摘要
新近系沙湾组是准噶尔盆地车排子凸重要的油气富集层位。在对沙湾组油藏分布、油性进行分析的基础上,结合前人研究成果,将沙湾组油气的成藏过程分为两个阶段:古油藏阶段和次生调整阶段,并分别论述各阶段的输导体系及其时空组合关系。古油藏阶段主要发育白垩系底部不整合面和红车断裂带同生逆断层组成的输导体系,研究区北部的白垩系底面不整合有效输导厚度大,向西逐渐减薄为0;同生逆断裂是控制红车断裂带发育演化的主干断裂,形成时间早,断距大。次生调整阶段则发育有沙湾组一段底部砂体、红车断裂带后生正断层、艾卡断裂带、凸起之上新近系张性断裂组成的输导体系,沙一段砂体在凸起之上分布广泛,沉积连续而稳定,呈"毯状"自南向北逐渐减薄,做为最底部的砂体层,是该阶段主要的横向输导体系;新近纪末期红车断裂带发育了一期正断裂,断裂活动强度大且规模较大,凸起之上则发育一期与红车断裂带后生正断层同期形成的新近系正断层,凸起南部四棵树凹陷的艾卡断裂活动期长、断距大、延伸远,这些断层构成了次生调整阶段的纵向输导体系。利用运移通道指数(MPI)及颗粒荧光定量分析(QGF)分别预测了白垩系底不整合面及沙一段毯状砂体的优势运移区。平面上将运移通道指数在0.3以上的区域作为不整合输导层的优势运移区,将QGF指数值大于3.8的区域作为沙一段毯状砂体的优势运移区。通过分析多套输导体系在油气成藏的不同阶段的空间组合以及油气分布与输导体系的关系,明确了输导体系对油气成藏的控制作用,预测609井区具备油气输导的有利条件,可作为下步勘探目标区。
The Neogene Shawan formation is one of the important hydrocarbon-rich strata in Chepaizi salient. Based on the analysis ofreservoir distribution and oil nature, coupled with results of previous studies, the accumulation process of Shawan hydrocarbon isdivided into two stages: paleoreservoir stage and secondary adjustment stage. The migration pathway systems and their spatialcombinations are discussed. In the paleoreservoir stage, the Cretaceous basal unconformity and syngenetic reverse faults composed themigration pathway in the Hongche fault zone formed system. The effective thickness of migration zone in the unconformity is thicker in the northern and estern part of the research area while pinching out toward the west; syngenetic reverse faults controlling the formationand development of Hongche fault zone have large fault displacements and beneficial for hydrocarbon migration. In the secondaryadjustment stage, sandstone in the first member of Shawan Formation (N1s), epigenetic normal faults in Hongche fault zone, Aika faultzone and Neogene normal fault in Chepaizi salient formed the migration pathway system, the N1s sandstone salient with continuous andstable deposition distributes in the Chepaizi, blanket-like pinching out from the south to the north. As the lowest sandstone bed, theblanket-liked sandstone is the most important transverse migration bed in this stage. Large-scale normal faults in the Hongche faultzone were developed in the late Neogene; Normal faults in the Chepaizi salient were also developed in the same period; the Aika faultzone continued to be active in the Neogene, all of which formed the vertical migration pathway system in the secondary adjustmentstage. The dominant migration zones of the Cretaceous unconformity and blanket-liked sandstone migration beds are predicted usingmigration pathway index (MPI) and Quantitative Grain Fluorescence (QGF). In the plane, area with MPI greater than 0.3 is regarded asthe dominant migration zone of unconformity migration bed and the area with QGF greater than 3.8 is regarded as the dominantmigration zone of N1s blanket-like sandstone. Based on the analysis of spatial combination of migration pathway systems in differentstages and the relationship between hydrocarbon distribution and migration pathway systems, the control action of migration pathwaysystem on hydrocarbon accumulation is confirmed prospecting to have. The well P609 area is predicted to have advantages ofhydrocarbon migration, which can be regard as the exploration target of further prospecting.
作者
王坤
任新成
马奎
黄擎宇
石书缘
高建文
WANG Kun;REN Xincheng;MA Kui;HUANG Qingyu;SHI Shuyuan;GAO Jianwen(Research Institute of Petroleum Exploration and Development, PetroChina, Beijing 100083, China;Western New Prospect Research Center of Shengli oilfield, SINOPEC, Dongying 257000, China;School of Earth Sciences and Engineering, Xi’an Shiyou University, Xi’an 710065, China)
出处
《高校地质学报》
CAS
CSCD
北大核心
2016年第2期350-359,共10页
Geological Journal of China Universities
基金
国家科技重大专项"准噶尔盆地碎屑岩层系大中型油气田形成规律与勘探方向"(2011ZX05002-002)资助
关键词
车排子凸起
输导体系
优势运移区
油气成藏
Chepaizi salient
migration pathway system
dominant migration zone
hydrocarbon accumulation
