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THE ROYAL SOCIETY OF CANADA 



Table III. 



Rise of Pressure on closing well ^ter 10 min. open flow. 



These curves and figures indicate how quickly the well, after 

 being open, will recover its pressure. It will be noticed that the rate 

 of recovery was lowest immediately after the seven day blow-off, but 

 from that on the rate of recovery became quicker from day to day. 

 Immediately after the seven day blow-off the pressure took 7-6 mins. 

 to rise to 150 pounds per square inch; on the fourteenth day it took 

 only 3 mins. for the pressure to rise to the same figure. 



At the end of the fourteen days' accumulation test just described, 

 the well was put on open flow for three hours. At the beginning of 

 this period the rate of delivery was 3,830,000 cubic feet per day and 

 at the end 3,190,000 cubic feet per day, a decrease of 16-7 per cent 

 in three hours. This fact indicates that the well on being opened 

 quickly delivers the gas which had accumulated at the bottom. It 

 does not necessarily imply that the gas supply of the surrounding 

 field is small, though this may be a possible conclusion. The gas 

 which had accumulated at the well had already forced its way through 

 the porous sandstone to the hole of the well, where it could be 

 quickly released. After its release the rate of flow of the well will 

 depend on the quantity and pressure of the gas supply connected 

 through the pores and capillaries of the sandstone with the well, 

 and on the porosity of the sandstone. A large supply under con- 

 siderable pressure may produce relatively a small flow of gas if the 

 porosity of the sandstone is low. 



To obtain some information on the behaviour of the well under 

 conditions as nearly as could be made to approximate to those of 

 actual service, the well was made to flow against a pressure at the out- 



