核磁共振技术能够直接探测样品中水、烃等含氢流体信号并对其含量及所处环境进行定量表征，广泛应用在油气勘探领域．在对页岩油气、致密油气等含有大量超快弛豫组分样品进行测量时，由于CPMG脉冲序列观测到的前端信号数据量过少导致测量信号不稳定，快弛豫组分结果可靠性较低．提出了多次微变回波间隔测量（MCTEM）的方法，在测量阶段加密了对核磁共振前端信号数据的采集，反演阶段采用了多次测量回波数据的联合反演，可以得到更加精确的快弛豫T₂谱．通过数值模拟和岩心物理实验对MCTEM方法进行了验证，结果显示MCTEM方法能够改善由回波间隔T_E偏高引起的T₂谱快弛豫组分峰消失的问题，可以有效提高快弛豫信号的测量精度．

Nuclear magnetic resonance (NMR) technology can directly detect hydrogen signals in hydrogen-containing fluids, such as water and hydrocarbon. It can provide quantitative characterization of the fluid content and surrounding environment, thus finding extensive application in oil and gas exploration field. However, when measured samples containing ultra-fast relaxation components, such as shale oil and gas, the reliability of measurement results tends to be very low because only a small number of front-end signals in Carr-Purcell-Meiboom-Gill (CPMG) pulse sequence can be obtained for the fast relaxation components. To address this problem, a multiple micro echo interval measurement (MCTEM) method was proposed in this research. In the measurement stage, the proposed method acquired more NMR front-end signals. In the inversion stage, multiple echo data were adopted for the joint inversion. It contributed to forming an accurate fast relaxation T₂ spectrum. MCTEM method was validated through numerical simulations and rock physics experiments. It was concluded from the results that MCTEM method could improve the problem of peak disappearance for fast relaxation components in T₂ spectrum caused by long echo interval. MCTEM method could enhance the measurement accuracy of fast relaxation signals effectively.