Quality control method of NMR T2 spectrum inversion

In order to improve the application effect of the NMR in Petroleum exploration and development, the quality of T2 spectrum inversion needs to be controlled. Based on the inversion theory of M-P Generalized Inverse, echo resolution matrix, T2 spectrum resolution matrix are deduced, the quality control indices of T2 spectrum inversion are provided: the stretch coefficient, maximum, minimum, average and range of principal diagonal elements of resolution matrix. Calculating the inversion quality control indices under different observation modes, choosing the observation mode of resolution matrix approximate to unit matrix for data acquisition can improve T2 spectrum inversion quality, thus to control inversion quality. Numerical experimentation indicates that there is very good consistency between inversion quality and its control index. Hence, the method may direct the design before NMR data acquisition, control inversion quality of T2 spectrum and lay a foundation for improving the effect of NMR geological application. (authors)