Miscellaneous Subsurface Methods 



727 



well, the improvement is not necessarily due to a mere increase in the 

 rate of production, but due to a greater effective permeability produced 

 as a result of the process; the ultimate recovery from the well so treated 

 will also be increased. 



Pressure and volume of injection changes during the course of Hydra- 

 frac treatment are shown in figures 388, 389, and 390. Well A in figure 

 388, completed in the Springer sand in the Sholem-Alechem field of Ok- 

 lahoma, shows a typical pressure curve with a declining pressure during 



WELL A 

 SHOLEM ALECHEM FIELD, OKLA. 



CLOSED IN PRESSURE 



40 BOPD AVG. 



63 BOPD AVG. 



23 BOPD 

 INCREASE 



PRODUCTION CURVE 



.1 



Figure 388. Pressure and volume of injection changes during Hydrafrac treatment. 



the injection period of gel but with no sharp pressure break. This well was 

 treated through perforations from 5345 to 5358 feet. Pressure while dis- 

 placing the gel with two cementing trucks handling the pumping, after 

 the gel was all in the formation, is about the same as with one truck 

 pumping oil into the formation before treatment. Obviously the fracture 

 produced had resulted in considerable increase in the effective permea- 

 bility of the hole. The production curve after treatment shows a typical 

 flush-production period lasting a few days. 



