Page 293 - Geology of Carbonate Reservoirs

274 INDEX

Nuclear magnetic resonance (NMR), 8, 107, 145. saturation, water (S w ), 49
See also Logs, wireline Photozoan biota, 123
T2 relaxation time, 53 Platform(s)
antecedent, 103
Oaks field (Smackover Formation), Jurassic, carbonate, defi ned, 77

North Louisiana, 117, 216 carbonate and siliciclastic, slopes on, 127
barrier island sequence in, 117 environmental “cells” or subdivisions on, 81
Oil isolated, 79
column, calculating height above free water margins, bypass and depositional, 127
level, 70 modern carbonate, examples of, 110
shales, 109 paleotopography of, 135
“window”, 145 slope failure, types of, 127
Olenellus, trilobite, 84 West Florida, 88
OOIP, see Original oil in place Polymorphs, CaCO 3 , 3
Oozes, siliciclastic, 98 Pore(s), see Porosity
Organic compounds, polar, 63. See also cavernous, 151, 156, 176
Wettability channel, 160, 176
Organic matter, sapropelic, 18 facies, 69
Organisms fracture, 44, 176–177
porosity in, 108–109 geometry, 107, 205
reef-building, 81, 108 interbreccia (karst), 162
rim-forming, 125 intercrystalline, 51, 144, 151
Original oil in place (OOIP), calculation of, 61 interparticle, 10
Orogeny, Ancestral Rocky Mountain enlarged, 160
(Carboniferous), 247 intraskeletal, 223
Overcompaction and stylolites, 154, 165, 243 moldic, 10, 147, 151, 156, 160, 162, 226

Overton field, Jurassic, Texas, 90, 159. 165, 227– roughness factor (a), in withdrawal effi ciency,
231. See also Porosity, “chalky” 73
vuggy, 10, 147, 151, 156, 160, 162, 176, 226
Paleosols, 155 vuggy and fracture, petrophysical behavior of,
Pathway, diagenetic, 164. See also Cross-cutting 190
relationships vugs, stromatactis, 210, 245, 248. See also
Periplatform talus, 128 Buildups, carbonate, “mud mounds”
Permeability Pore categories (types)
absolute, 45 depositional, 14
capacity to transmit fl uids, 34 diagenetic, 14
Darcy–Ritter equation for (Darcy’s law), 31, in detrital rocks, 108
186–187 fracture-related, 14
flow test, 194 Pore throats, 7

fracture, 182, 186 dimensions of, 17
intrinsic, 186 effective radius of, 66
matrix, 187 median diameters of, 107
relative, 46 sheet-like, 66
specifi c, 45 size-sorting of, 66
statistical relationship with porosity, 7 Pore-to-pore throat (size) ratio, 34
Permian Basin, Texas, 128 Pore volume, minimum unsaturated, 66
Persian Gulf, 211 Porosity

water depth, 129 Ahr genetic classification of, 26, 42–44
tidal fl ats (sebkhas), 117 Archie classifi cation of, 35–36
Petrographic image analysis (PIA), see Image bimodal, 30, 50, 160
analysis, petrographic “bird’s eye”, 108
Petroleum system, elements in, 76 calculated from neutron logs, 194
Petrophysical calculations from wireline logs capacity to store fl uids, 34
density, 49 core (measured), 194
lithology, 49 “chalky”, 151. See also Cotton Valley
porosity, 49 Formation
resistivity, formation water (R w ), 49 Choquette and Pray classifi cation of, 36–39