Physical properties of the shallow sediments in late Pleistocene formations, Ursa Basin, Gulf of Mexico, and their implications for generation and preservation of shallow overpressures

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doi: 10.1016/j.marpetgeo.2009.01.018
Author(s): Binh, N. T. T.; Tokunaga, T.; Nakamura, T.; Kozumi, K.; Nakajima, M.; Kubota, M.; Kameya, H.; Taniue, M.
Author Affiliation(s): Primary:
University of Tokyo, School of Frontier Sciences, Chiba, Japan
Dia Consultants, Japan
Oyo Corporation, Japan
Volume Title: Basin modeling perspectives
Volume Author(s): Verweij, Hanneke, editor; Kacewicz, Marek; Wendebourg, Johannes; Yardley, Gareth; Cloetingh, Sierd; Duppenbecker, S.
Source: Basin modeling perspectives, edited by Hanneke Verweij, Marek Kacewicz, Johannes Wendebourg, Gareth Yardley, Sierd Cloetingh and S. Duppenbecker. Marine and Petroleum Geology, 26(4), p.474-486. Publisher: Elsevier, Oxford, United Kingdom. ISSN: 0264-8172
Note: In English. 59 refs.; illus., incl. sect., 5 tables, sketch map
Summary: Understanding the evolution of abnormally high fluid pressures within sedimentary formations is critical for analysing hydrogeological processes and assessing drilling risks. We have constructed a two-dimensional basin model and have performed numerical simulations to increase the understanding of the history of fluid flow and shallow overpressures in the Pleistocene and Holocene formations in the Ursa basin, deepwater Gulf of Mexico. We measured physical properties of sediments, such as porosity and permeability, in the laboratory and estimated in situ pore pressures from preconsolidation pressures. We obtained porosity-effective stress relationships from measurements of bulk density, grain density and preconsolidation pressures in the laboratory. Porosity-effective stress relationships were also obtained from downhole density logs and measured pore pressures. The porosity-effective stress and porosity-permeability relationships obtained were applied in two-dimensional basin simulations. Results showed that high pore pressures developed shortly after sediment deposition. Peaks in pore pressure ratios were related to high sedimentation rates of mass transport deposits and the incision of the Ursa channel. Lateral flows from the area where the overburden is thick towards the area where it is thin have occurred at least since 30 ka. Present pore pressure and temperature distributions suggest that lateral flows play a role in re-distributing heat in the basin. Abstract Copyright (2009) Elsevier, B.V.
Year of Publication: 2009
Key Words: 29 Economic Geology, Energy Sources; 30 Engineering Geology; Atlantic Ocean; Basin analysis; Basins; Boundary conditions; Cenozoic; Consolidometer tests; Deep-water environment; Fluid phase; Gulf of Mexico; Marine sediments; Mechanical properties; Models; North Atlantic; Offshore; Overpressure; Permeability; Petroleum; Petroleum exploration; Physical properties; Pleistocene; Porosity; Quaternary; Reservoir properties; Reservoir rocks; Sedimentary basins; Sediments; Shallow-water environment; Soil mechanics; Upper Pleistocene; Ursa Basin; Ursa Channel
Coordinates: N280000 N282000 W0880000 W0890000
Record ID: 2011026933
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from CAPCAS, Elsevier Scientific Publishers, Amsterdam, Netherlands