Progress on Experimental Techniques for T1-T2 2D NMR Measurements in Tight Oil Reservoirs—A Review

The microscopic pore structure and fluid occurrence laws of tight oil reservoirs are intricate, leading to relatively low oil production rates. The T1-T2 two-dimensional nuclear magnetic resonance (2D NMR) technique presents significant advantages for fluid identification and the quantitative characterization of fluids and pore spaces in these reservoirs. Nonetheless, systematic and in-depth investigations into its experimental measurements remain scarce. A comprehensive review of both domestic and international literature on T1-T2 2D NMR measurement techniques was conducted for oil reservoirs. The fundamental principles, data acquisition and inversion mechanisms of 2D NMR technology were elucidated. Additionally, the signal distribution laws of hydrogen-containing components under varying test parameters were summarized. The relationship between NMR experimental testing and reservoir characteristics was explored, elucidating the mechanism of the T1-T2 spectra. Building upon this foundation, the strategic optimization of data acquisition and inversion methodologies, along with critical parameters for T1-T2 NMR measurements, significantly enhanced the precision of NMR datasets and the fidelity of 2D NMR spectral imaging. These advancements provide a theoretical basis and technical support for the characterization of rock and fluid in tight oil reservoirs.