THE SEARCH FOR OIL — LEES 241 



These various geophysical methods do not, of course, determine 

 directly the existence or otherwise of underground oil, but they do 

 assist greatly in providing a structural picture of the subsurface by 

 which deductions regarding the probability or otherwise of oil may 

 be made, and they assist greatly in locating exploration wells to best 

 advantage. They are, however, far from being a universal panacea 

 and there are frequently many difficulties of interpretation of the 

 results obtained. 



During recent years a geochemical method has been attempted 

 wliich deals more directly with underground oil. Small quantities 

 of surface rocks or soils are analyzed for their hydrocarbon gas con- 

 tent, and it has been found that minute escapes of gas, not detectable 

 by ordinary means, may give a clue to underground oil accumula- 

 tions. This method is at present at a stage of early development and 

 much research work is required before it can be looked upon as an 

 established method for routine application. 



The hazards of oil exploration are well known to the investing 

 public, but the reasons for them are probably less well appreciated. 

 After as complete a survey of a potential oil region as is possible, 

 using all geologic and geophysical assistance, the average chance of 

 success of an exploration boring cannot ever be rated, on the basis of 

 past experience, as better than perhaps one in ten ; but past experience 

 has also shown that if financial resources can stand the strain of the 

 nine unsuccessful efforts the reward from the fortunate tenth may be 

 expected to give sufficient compensation. 



OIL EXPLORATION IN ASIA 



The intensity of exploration in various parts of Asia has consid- 

 erably increased during recent years, and most of the large British 

 and American oil companies are involved. British and British- 

 Dutch companies have been actively engaged in the Asiatic field for 

 many years, and many important oil fields have been discovered and 

 developed ; but the new interest now being taken by American com- 

 panies is, as I have already said, based on the belief that American 

 oil reserves will not stand the present rate of production for many 

 years. The necessity to discover and develop additional reserves 

 well ahead of demand forces the American companies to carry the 

 search to whatever parts of the world offer even remote prospects. 

 Exploration work under modern conditions is a lengthy and ex- 

 pensive undertaking, and the interval between the commencement 

 of an examination of a new concession and the time when an oil field 

 is found and sufficiently developed for export may cost many 

 hundred thousand pounds in money and 5 or even 10 years in time. 

 For this reason exploration work must be years ahead of the neces- 



