元坝地区灯影组四段丘滩体相控储层预测

在川中地区灯影组油气勘探取得重大突破后,研究发现,川北元坝地区灯影组四段与其同处于台地边缘有利相带,认为该地区具有较高的油气勘探潜力。针对元坝地区灯影组四段(灯四段)埋藏深、缺乏钻井资料等问题,以相控思路为核心,结合地质、物探资料从地震相带刻画、丘滩体地震识别和无井相控储层反演等方法,开展了灯四段丘滩体的相控储层预测研究。首先,以沉积模式为基础,分析古地貌和地震资料响应特征,建立元坝地区灯四段地震相识别模式,刻画有利相带分布范围;然后,分析藻类丘滩体沉积环境和发育模式,正演分析丘滩体地震响应特征,建立灯四段丘滩体地震识别模式,描述该丘滩体发育有利带;最后,分析该丘滩储层地球物理特征,结合地质资料及地震相带开展无井相控储层反演研究,预测丘滩储层发育范围。由丘滩体相控储层预测得到的川北元坝地区灯四段丘滩储层展布特征可知,储层主要发育在沿“陡坎”的台缘条带及台缘内侧微古地貌较高的条带,符合地质规律,为川北元坝地区灯四段的油气勘探奠定了良好基础。

In the light of the great breakthrough in the oil and gas exploration of the Dengying formation in central Sichuan,China,it is estimated that the fourth member of the Dengying formation in the Yuanba area,northern Sichuan,also lies in a favorable facies belt of the platform margin.To address the issues deriving from the large burial depth and lack of drilling data of the Dengying formation,this study proposed a facies-controlled reservoir prediction for the bioherm beach of the fourth member based on geological and geophysical data.First,in the light of the sedimentary model,paleo-geomorphological and seismic data were analyzed,so as to establish an identification pattern for the seismic facies and describe the distribution of the favorable ones.Second,the sedimentary environment and the development model of the algae in the bioherm beach were analyzed,and the seismic response of the bioherm beach was obtained through forward modeling,so as to establish the seismic recognition model of the bioherm beach and describe the favorable zone for the development of the bioherm beach.Finally,the geophysical characteristics of the bioherm beach reservoir were analyzed,and a facies-controlled reservoir inversion in the absence of drilling data was finally performed.Using the results of the inversion,the spatial characteristics of the bioherm beach reservoir were described.The proposed method provides a foundation for the exploration of the Dengying formation in northern Sichuan.

国家科技重大专项(2017ZX05005-004)资助。