Subsurface maps and 

 illustrations — Cont. 

 miscellaneous models, 912 

 paleogeologic maps, 923 

 panel map, 930 

 peg models, 909 

 percentage maps, 940 

 preparation of subsurface data, 895 

 ratio maps, 939 



reduction of datum elevation, 895 

 reproduction of maps, 961 

 section models, 912 

 shadow-graphic structure map, 937 

 solid models, 911 

 spalinspastic map, 956 

 stratigraphic and isometric- 

 projection drawing, 932 

 structural contour map, 897 



Subsurface problems, 5 

 Subsurface techniques, 10 

 comparative use of, 10 



Temperature logging, 444 



instrumentation, 444 



interpretation, 446 



uses, 449 

 Thin sections, 174 



of fragments, 178 



of heavy concentrates, 178 



preparation of, 174 



study of, 179 



correlation, 183 



porosity and permeability, 181 



storage of, 183 



vug and opening studies, 183 

 Traps, oil and gas, 55 



Clapp's classification of, 56 



Wilson's classification of, 57 

 Unconformities, 32 



chemical sediments, 44 



continental, 36 



criteria for recognition of, 40 



definition, 33 



evidences of erosion or 

 weathering, 42 

 . genesis of, 36 



marine, 37 



nomenclature, 33 



recognition of, 39 



structural features, 41 

 Unconformities, importance of, 45 



oil reservoirs, 46 



ore deposits, 49 



stratigraphic, 45 

 Valuation and subsurface 



geology, 792 



checking the value, 808 



engineering valuations, 795 



figuring the reserve, 796 



gas properties, 805 



Valuation and subsurface 

 geology — Cont. 

 hypothetical case, 798 

 market value, 794 

 proration, 793 



Water analysis (Rocky Mtn. 

 oil fields), 272 

 classification, 272 

 Colorado group, 277 

 Cretaceous, Lower, 281 

 Cretaceous, Upper, 275 

 Devonian and older, 292 

 Frontier formation, 279 

 Green River formation, 274 

 Jurassic, 283 

 Mississippian, 292 

 Montana group, 275 

 Muddy (Newcastle) sand, 279 

 Pennsylvanian, 285 

 Permian, 285 

 Shannon sandstone, 278 

 surface waters, 273 

 Tertiary, 274 

 Triassic, 285 

 Wasatch formation, 274 



Well acidization, 750 

 dolomite, 750 

 examples of, 753 

 limestone, 750 

 methods of locating 



porous zones, 755 

 procedure, 756 

 production increase by, 754 

 sandstone, ,751 

 shooting, 758 

 structural, stratigraphic, and 



lithologic influence on, 753 



Well information, sources of, 1150 

 Arkansas Geol. Survey, 1156 

 Chemical and Geol. 



Laboratories, 1155 

 Colorado School of Mines 



Well Sample Library, 1150 

 Denver Sample Log Service, 1155 

 Kansas Geol. Soc, 1151 

 Kansas Sample Log Service, 1152 

 New Mexico Bur. Mines and 



Mineral Resources, 1156 

 Paleontological Laboratory, 1150 

 Petroleum Information, Inc., 1153 

 South Dakota School of Mines 



and Technology, 1151 

 Texas Univ. Well-Sample 



Library, 1154 

 Well logging by drilling-mud 

 and cuttings analysis, 499 

 application, 453 

 correlation of data, 452 

 methods of analysis, 450 

 theory, 450 



