A New Correction Algorithm of the Eccentric Ultrasonovision Time Image in the Casing Hole

Abstract

The ultrasonovision image caused by the tool eccentricity can often present two pieces of vertical black strips in the Casing Well. To solve this problem, this paper proposes a correction algorithm of time eccentricity image based on ellipse fitting algorithm. This algorithm firstly utilizes borehole diameter data to fit ellipse and compute ellipse’s center, major axis, minor axis and inclination angle and other parameters, and then uses these parameters to correct eccentrical ultrasonovision time image. The tested results show that the algorithm can accurately fit ellipse and correct the eccentrical ultrasonovision time image, which is very important practical significance on processing the well logging.