开江—梁平海槽东南缘长兴组沉积相及储层分布规律研究

发布时间：2018-04-05 05:26

  本文选题：开江-梁平海槽东南缘　切入点：长兴组　出处：《西南石油大学》2015年硕士论文

【摘要】：开江-梁平地区上二叠统长兴组作为区域内重要的天然气产层,受到了国内的广泛关注,但针对长兴组沉积相和储层的发育分布规律意见不一。本文以经典层序地层学、沉积学及储层地质学等为理论指导,以开江-梁平海槽东南缘上二叠统长兴组为对象,通过分析区内钻测井、岩心薄片、地震剖面及邻区露头资料,对长兴组进行地层划分,建立层序地层格架,并在格架内对长兴组沉积相及储层展开研究,厘清了长兴组储层发育与层序、沉积相的关系,确定了长兴组储层的发育分布规律。 根据岩石类型组合、沉积旋回等特征,研究区长兴组自下而上可划分为长一段(P3chl)、长二段(P3ch2)和长三段(P3ch3)。同时,通过岩心薄片、钻录测井和地震剖面等资料分析,长兴组可划分为两个均由海侵域(TST1)、TST2)和高位域(HST1、HST2)组成的Ⅱ型三级层序(SQ1、 SQ2),并建立三级层序地层格架。其中,TSTl、HST1、TST2-HST2分别与长一段、长二段、长三段对应,区域可对比性好。 结合岩心薄片与钻测井等资料对长兴组进行沉积相分析,以体系域为单元,等时动态地揭示了研究区长兴组沉积相(尤其礁滩相)的时空分布及演化。TST1时期,区内以开阔台地沉积为主,局部发育生屑滩,其后期台缘相带雏形形成；HST1时期,礁滩相大规模分布,台地边缘迅速沉积增厚,台缘相带演化成熟,台地内以开阔台地为主,局部发育生屑滩；TST2时期,继承了前期相带分布格局,但台缘礁滩相规模明显缩小,台地内以开阔台地为主,局部发育生屑滩；HST2早期,台缘礁仅五百梯地区有小规模分布,末期台缘带局部发育潮坪沉积,开阔台地演变为局限台地。 综合岩心薄片、测录井和物性资料等分析,长兴组主要发育生物礁相云岩或灰岩类、生屑滩相云岩或灰岩类、潮坪或礁坪或滩后坪晶粒云岩类溶蚀孔隙(洞)型储层,以云岩类储集性最佳,灰岩类次之。垂向上,长兴组储层主要发育于高位域中后期,与生物礁滩相沉积体系关系密切,主要分布在向上水体变浅的单体礁滩相沉积体系的中上部,溶蚀、云化作用强烈,孔洞发育好；而海侵域时期或在向上水体变深的单体礁滩相沉积体系中,溶蚀、云化程度低,以灰岩类储层为主,孔隙性较差。平面上,长兴组储层主要分布在台地边缘相带和台地内部,斜坡-海槽区储层不发育。根据储层类型、溶蚀云化程度及规模、优质储层数量及规模等指标,研究区可定性划分为4类长兴组储层发育区：溶蚀、云化作用强烈且规模较大的台缘礁滩相分布区属于Ⅰ类发育区,溶蚀、云化作用较强的台缘礁滩相或台内浅滩相分布区属于Ⅱ类发育区,溶蚀、云化较弱的台缘或台内浅滩相灰岩沉积区属于Ⅲ类发育区,而开阔台地或局限台地内非礁滩相灰岩沉积区属于Ⅳ类发育区。
[Abstract]:The Changxing formation of Upper Permian in Kaijiang-Liangping area, as an important natural gas layer in the region, has received extensive attention in China, but there are different opinions on the development and distribution of sedimentary facies and reservoirs in Changxing formation.Based on the theory of classical sequence stratigraphy, sedimentology and reservoir geology, and taking the upper Permian Changxing formation in the southeast margin of Kaijiang-Liangping trough as the object, this paper analyzes the drilling log, core slice, seismic profile and outcrop data of adjacent areas.The stratigraphic division of Changxing formation, the establishment of sequence stratigraphic framework, the study of sedimentary facies and reservoir of Changxing formation in the framework, the relationship between reservoir development and sequence and sedimentary facies of Changxing formation, and the distribution law of reservoir development in Changxing formation are clarified.According to the characteristics of rock type assemblage and sedimentary cycle, the Changxing formation in the study area can be divided from the bottom to the top into long first member P3chlang, long second member P3ch2) and Chang3 member P3ch3.At the same time, the Changxing formation can be divided into two types: type 鈪，

本文编号：1713415