摘要
地层承压能力是钻开井眼后地层不发生钻井液漏失时所能承受的井筒压力极限。由于天然裂缝发育,裂缝性地层通常表现出较低的承压能力,在固井和多压力系统钻井过程中频发井漏复杂。为了顺利完成固井和窄(负)安全密度窗口钻井施工,通常需要进行提高裂缝性地层承压能力作业,以扩大钻井液安全密度窗口上限。文章首先分析了不同地层的承压能力模型,然后从地层表观破裂压力、周向应力、裂缝闭合压力、裂缝延伸阻力和温度效应五个方面综述了提高地层承压能力的力学机理、适用条件和关键技术。现有提高地层承压能力技术得到了广泛的应用,但其背后的力学机理还尚存争议,应用成功率也有待提升。建议继续开展提高地层承压能力力学机理研究,研制更加符合力学机理要求的堵漏材料,进一步强化提高地层承压能力作业效果。
The pressure-bearing capacity of formation is the upper limit of wellbore pressure that a formation can withstand without lost circulation after a borehole is drilled out.Due to the development of natural fractures,fractured formations usually have low pressure-bearing capacity,leading to frequent lost circulation events during cementing and drilling in multiple pressure formation.In order to successfully finish cementing and narrow(negative)safe mud weight window drilling,it is usually necessary to conduct operations to increase the pressure-bearing capacity of fractured formations for expanding the upper limit of the safe mud weight window.This paper presents an analysis of the pressure-bearing capacity models for different formations firstly and a review of the mechanical mechanisms,applicable conditions and key technologies for improving formation pressure-bearing capacity from five aspects:apparent formation fracturing pressure,hoop stress,fracture closure pressure,fracture propagation resistance and temperature effect.These existing technologies for improving formation pressure-bearing capacity have been widely used,but the mechanical mechanisms behind them are still controversial and the application success rate needs to be improved.It is recommended to continue the research on the mechanical mechanisms of improving the formation pressure-bearing capacity,and develop the lost circulation materials that meet the requirements of the mechanical mechanisms to further enhance the effect of improving formation pressure-bearing capacity operations.
作者
黄宁生
HUANG Ningsheng(Drilling&Production Engineering Technology Research Institute,CNPC Chuanqing Drilling Engineering Co.,Ltd.,Guanghan,Sichuan 618300,China)
出处
《钻采工艺》
CAS
北大核心
2023年第2期133-138,共6页
Drilling & Production Technology
关键词
裂缝性地层
地层承压能力
井漏
堵漏
井筒强化
fractured formations
formation pressure-bearing capacity
lost circulation
lost circulation control
wellbore strengthening
作者简介
黄宁生(1964-),工程师,2011年毕业于中国石油大学(华东)石油工程专业,长期从事钻井液技术研究与应用。地址:(643000)四川省广汉市中山大道南二段88号钻采工程技术研究院,电话:0838-5151375,13778218311,E-mail:huangns@cnpc.com.cn。
