structure of the basin. Figures 41-9 and 41-10 show very generalized copies of 

 two dip sections, D-D' and A-A', respectively, that traverse the basin from west 

 to east, and Figure 41-11 shows a copy of a south-north section, Z-Z'. Figure 

 41-12 is a copy of the northernmost of the regional seismic profiles. D-D'. The 

 trend of the cross sections and of the regional seismic profile is indicated in 

 Figure 41-5. By utilizing these sections and the geological and geophysical maps, 

 it was possible to determine the approximate position within the basin of the 

 trends of the most attractive facies, regional trends of anticlinal and fault 

 structures, the most likely basin position for the growth of reefs in various 

 stratigraphic units, and the approximate positions of the major hinge belts. 

 Amprex's exploration management considered that the cross sections, the 

 regional structure maps, the regional thickness maps, and the regional facies 

 maps were the end products of this phase of exploration. In addition to com- 

 pleting the regional picture, the geological and geophysical surveys found many 

 structural and stratigraphic areas that would be investigated by more detailed 

 work in the event Amprex's management decided to continue exploring the basin. 

 Figure 41-13 is a generalized copy of a map showing hypothetical contours of 

 the basement surface of the basin. These contours were based upon all of the 

 geological and geophysical information developed to date. 



Approximately a year had elapsed since Amprex had initiated its recon- 

 naissance stage of exploration. More than two million dollars had been expended 

 in stratigraphic drilling, geological work, geophysical surveys, acreage acquisi- 

 tions, and work allied to this program. When management had approved this 

 original expenditure, it was aware that this was a considerable risk, for this 

 relatively large sum of money was committed even though the results of the 

 reconnaissance exploration might indicate that the area appeared unfavorable, 

 and all exploration would be discontinued. Leases that had been acquired would 

 be dropped, and money expended on this project would be charged against 

 company income. 



Although geologists and geophysicists had been studying and interpreting 

 information as it accumulated, this was the real period of interpretation. Ad- 

 ditional subsurface geologists were added to the original staff, and the sub- 

 surface data were reworked in order to investigate all possibilities of interpreta- 

 tions. Experienced geologists and geophysicists familiar with the occurrences 

 of oil in different parts of the world were best qualified to interpret the geological 

 and geophysical data, for at this stage of exploration, most conclusions were 

 empirical. It was essential that Amprex expend the right type of exploration in 

 the most attractive areas. 



Advanced Exploration Program 



The management of Amprex's Exploration Department examined the avail- 

 able information and studied the recommendations of the key geologists and 



835 



