590 



Subsurface Geologic Methods 



consisted of the short survey barrel, stabilized by spring baskets, to- 

 gether with two universal joints separated by a short torque tube. This 

 unit was screwed to the drill pipe or tubing by an upper connection. The 

 articulated assembly followed the course of the bent casing accurately. 

 Oriented surveys were made by taking readings at intervals of six inches 

 or one foot through the fault planes. Subsequent surveys plotted over 

 the originals indicated the direction and amount of movement taking place 

 in the wells. The operators concerned have been able to predict the speed 



VERTICAL SECTION 



MAT PLAN 



PLAN VIEW 



o 



Figure 305. 



Report of sucker-rod survey made on producing well for pump align- 

 ment. 



of the movement from this survey information. Successful remedial meas- 

 ures have been devised to prolong the life of the producing wells. New 

 methods to combat the effect of this earth movement have been used in 

 drilling new wells. 



A major company has surveyed all the wells on one of its large leases 

 in order that a study could be made of the difficulties experienced in 

 pumping some of the wells. Vertical sections on a distorted scale were 

 made for each well so that "dog legs" could be detected more readily. 

 It was found that, by relocating pumps in some wells and by protecting 

 the rods at other points where sharp kinks were evident, the difficulty and 

 attendant expense of pumping were reduced materially. 



