地层岩性与钻头工况的评估方法研究及其应用

STUDY AND APPLICATION OF ASSESSMENT METHOD FOR FORMATION LITHOLOGY AND THE WORKING CONDITON OF BIT

地层岩性与钻头工况的评估对钻井工程技术人员和地质人员十分重要。根据能量守衡原理和钻头破岩机理，建立了地层岩性与钻头工况评估模型。该模型在钻井过程中，利用钻压、扭矩、钻速、转速等井下或地面的各种信息，预测所钻遇的地层岩性、岩石视抗钻强度、岩石视抗剪强度及当前的钻头工况，并且开发研制出地层岩性与钻头工况实时评估软件系统。该软件在现场得到初步应用，取得了较好的效果。

It is very important for drilling engineering and geological staff to assess formation lithology and the working condition of bit. According to the conservation principle of energy and the rock-breaking mechanism of bit, the assessment model was set up for formation lithology and the working condition of bit. The model can predict the formation lithology, the apparent drilling strength, shearing strength of rock and the current working condition of bit by using various downhole or surface information about WOB, torque,drilling speed and revolution during drilling. And the real-time assessment software system for formation lithology and the working condition of bit was also developed. The initial onsite application of the software showed good results.