blocks. A liberal buying outline was used in each of the prospects, for a lead 

 may be located several miles from the center of the final prospect. 



In order to acquire the hundreds of thousands of lease acres as quickly as 

 possible, Amprex's Land Section utilized a staff of landmen, titlemen, and con- 

 tract lease brokers. After receiving from the exploration manager the outlines 

 of the areas or prospects to be leased, the landmen and titlemen checked land 

 records in the courthouses to determine mineral ownerships. Company land- 

 men and contract brokers then contacted the landowners and attempted to 

 acquire oil and gas leases on the acreage within the buying outlines. Amprex's 

 management of exploration had authorized a top lease bonus and rental price 

 which the landmen were not to exceed. Because so little was known of the 

 possibilities of the basin at this time and because the odds against discovering 

 oil were so great in this frontier area, the cost per acre was relatively inexpensive, 

 although the bonus, rental, and royalty were considered fair to the landowners. 

 Amprex realized that these initial contacts with the owners were extremely 

 important, since the good will acquired through fair trading would be one of 

 the company's most valuable assets in future operations in the area. 



Coincident with the leasing program, Amprex's management of exploration 

 initiated its program of detailed exploration. With a much larger force to be 

 used in this stage of attack, management very carefully planned and organized 

 this phase of operations. Both old and new exploration tools were used. De- 

 tailed rather than regional surveys were conducted with the seismograph and 

 the gravity meter. The core drill was utilized in mapping the structure and 

 stratigraphy of the shallow subsurface. Field geologists began mapping in 

 detail some of the anomalous areas they noted in their reconnaissance surveys. 



Because most of the basin was covered with alluvium, the seismograph and 

 the core drill were the most useful tools in the definition of structural and 

 stratigraphic traps. During the reconnaissance phase of exploration, the seis- 

 mograph was utilized primarily in running seismic profiles in the search for 

 regional structural and stratigraphic features. Now the seismograph was used 

 chiefly for locating and defining local structural and stratigraphic anomalies. 

 It was mapping anticlines, foothill folds, reefs, buried anticlines, truncated 

 wedge edges, updip sand pinchouts, fault traps, lenticular sands, and faulted 

 noses. Extremely careful planning was required for this detailed type of seismic 

 exploration. The seismic program was designed, to a large extent, for the type 

 of exploration the company had planned. Since seismic techniques and pro- 

 cedures vary with different areas due to both surface and subsurface conditions, 

 several different methods were tried in the field before a successful one was 

 established. 



In those areas where seismic results were poor to absent, the core drill 

 became a valuable complementary tool to the seismograph. Where shallow 

 mapping horizons were found in the basin, the core drill proved to be an excel- 



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