104 DE. EGBERT BELL ON 



vast quantities of gas and oil have in many instances escaped to the surface, or have 

 saturated the higher porous strata, as, for example, the remarkable and very extensive 

 petroleum-bearing sand-beds of the Athabasca district, in the Northwest Territories of 

 Canada. 



Another necessary feature for a productive oil-field is a sufficient body of porous or 

 fissured and channelled rock for storing the accumulated oil. This may be the oil-pro- 

 ducing formation itself, or it may be a non-productive rock lying above the source of the 

 oil or below the impervious cap. Sometimes, leading fissures or joints and spaces between 

 beds communicate with a vast number of other fissures or channels, and when one of 

 these, or a branch closely connected with it, happens to be struck by a bore-hole, a great 

 reservoir of the pent-up oil may be freely let out. In the commoner case of small fissures, 

 it is now customary in Enniskillen, when the proper depth has been bored, to explode a 

 torpedo in the bottom of the hole, in order to open new channels for the oil, before attempt- 

 ing to pump at all. The conditions necessary for a productive oil-field are, therefore : (1) 

 An anticlinal or a dome-like structure on a large scale, in unaltered sedimentary strata ; 

 (2) Deeply-seated petroleum-forming rocks of considerable volume ; (3) A stratum of porous, 

 fissured or channelled rock, which may be either coincident with or above the oil-producing 

 beds, sufficiently thick to store the petroleum ; (4) An impervious layer of argillaceous rock 

 to prevent its escape. 



It is not to be supposed that peti'oleum may be found at all points along anticlinals 

 over oil-producing strata, even where the conditions are favorable for sealing it down. 

 In addition to the main anticlinal line, there must be a secondary upheaval, so as to 

 produce a dome or an elevation, at the crown of which the oil may gather and rest. The 

 process by which petroleum is thus concentrated may be compared to a reversal of the 

 drainage of streams of w^ater into a central basin or pond, the attitude of the petroleum 

 basin being inverted, owing to the difference in the specific gravities of the fluids. On 

 the map of a country, therefore, the forms of oil-producing areas are found not to follow 

 long lines, but to occur in isolated areas, or to be " spotty," as this mode of distribution is 

 called by the well-drillers. 



The oil wells at present worked in the township of Enniskillen belong to two distinct 

 areas of permanently productive territory. That of Oil Springs is of small extent, and 

 lies between the village of the same name and the south line of the township. The once 

 celebrated " Hendricks Spouting-well " is just across this boundary line, in the township of 

 Dawn, but it is a little outside of the area which has proved to be continuously productive 

 for twenty-seven years. The oil field of Petrolia begins a little to the south-east of the 

 centre of Enniskillen, and extends in a west-north-westerly course, taking in the north- 

 east corner of Moore, nearly to the centre of Sarnia Township, a distance of twelve to 

 thirteen miles, with a breadth of between two and three miles. The central belt of this 

 area, one mile or less in width, is the most productive. A third oil-bearing area has lately 

 been found a little to the north-west of the centre of the township of Euphemia. The 

 first well in this " territory" was put down about July 1st, 1886, and up to November 1st 

 of that year, nearly twenty wells had been sunk, but only four were in operation at the 

 latter date, when about 1,000 barrels of oil had been produced. The petroleum is here 

 found at a depth of 255 feet from the surface, in what is called the " upper show," which 

 will be again referred to. The Euphemia and Oil Springs areas lie in a straight line, 



