煤系地层钻进仿真响应特征及其在岩性智能识别中的应用

Simulation response characteristics of coal measure strata drilling and their applications in intelligent lithology identification

  • 摘要: 煤矿井下复杂施工环境导致超前钻探中钻具响应与岩性映射关系通常难以直接建立,制约岩性识别精度。针对此问题,构建了聚晶金刚石复合片(PDC)钻头−钻杆破岩仿真模型,揭示了不同钻进条件下钻具对复合岩层的响应特征:固定钻速,提升转速会使钻头扭矩降低且波动减弱,而钻压波动相对稳定;固定转速,提升钻速会使钻压与扭矩同步升高。钻杆三轴向振动加速度随转速增大而增大,随钻速增大呈先减小后增大趋势。在岩性界面处,上述参数呈现突变特征,表明多参数联合可作为岩性识别特征。基于此,提出了一种融合双向长短期记忆网络(BiLSTM)、注意力机制与KAN (Kolmogorov-Arnold Network)的岩性识别模型——BiLSTM-Att-KAN,以KAN替代BiLSTM模型中多层感知机(MLP)分类器,突破MLP因使用Sigmoid/Rectified Linear Unit (ReLU)等固定激活函数导致的非线性映射局限,可提高复杂岩性识别精度。利用仿真数据和实际数据进行模型测试,结果表明:BiLSTM-Att-KAN在仿真数据集上的识别准确率达91.64%,优于K近邻、随机森林等传统分类模型,提升幅度7.00%~22.08%;在实际训练钻孔数据测试集与独立测试数据上的准确率分别为86.81%和85.28%,验证了模型有效性,可为煤系地层岩性识别提供技术支撑。

     

    Abstract: Underground coal-mine construction presents a complex environment in which direct mapping between downhole drilling-tool responses and lithology is difficult, limiting the accuracy of lithology identification. To address this challenge, we developed a polycrystalline diamond compact (PDC) bit-drill-rod rock-breaking simulation model in Abaqus and analyzed tool response characteristics across composite strata under different drilling conditions. With Rate of Penetration (ROP) held constant, increasing revolutions per minute (RPM) reduced bit torque and its fluctuation while leaving weight on bit (WOB) fluctuations relatively unchanged; with RPM held constant, increasing ROP raised both the mean WOB and torque. The tri-axial vibration acceleration of the drill rod increased with RPM, whereas with increasing ROP it showed a nonmonotonic trend (initial decrease followed by increase). All of these parameters display abrupt changes at lithologic interfaces, indicating that their joint use can serve as effective features for lithology recognition. On this basis, we propose a lithology recognition model—BiLSTM-Att-KAN, which integrates a Bidirectional Long Short-Term Memory Network (BiLSTM), an attention mechanism, and a Kolmogorov-Arnold Network (KAN). Replacing the conventional Multilayer Perceptron (MLP) classifier with KAN overcomes the nonlinear-mapping limitations imposed by fixed activation functions (e.g., Sigmoid/ Rectified Linear Unit (ReLU)) in MLPs and, in theory, enhances recognition of complex lithologies. Tests using both simulated and field drilling data show that BiLSTM-Att-KAN achieves 91.64% accuracy on the simulation dataset, outperforming traditional classifiers such as k-nearest neighbors and random forest by 7.00%~22.08%. On real borehole data, the model yields accuracies of 86.81% on the training-test split and 85.28% on an independent test set, validating its effectiveness and demonstrating its potential as a technical tool for lithology identification in coal-bearing strata.

     

/

返回文章
返回