摘要
鄂尔多斯盆地西南部晚三叠世延长组碎屑岩储层油气成藏复杂,勘探开发难度大。文章在大量钻井岩心、薄片鉴定、测试分析及试油成果资料等系统分析基础上,研究了镇北地区延长组长4+5储层及成藏特征,揭示了成藏差异性,建立了成藏模式,分析了主控因素及富集规律。结果表明:盆地西南部发育了辫状河-三角洲沉积体系,西部发育三角洲平原亚相,东部为三角洲前缘亚相,东部储集砂岩结构成熟度和成分成熟度较西部高;储层孔隙度8%~15%,渗透率0.1×10^(-3)μm^(2)~1.0×10^(-3)μm^(2),储层整体为低孔、低渗储层,局部发育高孔高渗区,东部储层物性优于西部;认为优质烃源岩、生烃异常高压、有利沉积相、优质储层分布是油气富集成藏的主要控制因素;盆地西南部长4+5主要发育了岩性油藏和构造-岩性油藏两种油藏类型,东部为岩性油藏,西部发则以构造-岩性油藏为主,东、西部成藏特征差异性明显;东部烃源岩厚度大且生烃增压形成的异常压力值高,可形成连续性好、规模较大的油藏,而西部所形成的油藏规模小。
The clastic rock reservoir of Late Triassic Yanchang Formation in southwestern Ordos Basin is a challenging area for exploration and development due to its complexity.On the basis of systematic analy-sis of drilling core,thin section identification,test analysis and oil test results,this paper focuses on stud-ying the characteristics of Yanchang 4+5 reservoir and its accumulation,in order to reveal its accumula-tion difference,establish the accumulation model,and analyze the main controlling factors and enrichment rules.The results show that the southwest of the basin has the braided river delta depositional system,with the delta plain subfacies in the west and the delta front subfacies in the east,and the reservoir sandstone structural maturity and compositional maturity are higher in the east than in the west of the basin.The porosity of Chang 4+5 reservoir is 8%to 15%and permeability is 0.1×10^(-3)μm^(2)to 1.0×10^(-3)μm^(2).Except local high porosity and high permeability area,the whole reservoir is a low porosity and low perme-ability reservoir.In addition,the physical property of the eastern reservoir is better than that of the western one.It is considered that high quality source rock,abnormal high pressure of hydrocarbon generation,favorable sedimentary facies and high-quality reservoir distribution are the main controlling factors of oil and gas accumulation.In the southwest of the basin,Chang 4+5 mainly develops lithologic reservoirs and tectonic-lithologic reservoirs,with lithologic reservoirs mainly developed in the east and tectonic-lithologic reservoirs in the west.In the eastern part of the reservoir,the thickness of source rocks is large and the abnormal pressure generated by hydrocarbon generation is high,which has a potential to form a continuous and large oil pool.While in the western part,the scale of oil pool is smali.
作者
赵俊兴
彭帅杰
熊哲
高航
杨森
张忠义
王龙玉
赵亮
孙志强
阮昱
ZHAO Junxing;PENG Shuaijie;XIONG Zhe;GAO Hang;YANG Sen;ZHANG Zhongyi;WANG Longyu;ZHAO Liang;SUN Zhiqiang;RUAN Yu(Institute of Sedimentary Geology,Chengdu University of Technology,Chengdu,Sichuan 610059,China;The 3rd Gas Production Plant of Changqing Oilfield Company,Wushen County,CNPC 500063,China;Research Institute of Exploration and Development,Changqing Oilfield Company of PetroChina,Xi'an,Shanxi 710021,China)
出处
《矿物岩石》
CAS
CSCD
北大核心
2023年第1期106-117,共12页
Mineralogy and Petrology
基金
国家科技重大专项任务(项目编号:2017ZX05036-004-006)。
关键词
晚三叠世
储层特征
成藏模式
成藏差异性
鄂尔多斯盆地
Late Triassic
reservoir characteristics
accumulation model
reservoir accumulation differences
Ordos Basin