苏里格气田S120区块山1-盒8沉积微相研究

Sedimentary microfacies research on the Shan1 and He8 in Block 120 of Sulige gas field

苏里格气田西区S120区块主力含气层段为山1-盒8段,为了查明该区砂体展布特征,笔者在资料收集和30余口钻井的测井曲线综合解释的基础上,对研究区内的沉积微相进行了详细的研究。研究结果认为:山1段发育曲流河沉积相,盒8段发育辫状河沉积相,优质储集砂岩主要形成于河道亚相;在山13段时期砂体发育较好,储集性能也较好,在山11、山12段时期河漫亚相占优势,砂体发育程度较低。盒8段具有显著辫状河沉积剖面结构特征,河道亚相占有明显优势,储集性能远优于山1段;从时序上看,从山1段到盒8段沉积相由曲流河过渡为辫状河,砂体厚度、砂地比随之增高;从平面分部看,区内较厚砂体多以南北走向展布,这与沉积相的分布是比较一致的;砂体厚度、发育规模以及砂体空间展布均受沉积相带的控制。

The main gas -bearing reservoir in Block 120 of Sulige gas field is Shanl and He8. In order to identify the sandbody distribution in this block, we studied the sedimentary microfacies based on sedimentology, paleogeography, and petrography and logging geology. It is suggested that the facies of Shanl segment belongs to precipitation facies of meandering river, while He8 segment belongs to braided river. The best reservoir sandstone is located in the river channel;In the period of Shanl3, the sandstone which is good for gas ＆ oil reservoir is better than Shanl 1 and Shanl2. With obvious structure features of braided deposition profile , He8 developed a lot of channel subfacies and its property for oil＆gas reservoir is far better than Shanl ;From the timing, Shanl is meandering river sedimentary while He8 is braided river sedimentary, with the thickness of sandbody and the proportion of sand increasing. From graphic division, thicker sandbody in this zone located from north to south, which is relatively consistent with sedimentary facies distribution. Sand body thickness, development scale and sand body space distribution are subject to the cloth of sedimentary facies control.