Full
CAO Shuchun,born in 1975,is a master degree candidate,senior engineer. His research primarily focuses on oil and gas field development geology and development seismology. E-mail: caoshch@cnooc.com.cn.
Outline
Submarine fans commonly accumulate on a large scale within continental slope minibasins,where their architectural evolution is predominantly governed by paleotopographic configuration. In settings influenced by dip-oriented synsedimentary normal faults,such minibasins frequently host laterally elongated fault-controlled troughs,which are associated with longitudinally distributed,multi-tiered slope breaks. Although these multi-step slope breaks exert first-order control on the spatial distribution,internal architecture,and stacking patterns of submarine fan reservoirs,the underlying geomorphic and dynamic mechanisms remain inadequately constrained. This study focuses on the Upper Jurassic B4 reservoir in the X Oilfield(North Sea,UK),integrating high-resolution well-log data and 3D seismic interpretation to reconstruct paleobathymetry and decipher reservoir-scale architectural heterogeneity. Our analysis reveals that the submarine fan developed within a structurally confined slope fault trough,characterized by: (i)a western primary upper slope with an average gradient of~7.5°;(ii)three distinct,longitudinally aligned deepwater slope breaks;(iii)a pronounced gradient differential of 6.3° across the primary slope break,contrasting with sub-3° differentials across the secondary and tertiary breaks. Critically,the longitudinal multi-step slope breaks dictate both planform architectural organization and temporal migration-stacking behavior of fan elements. Elevated sediment supply coupled with steep upper-slope gradients promotes high-velocity,supercritical turbidity currents(Froude numbers>1),resulting in proximal bypass dominance—wherein sediment largely bypasses the primary lower slope. The large gradient differential at the primary break enhances flow confinement and sand-body thickness through hydraulic jump-induced deposition. In contrast,reduced gradient differentials across downstream(secondary-tertiary)slope segments decelerate flows,fostering the development of multibranched avulsion channels,levee-channel complexes,and distributary lobes on the lower slopes. As successive lower-slope tiers become progressively filled and aggraded,lobe deposition preferentially shifts toward lower-tier slopes possessing greater accommodation space,producing retrogradational stacking geometries. Furthermore,enhanced lateral confinement—imposed by adjacent fault-bounded margins—deflects lobe progradation trajectories and modifies lobe morphology from classic lobate to elongate,tongue-shaped forms.
108
51
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |
关闭全屏
No. 86 Xueyuan South Road, Haidian District, Beijing
010-62662699(Operation and Technical Support)
qkjq@cast.org.cn
Copyright © 2025 China Association for Science and Technology. All rights reserved. For all open access content, the relevant licensing terms apply.
Sponsored by the Office of the Leading Group for Cybersecurity and Informatization of CAST, and supported by Science and Technology Review Publishing House
