地层岩性的随钻评估方法研究及应用

Research and Application of the Method for Evaluating Formation Lithology While Drilling

地层岩性的随钻评估对钻井工程技术人员和地质人员十分重要。本文根据钻头破岩机理和能量守衡原理,建立了地层岩性随钻评估模型。使用PDC钻头钻井时,岩屑破碎很细,通过岩屑录井来判断地层岩性十分困难。针对PDC钻头的切削机理,从PDC钻头切削刃受力平衡角度出发,建立了PDC钻头钻井时地层岩性随钻评估模型。现场初步试验表明,该模型具有一定的合理性和实用性。

It is very important for drilling engineers and geologists to be able to evaluate formation lithology while drilling. According to mechanism of rock cracking and conservation of energy, this paper describes a model for evaluating formation lithology while drilling. Because of the fine cuttings while drilling with PDS bits.it is difficult to identify the lithology changes by way of lithology logging. A model is established based on the balances of forces acting on the PDC cutter. Actually,these models have been proved to be reasonable and practical.