Miscellaneous Subsurface Methods 



723 



tion of the drill pipe are of primary importance, such as 

 in directional drilling and drilling into the production 

 zone. 



General Commejvt on Drilling Fluids 



The history of drilling fluids is so recent that advances in the tech- 

 nology have largely consisted in improving testing techniques, determining 

 the desirable properties of drilling fluids, and making studies of the com- 

 mercial fluid-making materials. The art of compounding and controlling 

 the properties of drilling fluids has passed the first experimental stage, 

 and the direction of future development seems to be toward the use of 

 standardized commercial materials and the increasing use of fluid systems 

 having specific properties for overcoming special difficulties in the drilling 

 and completion of wells. 



HYDRAFRAC* TREATMENT 

 W. E. HASSEBROEK 

 The Hydrafrac treatment increases the production of a well to which 

 it is applied by generating new and greater effective permeability within 

 the zone of the well being treated. It was originally intended as a means 

 of rejuvenating wells, especially in sand, but has found excellent applica- 

 tion as a new well-completion method. 



Hydrafrac treatment produces new permeability by fracturing or 

 splitting the formation to which it is applied, as illustrated in figure 386. 



Figure 386. Fracture pattern developed by hydraulic pressure transmitted with a 

 high-viscosity liquid pumped into zone to be treated. 



* Hydrafrac is a service mark owned by Stanolind Oil & Gas Company, 



