塔里木盆地柯坪地区奥陶系鹰山组台内滩储层地层特征对比研究:以石灰窑和大湾沟剖面为例

A comparative study of sequence characteristics of intraplatform shoal reservoirs of Ordovician Yingshan Formation in Keping Area,Tarim Basin:Taking the Shihuiyao and Dawangou sections as examples

塔里木盆地碳酸盐岩礁滩体储层已经成为当前油气勘探的热点。以塔里木盆地柯坪地区石灰窑和大湾沟露头剖面为例,对奥陶系鹰山组台内滩地层的岩相组成及层序地层特征两个方面进行深入对比研究,并在此基础上分析了碳酸盐岩台内滩地层发育的控制因素。结果表明:(1)石灰窑地区和大湾沟地区鹰山组地层发育特征存在差异,石灰窑剖面以薄层颗粒灰岩与泥岩互层为主,大湾沟剖面为厚层状颗粒灰岩沉积;(2)石灰窑剖面层序特征表现为退积序列,而大湾沟剖面呈加积沉积样式,反映了海平面变化对不同微地貌区碳酸盐岩发育的控制作用不同,海平面的上升不利于地貌低处石灰窑地区灰岩的发育,而促进了地貌高点大湾沟地区灰岩的发育;(3)柯坪地区鹰山组沉积期的这两类台内滩地层沉积样式都有可能成为塔里木盆地油气勘探的有利目标。

Carbonate reef-bank reservoirs have been the current hot spot of oil and gas exploration in Tarim Basin.Taking the Shihuiyao and Dawangou outcrop profiles in Keping Area of Tarim Basin as the examples,the intraplatform shoal petrographic constitute and sequence stratigraphic features in Ordovician Yingshan Formation are deeply compared,based on which,the controlling factors of intraplatform shoal strata development are analyzed.The results show that：（1）There are some differences on Yingshan Formation development in Shihuiyao and Dawangou Areas.Shihuiyao section mainly develops thin grain limestone and mudstone,while Dawangou section deposits thick layered grain limestone.（2）The sequence characteristics of retrogradation in Shihuiyao Area and aggradation in Dawangou Area reflect that the sea-level change has different control actions in different microtopography fields.The sea-level rising inhibited the limestone development of Shihuiyao Area in the lower topography field,but promoted the limestone development of Dawangou Area in the high topography field.（3） The two intraplatform shoal sedimentary styles of Yingshan Formation in Keping Area may become the favorable targets for oil and gas exploration.