1. n. [Formation Evaluation]

An algorithm for correcting the effects of dip or borehole deviation on the response of a logging measurement. These effects are significant for deep-reading logs such as induction and electrode devices. The standard processing used to produce these logs assumes a vertical well with horizontal formation layers. In the presence of a relative dip between the borehole and formation layers, the logs may read incorrectly. For older logs such as the dual induction, a set of inverse filters can be designed to correct for dip effect up to about 60. For modern array logs, iterative forward modeling with a one-dimensional layered earth model can correct up to about 85.

See: array induction,  dual induction,  electrode device,  inverse filter,  inversion