石油与天然气地质 ›› 2020, Vol. 41 ›› Issue (6): 1288-1298.doi: 10.11743/ogg20200617

• 方法技术 • 上一篇    下一篇

致密油藏压裂水平井缝网系统评价方法——以准噶尔盆地吉木萨尔地区为例

陈志明(), 陈昊枢, 廖新维, 曾联波*(), 周彪   

  1. 中国石油大学(北京) 油气资源与探测国家重点实验室, 北京 102249
  • 收稿日期:2019-02-02 出版日期:2020-12-28 发布日期:2020-12-09
  • 通讯作者: 曾联波 E-mail:zhimingchn@cup.edu.cn;lbzeng@cup.edu.cn
  • 作者简介:陈志明(1989-),男,博士、副教授,非常规油气藏试井反演理论与动态分析技术方法。E-mail:zhimingchn@cup.edu.cn
  • 基金资助:
    国家自然科学基金项目(52074322);国家自然科学基金项目(U762210);国家科技重大专项(2016ZX05047004);北京市自然科学基金项目(3204052)

Evaluation of fracture networks along fractured horizontal wells in tight oil reservoirs:A case study of Jimusar oilfield in the Junggar Basin

Zhiming Chen(), Haoshu Chen, Xinwei Liao, Lianbo Zeng*(), Biao Zhou   

  1. State Key Laboratory of Petroleum Resources and Prospecting, China University of Petroleum(Beijing), Beijing 102249, China
  • Received:2019-02-02 Online:2020-12-28 Published:2020-12-09
  • Contact: Lianbo Zeng E-mail:zhimingchn@cup.edu.cn;lbzeng@cup.edu.cn

摘要:

压裂水平井缝网系统评价是致密油藏高效开发的关键。针对目前缺乏完善的评价方法这一现状,基于动态反演理论建立了一种致密油藏压裂水平井缝网系统评价方法。首先,基于致密油渗流特征和缝网形态,考虑了非均匀缝网和弱补给等复杂因素,推导了其试井数学模型。利用解析方法获得了其井底压力解,并建立了压裂水平井缝网系统评价方法。其次,为验证评价方法的可靠性,以准噶尔盆地吉木萨尔地区为例,开展了实例应用分析。结果表明,复杂缝网水平井流动阶段包括井筒储集效应和表皮效应阶段、裂缝双线性流、裂缝线性流、压裂改造区窜流、压裂受效区线性流和拟稳态流阶段。同时发现,经过压裂改造后,实例井附近形成了主裂缝和压裂改造区,主裂缝半长为135 m,导流能力为118.87×10-3 μm2;次裂缝网络储容比为6.30%~17.99%,压裂改造区渗透率为100.8×10-3 μm2。本次研究工作为致密油藏参数反演、压裂评价及动态监测提供了理论基础。

关键词: 试井模型, 动态反演, 缝网系统, 压裂水平井, 致密油, 吉木萨尔地区, 准噶尔盆地

Abstract:

Evaluation of fracture-network systems along fractured horizontal wells is vital to an efficient development of tight-oil reservoirs.Given the lack of efficient evaluation means, we propose a method based on the dynamic inversion theory for the evaluation of fracture networks along fractured horizontal wells in tight-oil reservoirs.To begin with, a mathematical model of well testing that takes into consideration the nonhomogeneous and insufficient fluid supply of the networks is developed based on seepage activities and fracture network geometry.The bottom pressure of wells is obtained through an analytical method from the mathematical model and then used to establish a method for evaluating the fracture-networks.Subsequently, a field application in Jimusar tight oil reservoirs in the Junggar Basin is performed to prove the reliability of the method.The results show that the flow stages in the fracture networks of horizontal wells in the reservoirs involve the wellbore storage and skin effects, fracture bilinear flow, formation linear flow as well as fluid channeling, linear and quasi-stable flow in stimulated areas.It is also found that after fracturing, networks composed of major hydraulic fractures with a half-length of 135 m and a conductivity of 118.87×10-3 μm2 are generated near wellbores.The storability of the minor fracture networks ranges between 6.30% and 17.99%, and the permeability of the stimulated areas is 100.8×10-3 μm2.This study provides a theoretical basis for research works or operations such as reservoir parameter inversion, fracturing evaluation and dynamic monitoring of tight oil reservoirs in the Junggar Basin.

Key words: well test model, dynamic inversion, fractured network system, fractured horizontal well, tight oil, Jimusar area, Junggar Basin

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