Perception vs. reality in deepwater exploration

Shanmugam, G

Title: Perception vs. reality in deepwater exploration

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Abstract

The common perception in exploration is that deepwater sands are predominantly a product of turbidity currents, and that submarine-fan models with channel/levee and lobe elements are the norm. The reality, however, is that in many cases, deepwater sands are deposits of sandy debris flows and bottom currents, not turbidity currents. Submarine-fan models with channels and lobes are designed for turbidite-dominated deepwater systems, and therefore, fan models are obsolete for debris-flow deposits. The subject is described here in a discussion that covers: Deepwater processes. How sediments move downslope from the shelf, definitions, and misunderstood effects of high-density turbidity and bottom currents; Submarine fan models, and sequence stratigraphic implications. Limitations of widely used models, and seismic geometries and log motifs. Better calibrations are needed. In the conclusion, the author states a critical need for developing additional models for debris flows, and that research should also focus on developing reliable methods for using seismic geometry and wireline-log motifs to recognize depositional facies. A comprehensive bibliography of published literature on the subject is liberally referenced. In this paper, the term deep water refers to bathyal water depths, i.e., area seaward of the shelf edge, that existed at the time of deposition of reservoir sands;more »« less

Authors:

Shanmugam, G ^[1]

Mobil Exploration and Producing Technical Center, Dallas, TX (United States)

Publication Date:: Sun Sep 01 00:00:00 EDT 1996

OSTI Identifier:: 392221

Resource Type:: Journal Article

Journal Name:: World Oil

Additional Journal Information:: Journal Volume: 217; Journal Issue: 9; Other Information: PBD: Sep 1996

Country of Publication:: United States

Language:: English

Subject:: 02 PETROLEUM; 03 NATURAL GAS; PETROLEUM DEPOSITS; EXPLORATION; GEOLOGIC MODELS; NATURAL GAS DEPOSITS; CONTINENTAL SLOPE; OFFSHORE DRILLING; STRATIGRAPHY

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                    Shanmugam, G. Perception vs. reality in deepwater exploration.  United States: N. p., 1996. 
        Web.

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                    Shanmugam, G. Perception vs. reality in deepwater exploration.  United States.

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                    Shanmugam, G. 1996.  
        "Perception vs. reality in deepwater exploration".  United States.

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@article{osti_392221,

  title        = {Perception vs. reality in deepwater exploration},

  author       = {Shanmugam, G},

  abstractNote = {The common perception in exploration is that deepwater sands are predominantly a product of turbidity currents, and that submarine-fan models with channel/levee and lobe elements are the norm. The reality, however, is that in many cases, deepwater sands are deposits of sandy debris flows and bottom currents, not turbidity currents. Submarine-fan models with channels and lobes are designed for turbidite-dominated deepwater systems, and therefore, fan models are obsolete for debris-flow deposits. The subject is described here in a discussion that covers: Deepwater processes. How sediments move downslope from the shelf, definitions, and misunderstood effects of high-density turbidity and bottom currents; Submarine fan models, and sequence stratigraphic implications. Limitations of widely used models, and seismic geometries and log motifs. Better calibrations are needed. In the conclusion, the author states a critical need for developing additional models for debris flows, and that research should also focus on developing reliable methods for using seismic geometry and wireline-log motifs to recognize depositional facies. A comprehensive bibliography of published literature on the subject is liberally referenced. In this paper, the term deep water refers to bathyal water depths, i.e., area seaward of the shelf edge, that existed at the time of deposition of reservoir sands; it does not necessarily refer to present-day water depths in offshore examples.},

  doi          = {},

  url          = {https://www.osti.gov/biblio/392221},
  journal      = {World Oil},
number       = 9,

  volume       = 217,

  place        = {United States},

  year         = {Sun Sep 01 00:00:00 EDT 1996},

  month        = {Sun Sep 01 00:00:00 EDT 1996}

}

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Perception vs. reality in deep-water exploration

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The common perception in exploration is that deep-water sands are predominantly a product of low- and high-density turbidity currents, and that submarine-fan models with channel/levee and lobe elements are the norm. The reality, however, is that deep-water systems are extremely complex and variable in terms of depositional processes and sand-body geometries. For example, the Bourna Sequence, composed of T[sub a], T[sub b], T[sub c], T[sub d], and T[sub e] divisions, is believed to be the product of a turbidity current. However, recent core and outcrop studies show that the complete and partial Bouma sequences also can be explained by processesmore »« less
Perception vs. reality in deep-water exploration

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The common perception in exploration is that deep-water sands are predominantly a product of low- and high-density turbidity currents, and that submarine-fan models with channel/levee and lobe elements are the norm. The reality, however, is that deep-water systems are extremely complex and variable in terms of depositional processes and sand-body geometries. For example, the Bourna Sequence, composed of T{sub a}, T{sub b}, T{sub c}, T{sub d}, and T{sub e} divisions, is believed to be the product of a turbidity current. However, recent core and outcrop studies show that the complete and partial Bouma sequences also can be explained by processesmore »« less
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