地层抗钻强度与钻头磨损实用评估方法

AN APPLICABLE METHOD FOR ESTIMATION OF FORMATION DRILLING STRENGTH AND BIT WEAR

詹俊峰 高德利 刘希圣

Zhan Zunfeng Gao Deli Liu Xisheng

石油大学·北京

以牙轮钻头单齿破岩机理和力峨量平衡理论为基础,综合考虑了钻头结构、地层特性、水力参数及钻井参数等的影响,提出利用钻井参数评估地层抗钻强度和钻头磨损程度的方法,将钻井过程中牙齿磨损和地层抗钻强度变化产生的耦合作用通过自定义参数描述,用新钻头的实钻数据确定钻头破岩的基本特性参数,从而为区分地层和钻头的影响提供了基础。本文方法,既可用于现场实时分层监测钻井工况的变化和诊断井下异常状态,也为钻后分析和钻头优选提供了定量依据。文中用实例进行了说明。

Based upon the theory of rock-breaking mechanism of one tooth of roller bit and the theory of force-power balance and taking in consideration of the influences of bit geometry, formation characteristics, hydraulic parameters and drilling parameters, a method of estimating formation drilling strength and bit wear by analysis of drilling parameters was advanced. By using the operating parameters of a new bit and according to the description of the coupled actions of bit wear and changes of formation drilling strength, this method creates a possibility of identification of influences formation and bit. With the method described in this paper, a rig-site simultaneous monitoring on drilling operation and diagnosis of downhole abnormal sltuatlons can be made. Meanwhile it can give some quantitative data for after-drilling analysis and bit optimization. Some practical examples are shown also in the paper.

10.3969/j.issn.1000-7393.1997.06.004