渤海辽中中洼东三段湖底扇沉积模式及储层展布特征

Sedimentary Mode and Reservoir Distribution Characteristics of Ed3 Sublacustrine Fan in Liaozhong Zhongwa of Bohai Sea

为研究渤海海域辽中中洼东三段湖底扇沉积模式,通过岩心观察、薄片鉴定、测井分析、沉积模式演化等方法,结合经典湖底扇沉积模式、重力流沉积理论和地震资料,定量刻画湖底扇砂体展布范围。研究表明,旅大A构造东三段为富砂型湖底扇沉积,可细分为辫状河三角洲前缘砂体远端带、滑动滑塌陡坡带、朵叶缓坡带等沉积单元。根据流变学特征,结合岩性组合、物源搬运距离,可将朵叶缓坡带细分为朵叶碎屑流沉积、朵叶前端浊流沉积。通过建立等时地层切片,优选最小振幅属性,将井震结合,定量刻画出湖底扇砂体的平面展布范围。

In order to study the sedimentary mode of sublacustrine fan in the Ed3 of Liaozhong Zhongwa,the distribution range of sublacustrine fan sand body is quantitatively described by means of core observation,thin section identification,logging analysis and sedimentary mode evolution and combined with the classical sedimentary mode of sublacustrine fan,the sedimentary theory of gravity flow and seismic data.The research shows that the Ed3 formation of LD A structure is sand-rich sublacustrine fan deposition,which can be subdivided into sedimentary units such as the distal zone of braided river delta front sand body,the sliding collapse steep slope zone and the lobed gentle slope zone.According to rheological characteristics,combined with lithology combination and provenance transportation distance,the lobed gentle slope zone can be subdivided into lobed debris flow deposition and lobed front turbidite deposition.The plane distribution range of sublacustrine fan sand body is quantitatively described by establishing isochronous stratigraphic slices,optimizing the minimum amplitude attribute and combining well logging with seismic data.