Comparison of different inversion methods of D-T_(2)two-dimensional nuclear magnetic resonance logging and applicability analysis  

D-T_(2)二维核磁共振测井反演方法对比与适用性研究

作　　者：Li Cheng-Lin Tan Mao-Jin Wang Ke-Wen Feng Zhou Liu Ying-Ming Zhang Hai-Tao and Xiao Li-Zhi 李成林;谭茂金;王克文;冯周;刘英明;张海涛;肖立志(中国地质大学(北京),北京100083;海洋油气勘探国家工程研究中心井筒探测技术分中心,北京100083;中国石油勘探开发研究院,北京100083;中国石油长庆油田公司勘探开发研究院,陕西西安710018;中国石油大学(北京),北京102249)

机构地区：[1]School of Geophysics and Information Technology of China University of Geosciences,Beijing 100083,China [2]Borehole Geophysical Detecting Branch,National Engineering Research Center of Offshore Oil and Gas Exploration,Beijing 100083,China [3]Research Institute of Exploration&Development,PetroChina,Beijing 100083,China [4]Research Institute of Exploration&Development,PetroChina Changqing Oilfield Company,Xi’an 730001,China [5]China University of Petroleum,Beijing 102249,China

出　　处：《Applied Geophysics》2022年第2期173-184,306,307,共14页应用地球物理（英文版）

基　　金：sponsored by the National Natural Science Foundation of China(Nos.42174149,41774144);the National Major Projects(No.2016ZX05014-001).

摘　　要：D-T_(2)two-dimensional nuclear magnetic resonance(2D NMR)logging technology can distinguish pore fluid types intuitively,and it is widely used in oil and gas exploration.Many 2D NMR inversion methods(e.g.,truncated singular value decomposition(TSVD),Butler-Reds-Dawson(BRD),LM-norm smoothing,and TIST-L1 regularization methods)have been proposed successively,but most are limited to numerical simulations.This study focused on the applicability of different inversion methods for NMR logging data of various acquisition sequences,from which the optimal inversion method was selected based on the comparative analysis.First,the two-dimensional NMR logging principle was studied.Then,these inversion methods were studied in detail,and the precision and computational efficiency of CPMG and diffusion editing(DE)sequences obtained from oil-water and gas-water models were compared,respectively.The inversion results and calculation time of truncated singular value decomposition(TSVD),Butler-Reds-Dawson(BRD),LM-norm smoothing,and TIST-L1 regularization were compared and analyzed through numerical simulations.The inversion method was optimized to process SP mode logging data from the MR Scanner instrument.The results showed that the TIST-regularization and LM-norm smoothing methods were more accurate for the CPMG and DE sequence echo trains of the oil-water and gas-water models.However,the LM-norm smoothing method was less time-consuming,making it more suitable for logging data processing.A case study in well A25 showed that the processing results by the LM-norm smoothing method were consistent with GEOLOG software.This demonstrates that the LM-norm smoothing method is applicable in practical NMR logging processing.D-T_(2)二维核磁共振测井技术能够直观地区分不同类型、不同赋存状态的孔隙流体,在油气勘探中应用广泛。目前,,国内外学者提出了很多二维核磁共振反演方法,但大多止步于数值模拟,需要研究不同反演方法针对不同采集序列的测井数据的适用性,优选反演方法,为二维核磁共振测井数据处理的软件模块开发提供参考。本文者,对此问题,基于二维核磁共振测井原理,详细研究了TSVD、BRD、LM-模平滑和TIST-L1正则化反演方法,分别对油水模型、气水模型数值模拟得到的CPMG和DE序列的回波信号,进行反演结果精度和计算效率的对比研究。通过数值模拟,对比分析了TSVD、BRD、LM-模平滑和TIST-L1正则化四种反演方法的反演结果和计算耗时,并优选反演方法对MR Scanner仪器SP模式测井数据处理。结果表明,对于油水和气水两种模型的CPMG和DE序列回波信号,TIST-L1正则化方法精度最高,LM-模平滑方法略差,但耗时较少,更适合测井数据处理,该方法针对A25井的处理结果与Geolog软件相符,能够满足数据处理的需要。

关 键 词：two-dimensional NMR logging D-T_(2)spectrum inversion method diffusion editing sequence data processing 

分 类 号：P631.81[天文地球—地质矿产勘探]