Page 15 - Origin and Prediction of Abnormal Formation Pressures

XIV CONTENTS

Chapter 7 SEISMIC METHODS OF PRESSURE PREDICTION
F. Aminzadeh, G.V. Chilingar and J.O. Robertson Jr ................... 169
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 169
Prediction of abnormal pressure from geophysical data .......................... 169
Empirical relationships . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 170
Eaton's exponent of pore pressure determination from sonic data .................. 170
Eaton's exponent for pore pressure determination from resistivity logs ............... 171
Eaton's fracture pressure gradient equation .............................. 171
Dutta's method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 172
Fillippone formula . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 172
Modified Fillippone formula . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 172
Practical applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 173
South Caspian Basin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 173
AVO effects of overpressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175
Real time pressure analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175
Lithology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 176
Empirical relationships based on laboratory measurements ..................... 177
Velocity and acoustic impedance inversion of seismic data ..................... 178
Pore pressure and seismic amplitude versus offset (AVO) ...................... 179
Pore pressure estimation from seismic velocities ........................... 179
Deep-water prospects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183
Mapping reservoir fluid movement and dynamic changes of reservoir pressure using time lapse
(4-D seismic) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 186
Estimation of sonic velocity from resistivity logs .......................... 187
Bibliography . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 188
Chapter 8 TECTONICS AND OVERPRESSURED FORMATIONS
G.V. Chilingar, W. Fertl, H. Rieke and J.O. Robertson Jr ................ 191
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 191
Faulting as a cause of overpressured formations ............................. 191
Shale diapirism (mud lumps, mud volcanoes) ............................... 198
Prediction of tectonically caused overpressures by using resistivity and density measurements of
associated shales . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 200
Origin and distribution of overpressures in carbonate reservoirs ..................... 200
Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 205
Bibliography . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 206

Chapter 9 PREDICTION OF ABNORMALLY HIGH PRESSURES IN PETROLIFEROUS
SALT-BEARING SECTIONS
V.I. Zilberman, V.A. Serebryakov, M.V. Gorfunkel, G.V. Chilingar and
J.O. Robertson Jr . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 209
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 209
Indicators of approaching the overpressured zones ............................ 211
Locating the areal positions of AHFP zones . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 213
Quantitative AHFP forecast . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 217
Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 220
Bibliography . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 220
Chapter 10 PORE WATER COMPACTION CHEMISTRY AS RELATED TO OVERPRESSURES
H.H. Rieke, G.V. Chilingar and J.O. Robertson Jr .................... 223
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 223
Overview and constraints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 224
Thermodynamic and reaction models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 225
Evolution of seawater into pore water . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 227