zones to take or produce fluid. The data have proved also of value for well-to- 

 well correlation of permeability zones. When used before and after acidizing 

 or fracturing a well, it indicates those producing sections that have received 

 the most benefit from the well-stimulation operation as well as those needing 

 additional treatment. 



The permeability profile is not used directly to determine fluid content of 

 zones or for estimating reserves, but it is helpful in such determinations when 

 integrated with other well data. 



Permeability profiles are useful in planning pressure-maintenance programs 

 or evaluating the efficiency of secondary-recovery operations. Surveys con" 

 ducted on input wells of water-flooding projects assist in determining injection 

 rates and locating by-passed zones. 



The surveying techniques followed in obtaining permeability profiles also 

 can be utilized for obtaining other valuable subsurface information such as 

 locating zones of lost circulation in drilling wells, zones of water entry, and 

 casing failures; channeling around faulty casing seats or extending above or 

 below perforations ; or controlling and evaluating remedial plug-back operations. 



Figure 20-1. Exterior view of electric pilot truck showing conductor cable being wound 

 on power-driven reel. 



396 



