A Quantitative Characterization Method for Lowstand Shelf Marginal Deltas

Abstract

The invention discloses a quantitative characterization method of a low-stand continental shelf edge delta, comprising the following steps: selecting a profile of a target delta, and dividing the third-order sequence boundary of the target delta by using an earthquake termination relationship based on the classic sequence stratigraphy theory; In the third-level sequence interface, identify the first super-upper point, the first lower-superior point of the initial flooding surface on the third-level sequence interface, and the point where the angle of the initial flooding surface changes the most; read Take the time values ​​of the above three points, and use the time-depth conversion formula to convert them into depth values; calculate the accretion distance of the delta according to the depth values; calculate the progress of the delta according to the plane positions of the above three points. calculating the slope of the delta according to the accumulation distance and the progradation distance; determining the type of the delta according to the calculation result of the slope. The invention can quantitatively classify the types of deltas at the edge of the low-stand continental shelf, and provide technical support for deep-water sediment research.

Description

technical field [0001] The invention relates to the technical field of deep-water deposition, in particular to a quantitative characterization method for deltas at the edge of low-stand continental shelves. Background technique [0002] Deep water sedimentation is a hotspot and frontier field of oil and gas exploration and development in the world today, and the study of low stand shelf edge deltas is an important research direction of deep water sedimentation theory. Lowstand domains often develop deep-water fans (slope fans and submarine fans) and shelf-margin delta sedimentary systems at the same time, and shelf-margin deltas have a good indicator effect on deep-water sand-rich systems. The study of lowstand shelf edge deltas not only has rich theoretical significance in sequence stratigraphy and marine sedimentology, but quantitative characterization of them is not only conducive to the identification of sand body development types and distribution rules, but also to dee...

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Problems solved by technology

[0003] However, although the study of deltas on the edge of the lowstand continental shelf has positive significance for the prediction of deep-water fans, their shapes are complex and changeable due to factors such as climate, sea level rise and fall, and sediment supply; various types of deltas are formed. , which also seriously affects the prediction accuracy of favorable deep-water sand bodies and oil and gas exploration areas

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