Miscellaneous Subsurface Methods 



545 



Their conclusion based on this study was that wear of rods and tubing 

 was no more severe in the deviated wells than it was in straight wells. 



Directional work often is done in drilling vertical wells where the 

 limiting drift angle may be three or five degrees as specified in contracts. 

 Deflecting tools faced in the opposite direction from the angle of drift of 

 a well will straighten its course. In many cases the contractor profits 

 through straightening the well by this method, owing to the time saved in 

 comparison with bringing the well back to vertical by conventional straight- 

 hole methods. 





Figure 269. Offshore marine structure in the Gulf of Mexico. Exploration work is 

 heing done by means of directionally drilled wells. 



Vertically drilled wells located near lease lines have been kept within 

 correct boundaries by turning their courses with deflecting tools. Strip 

 and very small locations have been exploited by careful drilling, consistent 

 surveying, and an occasional deflection-tool run to correct the course of 

 the well. 



The occasional loss of tools in the well are hazards of well drilling. 



Expensive fishing operations ensue, sometimes to no avail. In cases of 



this sort the hole is bridged with cement and deviated away from the 



fish" by directed drilling, effectually sidetracking the lost equipment. A 



few very skillfully executed jobs have been successfully done when casing 



