兴西洼陷沙四段近岸水下扇的识别

Identification of near-shore subaqueous fans in Es4,Xingxi sub-sag

兴西洼陷是一个位于辽西凹陷中段的狭长沉积构造,以往大多认为该区沙四段地层不发育,从而制约了该区油气勘探的深化。本文通过对兴西洼陷的地震层位进行对比,落实了该区的最有利储层———沙四段。综合分析区域构造背景和沉积特点,认为该区存在东部陡坡带控制下的近岸沉积扇体;运用多种物探技术手段预测和刻画了一系列近岸水下扇储集体。部署在该区的兴西2井成功揭示了沙四段近岸沉积扇体的存在,并喜获工业油流,打开了该区的油气勘探局面。

Xingxi sub-sag in middle of western sag of Liaohe Basin is a narrow and long sedimentary sub-sag.It was considered that the 4th member of Shahejie Formation was not well developed in the region.Based on the comparison of seismic strata of Xingxi sub-sag,we see the 4th member of Shahejie Formation as the most favorable reservoir in the area.By comprehensive analysis of regional tectonic background and sedimentary characteristics,we conclude that there are coastal sedimentary fan bodies controlled by east fault zone.We predict and delineate a series of near-shore submarine fan reservoirs with various geophysical techniques.Well XX2 in this area,with commercial oil discovery,reveals the existence of sedimentary fan bodies in the 4th member of Shahejie Formation.