IN THE UPPER EIO OKANDE EMBAYMENT IN TEXAS. 99 



gravity is about 2 degrees lighter. The flash and burning 

 points are mucli higher than those of crudes which are being 

 refined upon a large scale with absolutely satisfactory results. 

 We do not mean to say that it could not be refined and a mode- 

 rate amount of light oils, such as kerosene's, naphtas, etc., be 

 obtained. However, as is almost invariably the case with this 

 class of oils, same would need special treatment before refining, 

 and even with this the lubricating or heavy products obtained 

 would not be of the high quality desired for this class of oils. 



While the heat value of the oil is not high for crudes, it is suf- 

 ficiently so to make the oil desirable for fuel purposes. The price 

 which could be had for the oil, would probably be proportionately 

 lower than that of some other oils, as the heat value is propor- 

 tionately lou'er than of other oils on the market. We do not 

 mean to say that this is lower than any other on the market, as 

 many are being used which is no better than this one." The 

 above quotation is from a letter written by the analysts to Col. 

 W. L. Evans, who submitted the sample. 



Probability of Existence of Oil. 



As to the existence of petroleum in commercial quantities in 

 this field, it would be hazardous to venture a definite opinion. It 

 is a well known fact that the first explorations in most oil regions 

 have been made on the basis of much less promise. The accumula- 

 tions of oil require the same kind of structures as are found to 

 hold gas. There must be present some impervious stratum to 

 arrest the rise of the oil under the pressure of ground water. The 

 structures which hold gas are just as efficient to hold oil, if it be 

 present. And usually the two are associated, though one or the 

 other is apt to prevail. When present in the same well, oil is usu- 

 ally produced only after the gas has escaped. Gas wells may 

 thus sometimes turn into oil wells. Both gas and oils are to be 

 regarded as products of a natural distillation and the presence of 

 one may be taken as a certain indication of the production of the 

 other. But the products of the same distillation may have be- 

 come separated and may not now be in the same reservoirs. As 

 a rule the oil is held lower down in the reservoirs than the gas. 

 Oil might hence be rather looked for south and east of this gas 

 well than in any other direction. 



