南泥湾长6油层组沉积微相及含油性研究

目的研究南泥湾地区长6油层组沉积微相,认识沉积微相与油气富集规律的关系。方法通过岩心观察、薄片观察、扫描电镜、粒度分析,结合钻井、测井资料,对南泥湾油田长6油层组岩性特征、沉积相特征及沉积微相含油性进行统计分析。结果该区长6为三角洲前缘亚相沉积,包括水下分流河道、河口砂坝、水下分流间湾、前缘席状砂、水下天然堤和水下决口扇等6种沉积微相,其平面展布由北向南呈鸟足状。结论水下分流河道微相是该区长6油层组含油砂体的骨架相,水下分流河道砂体是该区今后勘探的主要目标。

A study on sedimentary microfacies and oil-bearing possibility in Chang 6 oil-bearing formation in the area of Nanniwan

Aim To study the sedimentary microfacies of Chang 6 oil-bearing formation and understand the relationship between sedimentary microfacies and oil-bearing possibility in the area of Nanniwan.Methods The lithological,sedimentary facies characteristics and oil-gas distribution are studied based on a series of work and data including observing and accounting of cores and crop sections,analysis of scanning electron microscope,grain size analysis,and data of well drilling and well logging.Results In Chang 6 period,the sedimentary faceies of Nanniwan area was delta front subfacies that included six types of sedimentary microfacies,and it extended to SW from NE in bird-foot delta.Conclusion Underwater channel microfacies was the dominant sedimentary microfacies of oil sand bodies of Chang 6 oil-bearing formation in the study area,and underwater channel sand bodies should be the main destinations of exploration of this area in the near future.