中国石油勘探 ›› 2025, Vol. 30 ›› Issue (2): 133-145.DOI: 10.3969/j.issn.1672-7703.2025.02.010

• 工程技术 • 上一篇    下一篇

庆城页岩油水力压裂试验场大斜度取心井裂缝描述与认识

曹炜1,2,马永宁2,3,孟浩2,3,拜杰1,2,张同伍1,2,鲜晟1,2,徐荣利1,2,赵国翔1,2,涂志勇1,2   

  1. 1 中国石油长庆油田公司油气工艺研究院;2 中国石油长庆油田公司油田开发事业部;3 低渗透油气田勘探开发国家工程实验室
  • 出版日期:2025-03-14 发布日期:2025-03-14
  • 通讯作者: 马永宁(1974-),男,甘肃甘谷人,硕士,2008 年毕业于西北大学,高级工程师,现主要从事油田开发研究与管理工作。地址:陕西省西安市未央区未央路151 号,邮政编码:710018。
  • 作者简介:曹炜(1999-),男,陕西西安人,硕士,2022 年毕业于中国石油大学(北京),工程师,现主要从事页岩油地质工程一体化工作。地址:陕西省西安市未央区明光路18 号,邮政编码:710018。
  • 基金资助:
    中国石油集团公司攻关性应用性科技专项“非常规储层改造关键技术研究”课题4“多类型页岩油个性化压裂技术与试验”(2023ZZ28YJ04) ;甘肃省联合基金“页岩油提高多簇裂缝扩展均衡程度技术研究”(24JRRM013) ;长庆油田分公司关键核心技术攻关项目“鄂尔多斯盆地页岩油渗流机理及有效开发关键技术研究”(2023DZZ04)。

Description and recognition of fractures in high-inclination coring well in Qingcheng shale oil hydraulic fracturing test site

Cao Wei1,2, Ma Yongning2,3, Meng Hao2,3, Bai Jie1,2, Zhang Tongwu1,2, Xian Cheng1,2, Xu Rongli1,2, Zhao Guoxiang1,2, Tu Zhiyong1,2#br#   

  1. 1 Oil & Gas Technology Research Institute, PetroChina Changqing Oilfield Company; 2 Development Department, PetroChina
    Changqing Oilfield Company; 3 National Engineering Laboratory for Exploration and Development of Low Permeability Oil & Gas Fields
  • Online:2025-03-14 Published:2025-03-14

摘要: 鄂尔多斯盆地庆城夹层型页岩油储层纵横向非均质性强,天然裂缝发育程度低,两向应力差较大,前期微地震认识表明双翼缝特征明显,裂缝形态较为单一。为进一步认识压后缝网形态与空间展布,在庆城页岩油水力压裂试验场开展了压裂井间大斜度井取心研究。通过CT 扫描、人工观察、显微镜成像和测井响应等多种手段,精细描述裂缝产状、缝面形态、充填特征等,对裂缝分类判别,同时结合染色支撑剂、泥浆示踪剂和空间距离与分布规律对压裂缝进行对应回归并开展综合分析。研究结果表明,不同类型裂缝特征存在差异,天然构造缝占比低,层理缝和压裂缝特征显著且二者占比高;压裂缝呈集群式分布且数量远超邻近压裂井对应段簇,同时存在局部扩展差异,但在应力差和方位影响下仍沿主应力方向延伸;压裂缝面明显支撑较少但岩屑支撑剂分布广泛且小粒径占比更高;示踪剂分析下各段对应的压裂缝条数是产油贡献的关键。本文通过综合多方法集成得到的裂缝识别、分类与回归方法可被其他非常规油气藏储层压后取心裂缝分析借鉴参考,取得的裂缝认识对下一步压裂优化具备一定指导意义。

关键词: 页岩油, 水力压裂试验场, 大斜度取心井, 压裂缝, 集群特征

Abstract: In Qingcheng area, Ordos Basin, the interlayered type shale oil reservoir is characterized by high heterogeneity in both lateral
and vertical directions, low degree of natural fracture development, and large two-direction horizontal stress difference. The preliminary microseismic data indicates that there is distinct feature of double-wing fractures, and the fracture pattern is relatively simple. In order to further understand the post-fracturing fracture pattern and spatial distribution, core section has systematically been taken in a high-inclination well in Qingcheng shale oil hydraulic fracturing test site. Using multiple methods such as CT scanning, core observation, microscopic imaging, and well logging data, the fine description of fracture occurrence, fracture surface morphology, and filling characteristics is conducted, and the fractures are classified and identified. Meanwhile, the dye proppant, mud tracer, and spatial distance and distribution law are used to perform corresponding regression and comprehensive analysis on hydraulic fractures. The study results show that different types of fractures show different characteristics. There is a low proportion of natural tectonic fractures, but a high proportion of bedding fractures and hydraulic fractures with significant characteristics. The hydraulic fractures are characterized by clustering features, and the fracture number is much higher than the corresponding stages in adjacent hydraulic fracturing wells. There are differences in fracture propagation in local areas, but they generally extend along the principal stress direction under the influence of stress difference and azimuth. There are few distinctly propped fractures, but the mud proppant is widely distributed in fractures with a higher proportion of small particles. The tracer analysis shows that the number of hydraulic fractures in each stage is the key contributor to oil production. The fracture recognition, classification, and regression
method obtained by integrating multiple methods can be used as a reference for post-fracturing coring fracture analysis of other unconventional oil and gas reservoirs, and the fracture understanding has certain guiding significance for further fracturing optimization.

Key words: shale oil, hydraulic fracturing test site, high-inclination coring well, hydraulic fracture, clustering feature

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