石油与天然气地质 ›› 2021, Vol. 42 ›› Issue (5): 1112-1123.doi: 10.11743/ogg20210509

• 油气地质 • 上一篇    下一篇

鄂尔多斯盆地姬塬地区延长组6段油藏差异成藏因素

时保宏1,2(), 秦馨雨1, 张才利3, 刘文4, 刘刚3, 史婵媛3, 张雷3, 勇子树1   

  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. 中国石油 长庆油田分公司 勘探开发研究院, 陕西 西安 710018
    4. 中国石油 长庆油田分公司 勘探事业部, 陕西 西安 710018
  • 收稿日期:2020-07-06 出版日期:2021-10-28 发布日期:2021-10-26
  • 作者简介:时保宏(1970-), 男, 博士、教授, 石油地质。E-mail: bh.sh@163.com
  • 基金资助:
    国家科技重大专项(2017ZX05039-001)

Insights on factors causing differential enrichment of Chang 6 Member in Jiyuan area, Ordos Basin

Baohong Shi1,2(), Xinyu Qin1, Caili Zhang3, Wen Liu4, Gang Liu3, Chanyuan Shi3, Lei Zhang3, Zishu Yong1   

  1. 1. College of Earth Sciences & Engineering, Xi'an Shiyou University, Xi'an, Shaanxi 710065, China
    2. Provincial Key Lab of Hydrocarbon Accumulation Geology, Xi'an, Shaanxi 710065, China
    3. Exploration and Development Research Institute of Changqing Oilfield Branch Company Ltd., PetroChina, Xi'an, Shaanxi 710018, China
    4. Exploration Department of Changqing Oilfield Co., PetroChina, Xi'an, Shaanxi 710018, China
  • Received:2020-07-06 Online:2021-10-28 Published:2021-10-26

摘要:

延长组6段(长6段)是鄂尔多斯盆地姬塬地区石油勘探的重要目的层。其油层埋深大、油-水关系复杂,油藏在垂向和平面分布上具有明显的差异性。利用大量岩心观察、铸体薄片和试油等资料,结合包裹体和原油生物标志化合物等地化资料,对姬塬地区长6段油藏地质特征进行了对比分析,并对油藏的差异富集因素进行探讨。研究结果表明,油源条件、砂体类型和储层物性是控制长6段油藏差异富集的关键因素。优质烃源岩、优势砂体和相对高渗区3个有利因素的叠加效应,形成了长6段油藏的富集区。受沉积环境影响,垂向上,姬塬地区长6段的3个亚段中长61亚段砂体厚度大,砂体类型以Ⅰ类为主,横向分布稳定,延伸较远,储层喉道半径较大,物性较好,油气富集程度最高;平面上,东、西部砂体具有厚度大、类型好、泥质夹层少和物性好的特征,加之区内烃源岩厚度大,供烃能力强,是源-储配置有利的成藏区带。姬塬地区中部砂体厚度虽大,但单层砂体薄且层数多,泥质夹层多,储层非均质性强,区内烃源岩厚度较薄。因此,中部储层物性虽较好,但区内储层含油性较差,以产水井为主。

关键词: 成藏因素, 差异富集, 油藏分布, 长6段, 延长组, 姬塬地区, 鄂尔多斯盆地

Abstract:

The 6th Member of Yanchang Formation (Chang 6 Member) is a key target layer for petroleum exploration in Jiyuan area, Ordos Basin.The reservoirs of Chang 6 Member are characterized by large burial depth and complex oil-water contact, resulting in markedly differential distribution both vertically and laterally.In order to find out the factors causing the differential enrichment of reservoirs in the study area, we make a comparative analysis of the geological conditions based on core and casting thin section observation, formation testing, and geochemical analysis of inclusions and crude oil biomarker compounds.The results show that the key factors of differential enrichment are the source rock quality, type of sand bodies and physical properties of reservoirs.As a result, high-quality source rocks, favorable sand bodies and relatively high permeability, work in unison to generate the enriched zone of Chang 6 reservoirs.In the particular sedimentary environment, vertically speaking, the Chang 61 submember with the thickest sand bodies dominated by Type Ⅰ and in steady lateral distribution, features larger radius of throats, better physical properties, high hydrocarbon abundance in the reservoirs; in planar view, sand bodies developed in the east and west of the study area, feature large thickness, favorable type, less argillaceous interlayers, and better physical properties.In addition, source rocks have large thickness and strong hydrocarbon generation capacity, so they are favorable play fairways with favorable source-reservoir configuration.While the sand bodies of large thickness in central Jiyuan area are characterized by multiple beds thin for each single, multiple argillaceous interlayers, strong reservoir heterogeneity, and the source rocks are thin, so although the reservoirs therein are of better physical properties, their oil-bearing properties are poor, with most wells producing water.

Key words: enrichment factor, differential enrichment, reservoir distribution, Chang 6 Member, Yanchang Formation, Jiyuan area, Ordos Basin

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