Report writing 



(cf. Subsurface geologist) 

 Resistivity, 376 



electrode spacing, 377 

 resistivity curves, 



characteristics of, 378 

 terminology, 377 

 Rock bits, design and 

 application, 643 

 bits for formations on the harder 



side of medium-soft, 654 

 bits for medium-hard to hard, 



nonabrasive formations, 655 

 compressive strength of 



various rock types, 658 

 drillability of formations, 659 

 drilling hard to hard, 



abrasive formations, 656 

 hard and hard, abrasive 



formation bits, 652 

 medium-hard formation bits, 648 

 medium-hard to hard, nonabrasive 



formation bits, 650 

 modifications of OWS, 



type owe, 651 

 OSC-1 tricone, 645 

 OSC tricone, 647 

 OSQ-2 tricone, 648 

 OWS tricone, 650 

 soft to medium-soft 



formation bits, 653 

 W7 and W7R tricones, 652 

 weight from tandem drill 



collars, 656 



Rotary samples, 346 



catching of, 350 



contamination from upper beds, 346 

 cuttings, loss of, 348 

 cuttings, powdering of, 347 

 elutriation, 348 

 methods of obtaining 



correct depths, 348 

 Sample logging, 344 

 cable-tool samples, 345 

 cuttings samples, 352 

 plotting, 360 

 rotary samples, 346 

 use of, 362 

 Secondary-recovery methods, 778 

 air and gas injection, 778 

 mining, 781 

 vacuum, 778 

 water flooding, 779 

 Secondary recovery of 

 petroleum, 775 

 costs and results, 785 

 history of operations (U. S.), 776 

 limiting factors, 788 

 methods, 778 

 operations in Rocky Mtn. 



states, 786 



Secondary Recovery of Petroleum — Cont. 



secondary oil reserves, 781 



susceptibility of oil fields to, 781 

 Sedimentary rocks, 71 



classification of, 72, 73 



color of, 82 



diagenesis of, 82 



structures in, 80 



texture of, 79 



types of, 71 

 Sedimentary rock types, 71 



breccias, 71 



carbonaceous rocks, 78 



conglomerates, 71 



dolostone, 76 



evaporites, 77 



limestone, 76 



miscellaneous, 78 



mudstone, 76 



sandstones, 74 



shale, 76 



siltstones, 75 

 Seismic prospecting, 1084 



applications, 1101 



interpretation methods, 1093 



principles, 1084 



prospecting methods, 1091 



rock properties, 1088 



velocities of selected rocks, 1090 

 Settling analysis, 193 

 Shale-density analysis, 329 



apparent specific gravity, 330 



application of results, 334 



bulk density, 330 



compaction, 331 



grain density, 330 



natural density, 330 

 Shale-density determination, 331 



method of, 331 



sources of error in, 333 

 Shape analysis, 199 

 Size analysis, 184 



computations, 190 



cumulative-frequency curve, 190 



histogram plot, 188 



plotting of data, 188 



preparation of sample, 184 



simple-frequency curve, 188 

 Spectrochemical sample logging, 487 



densitometry, 493 



instrumentation, 491 



interpretation, 493 



sample treatment, 489 



sampling, 489 



standards, 492 

 Spontaneous potential, 364 



effect of bed thickness, 373 



effect of drilling mud, 370 



effect of porosity and 

 permeability, 370 



effect of special muds, 373 



