Adaptive Gradient Projection Correction Method for Resistivity Array Imaging Logging

In this article, an adaptive gradient projection correction (AGPC) method for resistivity array imaging logging is proposed. Due to the irregular spin and swing of the subsurface resistivity array instrument, the time-varying nonuniform sampling is induced between the electrodes, which reduces the resolution of the wellbore image. In the proposed method, the nonuniform sampled image is reconstructed via the proposed adaptive transform determined by gradient domain minimization constraint for image correction and least-square constraint for loss minimization. The imaging correction capabilities of AGPC are theoretically simulated and experimentally demonstrated in multiple scenes. The indexes of edges correction error (ECE) and average gradient difference (AGD) are devised and provided to assess the AGPC performance in simulations and field experiments. The results show that AGPC achieves better balance between image loss and resolution compared with traditional methods.