Chapter 13 

 LUMINESCENCE LOGGING 



T. V. Shcherbakova 



Bitumens, including petroleums and petroleum products, possess the abil- 

 ity to luminesce. This property of bitumens is used to determine the content 

 of petroleum in rock samples and the drilling fluid. Systematic luminescence 

 analysis of the drilling fluid during ^\ell drilling, carried out with the object 

 of singling out oil-bearing beds penetrated by the well, is called lumines- 

 cence logging. 



At the present time, luminescence logging is carried out by taking samples 

 of the drilling fluid every 1-3 m of penetration and viewing them in ultra- 

 violet light. For this a luminoscope is used, which consists of a light-tight 

 chamber equipped with a source of ultra-violet light (UFO-2 or PARK-4 

 lamp with a filter passing only idtra -violet rays). The sample of drilling fluid, 

 which is sometimes specially treated, is placed in the ultra-violet light, 

 while the luminescent glow is observed through a window in the chamber 

 (the viewing window). The luminescence is arbitrarily characterized by some 

 relative quantity, for exanrple by the fraction of the svu-face area of the sample 

 occupied by luminescent spots. Together with this, during the examination 

 of the drilling fluid samples, the colour of the luminescent radiation is de- 

 termined. 



Curves, showing the variation in luminescence capacity of the drilling 

 fluid with variation in depth of the well drilling, are constructed from the 

 data obtained, and constitute a luminescence log. These curves, to greater 

 or lesser extent, represent the content of oil in beds penetrated by 

 the well. 



The main drawback of luminescence logging is the subjectiveness of the 

 evaluation of the intensity and colour of the drilling fluid luminescence, 

 which precludes the possibility of a reliable determination of the content 

 of oil in the drilling fluid from the data obtained in luminescence logging. 

 Moreover, the method employed for observing the luminescence makes 

 automatization of luminescence logging difficult. 



In this connection, work was carried out to elucidate the possibility of 

 evaluating luminescence objectively and, on the basis of this, to determine 

 from luminescence analysis data the oil content in a drilling fluid. 



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