BUZZ-Cairn Energy: Better-than-expected results from Senegal well
** Oil producer's shares up 4.5 pct, top FTSE mid-250 gainer, after announcing positive results at its SNE-2 appraisal well
** Co says further appraisal activity is expected to lead to future revision of estimates
** Jefferies analysts raise PT to 230p from 170p, say results beat all expectations
** A fifth of co's 30-day avg volume gone through in the first 10 minutes of trade (venkateshasoumithri.mamidipudi.thomsonreuters.com@reuters.net)