394 



2 



(porosity and permeability). The Sale No. 42 bidding increased the Department's 

 optimisiii regarding these deep structuresand other deep potential stratigraphic 

 traps. 



In April 1982 updated resource estimates were developed for the SID and in de- 

 signing appropriate alternative bidding systems to use in the sale. These condi- 

 tional mean resource estimates were 56 million barrels of oil and 280 billion cubic 

 feet of gas. The dramatic decrease in resource estimates was a result of additional 

 geophysical and geological information and a different scope of potential hydro- 

 carbon prospects being considered in this appraisal. In the period between January 

 and March 1982 the Department acquired new seismic data on approximately a 1 x 3 

 mile grid that were of a significantly better quality than the data used to develop 

 resource estimates for the EIS. Analysis of the newly acquired geophyscial and geo- 

 logical data indicated that many previously mapped prospects were smaller or did not 

 exist and that others were much more questionable and, therefore, more risky. The 

 April 1982 resource estimates incorporate the data obtained from three dry holes 

 drilled in the Sale No. 42 area. These wells indicate a lack of potential hydro- 

 carbon reservoir formations in the deeper stratigraphic section and condemned two 

 patch reefs as well as a geophysical bright spot (a possible indication of a gas accumu- 

 lation). These new data resulted in the elimination of many potential deep strati- 

 graphic prospects and an increase in the risk associated with others. In addition 

 to the new geophysical and geological data, the resource estimates developed for 

 the SID did not include some possible stratigraphic traps that could not be ade- 

 quately delineated for purposes of a resource economic evaluation. The SID resource 

 appraisal included only those prospects that were being considered for resource 

 economic evaluations prior to the sale. 



