Mud 



Mud 



Mud Cake 



Permeable 

 Formation 



Mud Cake 



Microlaterolog MicroLog 



Figure 14-21. Comparative current distribution of microlaterolog and microlog. 



The equipment used at the present time enables the recording of one single 

 curve run with an electrode system referred to as type A (spacing between suc- 

 cessive elecrodes = 9/16") . Laboratory tests and field experience have proved 

 that this equipment gives the measurement of R x0 and, hence, of formation 

 factor and porosity, without correction, when the mud cake thickness is not 

 greater than about % inch. 



Interpretation and Applications 



Inasmuch as the current beam has a very small diameter (about 2"), the 

 power of resolution of the MicroLaterolog is very high; the recorded curves 

 for formations with low porosity (fig. 14-21). Therefore, when the mud cake 

 is relatively thin, measurements obtained with the MicroLaterolog involve 

 chiefly the flushed zone. 



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