--> Abstract: Meandering River Channel Sand Identification and Description, by Guangjun Chen, Jianxiang Yuan, and Helin Wang; #90072 (2007)

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Meandering River Channel Sand Identification and Description

Guangjun Chen1, Jianxiang Yuan2, and Helin Wang3
1Schlumberger, Beijing, China
2Schlumberger,
3PetroChina,

One of the major target layers in the Guanjiapu oil field of the shallow sea area of the Bohai Bay is a meandering river channel sand of fluvial deposition. The reservoir is usually very thin and inhomogeneous while the field is situated within two major faults. The thickness of the oil-bearing river channel sands is around 5 m. There are already 16 wells drilled and some of them have been producing at a relatively high rate. Using traditional seismic interpretation, we could not track the respective channel sands accurately. This challenge presents an obstacle for field development.
In an attempt to characterize the river channel sands, seismic variance and attribute analysis were used. Variance calculates the direct measurement of dissimilarity of seismic traces and produces much sharper and more distinct terminations than those observed in normal amplitude data; meanwhile, seismic attributes can help identify and describe inconspicuous river channels, more distinctly focusing on a specific layer. Through vertical seismic profile processing, we calibrated the target layers exactly, guided by fine geological classification. Controlled by well log processing and integrated interpretation data, we applied seismic attribute analysis and variance processing to identify and to describe the intended meandering river channel sands.
Finally, we were able to identify those meandering channel sands around some major producers within the field and we described their distributions laterally. These identifications and descriptions could be verified and validated by existing and producing wells. Then the results were output as a static model that we can subsequently optimize for further exploration and development.

 

AAPG Search and Discovery Article #90072 © 2007 AAPG and AAPG European Region Conference, Athens, Greece