东营凹陷沙三中东营三角洲地层格架与油气勘探

通过钻井和三维地震资料的综合解释，较好地建立了东营凹陷少三中东营三角洲的等时地层格架，由三角洲前积层中厚层泥岩的研究，识别出六个准层序，每个准层序代表着一个或多个三角洲朵状体。东营三角洲层序极不对称主要与较高的沉积物供应量有关。高位体系域形成时期更高频的沉积物供应的变化是准层序形成的主要原因。随着研究时段或地层厚度减小，地层格架越来越受到局部因素的限制。此外，浊积岩分布及其三角洲进积方向和速率的关系，对指导岩性油藏也有重要意义。

Preliminary Study on Stratigraphy Architecture of Middle- shasan Dongying Delta and Its Significance to Hydrocarbon Exploration

According to integrated research on three-dimension seismic and well data,high-resolution stratigraphic architecture of Middle-Shasan Dongying Delta,Dongying sag,was well established.The sequence of Middle-Shasan Dongying Delta is controlled by abundant sediment supply from the east and the southeast of this sag,vertically consisting of thinner lower aggradational section and thicker upper progradational section.Six parasequences are recognized from the progradational section by study on thick muddy layers at deltaic front and integrated interpretation of related seismic and well data,each of which behaves as progradational superposition of bedsets representing one or more deltaic lobes.Vertical asymmetrical structure of the sequence primarily rests on both the position at the multi-order sequence architecture,and the key factor formatting the sequence and its system tracts,i.e.,abundance of sediment supply.Influence of deposition on strata frame is amplified due to ancient open-lake background and relative tectonic stability of gentle slope of Dongying sag.Higher-order sediment supply in high system tracts promotes the formation of parasequences,and the changes in ancient lakebed topography impose on the strata distributing of these parasequences.Sedimentary system or local factories restrict identification of strata frame in a greater degree,when the time or thickness span of strata unit at attention reduces.The discussion to this stratigraphic architecture will help investigation to both development,distribution of related turbidites,and their relationship to the direction and speed of delta progradation,boosting up the degrees of study and exploration of accompanying lithological reservoirs.