Sequence stratigraphic analysis of the first layer, upper second submember, Shahejie formation in Pucheng oilfield

Abstract

In view of the high accuracy and predictability, high-resolution sequence stratigraphy had been extensively applied to oil exploration and gotten prominent practicable results. This article takes the first layer, upper second submember, Shahejie (沙河街) Formation from Pucheng (濮城) oilfield as an example to analyze the application of high-resolution sequence stratigraphy in reservoir study on the basis of a comprehensive study of core log data. Firstly, facies analysis of this area reveals the corresponding terminal fan system occurring where sediment-laden streams decrease in size and vanish as a result of evaporation and transmission losses. The model includes a tripartite zonation of terminal fan into feeder, distributary, and basinal zones. Secondly, electrofacies were made by well-log analysis and then matched with sedimentary facies defined by core analysis. Four electrofacies characterizing the main sedimentary facies association and depositional environments within target area are defined (channel, lag deposit, lake or flood-plain, and overflow deposits). Thirdly, related correlations based on high-resolution sequence stratigraphy were established. By observing the stacking arrangement of genetic sequences, different scales of stratigraphic cycle can be identified. Within scale and duration, the stratigraphic cycles are termed as genetic sequences, genetic sequence sets, and minor cycles.

Keywords

terminal fan / high-resolution sequence stratigraphy / electrofacies / base level

References

[1] Bourquin S., Friedenberg R., Guillocheau F.. Depositional Sequences in the Triassic Series of the Paris Basin: Geodynamic Implications. Journal of Iberian Geology, 1995, 19: 337-362.

[2] Bourquin S., Person S., Durand M.. Lower Triassic Sequence Stratigraphy of the Western Part of the Germanic Basin (West of Black Forest): Fluvial System Evolution through Time and Space. Sediment. Geol., 2006, 186(3–4): 187-211.

[3] Bourquin S., Rigollet C., Bourges P.. High-Resolution Sequence Stratigraphy of an Alluvial Fan-Fan Delta Environment: Stratigraphic and Geodynamic Implications and an Example from the Keuper Chaunoy Sandstones, Paris Basin. Sediment. Geol., 1998, 121(3–4): 207-237.

[4] Cross, T. A., Lessenger, M. A., 1998. Sediment Volume Partitioning: Rational for Stratigraphic Model Evaluation and High-Resolution Stratigraphic Correlation. In: Gradstein, F. M., Sandvisk, K. O., Milton, N. J., eds., Sequence Stratigraphy Concepts and Applications. NPF Special Publication, 8: 171–195

[5] Deng H. W., Wang H. L., Ning N.. Sediment Volume Partition Principle: Theory Basis for High Resolution Sequence Stratigraphy. Earth Science Frontiers, 2000, 7(4): 305-313.

[6] Galloway W. E.. Genetic Stratigraphic Sequences in Basin Analysis I: Architecture and Genesis of Flooding-Surface Bounded Depositional Units. AAPG Bulletin, 1989, 73: 125-142.

[7] Graham J. R., Reily T. A.. The Sherkin Formation (Devonian) of South-West County Cork. Bulletin—Geological Survey of Ireland, 1972, 1(3): 281-300.

[8] Hong Y. M.. The Principle and Integrated Interpretation of Well Logging, 1998, Dongying: China University of Petroleum Press

[9] Kelly S. B., Olsen H.. Terminal Fans: A Review with Reference to Devonian Examples. Sediment. Geol., 1993, 85(1–4): 339-374.

[10] Vail, P. R., 1977. Seismic Stratigraphy and Global Changes of Sea-Level. In: Payton, C. E., ed., Seismic Stratigraphy—Applications to Hydrocarbon Exploration. Am. Assoc. Pet. Geol. Mem., 26: 49–212

[11] Van Wagoner J. C., Mitchum R. M., Campion K. M.. Siliciclastic Sequence Stratigraphy in Well Logs, Cores and Outcrops: Concept for High-Resolution Correlation of Time and Facies. AAPG Methods in Exploration Series, 1990, 7: 55

[12] Van Wagoner, J. C., Posamentier, H. W., Mitchum, R. M., et al., 1988. An Overview of the Fundamentals of Sequence Stratigraphy and Key Definitions. In: Wilgus, C. K., Hastings, B. S., Kendall, C. G. St. C., et al., eds., Sea-Level Changes: An Integrated Approach. Soc. Eon. Paleontol. Mineral. Spec. Publ., 42: 39–46

[13] Zhang J. L., Dai Z. Q., Zhang X. H.. Terminal Fan—A Type of Sedimentation Ignored in China. Geological Review, 2007, 53(2): 170-179.