和PC机等设备相连后,对整个系统进行了测试评价。实验测试结果表明,本文设计的声波测井数据压缩系统实现了声波测井数据压缩、数据存储、数据传输以及数据解压恢复的功能。所提出的基于MED预测的LZW压缩算法能够大幅度提高压缩效率,且能够无失真地恢复数据,达到了预期的效果。这对声波测井仪中声波数据的压缩与传输具有较高的应用价值。
[Abstract]:Logging is an important method of evaluating reservoir oil exploration and development process, and acoustic logging has become a mainstream. Because of logging acoustic logging will produce a large amount of data, when the data transmission rate is too high and can not require real-time transmission, recoverable underground storage of these data storage in order to reduce the storage pressure instrument. The instrument, the need for data compression processing. In this paper, based on the design of a Lempel-Ziv-Welch (LZW) of the acoustic logging data compression algorithm, and realizes the embedded development. Firstly, the advantages and disadvantages of the common data compression algorithm analysis and comparison, combined with the design requirements of the system actually, select the LZW algorithm as the core algorithm, and LZW algorithm for encoding the fixed code length compression encoding and storage capacity is limited, the dictionary The shortcomings of the LZW algorithm is improved. In order to improve the compression efficiency, this paper introduced Median Edge Detector (MED) a compression algorithm model and LZW integration. The original data on acoustic prediction by MED model, and the prediction error as the object of data compression, and then through the improved LZW algorithm to compress. To further improve the compression efficiency. Secondly, based on the embedded system development process, based on the analysis of system requirements, determine the composition of the system hardware and operating system, OK6410 microprocessor is chosen as the system core and Linux as the development of embedded operating system, based on the overview of hardware and software design of the system is determined, and then gradually the data compression, a key technique to be solved in the process of transmission. Finally, the development board and PC machines connected, test and evaluation of the whole system. Test results show that the acoustic logging data compression, the paper design of acoustic logging data compression system of data storage, data transmission and data decompression function. MED prediction LZW compression algorithm can greatly improve the compression efficiency based on, and can recover the data without distortion, to achieve the desired results. The acoustic wave acoustic logging data compression and transmission has high application value.

【学位授予单位】：西安科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P631.81

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