840 Subsurface Geologic Methods 



casing line. The top and bottom of the gun-perforated interval 

 are indicated by 4-mm. horizontal lines. 

 .07 Plugs 



a. Cement plugs are represented by the conventional hour-glass and 

 cement symbols. 



b. Bridge plugs are represented by a condensed hour-glass symbol, 

 the top of which is drafted at the recorded depth of the top of 

 the plug. 



.08 Surveys 



a. Electrode spacing of each resistivity curve made is recorded in a 

 place where it will not interfere with the interpretation of the log. 

 If more than one run is made, each run used for the completion 

 log should have the electrode spacings recorded on the film. Like- 

 wise the temperature (degrees Fahrenheit), and the resistivity of 

 the mud are recorded on the film for each run. 



b. Mud resistivity is the resistivity of the mud as measured by the 

 loggers at the time the survey was made. Entered with the re- 

 sistivity is the temperature in degrees Fahrenheit at which it was 

 measured. On completion logs, where two or more runs make 

 up a composite log, the mud resistivity and temperature for each 

 run and the interval surveyed on each run are plotted at the 

 top of the log of the respective runs. Hole size and run number 

 should also be recorded. This data is usually entered on the pre- 

 liminary log. 



c. "SCHLUMBERGER DEPTH," "DRILLER'S DEPTH," and the 

 final "TOTAL DEPTH" of the well are recorded with a Wrico 

 Guide CVC, CVL, CVN-185, Pen No. 7 at the foot of the log in 

 the space indicated by the draftsman's guide. "FIRST READ- 

 ING" is no longer recorded at the bottom of the completion log 

 unless it varies appreciably from the logger's total depth. 



d. Whenever a well is carried deeper after an electrical survey has 

 been run and no additional surveys have been made, a notation 

 explaining the discrepancy between "TOTAL DEPTH" and 

 "SCHL. DEPTH" appears at the foot of the log. 



.09 Well Number and Scale 



a. The well number and scale, having been drafted on the negative 

 prior to the reproduction of the 1 :500 preliminary log, remain 

 unchanged for single wells in the preparation of the completion 

 log. 



.10 Production Data 



a. Intervals tested are embraced by brackets drafted on the resis- 

 tivity side of the log. Each bracket is labeled with the test 

 number in a circle. Results of tests, including test number, sand 

 or sands tested, interval, what obtained on test, indication as to 

 type of testing method used and length of test, size of choke (if 



