Porosity 



The relative porosity of the rocks may be shown on the extreme right 

 edge of the strip in different ways. The character may be indicated by dots, 

 circles, and irregular figures, the relative degree of the porosity being suggested 

 by the distance the pattern is carried to the left from the edge. A pencil shadow 

 graph based on relative porosity or estimated percent of pore space can be 

 shown on the right margin of the log in much the same manner as grain sizes 

 are shown. In this case, the increase is shown from right to left (fig. 3-5A). 



Cored Intervals 



It is important to show the intervals cored in the well. Chip samples obtain- 

 ed during coring are inferior to regular cuttings. Chip samples taken from the 

 cores are usually superior to cuttings. In the first case the log is likely to be 

 less reliable through the cored interval than elsewhere. The reverse is true 

 where core chips are used for the lithologic determinations. 



Cored intervals are shown by a black line on the left side, and adjacent 

 to the color column (fig. 3-5A). 



Casing Points 



After casing has been run in the well, there will be no caving from the 

 wall above the bottom of the casing; therefore, the samples should be taken 

 immediately after the casing is set. For this reason, the casing points should 

 be indicated on the log, as shown in Figure 3-5B. The diameter of the casing is 

 indicated at the casing point. 



Title Information 



The heading of the strip log (or typed log) should contain all information 

 pertinent to the operation of the well. 



Following is an outline for the completion of the title head: 



Location: State, county, section, township, range, and section sub- 

 division 

 Names of operator and landowner 

 Name of structure or area 

 Elevation above sea level 

 Total depth of well 



Kind of equipment: rotary, cable tools 

 Dates of starting and completion 

 Daily rate of production (oil and gas) 

 Stratigraphic unit from which production is obtained 

 Casing points (if not plotted) 

 Name of microscopist and date of sample examination 



46 



