石油学报 ›› 2013, Vol. 34 ›› Issue (3): 556-562.DOI: 10.7623/syxb201303021

• 石油工程 • 上一篇    下一篇

定向射孔水力压裂起裂压力的预测模型

朱海燕1, 邓金根1, 刘书杰2, 闫伟1, 陈峥嵘1, 文敏2, 彭成勇2   

  1. 1. 中国石油大学油气资源与探测国家重点实验室 北京 102249;
    2. 中海油研究总院 北京 100027
  • 收稿日期:2012-11-26 修回日期:2013-02-13 出版日期:2013-05-25 发布日期:2013-04-09
  • 通讯作者: 邓金根,男,1963年8月生,1983年获华东石油学院学士学位,2000年获石油大学(北京)油气井工程专业博士学位,现为中国石油大学(北京)博士生导师、长江学者,主要从事石油工程岩石力学方向的研究。Email:dengjg@cup.edu.cn
  • 作者简介:朱海燕,男,1984年4月生,2006年毕业于西南石油大学,现为中国石油大学(北京)博士研究生,主要从事石油工程岩石力学与控制等方面的研究。Email:zhuhaiyan040129@163.com
  • 基金资助:

    国家自然科学基金项目(No.51174219)、国家重大科技专项(2011ZX05009-005)和国家自然科学基金创新群体项目(No.51221003)资助。

A prediction model for the hydraulic fracture initiation pressure in oriented perforation

ZHU Haiyan1, DENG Jingen1, LIU Shujie2, YAN Wei1, CHEN Zhengrong1, WEN Min2, PENG Chengyong2   

  1. 1. State Key Laboratory of Petroleum Resource & Prospecting, China University of Petroleum, Beijing 102249, China;
    2. CNOOC Research Institute, Beijing 100027, China
  • Received:2012-11-26 Revised:2013-02-13 Online:2013-05-25 Published:2013-04-09

摘要:

目前水力压裂起裂压力的预测模型均针对螺旋射孔的情形,忽略套管对井周应力场的影响,已不适用于定向射孔水力压裂起裂压力的预测。定向射孔时,井周未产生微环隙,以此建立了套管井井周应力的解析模型。以渤海BZ25-1油田A1井为例,将该井周应力解析模型与有限元模型进行对比,其最大误差仅为2.3 % 。同时,结合Hossain模型和最大拉应力准则, 建立了套管井定向射孔时孔眼的起裂压力和起裂角的预测模型。考虑流体渗流和套管的共同作用,采用水力压裂的渗流与变形耦合的数值计算方法进行验证,该模型得到的起裂压力与数值计算的误差仅为2.9 % ,表明该模型准确可靠,可以用于指导定向射孔水力压裂的设计。

关键词: 定向射孔, 水力压裂, 起裂压力, 井周应力, 模型

Abstract:

Current prediction models for the hydraulic fracture initiation pressure are all applicable to spiral perforation, in which the casing effect on circumferential stress field can be ignored, however, they are not suitable to the prediction of the hydraulic fracture initiation pressure in oriented perforation. An analytical model was established for circumferential stress distributions of cased boreholes based on the effect of the micro-annulus of the first or second interface between the pipe, cement sheath and reservoir rock in oriented perforation. Taking the A-1 well of the BZ25-1 oilfield as an example, this circumferential stress model was compared with the finite element model and the maximum error is only 2.3 % . At the same time, combined with the Hossain’s model and the maximum tension criterion, a prediction model for the fracture-initiation pressure and angle in oriented perforation of cased boreholes was built. A numerical method coupled with hydraulic fracture seepage and rock deformation was adopted to verify this prediction model for the fracture-initiation pressure when co-functions of liquid seepage and casing were taken into consideration. The result showed that compared with the numerical calculation method, the prediction error of this model for the fracture-initiation pressure is only 2.9 % , indicating the credibility of this model and its feasible application in guiding the hydraulic fracturing design of oriented perforation.

Key words: oriented perforation, hydraulic fracturing, fracture-initiation pressure, circumferential stress, model

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