地学前缘 ›› 2023, Vol. 30 ›› Issue (6): 351-364.DOI: 10.13745/j.esf.sf.2023.2.27

• 海相深层-超深层碳酸盐岩油气藏开采数值模拟 • 上一篇    下一篇

深层碳酸盐岩缝洞介质应力敏感特性研究

孙科1,2(), 刘慧卿1,*(), 王敬1, 刘人杰1, 冯亚斌1, 康志江3, 张允3   

  1. 1.中国石油大学(北京) 石油工程教育部重点实验室, 北京 102249
    2.中国石油集团工程技术研究院有限公司, 北京 102206
    3.中国石化石油勘探开发研究院, 北京 100083
  • 收稿日期:2023-01-15 修回日期:2023-02-14 出版日期:2023-11-25 发布日期:2023-11-25
  • 通信作者: * 刘慧卿(1966—),男,博士,教授,博士生导师,主要从事油气田开发工程研究工作。E-mail: liuhq110@126.com
  • 作者简介:孙科(1995—),男,博士,工程师,主要从事石油与天然气工程研究工作。E-mail: sunkedr@cnpc.com.cn
  • 基金资助:
    国家自然科学基金企业创新发展联合基金项目“海相深层油气富集机理与关键工程技术基础研究(U19B6003);国家自然科学基金面上项目(51974331);国家自然科学基金面上项目(52004303)

Stress sensitivity characteristics of deep carbonate fractured porous media

SUN Ke1,2(), LIU Huiqing1,*(), WANG Jing1, LIU Renjie1, FENG Yabin1, KANG Zhijiang3, ZHANG Yun3   

  1. 1. MOE Key Laboratory of Petroleum Engineering, China University of Petroleum (Beijing), Beijing 102249, China
    2. CNPC Engineering Technology R & D Company Limited, Beijing 102206, China
    3. Petroleum Exploration and Production Research Institute, SINOPEC, Beijing 100083, China
  • Received:2023-01-15 Revised:2023-02-14 Online:2023-11-25 Published:2023-11-25

摘要:

深层缝洞型碳酸盐岩油藏具有埋藏环境复杂、作用机制复杂、储集空间复杂3大特征,这使得这类油藏难以有效动用和高效开发。为了揭示深层高温、高压和高应力条件下碳酸盐岩缝洞储层的应力敏感特征,本文基于改进的储层应力敏感性流动实验方法,构建了具有不同裂缝发育程度、不同裂缝粗糙度、不同孔洞类型以及不同充填类型的碳酸盐岩缝洞介质模型,深入探究了不同缝洞发育特征对碳酸盐岩介质应力敏感性的影响规律。研究结果表明:(1)深层条件下碳酸盐岩缝洞介质普遍存在“应力敏感滞后效应”,孔隙压力恢复阶段的实测绝对渗透率均小于孔隙压力降低阶段的绝对渗透率;(2)具有相同发育特征的碳酸盐岩缝洞介质的最大渗透率损害率与不可逆渗透率损害率之间存在较好的相关性,即最大渗透率损害率越大,相应的不可逆渗透率损害率也越大;(3)不同充填型碳酸盐岩缝洞介质的应力敏感效应表现出明显的孔隙型介质特征,孔隙压力降低和恢复阶段的渗透率损害率普遍偏小;(4)裂缝是影响碳酸盐岩复合介质应力敏感程度的主控发育结构,裂缝型介质的应力敏感效应明显强于孔洞型介质;(5)随着裂缝数量和形态展布复杂性的增加,深层条件下碳酸盐岩缝洞介质的应力敏感性明显减弱,而溶蚀孔洞和溶洞的存在进一步减弱了复合介质的应力敏感效应。本研究阐明了深层条件下不同发育特征碳酸盐岩缝洞介质的应力敏感特性及其存在的显著差异,为深层碳酸盐岩缝洞型油藏开发技术政策的制定提供了理论依据。

关键词: 深层, 碳酸盐岩, 缝洞介质, 发育特征, 应力敏感

Abstract:

The deep, vuggy, fractured porous carbonate reservoirs have three main characteristics, namely complex burial environment, rock-fluid interaction and storage space, which hinders the effective reservoir utilization and development. In order to reveal the stress sensitivity characteristics of this reservoir type under high temperature, pressure and stress conditions, several porous media models with different fracture development, fracture roughness and pore/filling type were constructed using an improved test method for stress sensitivity evaluation; the impacts of different porosity development characteristics on the stress sensitivity of carbonate fractured porous media with vuggy porosity were investigated in depth. Study results show that (1) the effect of stress sensitivity hysteresis generally exists at depth in the studied media, and the measured absolute permeability in the pore-pressure recovery stage is always smaller than in the pressure reduction stage. (2) There is a good positive correlation between the maximum and irreversible permeability-loss ratios for the studied media with similar porosity development characteristics. (3) The stress sensitivity performance of the studied media with different filling types is consistent with that of porous media, with small permeablity-loss ratios for both pore-pressure reduction and recovery stages. (4) Fractures are the main structural control factor affecting the stress sensitivity of the studied media, and the stress sensitivity performance of fractured media is significantly stronger compared to vuggy media. (5) With the increase of fractures and complexity of media morphology, the stress sensitivity of the studied media decreases significantly, while the presence of dissolved vugs and caves causes further reduction in stress sensitivity. This study clarifies the stress sensitivity characteristics and major differences between carbonate vuggy fractured porous media with different porosity developmental characteristics at depth, and provides a theoretical basis for reservoir development decision making.

Key words: deep formations, carbonate rocks, fractured-vuggy media, development characteristics, stress sensitivity

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