Patent Document ID: 4817059
Application ID: 07067677
Patent Status: 1

Claim One:
1. The method of imaging features of a formation in the vicinity of a borehole, using a sonic device located in the borehole traversing the formation, the device having a sonic source and a plurality of spaced sonic detectors, said method comprising the steps of: (a) establishing a first and a second matrix representative of geometric locations in the formation in the vicinity of the borehole, said first matrix longitudinally offset from said second matrix, each of said matrices having a plurality of rows and columns, the rows of the first and second matrices referenced, from top to bottom relative to the borehole, as r.sub.1,. .. , r.sub.m, and r.sub.1,. .. , r.sub.n, respectively, each (r,c) value constituting a matrix point; (b) determining the distance from the sonic source to each matrix point to each detector for each matrix point; (c) positioning the sonic device in a first predetermined location; (d) deriving a value for each matrix point subsequent to firing the source at the first predetermined location based on the arrival of waveforms at each detector, said waveforms based on slowness of the sonic energy and the length of the path traversed by the energy from the source to the detectors via each matrix point; (e) storing said derived value for each matrix point; (f) moving the sonic device a predetermined distance, said predetermined distance being proportional to the distance between the rows; (g) storing rows r.sub.m and r.sub.n of the first and second matrix, respectively, said rows being indicative of images in the vicinity of the borehole for depths corresponding to the location of rows r.sub.m and r.sub.n in the formation; (h) shifting all matrix point values by one row such that row r.sub.n-1 of the second matrix is row r.sub.n, row r.sub.1 of the second matrix is row r.sub.2, row r.sub.m-1 of the first matrix is row r.sub.m, and row r.sub.1 of the first matrix is row r.sub.2 ; (i) deriving a value for each matrix point subsequent to firing the source at the translocated location based on the arrival of waveforms at each detector, said waveforms based on slowness of the sonic energy and the length of the path traversed by the energy from the source to the detectors via each matrix point; (j) cumulating said derived value of each matrix point with each respective existing matrix point value; and (k) repeating steps (f) through (j) a plurality of times; said first matrix being indicative of scattering of sonic energy back from features dipping downward, relative to the borehole, said second matrix being indicative of scattering of sonic energy back from features dipping upward, relative to the borehole.