摘要
【目的】沥青填隙物作为石油或天然气残留在烃源岩或储层中的烃类有机质,无论其形成还是演化均与油藏的演化史密切相关,是油气成藏及改造过程的重要标志。前人围绕储层内沥青组分的类型、成因及热演化程度等方面开展了诸多分析,但沥青对储层制约机制仍不明确。【方法】以塔北西部英买467井区白垩系巴西改组储层为例,借助铸体薄片、荧光薄片、激光拉曼实验,结合测井参数识别,探讨沥青与油气藏期次的关系,查明不同沥青类型对储层质量的影响。【结果】(1)依照主要组分与形成期次,研究层段内沥青填隙物分为两类:Ⅰ类以粒间充填为主,荧光显微镜下多呈黄褐色和褐黑色,主要组分为油质、沥青质沥青,沥青反射率多大于1%;Ⅱ类以沥青衬边的形式分布于孔隙边缘,荧光显微镜下多呈橙色和蓝(白)色,以胶质沥青为主要组分,沥青反射率偏低,介于0.42%~0.79%。(2)英买467井区Ⅰ类沥青与黄山街组烃源岩原油充注有关,受控于舒善河底不整合面和英买467同沉积断层,主要分布于巴西改组块状砂岩段Ⅲ-1砂组顶部和巴西改组薄层砂岩段Ⅱ砂组;Ⅱ类沥青与恰克马克组烃源岩油气有关,受砂体厚度影响,主要分布在块状砂岩段Ⅲ-2砂组。(3)Ⅰ类沥青对储层改造作用强,占据部分孔隙空间;Ⅱ类沥青对储层孔隙度影响较小。【结论】查明塔北西部英买467井区白垩系巴西改储层沥青填隙物类型,明确不同沥青类型对储层质量的影响,对深化研究区地质认识具有现实意义。
[Objective]As hydrocarbon organic matter,oil or natural gas remains in source rocks or reservoirs,and the formation and evolution of bitumen interstitials are closely related to the evolution history of oil reservoirs.It is an important symbol of oil and gas accumulation and transformation processes.Previous studies have conducted many analyses on the types,genesis,and thermal evolution of bitumen components in reservoirs,but the restriction mecha⁃nism of bitumen on reservoirs is still unclear.[Methods]This study takes the Cretaceous Baxigai Formation reservoir in the Yingmai 467 well block in the west of Tabei as an example.With the help of casting thin sections,fluorescent thin sections,and laser Raman experiments,combined with logging parameter identification,the relationship be⁃tween bitumen and oil and gas reservoir stages was discussed,and the influence of different bitumen types on reser⁃voir quality was identified.[Results](1)Based on the main components and formation stages,the bitumen intersti⁃tial materials in the study section are divided into two categories;type I is mainly intergranular filling,and most are yellow-brown and brown-black under the fluorescence microscope.The main components are oily and bituminous bitu⁃men,and the bitumen reflectivity is more than 1%.Type II is distributed on the edge of the pore in the form of bitu⁃men lining.Under the fluorescence microscope,it is mostly orange and blue(white)in color,with colloidal bitumen as the main component.The bitumen reflectivity is low,ranging from 0.42%-0.79%.(2)The bitumen interstitial ma⁃terial in Yingmai 467 well block is mainly type I bitumen.Because the oil and gas in the source rock of the Huang⁃shanjie Formation migrated through the unconformity at the bottom of the Shushanhe Formation,the fault was filled into Brazilian reorganized massive sand layer 2 and the Brazilian reorganized thin sand layer,and gas washing oc⁃curred.Type II bitumen was precipitated by retrograde condensation from the source rock oil and gas of the second phase of the Qiakemake Formation along the Cretaceous bottom and the Yingmai 7 fault zone into the Baxigai Forma⁃tion.It was affected by the thickness of the sand body and mainly distributed in the first layer of massive sand.(3)Type I bitumen has a strong effect on reservoir reconstruction and occupies part of the pore space;type II bitu⁃men has little effect on reservoir porosity[.Conclusions]It is of practical significance to find out the types of bitumen interstitials in the Cretaceous Baxigai Formation in Yingmai 467 well block in the west of Tabei,and to clarify the influence of different bitumen types on reservoir quality,which is of practical significance to deepen the geological understanding of the study area.
作者
陈思淼
韩登林
闫康
张吉振
马斌玉
杜皓
武倩宇
CHEN SiMiao;HAN DengLin;YAN Kang;ZHANG JiZhen;MA BinYu;DU Hao;WU QianYu(College of Earth Sciences,Yangtze University,Wuhan 430100,China;Laboratory of Reservoir Microstructure Evolution and Digital Characterization,Wuhan 430100,China;College of Resources and Environment,Yangtze University,Wuhan 430100,China)
出处
《沉积学报》
北大核心
2025年第6期2135-2150,共16页
Acta Sedimentologica Sinica
基金
国家自然科学基金项目(42072121)。
关键词
沥青砂岩
储层沥青
巴西改组
油气成藏
塔北隆起
bitumen sandstone
reservoir bitumen
Baxigai Formation
oil and gas accumulation
Tabei uplift
