新疆石油地质 ›› 2020, Vol. 41 ›› Issue (2): 237-242.doi: 10.7657/XJPG20200217

• 应用技术 • 上一篇    下一篇

基于黏土矿物分析的低电阻率油层识别

冯渊1a,1b, 秦康2, 李二党3, 张仁燕1b,1c   

  1. 1. 中国石油 长庆油田分公司 a.科技处;b.低渗透油气田勘探开发国家工程实验室;c.勘探开发研究院,西安 710021
    2. 中国石油 长庆油田分公司 第十一采油厂,甘肃 庆阳 745000
    3. 中国石油 长庆油田分公司 第一采油厂,陕西 延安 716009
  • 收稿日期:2019-01-29 修回日期:2019-07-23 出版日期:2020-04-01 发布日期:2020-04-07
  • 作者简介:冯渊(1985-),男,甘肃静宁人,工程师,硕士,油气田开发地质,(Tel)029-86594279(E-mail)fengyuan8501@163.com
  • 基金资助:
    国家科技重大专项(2016ZX05050)

Identification of Low-Resistivity Oil Layers Based on Clay Mineral Analysis

FENG Yuan1a,1b, QIN Kang2, LI Erdang3, ZHANG Renyan1b,1c   

  1. 1. PetroChina Changqing Oilfieid Company, a.Department of Science and Technology; b.National Engineering Laboratory for Exploration and Development of Low Permeability Oil/Gas Fields; c.Research Institute of Exploration and Development, Xi’an, Shaanxi 710021, China
    2. No.11 Oil Production Plant, Changqing Oilfield Company, PetroChina, Qingyang, Gansu 745000, China
    3. No.1 Oil Production Plant, Changqing Oilfield Company, PetroChina, Yan’an, Shaanxi 716009, China
  • Received:2019-01-29 Revised:2019-07-23 Online:2020-04-01 Published:2020-04-07

摘要:

鄂尔多斯盆地镇北油田西部区块长81油层电阻率明显小于东部区块,且局部存在低电阻率油层,使得西部区块的油、水层难以识别,给油田开发带来一定难度。基于铸体薄片、X射线衍射、扫描电镜、压汞、测井解释等数据分析,对镇北油田长81油层黏土矿物特征及其对油层电阻率的影响进行了研究。结果表明,黏土矿物对镇北油田西部区块低电阻率油层的控制作用主要体现在3个方面:一是黏土矿物的附加导电作用,阳离子交换能力较强的伊利石和绿泥石含量高,其附加导电作用较强;二是黏土矿物对水分子的吸附作用,水分子吸附能力强的绿泥石含量高,容易形成水膜而增加导电能力;三是较高含量的黏土矿物使储集层孔隙结构更为复杂化,以致束缚水饱和度增高。对于此类高黏土矿物含量类型的低电阻率油层,通过测井曲线的响应特征,建立储集层黏土矿物含量的计算模型,结合生产情况拟合低电阻率油层的产水率,提高了低电阻率油层的识别精度。

关键词: 鄂尔多斯盆地, 镇北油田, 延长组, 低电阻率油层, 黏土矿物, 产水率

Abstract:

There are distinct differences between the resistivity of Chang 81 reservoir of the western and eastern blocks in Zhenbei Oilfield, Ordos basin. The reservoir resistivity in the western block is significantly lower than that of the eastern block of Zhenbei oilfield and there are low resistivity oil layers in local areas. As a result, it is hard to identify oil and water layers in the western block, which brings difficulties for oilfield development. Based on the data of cast thin section, X-ray diffraction, SEM, mercury injection and logging interpretation, the characteristics of clay minerals and their effects on the resistivity of Chang 81 oil reservoir in Zhenbei oilfield are studied in this paper. The results show that the controls of clay minerals on low-resistivity oil layer in western Zhenbei oilfield are mainly manifested in three aspects. The first is the additional conductivity of clay minerals—the contents of illite and chlorite with relatively strong cation exchange capacity are high in the reservoir of the western block, leading to stronger additional conductivity. The second is the adsorption of water molecules to clay minerals—the content of chlorite with strong adsorption capacity is high, so it is easy to form water film and increase electric conductivity. Thirdly, the relatively high contents of clay minerals make the pore structures of the reservoir more complicated, which increases irreducible water saturation. For this kind of low-resistivity oil layers with high clay mineral content, a model is established to calculate the clay mineral content in reservoir through analyzing the response characteristics of logging curves. Combining with production status, the water productivity of low-resistivity oil layer is eventually matched and finally the identification accuracy of low-resistivity oil layer is improved.

Key words: Ordos basin, Zhenbei oilfield, Yanchang formatioan, low resistivity oil layer, clay mineral, water productivity

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