viii, a, 5 Pratt and Smith: Petroletim Resources 369 



prospect the eastern limb of the anticline through the Bacau 

 stage of the Vigo shale by two or three wells located at varying 

 distances from the axis in the valley of Bahay River below the 

 mouth of Milipilijuan Creek. Wells in this position would also 

 pass through any members of the Vigo shale which may be 

 concealed by the overlap of the Canguinsa sandstone. Similarly, 

 the crest and the western limb could be explored by a line of 

 wells up the valley of Apad Creek. 



This general site is from 40 to 50 meters above sea level and 

 from 4 to 5 kilometers from the coast. An old roadway, which 

 might be utilized, leads into the region from the beach at the 

 mouth of Bahay River. 



Exploration of the limbs of the Maglihi anticline in the imme- 

 diate vicinity of the oil seep on Bahay River or that on Milipili- 

 juan Creek would involve more difficult transportation problems. 

 Moreover, while the earliest drilling in many oil fields has been 

 done in the vicinity of actual seeps, very often the larger produc- 

 tion has developed in areas where oil seeps are not prominent. 

 In exploration on Bondoc Peninsula it would be unwise to ignore 

 the presence and distribution of the oil seeps, but it would be 

 equally unwise to drill only where oil is to be seen. 



The Central anticline should be explored by series of wells 

 across its axis and both limbs adjacent to the axis in the vicinity 

 of Bacau and, also, farther north near Balinsog. The structure 

 is favorable at these places, and the presence of oil is established 

 by the seep at Bacau. On account of its larger size, the Central 

 anticline may contain larger accumulations of petroleum than 

 would be expected in the Maglihi anticline. Bacau and Balinsog 

 are each about 9 kilometers from the coast, and the intervening 

 country reaches an elevation of 300 meters making these regions 

 very inaccessible. 



The Central anticline in the northern part of the field will 

 afford valuable drilling territory if petroleum is found in the 

 Vigo shale below the Bacau stage. On the other hand, if only 

 the Bacau stage proves to be productive, the northern part of 

 the Central anticline from which the Bacau stage has been re- 

 moved by erosion loses its importance. South of Bacau the 

 southerly plunge of the Central anticline probably carries- the 

 petroleum horizons down beyond the reach of the drill. Pros- 

 pecting in the southern part of the peninsula in line with the 

 Central anticline would determine this point and might prove 

 successful. 



The possible locations which have been discussed are all near 

 oil seeps and are on sharp anticlinal folds. The Ayoni anti- 



