TY - JOUR
T1 - Corrigendum to “Disequilibrium compaction overpressure in shales of the Bavarian Foreland Molasse Basin
T2 - Results and geographical distribution from velocity-based analyses” (Marine and Petroleum Geology (2018) 92 (37–50), (S0264817218300618), (10.1016/j.marpetgeo.2018.02.017))
AU - Drews, Michael C.
AU - Bauer, Wolfgang
AU - Caracciolo, Luca
AU - Stollhofen, Harald
N1 - Publisher Copyright:
© 2019 Elsevier Ltd
PY - 2020/2
Y1 - 2020/2
N2 - The authors regret that the following mistakes in the description and graphical representation of the normal compaction trend (NCT) have been erroneously carried forward by the authors from an earlier version of the manuscript to the final version of the manuscript, which does not allow for reproduction of the normal compaction trend used in the study: 1. For all pressure analyses conducted in the study, the constant exponent n of equation (3) has been set to 2.0, instead of 2.19. Therefore, paragraph 1 on page 41 should be read as “[…] which we set to a value of 2.0 for shale, similar to Issler (1992).”2. The vertical stress, necessary to calculate the NCT as represented in Figs. 4, 5 and 6, has been erroneously calculated with a phi0-parameter of 0.35 instead of 0.3 (compare equation (2) and table 1). For the three green data points (Oligocene Normal Pressure, NW-Molasse) of Fig. 5 we spotted an additional minor error in the calculation routine of the vertical effective stress. We attached the corrected figures to the end of this corrigendum.We would like to emphasize that the errors have not been carried forward in the remainder of the study and manuscript. The corrections are only necessary to being able to reproduce the used normal compaction trend, but do not affect any of the results, conclusions or any other figures or written passages of the manuscript. The authors would like to apologize for any inconvenience caused. [Formula presented] Fig. 4. Shale velocities vs. true vertical depth (TVD) for normally pressured Oligocene (yellow and green dots) and Mesozoic shales (blue dots). Oligocene shales from wells in the north-western Bavarian Foreland Molasse Basin (wells marked by green dotted envelope on the map inset and green dots on the velocity-depth plot) generally have faster velocities, which might be attributed to more heterolithic sequences and/or increased uplift. The calculated normal compaction trend (NCT) derived from the combination of the modified Athy equation and the porosity-velocity transform of Raiga-Clemenceau et al. (1988) is represented by the black dashed line. [Formula presented] Fig. 5. Vertical effective stress vs. shale velocity relationship from both normally pressured and overpressured wells. Vertical effective stress values have been derived from drill stem and production tests and wireline formation pressure tests and associated shale velocities are captured from sonic and VSP data from adjacent shale sequences. The dashed black curve represents the normal compaction trend (NCT) established for the Bavarian Foreland Molasse Basin. [Formula presented] Fig. 6. Shale velocities compiled from seismic (VSP) and sonic velocities vs. true vertical depth (TVD) for both normally pressured and overpressured Oligocene and Mesozoic (Cretaceous and Jurassic) shales. Velocities from overpressured Oligocene and Cretaceous shales clearly depart from the normal compaction trend around 2500 m, with some minor diversions even in shallower sections.
AB - The authors regret that the following mistakes in the description and graphical representation of the normal compaction trend (NCT) have been erroneously carried forward by the authors from an earlier version of the manuscript to the final version of the manuscript, which does not allow for reproduction of the normal compaction trend used in the study: 1. For all pressure analyses conducted in the study, the constant exponent n of equation (3) has been set to 2.0, instead of 2.19. Therefore, paragraph 1 on page 41 should be read as “[…] which we set to a value of 2.0 for shale, similar to Issler (1992).”2. The vertical stress, necessary to calculate the NCT as represented in Figs. 4, 5 and 6, has been erroneously calculated with a phi0-parameter of 0.35 instead of 0.3 (compare equation (2) and table 1). For the three green data points (Oligocene Normal Pressure, NW-Molasse) of Fig. 5 we spotted an additional minor error in the calculation routine of the vertical effective stress. We attached the corrected figures to the end of this corrigendum.We would like to emphasize that the errors have not been carried forward in the remainder of the study and manuscript. The corrections are only necessary to being able to reproduce the used normal compaction trend, but do not affect any of the results, conclusions or any other figures or written passages of the manuscript. The authors would like to apologize for any inconvenience caused. [Formula presented] Fig. 4. Shale velocities vs. true vertical depth (TVD) for normally pressured Oligocene (yellow and green dots) and Mesozoic shales (blue dots). Oligocene shales from wells in the north-western Bavarian Foreland Molasse Basin (wells marked by green dotted envelope on the map inset and green dots on the velocity-depth plot) generally have faster velocities, which might be attributed to more heterolithic sequences and/or increased uplift. The calculated normal compaction trend (NCT) derived from the combination of the modified Athy equation and the porosity-velocity transform of Raiga-Clemenceau et al. (1988) is represented by the black dashed line. [Formula presented] Fig. 5. Vertical effective stress vs. shale velocity relationship from both normally pressured and overpressured wells. Vertical effective stress values have been derived from drill stem and production tests and wireline formation pressure tests and associated shale velocities are captured from sonic and VSP data from adjacent shale sequences. The dashed black curve represents the normal compaction trend (NCT) established for the Bavarian Foreland Molasse Basin. [Formula presented] Fig. 6. Shale velocities compiled from seismic (VSP) and sonic velocities vs. true vertical depth (TVD) for both normally pressured and overpressured Oligocene and Mesozoic (Cretaceous and Jurassic) shales. Velocities from overpressured Oligocene and Cretaceous shales clearly depart from the normal compaction trend around 2500 m, with some minor diversions even in shallower sections.
UR - http://www.scopus.com/inward/record.url?scp=85075455529&partnerID=8YFLogxK
U2 - 10.1016/j.marpetgeo.2019.104102
DO - 10.1016/j.marpetgeo.2019.104102
M3 - Comment/debate
AN - SCOPUS:85075455529
SN - 0264-8172
VL - 112
JO - Marine and Petroleum Geology
JF - Marine and Petroleum Geology
M1 - 104102
ER -