834 Subsurface Geologic Methods 



It is particularly desirable that the rock name appear near 

 the beginning of the description so that it does not become lost 

 in the mass of less important detail. In the following outline 

 probably only half or less than half of the features listed need be 

 noted for any one sample. Items which are of greatest import- 

 ance and which should be particularly checked in each descrip- 

 tion are shown in capitals in the outline. In the description it is 

 desirable that the rock name be written in capitals and that re- 

 marks concerning special features such as "fossils" and "oil and 

 gas" be underlined. 



ROCK NAME— texture— COLOR— luster— HARDNESS— 

 cohesion — fracture feel — BEDDING — original structure — second- 

 ary structures — concretions mineral and mechanical composition 

 —special features— FOSSILS— OIL and GAS— DIP. 



When a core is described (see example given for core No. 

 56) , the total recovery is shown first, followed by the description 

 of each lithologic unit fjom top to bottom. 

 9. Use of abbreviations in core and sample descriptions is op- 

 tional. If the geologist describing cores prefers to write out the 

 full descriptive terms, he may do so. 



10. Dips as measured from cores should be indicated in a column 

 titled "Dip." 



11. A "Remarks" column is used for clarifying any data shown in 

 the lithologic description. 



a. Estimated percentage of minor constituent of rock described 

 should be given: i.e., 5% ss. 



b. Presence of fossils should be noted. 



c. Determination of oil gravities should be given, including the 

 method used, whether "Suspension" or "Refractive Index." 



d. Any formation top, faunal zone, sand top, etc., should be 

 indicated, together with their respective depths. These data 

 should be underlined to make them stand out. 



Method of Preparation — All entries must be typewritten. Elite type is 

 preferred. A sheet of carbon paper is reversed in order that the print 

 appears on both sides. Reproductions of this report are made by the 

 Ozalid process. 



Copies — The original copy is retained in the district geological group 

 files for additional reproduction for possible well-exchange trades, par- 

 ticularly on wildcat wells. 



Normal distribution (Creole 100% acreage — operated by Creole) re- 

 quires one copy for each well file. 



Completion Log Report 



It has become a common practice among geologists in many areas to 

 prepare a completion log report upon termination of drilling a well. 



