Duties and Reports of the Subsurface Geologist 839 



chemical sediments on right. When an oil cut is obtained from 

 ditch samples, it is represented by a 3-mm. circle located in the 

 center of the graphic log. 

 q. Any show, which is considered significant by the geologist, of 

 oil, gas, or water, is represented by the letters So, Sg, or 5m; re- 

 spectively in the center of the log at the depth where encountered. 

 The letter 5 is colored by red, yellow, or blue, depending on the 

 type of show, 

 r. Whenever a well blows out, the sand from which the blowout 

 originated is indicated by an X in the center of the log. The 

 word Blowout and depth at which it occurred are recorded to the 

 left of the X symbol in accordance with the draftsman's guide. 



.05 Mechanical Data 



.051 Casing and C.O.S. 



a. Blank casing is represented in the conventional manner by a 

 solid, thin, vertical line. 



b. "C.O.S." is represented in the conventional manner by a solid line 

 (blank pipe), and a dashed (preperf orated pipe) vertical line. 



c. The size of the blank casing and depth at which cemented are rep- 

 resented numerically to the left of the casing shoe and graphically 

 by a solid casing shoe pointing to the left. The size of the pre- 

 perf orated casing and depth where set are represented numerically 

 to the left of the "C.O.S." and graphically by an open shoe point- 

 ing to the left. 



d. Tubing is represented graphically only for dually completed wells 

 or where a packer is run on the tubing. 



.06 Perforations 



a. In "C.O.S." a solid line representing the blank casing is drafted 

 to the point where the preperforated pipe begins. The graphic 

 representation of the preperforated pipe always commences with 

 a gap, then a dash and gap, etc. The bottom of a preperforated in- 

 terval, when located between two pieces of blank pipe, likewise 

 always begins and ends in a gap. 



b. Gun-perforated intervals open to production are represented by a 

 series of horizontal lines 2 mm. long that intersect the solid casing 

 line. The top and bottom of a gun-perforated interval are indi- 

 cated by a 4-mm. horizontal line. 



c. Gun-perforated intervals not open to production and not squeezed 

 off are identical to those open to production. A bridge plug or 

 reason for the section not being open is indicated. 



d. Gun-perforated intervals for squeeze-cementing operations are rep- 

 resented by top and bottom lines and in-between lines, none of 

 which intersect the casing. 



e. Intervals gun-perforated for production test and squeezed off are 

 represented by a series of 1-mm. lines on the left side of the 



