石油与天然气地质2026，Vol.47Issue(2)：460-474,15.DOI:10.11743/ogg20260207
渤海湾盆地沧东凹陷枣园油田古近系孔店组储层特征与致密化过程
Characteristics and tightening process of reservoirs in the Paleogene Kongdian Formation,Zaoyuan oilfield,Cangdong Sag,Bohai Bay Basin
刘凤和 1钱其豪 2宋弘明 3鲜成钢 3宗杰 4赵明 4刘东成 4伍坤宇 5刘睿 6吴松涛2
作者信息
- 1. 中国石油大学(北京),北京 102249||中国石油 大港油田分公司,天津 300280
- 2. 中国石油 勘探开发研究院,北京 100083
- 3. 中国石油大学(北京),北京 102249
- 4. 中国石油 大港油田分公司,天津 300280
- 5. 中国石油 青海油田分公司,甘肃 敦煌 736202
- 6. 西南石油大学 地球科学与技术学院,成都 四川 610500
- 折叠
摘要
Abstract
The Paleogene Kongdian Formation in the Zaoyuan oilfield within the Cangdong Sag of the Bohai Bay Basin,a faulted lacustrine basin,contains tight-sand reservoirs.However,there remains a lack of consensus on the relationship between the reservoir tightening and hydrocarbon charging.In this study,we examine representative samples from the 2nd member of the Kongdian Formation(also referred to as the Kong 2 Member)in the Zaoyuan oilfield.By integrating thin section observations,field emission scanning electron microscopy(FE-SEM),high-pressure mercury injection(HPMI),low-temperature nitrogen adsorption,and fluid inclusion analysis,we reconstruct the reservoir tightening process and analyze its impact on hydrocarbon accumulation.The results reveal the presence of three types of microfacies in the Kong 2 Member:channel,lobe,and levee.Reservoirs in this member consist primarily of fine-grained sandstones and siltstones,with pores dominated by primary intergranular pores and secondary dissolution pores.The reservoir tightening in the Kong 2 Member is governed by sedimentary components and textural maturity,along with the imprint of diagenesis.The tightening process can be divided into three stages:moderate compaction-induced porosity reduction,weak to moderate dissolution-induced porosity increase,and weak to moderate cementation-induced porosity reduction.Reservoirs of varying sedimentary microfacies show differential reservoir tightening characteristics.Compared to sandstone reservoirs of the lobe microfacies,those of the levee and channel microfacies exhibit higher degrees of cementation-induced tightening due to a more open diagenetic chemical reaction system.Overall,in the Kong 2 Member,reservoir tightening occurred earlier than hydrocarbon accumulation.Variation in the tightening intensity across different sedimentary microfacies of sandstones is identified as the primary cause of the differential hydrocarbon enrichment.Additionally,natrolite cementation formed after hydrocarbon charging can be observed locally.关键词
堤坝/朵体/深水水道/成岩作用/致密砂岩/孔店组/沧东凹陷/渤海湾盆地Key words
levee/lobe/deep-water channel/diagenesis/tight sandstone/Kongdian Formation/Cangdong Sag/Bohai Bay Basin分类
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刘凤和,钱其豪,宋弘明,鲜成钢,宗杰,赵明,刘东成,伍坤宇,刘睿,吴松涛..渤海湾盆地沧东凹陷枣园油田古近系孔店组储层特征与致密化过程[J].石油与天然气地质,2026,47(2):460-474,15.
