A practical fast iterative inversion(PFII)technique of Dual Induction Logging(DIL) data developed by authors recently and its application in Daqing Oilfield are introduced.

The paper studies and creates a fast iterative inversion algorithm for multi array induction log data in horizontal layered medium,which fast and effectively reconstructs the original resistivity of formation,resistivity in flushed zone,invasion radius and depth of interface.

Based on Cauchy criteria, the regularized sparse inversion can be made by using pre-conditional conjugate gradient algorithm (PCGA) in simultaneously iterative inversion of reflection factor and wavelet.

A fast iterative algorithm for image segmentation based on 2D maximum between-cluster variance;

Based on BOSTICK inversion method and 2D magnetotelluric forward solution and combainating with asymptotic iteration, this paper presents a rapid inversion method for 2D magnetotelluric method, which is proved to be effective in theroy models inversion.