石油与天然气地质 ›› 2025, Vol. 46 ›› Issue (5): 1485-1503.doi: 10.11743/ogg20250507

• 油气地质 • 上一篇    

三角洲与重力流砂体构型特征及其对油藏分布的控制——以鄂尔多斯盆地甘泉地区三叠系延长组长7油层组为例

李晓龙1,2(), 白玉彬1,2(), 陈珊珊3, 张刚4, 王聪娥5   

  1. 1.西安石油大学 地球科学与工程学院,陕西 西安 710065
    2.陕西省油气成藏地质学重点实验室,陕西 西安 710065
    3.延长油田股份有限公司勘探开发技术研究中心,陕西 延安 716000
    4.延长油田股份有限公司,陕西 延安 716000
    5.延长油田股份有限公司 下寺湾采油厂,陕西 延安 716100
  • 收稿日期:2025-06-07 修回日期:2025-09-17 出版日期:2025-10-30 发布日期:2025-10-29
  • 通讯作者: 白玉彬 E-mail:1326030435@qq.com;baiyubin@xsyu.edu.cn
  • 第一作者简介:李晓龙(2000—),男,硕士研究生,致密油、致密储层。E‑mail: 1326030435@qq.com
  • 基金项目:
    国家自然科学基金项目(42372155);陕西省自然科学基础研究计划项目(2025JC-YBQN-437);陕西省教育厅专项科研计划项目(24JK0603)

The configuration characteristics of delta and gravity flow sand bodies and their control on reservoir distribution—Chang 7 of Triassic Yanchang Formation in Ganquan area of Ordos Basin Oil layer group as an example

Xiaolong LI1,2(), Yubin BAI1,2(), Shanshan CHEN3, Gang ZHANG4, Cong’e WANG5   

  1. 1.School of Earth Sciences and Engineering,Xi’an Shiyou University,Xi’an,Shaanxi 710065,China
    2.Shaanxi Key Laboratory of Petroleum Accumulation Geology,Xi’an,Shaanxi 710065,China
    3.Exploration and Development Technology Research Center,Yanchang Oilfield Co. ,Ltd. ,Yan'an,Shaanxi 716000,China
    4.Yanchang Oilfield Co. ,Ltd. ,Yan’an,Shaanxi 716000,China
    5.Xiasiwan Oil Production Plant,Yanchang Oilfield Co. ,Ltd. ,Yan’an,Shaanxi 716100,China
  • Received:2025-06-07 Revised:2025-09-17 Online:2025-10-30 Published:2025-10-29
  • Contact: Yubin BAI E-mail:1326030435@qq.com;baiyubin@xsyu.edu.cn

摘要:

鄂尔多斯盆地甘泉地区三叠系延长组长7油层组发育三角洲前缘和重力流型致密油藏。为了明确不同沉积构型单元储集性能的差异及其对油藏分布与富集的控制机制。综合利用岩心、测井和生产动态资料,分析了长7油层组三角洲和重力流沉积内部单砂体构型特征、纵向接触关系和分布规律。研究了砂体构型对油藏分布的控制作用,结合试油、试采资料,建立了砂体构型油气成藏模式。研究结果表明:①长7油层组纵向上主要发育连续叠加型、间隔叠加型、薄互层型和单层型4种砂体构型,横向上发育稳定型、摆动型和迁移型3种砂体构型。②纵向上长71油层亚组主要发育连续叠加型,间隔叠加型次之;长72油层亚组主要发育间隔叠加型,薄互层型次之;长73油层亚组主要发育薄互层型和单层型。平面上连续叠加型和间隔叠加型主要分布于研究区北部和东北部;薄互层型主要发育在研究区中部向南一侧区域;单层型集中分布于南部地区。③储集性能最优的构型为连续叠加型和间隔叠加型,其中连续叠加型砂体的油气产量最高。④不同构型砂体与烃源岩的叠置关系存在差异,研究区砂体构型和烃源岩有4类源-储配置关系。长71油层亚组的连续叠加型油气富集程度最高;长72油层亚组的的间隔叠加型次之;长73油层亚组主要为烃源岩。长71油层亚组的连续叠加型砂体是下一步勘探的优选目标。

关键词: 源-储配置, 成藏模式, 油气分布规律, 砂体构型, 长7油层组, 甘泉地区, 鄂尔多斯盆地

Abstract:

The oil layer group of the 7th member of the Yanchang Formation (also referred to as the Chang 7 oil layer group) in the Ganquan area of the Ordos Basin hosts tight oil reservoirs of the delta-front and gravity-flow origin. This study aims to determine the differences in reservoir properties across varying sedimentary architectural units and the mechanisms through which these units control oil reservoir distribution and hydrocarbon enrichment. Using data from core observations, logging, and production performance, we analyze the architectural characteristics, vertical contact relationships, and distribution patterns of individual sand bodies within the deltaic and gravity-flow deposits in the Chang 7 oil layer group and explore the role of sand body architectures in controlling oil reservoir distribution. By combining data from well and production tests, we establish the hydrocarbon accumulation models associated with sand body architectures. The results indicate that the Chang 7 oil layer group contains four primary vertical sand body architecture types: continuously superimposed, intermittently superimposed, thinly interbedded, and single-layer types. Meanwhile, three lateral sand body architecture types are identified in the oil layer group: stable, swinging, and migrating. Vertically, the 1st subgroup of the Chang 7 oil layer group (also referred to as the Chang 71 oil layer subgroup) primarily exhibits the continuously superimposed sand body architecture, followed by the intermittently superimposed type. In contrast, the Chang 72 oil layer subgroup is dominated by the intermittently superimposed sand body architecture, succeeded by thinly interbedded type, while the Chang 73 oil layer subgroup predominantly contains the thinly interbedded and single-layer architectures. Literally, continuously and intermittently superimposed sand body architectures are widely seen in the northern and northeastern parts of the study area. In contrast, thinly interbedded architectures are mainly found in the south-central part of the study area, whereas the single-layer architecture is concentrated in the southern part. Continuously and intermittently superimposed sand bodies exhibit the most favorable reservoir properties, with the continuously superimposed sand bodies yielding the highest hydrocarbon production. Different types of sand body architectures exhibit varying superposition relationships with source rocks, with four types of source rock-reservoir configurations detected in the study area. The continuously superimposed sand bodies in the Chang 71 oil layer subgroup, among others, show the highest degree of hydrocarbon enrichment, followed by the intermittently superimposed sand bodies in the Chang 72 oil layer subgroup. The Chang 73 oil layer subgroup consists primarily of source rocks, while the continuously superimposed sand bodies in the Chang 71 oil layer subgroup are identified as the most promising target for future hydrocarbon exploration.

Key words: source-reservoir combination, accumulation mode, oil and gas distribution law, Sand body configuration, Chang 7 oil layer group, Ganquan area, Ordos Basin

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