钻采工艺 ›› 2021, Vol. 44 ›› Issue (4): 132-136.DOI: 10.3969/J. ISSN.1006-768X.2021.04.30

• 生产线上 • 上一篇    下一篇

深层页岩气井高强度弹韧性水泥石力学性能研究

张佳滢1, 严俊涛2, 周迎春3, 张鹏4, 徐璞1, 张海志1   

  1. 1 中国石油集团工程技术研究院有限公司 2 中国石油川渝页岩气前线指挥部  3 中国石油川庆钻探井下作业公司 4 中国石油集团长庆油田公司第七采油厂 
  • 出版日期:2021-07-25 发布日期:2021-07-25
  • 作者简介:张佳滢(1994-) , 硕士,2020 年毕业于中国石油大学( 北京) 石油与天然气工程专业, 现从事固井水泥浆方面的研究工作。地址: (102206) 北京市昌平区黄河街 5 号院 1 号

Study on Mechanical Properties of High Strength Elastic-Toughness Cement for Deep Shale Gas Wells

ZHANG Jiaying1 , YAN Juntao2, ZHOU Yingchun3, ZHANG Peng4, XU Pu1 , ZHANG Haizhi1   

  1. 1 . CNPC Engineering Technology R&D CO. , LTD. , Beijing 102206, China; 2. PetroChina Sichuan & Chongqing Shale Gas Headquarter, Chengdu, Sichuan 610000, China; 3. Downhole Service Company ofCNPC Chuanqing Drilling Engineering CO. , LTD. , Suining, Sichuan 629000, China; 4. No. 7 Oil Production Plant of Changqing Oilfield Branch of PetroChina, Xi'an, Shaanxi 710000, China
  • Online:2021-07-25 Published:2021-07-25

摘要: 深层页岩气破裂压力高,压裂荷载大,分析认为在压裂荷载下水泥环可能发生界面胶结破坏和拉伸破坏。为了满足深层页岩气井在高压裂施工荷载下水泥环的密封完整性,需形成高强度弹韧性水泥石。在水泥浆中掺入弹性粒子、纳米硅灰和晶须,测试了水泥石的力学性能和微观结构。弹性粒子改善了水泥石的脆性,降低了水泥石的弹性模量;纳米硅灰填充水泥石中的孔隙,显著增加水泥石的抗压强度;长径比较大的晶须阻碍微裂缝的发展,起到桥链作用,提高水泥石的抗拉强度。三者复掺形成了弹性模量低且强度高的水泥石,有利于水泥环长期密封完整性。

关键词: 深层页岩气, 弹性模量, 高强度, 水泥环, 密封完整性

Abstract:

High fracturing pressure exists in deep shale gas and high fracturing load is needed. It is considered that interface cementation failure and tensile failure may occur in cement sheath under fracturing load. In order to satisfy the sealing integrity of cement sheath under high-pressure fracturing load, high strength elastic-toughness cement is needed. Elastic particle, nano-silica fume and whisker are added into the cement slurry, mechanical properties and microstructures are test-ed. Elastic particles improve the brittleness and reduce the elastic modulus of cement. Nano-silica fume fills the pore and significantly increases the compressive strength of cement. Large slender whiskers hinder the development of micro-cracks, play a role of bridge chain and increase the tensile strength of cement. Thus, high-strength elastic-tough cement paste is formed, which is beneficial to the long-term sealing integrity of cement sheath.

Key words: deep shale gas, elastic modulus, high strength, cement sheath, sealing integrity