摘要
四川盆地开江–梁平海槽两侧的长兴组是重要的油气勘探层系,先后发现了龙岗、普光、元坝和罗家寨等多个大气田,但西北侧的勘探及研究程度相对较低。本文通过薄片和测录井等资料,分析研究川西北双鱼石地区上二叠统长兴组台地边缘相、开阔台地相的岩石学和沉积学特征与差异性。结果显示双鱼石地区长兴组岩性以生屑灰岩、泥晶灰岩以及晶粒白云岩为主。台地边缘相自然伽马平均约31 API,开阔台地相自然伽马平均值略大,约35 API。台缘带滩相厚度占比较大,开阔台地内部长二段发育台内洼地,其台内滩与滩间海沉积厚度占比均减小。台地边缘主要发育台缘滩,开阔台地内部整体以滩间海沉积为主,ST107井区、SYX133井区以及SY132井区主要发育台内滩沉积,面积约110 km2。
The Changxing Formation on both sides of the Kaijiang Liangping Trough in the Sichuan Basin is an important oil and gas exploration layer series. Multiple large gas fields such as Longgang, Pu-guang, Yuanba, and Luojiazhai have been discovered, but the exploration and research level on the northwest side of the trough is relatively low. This paper analyzes and studies the petrology and sedimentology characteristics and differences of platform margin facies and open platform facies of the Upper Permian Changxing Formation in Shuangyushi area, northwest Sichuan, through thin section and logging data. The results show that the lithology of the Changxing Formation in the Shuangyushi area is mainly composed of bioclastic limestone, micrite limestone, and crystalline dolomite. The average natural gamma ray of the platform edge facies is about 31 API, while the average natural gamma ray of the open platform facies is slightly higher, about 35 API. The thickness of the shoal facies in the platform margin zone accounts for a relatively large proportion, and the second member of the Changxing Formation within the open platform develops a depression within the platform. The proportion of sediment thickness in the shoal and inter shoal areas decreases. The edge of the platform mainly develops platform margin shoals, while the interior of the open platform is mainly composed of intertidal sea deposits. The ST107 well area, SYX133 well area, and SY132 well area mainly develop intra platform shoal deposits, covering an area of approximately 110 square kilometers.
出处
《地球科学前沿（汉斯）》
2023年第6期601-611,共11页
Advances in Geosciences
