石油学报 ›› 2008, Vol. 29 ›› Issue (1): 135-138.DOI: 10.7623/syxb200801030

• 石油工程 • 上一篇    下一篇

考虑岩样尺度效应时钻井液对岩石力学性质影响的试验评价

谢润成1, 周文2, 单钰铭2, 王世泽3, 闫长辉2, 郭新江3   

  1. 1. 成都理工大学能源学院, 四川成都, 610059;
    2. 成都理工大学油气藏地质及开发工程国家重点实验室, 四川成都, 610059;
    3. 中国石化西南分公司工程技术研究院, 四川德阳, 618000
  • 收稿日期:2007-01-08 修回日期:2007-02-25 出版日期:2008-01-25 发布日期:2010-05-21
  • 作者简介:谢润成,男,1979年8月生,2006年获成都理工大学油气田开发工程专业工学硕士学位,现为成都理工大学能源学院石油工程系讲师,油气田开发工程专业在读博士研究生,主要从事油气藏工程地质评价方面的教学与科研工作.E-mail:xxrc_1980@tom.com
  • 基金资助:
    中国石油化工股份有限公司科技项目“川西特低渗透深层砂岩气藏压裂技术研究与应用”(P02034-T01)部分成果

Trial evaluation on drilling fluid and mechanical properties of rock while considering size of rock

XIE Runcheng1, ZHOU Wen2, SHAN Yuming2, WANG Shize3, YAN Changhui2, GUO Xinjiang3   

  1. 1. College of Energy Resource, Chengdu University of Technology, Chengdu 610059, China;
    2. State Key Laboratory of Oil & Gas Reservoir Geology and Exploitation Engineering, Chengdu University of Technology, Chengdu 610059, China;
    3. Research Institute of Technology, Sinopec Southwest Company, Deyang 618000, China
  • Received:2007-01-08 Revised:2007-02-25 Online:2008-01-25 Published:2010-05-21

摘要: 在考虑试验岩样尺度效应的基础上,进行的模拟地层条件下钻井液对岩石力学性质影响的试验研究结果表明:经钻井液处理后的Φ25mm×25mm岩样的抗张强度高于未经钻井液处理的Φ50mm×50mm岩样,且处理后的岩样抗张强度均高于未处理的岩样。对于钻井液处理前后同尺寸的岩样,由于试验岩样中泥质软颗粒含量高低不同,在孔隙度小于2.5%时,孔隙度越小,处理前后的抗张强度相差越大,且处理前的岩样抗张强度比处理后的岩样大4MPa左右;在孔隙度大于2.5%时,钻井液处理前后的岩石抗张强度趋于一致。在模拟地层条件下,钻井液处理后的岩样抗压强度和弹性模量显著下降,泊松比增大。岩石矿物中的泥质黏土矿物遇到钻井滤液后产生软化效应,致使岩样呈现:经钻井液处理时间越长,其抗压强度和弹性模量下降越多的趋势。

关键词: 岩石力学性质, 尺度效应, 钻井液, 试验评价, 抗张强度, 致密储层

Abstract: On the basis of size effects of trial rock,the effects of drilling fluid on the mechanical properties of rocks were investigated experimentally under the simulated formation conditions.The results showed that rock tensile strength of sample with a diameter of 25 mm and a length of 25mm treated by drilling fluid was higher than that of untreated rock samples with a diameter of 50mm and a length of 50mm.Because of different content of shale in trial samples,difference of tensile strengths of samples before and after treated by drilling fluid got greater and porosity of sample got smaller as the porosity was less than 2.5%.Difference of tensile strengths of treated and untreated samples was about 4 MPa.As porosity of rock sample was larger than 2.5%,tensile strength of treated sample was nearly consistent with that of the untreated samples.Under simulating rock formation conditions,the compressive strength and Young's modulus of the sample treated by drilling fluid decreased significantly,the Poisson's ratio increased.The longer treatment time of samples would result in the more reduction of compressive strength and Young's modulus,because the shale or clay in rock sample would get soft by the drilling fluid filling.

Key words: mechanical properties of rock, size effect, drilling fluid, trial evaluation, tensile strength, compact reservoir

中图分类号: