Apparatus and method for evaluation of score failures in picking of 3-D seismic data

An improved method of automatically selecting a horizon of earth formations from a three-dimensional volume of seismic wavelet traces including the steps of

• (a) designating a predetermined input score for iterative picking,
• (b) designating a seed depth point at a depth of a wavelet of one of said seismic traces, said one seismic trace being designated a seed trace,
• (c) designating target traces such that a path is defined between said seed trace and a target trace, where a path includes at least one path link including a seed trace to a target trace, and
• (d) picking for each path link is achieved where a characteristic of a wavelet of said target trace corresponds in depth to such characteristic of a wavelet of said said trace,
• and wherein a target trace is iteratively picked along said path link with respect to a seed trace including the steps of
• (i) recording a numerical value of said characteristic of a seed wavelet at a seed depth point of said seed wavelet;
• (ii) transferring the depth of said seed depth point to said target trace and finding the closest depth point of said characteristic of said target wavelet that exists between zero crossings of a wavelet of said target and recording said depth point and a numerical value of said characteristic of said target trace wavelet, and
• (iii) transferring the depth of said depth point of said target trace back to said seed trace to determine if it is between zero crossings of said wavelet of said seed depth point of said seed trace, and
• (iv) determining whether or not a score function of the difference between said numerical value of said characteristic of said seed wavelet and said numerical value of said characteristic of said target wavelet is greater than said predetermined input score, and
• (v) if it is, designating said target trace as a new seed trace and designating said depth point of said target trace as a new seed depth point and returning to step (c), and
• (vi) if it is not, designating said target trace as a score failure and not designating said depth point of said target trace as a new seed point and returning to step (c)
• wherein the improved method includes the additional steps of
• recording the number of score failures to pick a target wavelet from a seed wavelet because the score achieved is less than said input score, and
• displaying on a CRT screen a characteristic of said number of score failures.