地层温度对科学超深井井壁稳定的影响

Effect of the Formation Temperature on the Hole-wall Stability in Ultra-deep Scientific Drilling

摘要:

井壁稳定问题包括井壁坍塌和地层破裂2种基本类型，科学超深井钻探的目的层是处于高地应力、高地温和高地层压力的深部岩层,井壁稳定问题更加突出。以12000 m科学超深井为例，从地层温度入手，分析钻井液循环温度变化所引起的当量静态钻井液密度和环空压力当量密度的变化，以及温梯应力、温差应力对井壁稳定的影响。

Abstract:

The problem of hole-wall stability includes the well collapsing and the well fracture. The formation of ultra-deep scientific drilling (UDSD) is provided with high stress, high temperature and high formation pressure. The hole-wall stability of UDSD is one of the focuses. Take the example of 12000m UDSD, starting from the formation temperature, analysis was made on the changes of equivalent static density of drilling fluid and annular pressure equivalent density caused by drilling fluid circulating temperature, and on the influence to hole-wall stability by formation temperature-gradient stress and formation temperature-difference stress.