CSEM efficiency – evaluation of recent drilling results

In 2011 and early 2012, seven exploration wells were drilled in locations where CSEM data existed. Three of these were discoveries, while the remaining four were dry. Four wells were drilled in locations with significant CSEM responses, and these four wells included all three discoveries. Three wells were drilled in locations without a significant CSEM response, and all those three wells were dry. Thus, the results from six of the seven wells are in accordance with previously published statistics in that a well targeting a prospect associated with a significant CSEM anomaly is likely to make a discovery whereas a well targeting a prospect without a significant CSEM anomaly is likely to be dry. In this respect, the rationale behind the drill decision for the four dry wells needs to be investigated through detailed post-drill evaluations. In particular, two of the wells did not show a clear fit between the main CSEM anomaly and the prospect outline, and it may be argued that these discrepancies should have been examined more closely before drilling.