石油学报 ›› 2015, Vol. 36 ›› Issue (5): 606-611,640.DOI: 10.7623/syxb201505010

• 油田开发 • 上一篇    下一篇

缝洞型碳酸盐岩油藏酸蚀裂缝导流能力模拟与分析

彭瑀1, 李勇明1, 赵金洲1, 王雷2, 张烨2, 罗攀3   

  1. 1. 西南石油大学油气藏地质及开发工程国家重点实验室 四川成都 610500;
    2. 中国石油化工股份有限公司西北油田分公司工程技术研究院 新疆乌鲁木齐 830011;
    3. 延长石油集团研究院 陕西西安 710054
  • 收稿日期:2014-11-29 修回日期:2015-03-03 出版日期:2015-05-25 发布日期:2015-06-10
  • 通讯作者: 赵金洲,男,1962年10月生,1982年毕业于西南石油学院采油工程专业,1985年获西南石油学院油气田开发工程专业硕士学位,现为西南石油大学校长、教授、博士生导师,主要从事油气田开采和增产新技术新理论的研究。Email:zhaojz@swpu.edu.cn
  • 作者简介:彭瑀,男,1988年12月生,2011年获西南石油大学石油工程专业学士学位,现为西南石油大学石油与天然气工程学院博士研究生,主要从事油气田增产改造理论与技术方面的研究工作。Email:pengyu_frac@foxmail.com
  • 基金资助:

    国家自然科学基金重大项目(No.51490653)和国家重点基础研究发展计划(973)项目(2013CB228004)资助。

Simulation and analysis of acid-etched fracture conductivity of fracture-cavity carbonate reservoirs

Peng Yu1, Li Yongming1, Zhao Jinzhou1, Wang Lei2, Zhang Ye2, Luo Pan3   

  1. 1. State Key Laboratory of Oil & Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Sichuan Chengdu 610500, China;
    2. Research Institute of Engineering & Technology, Sinopec Northwest Oilfield Company, Xinjiang Urumqi 830011, China;
    3. Research Institute of Yanchang Petroleum(Group) Company Limited, Shaanxi Xi'an 710054, China
  • Received:2014-11-29 Revised:2015-03-03 Online:2015-05-25 Published:2015-06-10

摘要:

缝洞型碳酸盐岩油藏是指以天然溶蚀孔、洞和多尺度裂缝作为储渗介质的一类复杂油藏。该类油藏的基质致密,一般都需要通过酸压改造来提高单井产量。但目前关于缝洞型油藏导流能力沿缝长方向分布的研究还不完善,现有的酸蚀裂缝导流能力模型都基于固定网格或复杂流场,其不能模拟排量变化或考虑缝洞对导流能力分布的影响。本文首先分析了缝洞型油藏与常规油藏酸压技术目标的差异,然后在经典模型的基础上建立了基于动网格的酸蚀裂缝导流能力数值模型。利用该模型进行了敏感性分析,认为采用高、低浓度组合的方式可以提高有效酸蚀裂缝长度和酸液利用效率;在酸压裂缝遇洞后,需要以其与井筒的距离远近作为依据,选择采用续注关井返排、停泵关井返排和停泵立即返排等不同的应对方案。该研究对于优化缝洞型碳酸盐岩油藏的酸压设计和提高酸液利用效率具有一定指导意义。

关键词: 缝洞型油藏, 碳酸盐岩油藏, 酸压, 导流能力, 数值模拟, 施工排量, 酸液浓度

Abstract:

Fracture-cavity carbonate reservoirs are a kind of complex reservoirs with natural solution pores, holes and multi-scale fractures as accumulation-permeation media. This kind of reservoirs is usually characterized by tight matrix, and it is always required to improve single-well production through acid fracturing treatment. However, there is no existing complete research on the conductivity distribution of fracture-cavity reservoir along the fracture length direction, while the current acid-etched fracture conductivity models are all based on fixed mesh or complex flow field, unable to simulate displacement change or the influences of fracture cavity on conductivity. At first, this study analyzed the differences in acid fracturing technical target between fracture-cavity reservoirs and conventional reservoirs. Then, a numerical conductivity model of fracture-cavity reservoir on dynamic mesh was built based on classical models. The sensitivity analysis was carried out using this model. It is considered that the length of effective etched fractures and utilization rate of acid can be enhanced through the combination of high and low concentrations; when the acid-etched fracture encounters with a cave, the corresponding measures such as continuous injection-well shut-flow back, pump off-well shut-flow back and pump off-instant flow back, should be selected on a basis of the distance from the shaft. This study is of a certain guiding significance to optimize the design of acid fracturing of fracture-cavity carbonate reservoirs and improve the utilization rate of acid fluid.

Key words: fracture-cavity reservoir, carbonate reservoir, acid fracture, conductivity, numerical simulation, operational displacement, acid concentration

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