Lesley.] *>80 [^Dec. 15, 1876. 



done, a 5|" casing (inside diameter) is inserted, with a device on the bot- 

 tom so arranged that it will form a water tight joint between the casing and 

 wall of the well. A 5^' hole is then continued down to the oil rocks from 

 the inside of this last '■ string of rasing." If the casing has been inserted 

 to the i)roi)er depth and no water is encountered below it, the sand-pump 

 will soon exhaust the water in the process of drilling, and the well be per- 

 fectly dry. But if lower veins of water are struck, the casing must be 

 diawn, the hole reamed out to a greater depth, and the casing continued 

 down l)elow them. After the water is exhausted, a few pails full are poured 

 in as circumstances demand; to moisten the drillings and furnish fluid for 

 the sand-pump. 



Comparing now the two wells when comjileted and re-ady for the pump, 

 we find them both to be of the same size, iik" in diameter. One has simpl}' 

 a conductor through the upper division, all the stratified rocks being bare, 

 is full of water, and has probably shown but very little indication of oil. 

 The other lias a conductor through the upper division, casinu; inside of this 

 to the bottom of the middle division, and is dry — or at least was drj' until 

 the striking of the oil sand, when it immediatelj' filled up several hundred 

 feet with oil, or perhaps flowed. 



The "dry " well is ready at once for the introduction of the pump tube ; 

 the " wet " one must be cased before it is tubed. Tiic casing used for this 

 purpose ("small casing,") is of S^" inside diameter. A "water packer" 

 or "seed bag" is attached to its lower end, which eftectually closes the 

 annular space between the outside of the casing and wall of the well. This 

 "small casing," of course, must extend down to the bottom of the second 

 division, the same as the large casing does in the "dry" well, for it has 

 precisely the same duty to perform, the shutting ott" of the water in the 

 ui)per rocks from the well shaft. 



The well is now tubed Avith the ordinary 2" " tubing, " having a " work- 

 ing barrel " or ])ump chamber at the bottom, which is placed at or near the 

 point where the oil enters. 



Inside of the " tubing" are inserted the "sucker rods" which are con- 

 nected in the derrick to the " walking beam," and operate the pump valves 

 below. 



Upon starting the pump, the "water packer " prevents any of the fluid 

 outside of the casing from entering the Avell, and the water inside of the 

 casing and in the uncased portion of the well is soon pumped out and the 

 well is said to be "exhausted." As the well exhausts, the oil, which has 

 been held back in the rock by the pressure of the heavy column of water 

 above it, gradually forces its way into the well and is raised by the pump 

 to the surface, unless it has a sufficient force of gas to flow of its own 

 accord afterwards. 



