828 



Subsurface Geologic Methods 



Example 3 — Drilling — Drilling operations should include footage 

 drilled with each bit, size and type of bit, bit changes, points of weight, 

 mud weight, viscosity, and deviation surveys. See figure 417. 



Example 4 — Cores — When core data is submitted, the first paragraph 

 should embody the usual well activities. The second paragraph should 

 contain the interval cored, recovery, and general description of each core. 

 Examples are also given for submitting side-wall cores. Detailed descrip- 

 tion should be included in the weekly core and sample-description reports. 

 See figure 418. 



Example 5 — Electrical Surveys — Before recording the information 

 obtained from the electrical surveys, the first paragraph should state in 



9-5 6I»69' 20 26 Want in hole and cored from &ih9-9t(9' f/7-5/B' 



Hu^es type J.C.B. w/l-l/s pts. vgt. Pulled out, 

 "recoT'd. core. New going In hole w/8-5/8" Hu£^es OSQ-2 

 tit. Mud wgt. 12 Ibfl/gal. Tlec, kO. 



Core Ho. 7, 6ltU9-6l»69', recoT'd. 20'. 



2' Sd, Mo cut. 



2' Sh. Tert. fauna. 



16' 3d. w/255t Ismln, eh., Good cut 2l»°API 

 Grav. oil. Dip 12°. 



S.Vf.C. should 'be deel^iated as follotfs: 



1*895', 2 cores, rocov'd. 2". Sh. 



6120', 1 core, recov'd. 1". 



Sh., Bdy.. Fair sat. w/30.5° API Ctbt. oil. 

 (refract. ) . 



7130', 1 core, recoT'd. 1/2". 



Sh. Frond, fauna. 



Figure 418 



chronological order the activities of the well during the past 24 hours. 

 The second paragraph should include the depth to which the log was run, 

 total depth, formation and zone tops based on the electrical log, cores and 

 ditch samples, correlation of the structural position, of the well with nearby 

 wells, and other geological data of interest or significance. Then a listing 

 of the sand data should follow. This listing should describe the sands 

 penetrated, intervals, and net sand content. Below these data a general in- 

 terpretation should be made of the sands. The interpretations should be 

 based on the electrical log, cores, ditch samples, and structural position.^ 

 See figures 419 and 420. 



Example 6 — Testing Program — The entire testing program should be 

 outlined and recorded below the information set forth in example 5. 



* These data are sometimes deleted from the chronological report on wildcat wells or other wells as 

 directed by the Division or Caracas offices. • 



