阿尔凹陷扇三角洲储集岩差异性分析及有利相带预测

Differential analysis of fan-delta reservoir and beneficial facies belt prediction for Aer sag

阿尔凹陷是一个典型的内陆湖泊型沉积凹陷,凹陷内油气聚集区主要受同时沉积的具不同岩性组合的两个扇三角洲控制。研究表明,该区储集层的岩性差异直接影响着储集层的储集性能和油气成藏,该区储集空间的发育程度主要受扇体部位、岩石成分及特征、成岩后生作用3个因素影响,其中最有利的储集相带位于凹陷东北部Ⅰ号扇三角洲的分布区,属于扇体前缘(河口沙坝)部位,以花岗岩作为主要母岩成分且成熟度高,次生孔隙和原生孔隙发育,成藏条件有利,为今后该区的勘探评价指明了方向。

Aer sag is a typical depositional sag of astatic lake,its oil-gas accumulative area is mainly controlled by two fan-deltas which have different lithologic combinations and simultaneously sedimented.The study of Aer sag indicated the lithologic discrepance of reservoirs directly affected storage properties and oil-gas reservization,the developed degree of storage space is mainly affected by three factors of fan body position,rock composition and features and diagenetic epigenesist.The most favourable facies belt is located in the northeast of Aer sag,which is the distribution area of Ⅰ fan-delta and belongs to the position of fan body front (debouch bar),the granite is the dominant parent rock composition and the maturity is high,secondary pore and primary pore are developed,reservoir conditions are good.The study pointed out the direction for the regional exploration and evaluation.