Distribution pattern of paleo and present BSRs in the toe-thrust belt of Niger Delta front

被引：0
|
作者：
Yang J. [1 ]
Song P. [1 ]
He W. [2 ]
Wang H. [3 ]
Wang M. [1 ]
Xiao D. [1 ]
机构：
[1] Key Laboratory of Deep Oil and Gas, China University of Petroleum (East China), Qingdao, 266580, Shandong
[2] Research Institute of Petroleum Exploration & Development-Northwest, PetroChina, Lanzhou, 730020, Gansu
[3] School of Energy Resources, China University of Geosciences (Beijing), Beijing
来源：
Oil and Gas Geology | 2019年 / 40卷 / 06期
关键词：
Bottom simulating reflection (BSR); Fluid migration; Gas hydrate; Niger Delta; Seismic interpretation;
D O I：
10.11743/ogg20190613
中图分类号：
学科分类号：
摘要：
Interpretation of 3D seismic data from the compression domain of Niger Delta, related seismic attribute extraction and BSR numerical modelling are carried out in this paper to study the seismic characteristics of the present and paleo-bottom simulating reflections (BSRs), and the controlling factors of BSR vertical migration.In the study area, the present and paleo-BSRs, representing present previous and locations of the base of gas hydrate stability zones (GHSZ), are scattered and mainly located in areas with well-developed fluid pathways including folding faults, gas chimneys, and diapire structures.This indicates that fluid migration conditions control the occurrence of BSR.Compared with the present BSR, the paleo-BSRs are of weaker amplitude, and distributed in much more limited areas.The amplitude of the paleo-BSRs is interpreted to represent petrophysical interfaces caused by diagenesis driven by previous gas hydrate.The depth of the present BSR deepens as the seabed water depth increases, but the thickness of GHSZ is relatively stable, about 425 m.The upward resetting of the BSR is a result jointly contributed by various factors in the geological history.The toe-thrust belt of the Niger delta is characterized by intense tectonic activities, high sedimentary rate, and well developed fluid migration pathways, including fault and diapire, for heat flows from deep to shallow.Besides, the underlying oceanic and transitional crusts allow higher heat flows, and marine mudstones have higher heat sealing capacity.All these are driving the upward resetting of the BSR.In addition, higher gas hydrate saturation formations in the study area feature higher amplitude anomalies on the present, upper BSR with positive polarity, mainly on top of anticlines and gas chimneys, indicating the effective control of fluid migration pathways on gas hydrate accumulation.The occurrence of free gas zones (FGZs) underlying the present BSR is limited, and only thin FGZs occurred in fold belts with well-developed fluid migration pathways. © 2019, OIL & GAS GEOLOGY Editorial Board. All right reserved.
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页码：1295 / 1307
页数：12
相关论文
共 38 条
  • [1] Kvenvolden K.A., Methane hydrates and global climate, Global Biogeochemical Cycles, 2, 3, pp. 221-229, (1988)
  • [2] Bunz S., Mienert J., Berndt C., Geological controls on the Storegga gas-hydrate system of the mid-Norwegian continental margin, Earth & Planetary Science Letters, 209, 3-4, pp. 291-307, (2003)
  • [3] Haacke R.R., Westbrook G.K., Hyndman R.D., Gas hydrate, fluid flow and free gas: Formation of the bottom-simulating reflector, Earth & Planetary Science Letters, 261, 3-4, pp. 407-420, (2007)
  • [4] Boswell R., Shipp C., Reichel T., Et al., Prospecting for marine gas hydrate resources, Interpretation, 4, 1, pp. SA13-SA24, (2016)
  • [5] Brown K.M., Bangs N.L., Froelich P.N., Et al., The nature, distribution, and origin of gas hydrate in the Chile Triple Junction region, Earth & Planetary Science Letters, 139, 3-4, pp. 471-483, (1996)
  • [6] Wang X., Wu S., Liu X., Factors affecting the estimation of gas hydrate and free gas saturation, Chinese Journal of Geophysics, 49, 2, pp. 504-511, (2006)
  • [7] Golmshtok A.Y., Soloviev V.A., Some remarks on the thermal nature of the double BSR, Marine Geology, 229, 3, pp. 187-198, (2006)
  • [8] Milkov A.V., Dickens G.R., Claypool G.E., Et al., Co-existence of gas hydrate, free gas, and brine within the regional gas hydrate stability zone at Hydrate Ridge (Oregon margin): evidence from prolonged degassing of a pressurized core, Earth & Planetary Science Letters, 222, 3-4, pp. 829-843, (2004)
  • [9] Clennell M.B., Hovland M., Booth J.S., Et al., Formation of natural gas hydrates in marine sediments: 1. Conceptual Model of Gas Hydrate Growth Conditioned by Host Sediment properties, Journal of Geophysical Research Solid Earth, 104, B10, pp. 22985-23003, (1999)
  • [10] Bangs N.L.B., Musgrave R.J., Trehu A.M., Upward shifts in the southern Hydrate Ridge gas hydrate stability zone following postglacial warming, offshore Oregon, Journal of Geophysical Research Solid Earth, 110, B3, pp. 67-99, (2005)
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