1188 



EXPLORATION GEOPHYSICS 



Mobile magnetometer, 231 



helicopter operations, 241 



operations, 237-241 



orientation, 234-237 

 Mobile seismic operations, 848, 849 

 Moon, effect on gravity, 249 

 Mott-Smith gravimeter, 380, 381, 382 

 Mud analysis logging, 961, 962 

 Multiple reflections, 891-895 

 Multiple shot points, 855 



N 



Navigational Radar system, 906, 907 

 Neutron curve, interpretation, 1105-1107 

 Neutron logging, 1010, 1011 

 Neutron logging instrument, 1097 

 Newton's law of gravity, 248, 249, 255 

 Nickel ore deposits, 231 

 Non-metallic deposits, 55 



o 



Offshore operations: 



Gulf underwater gravimeter in, 386-389 



history of, 17, 18 



seismic operations {see Seismic offshore 

 operations) 



shipborne magnetometer, 244 

 Ohm's law, 467-469 

 Oil: 



barrels per dry hole, 2 



cost of, 39 



reserves, 4 

 Oil structures classification, 33 

 Oil wells: 



and fluid-level data (Table 28), 1133 



circulation, 1068 



depth of, 3 



fluid content, 1054 



recovery problems {see Production problems) 



water {see Water location methods) 

 Onan power supply, 1069 

 Options, 1145 

 Ore deposits, 46 



bedded, 47, 51 



classification of, 46 



concentrated, 47, 50 



dikes, 47 



disseminated, 47, 50 



electromagnetic inductive investigations of, 

 603, 604 



gravimeter, survey over, 426, 427 



lodes, 47, 49 



magnetic investigation of, 231 



placer deposits, 46, 47 



resistivities of, 441 



self-potential survey over, 453, 454 



veins, 47, 49 

 Oscillograph, 740, 825 

 Oscillograph galvanometer, 546 

 Overlapping seismic recording, 854 



Paleontological studies, 1090, 1091 

 Paramagnetic materials, 63 

 Patents: 



bore-hole investigations, 1113-1121 



chemical, 962-965 



electrical, 631-638 



gamma-ray logging, 1119 



gravity, 434-436 



Halliburton vs Walker, et al, 1158-1161 



licensing, 1155, 1156 



magnetic, 244-246 



neutron logging, 1119, 1120 



patent infringement suit, 1155, 1156 



production problems, 1141, 1142 



radioactivity, 1015 



radioactivity logging, 1120, 1121 



rights, 1153-1161 



seismic, 930-937 



thermal, 986 

 Pendulum, 269-285 



Brown, 279 



compound pendulum (reversible), 271 



corrections for, 283, 284 



field technique, 281-283 



history of, 274-276 



limitations of, 273 



Mendenhall, 275 



reversible, 271 



simple pendulum, 270 



Vening Meinesz, 269 



Von Sterneck type, 277-279 

 Periodic heat flow, 978, 979 



calculations for variations, 979, 980 



lag, velocity and wave length, 980, 981 

 Permit and trespass practice, 1146-1151 



receipt and discharge form, 1149 



receipt and release form, 1150 

 Petroleum land lease, 1144 

 Photoclinometer, 1081-1083 



arrangement of parts, 1081, 1082 



in dipmeter survey, 1078, 1079 

 Photoclinometer surveys, 1082 



field procedure, 1082 



presentation of results, 1082 

 Photoelectric absorption, 991 

 Photoelectric instrument, 1075, 1076 

 Photoelectric method, 1075, 1076 

 Photoelectric seismometer, 804 

 Photogrammetric mapping {see Terrestrial 



photogrammetric mapping), 392-398 

 Photographic nuclear emulsion, 1005 

 Piezoelectric seismometer, 801, 802 

 Placer deposits, 47, 48, 228, 229, 557-560 

 Polarization ellipse (electrical) 614, 615 

 Porosity zone, location of, 1110-1113 

 Portable gravimeter, 382, 383 

 Portable seismic equipment, 836, 838, 839, 



881-883 

 Potassium, 992 

 Potential: 



-bowl theory, 508, 511 « 



-drop method, 468, 1092 



