YENANGYOUNG. 123 



years. The Berne wells have nearly extracted the oil existing in the 

 oil bearing sandstone and a decrease of production is to be 

 expected." 



B. The area exploited by the drilled wells [Kodoung). 



No such difficulties as regards limited depth obstruct the drilled 

 wells. If it were known certainly that an exceedingly rich oil 

 sand were to be found at 2,000 feet, every well would at once be 

 brought down to that depth. The future of this area is therefore 

 simply dependent upon the quantity of oil stored in the different 

 sands and the annual off take. Although the latter is well known it 

 would be exceedingly rash to form an opinion about the former. We 

 know that the Kodoung wells draw their supply chiefly from the third 

 oil sand, but how long this will last is difficult, if not impossible, to say. 

 The question will be the more difficult to answer if we assume a 

 general flow of oil towards the wells ; in this case the production 

 will of course last longer than if only dependent on the oil within the 

 boundaries of Kodoung, because the oil is attracted from the more 

 distant places towards the deep wells. 



However there will probably come a day when the third oil sand 

 will be entirely dry ; in this case the wells will have to exploit the 

 deeper sands. Whether those are capable of supporting the present 

 large production is impossible to say, so far as can be judged from 

 the few observations the chances are not favourable, however I do 

 not wish, considering the inconstancy of the strata, to attach too 

 much weight to those few instances in which we have become ac- 

 quainted with the sequence of the beds below the third oil sand. 



Taken as a whole the Yenangyoung oilfield has by no means 

 answered the expectations which were entertained about it. It is 

 limited in area, and we may almost certainly assume that its pro- 

 duction will always be a modest one. It is almost certain that its 

 production will rise somewhat during the next few years, but it is 

 most probable that then a decline will set in. My opinion is that 



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