YIELD OF WELLS. 



igl 



realise how much it actually means ; there are 519 productive 

 wells, which if the average for 1893 were kept up would produce 

 1,21,788 viss per mensem more, or instead of an average turn out of 

 7 % 9 lakhs of viss there would be a production of 9 lakhs of viss. 



The decline in the average yield of 1895 can certainly be 

 attributed to a decline in the yield of the deeper wells which is by no 

 means balanced by a corresponding rise in the yield of the shallow 

 wells. In fact it may almost be considered as certain that if that 

 rise had not happened and if the shallow wells had retained the 

 average production recorded during the years 1888, 1891 and 

 1893, vis., 34*9, 307 and 34'6 respectively, instead of rising to the 

 average of 42^5 viss, the present rise in the production would not 

 have happened at all, but instead of it, we should probably have 

 seen a decrease in the production. 



That such a rise in the average production of the shallow wells 

 has taken place, is as already pointed out solely due to the exploitation 

 of the 1st and 2nd oil sand in a part of the Twingon Reserve by 

 means of a number of recently constructed wells. 



(B) Unproductive wells. 



(1) Abandoned wells.— The remarkable feature in connection with 

 the unproductive wells is the apparent constancy in the number of 

 abandoned wells, which as will be seen from the table on page 180 

 has undergone very slight changes only. This may be explained 

 thus : during the years 1 89 1 to 1893 some of the better preserved 

 abandoned wells were repaired and deepened, thus changing them 

 into productive wells while others which could no longer be kept 

 up fell in disuse. This fact has been recorded in several instances, 

 but it would be useless to mention each case in detail, but for 

 reasons already explained, I fear that there will be a considerable 

 increase in the number of unproductive wells, within the next few 

 years. 



The proportion between productive and abandoned wells may be 



( 237 ) 



