Seismic Sedimentology And Its Application Of E₂d₁ In Yongan Area

Seismic sedimentology is an emerging and developing interdisciplinary research field. It mainly deal with ideas and concepts of sedimentology to describe underground reservoirs and Predict sedimentary facies with seismic and geological methods. Yongan oilfield is located in Hanliu tectonic belt at the structure belt in the northern of Gaoyou Sag eastern China. Hanliu fault formed by regional strike-slip effect during the deposition of E2 d and E2 s. Influenced by Hanliu fault, it is formed by broken anticline structure background in Yongan oilfield and developed a lot of faults. Due to the uneven distribution network of wells in Yongan oilfield, the seismic data need to be used for reservoir prediction and sedimentary facies division. Volcanism activity in Yancheng period developed diabase intrusions, which cause poor quality of seismic data that result in great difficulty with structural interpretation, sedimentary division, stratigraphic correlation, sand body tracking and so on. For these reasons, this paper apply Seismic Sedimentology which developed base on the research in marine strata to complex fault block and complex lithology of continental basin, and carry out seismic sedimentology studies.This paper integrated utilization of well drilling data, well logging data, core data and seismic data. Using principle of sequence stratigraphy correlated and divided isochronous stratigraphic units at E2d1 layer in Yongan oilfield, a stratigraphic framework is established. After using median filtering process the seismic data, identify and track the isochronous interface on seismic data based on division of sequence stratigraphy on wells, marker bed and combination of frequency technology. Using stratal slice in isochronous stratigraphic framework, combined with seismic attribute technology, 90 o phase shifting, frequency technology and seismic facies technology, determined the distribution of sand and improve prediction and accuracy sedimentary microfacies. Furthermore, classified sedimentary facies and effective reservoir is predicted. In the end, summarized seismic sedimentary facies research methods and preferred parameters suitable for Yongan area, and provided the basis for further rolling oilfield development.