Rock mass structural recognition from drill monitoring technology in underground mining using discontinuity index and machine learning techniques

A procedure to recognize individual discontinuities in rock mass from measurement while drilling(MWD)technology is developed,using the binary pattern of structural rock characteristics obtained from in-hole images for calibration.Data from two underground operations with different drilling technology and different rock mass characteristics are considered,which generalizes the application of the methodology to different sites and ensures the full operational integration of MWD data analysis.Two approaches are followed for site-specific structural model building:a discontinuity index(DI)built from variations in MWD parameters,and a machine learning(ML)classifier as function of the drilling parameters and their variability.The prediction ability of the models is quantitatively assessed as the rate of recognition of discontinuities observed in borehole logs.Differences between the parameters involved in the models for each site,and differences in their weights,highlight the site-dependence of the resulting models.The ML approach offers better performance than the classical DI,with recognition rates in the range 89%to 96%.However,the simpler DI still yields fairly accurate results,with recognition rates 70%to 90%.These results validate the adaptive MWD-based methodology as an engineering solution to predict rock structural condition in underground mining operations.

Study on temperature field of the drilling machine during the course of drilling in coal mine

The working conditions of the MK-3 type full hydraulic tunnel drilling machine during the course of drilling were analyzed. Based on the energy balance governing equations for the drill rod, the temperature field of drill rod at the normal and non-normal working conditions was numerically obtained. The numerical results show that the maximum temperature at the head of drill rod under the normal working circumstance is insufficient to ignite the gas. But under the non-normal working condition, the local high temperature can ignite the gas easily and cause the fire. In order to prevent the gas fire, the occurrence of the non-normal operating condition must be prevented as far as possible during the drilling.

A BiGRU joint optimized attention network for recognition of drilling conditions

The identification and recording of drilling conditions are crucial for ensuring drilling safety and efficiency. However, the traditional approach of relying on the subjective determination of drilling masters based on experience formulas is slow and not suitable for rapid drilling. In this paper, we propose a drilling condition classification method based on a neural network model. The model uses an improved Bidirectional Gated Recurrent Unit (BiGRU) combined with an attention mechanism to accurately classify seven common drilling conditions simultaneously, achieving an average accuracy of 91.63%. The model also demonstrates excellent generalization ability, real-time performance, and accuracy, making it suitable for actual production. Additionally, the model has excellent expandability, which enhances its potential for further application.

A Novel Half-Bridge Power Supply for High Speed Drilling Electrical Discharge Machining

High Speed Drilling Electrical Discharge Machining (HSDEDM) uses controlled electric sparks to erode the metal in a work-piece. Through the years, HSDEDM process has widely been used in high speed drilling and in manufacturing large aspect ratio holes for hard-to-machine material. The power supplies of HSDEDM providing high power applica-tions can have different topologies. In this paper, a novel Pulsed-Width-Modulated (PWM) half-bridge HSDEDM power supply that achieves Zero-Voltage-Switching (ZVS) for switches and Zero-Current-Switching (ZCS) for the dis-charge gap has been developed. This power supply has excellent features that include minimal component count and inherent protection under short circuit conditions. This topology has an energy conservation feature and removes the need for output bulk capacitors and resistances. Energy used in the erosion process will be controlled by the switched IGBTs in the half-bridge network and be transferred to the gap between the tool and work-piece. The relative tool wear and machining speed of our proposed topology have been compared with that of a normal power supply with current limiting resistances.

DEVELOPMENT AND EXPERIMENT OF NEW AlTiN COATED DRILLS FOR HIGH EFFICIENCY DRY DRILLING OF 40Cr

Two new AlTiN coated cemented carbide drills with Al content of 40% and 55% in weight are developed for high efficiency dry drilling of 40Cr. By studying tool durability, machined hole quality, tool wear mechanism, chip deformation, and lubrication, the dry drilling performance of the two kinds of coated drills is analyzed. Experimental results show that the AlTiN coated drills are suitable for high efficiency dry drilling and can obtain higher quality of machined holes. The tool durability of the drill with 55% Al content is 1. 3 times of that of the drill with 40% Al content at the cutting speed of 90 m/min. The wear mechanism of two AlTiN coatings are studied in experiments. During dry drilling process, oxidative wear appears in both two kinds of drills. The oxide film is formed on the top of the coated drill containing Al content of 55%. And the oxide film helps to increase its high temperature resistance and decrease the coating flaking, thus the drill is failed because of coating subsidence. The drill with less Al content is failed due to peeling and breakage. The lubricated condition in dry drilling is improved by the high Al content coating. It helps to reduce the cutting deformation and benefits to improve the quality of machined holes. The AlTiN coating with higher Al content shows longer tool life and higher quality of machined holes in high efficiency dry drilling. Its tool life increases by 30% compared with that of the coating with less Al content.

Formation and Control of Drilling Burrs

In this paper, a new forming model of the feed direction burr for drilling process is presented. The feed direction burr formation is experimented and studied. The related theories are analyzed, and the influential factors of the feed direction burrs are pointed out. Furthermore, a certain number of new measures to prevent and decrease the burr in drilling process are advanced.

A novel algorithm of normal attitude regulation for the designed end-effector of a flexible drilling robot

An end-effector for a flexible drilling robot is designed, and a novel four-point algorithm of normal attitude regulation for this end-effector is presented. Four non-coplanar points can define a unique sphere tangent to them in spatial geometry, and the center point of the sphere and the radius can be calculated. The shape of a workpiece surface in the machining area is approximately regarded as such a sphere. A vector from the machining point to the center point is thus approximately regarded as a normal vector to the workpiece surface. By this principle, the algorithm first measures four coordinates on the curve in the drilling region using four sensors and calculates the normal vector at the drilling point, then calculates the error between the normal vector and the axis of the spindle. According to this error, the algorithm further figures out the angles of two revolving axes on the end- effector and the displacements of three linear axes on the robot main body, thus it implements the function of adjusting the spindle to be perpendicular to the curve at the drilling point. Simulation results of two kinds of curved surfaces show that accuracy and efficiency can be realized using the proposed algorithm.

Evaluation of the energy efficiency of rotary percussive drilling using dimensionless energy index

This paper sets forth a geomechanics framework for assessing the energy efficiency of rotary percussive drilling using the energy criterion, which has been proposed by Victor Oparin for volumetric destruction of high-stress rocks having nonuniform physico-mechanical properties. We review the long-term research and development in the specified area of science and technology, including research and development projects implemented at the Institute of Mining, Siberian Branch of the Russian Academy of Sciences. A new modified expression of Oparin’s dimensionless energy criterion of volumetric rock destruction k is introduced. The range of in situ values is determined for the energy criterion of volumetric rock destruction at the optimized energy efficiency of rotary percussive drilling. The temporospatial intervals of geotechnical monitoring are found to control pneumatic drilling energy efficiency at subsoil use objects in Russia. The integrated experimental, theoretical and geotechnical approach to the comprehensive investigation of real-time processes of rock fracture in rotary percussive drilling using the energy concept possesses the necessary geomechanical performance-and-technology potential to create the next level geotechnical monitoring of drilling systems for various purposes, including determination of physico-mechanical properties and the stress-strain analysis of rock mass in full-scale drilling.

Positioning of Screw Holes Group Based on Digital Camera and Digital Control Drilling

Positioning of screw holes is an important production procedure for steel construction connecting with bolts. In this paper, a new production method is presented, in which the digital camera is used for taking pictures of screw holes and other techniques are advanced. This paper also indicates that the pixels of CCD chip in photogrammetry should be chosen as all geometric units in an image, such as interior elements and all kinds of distortions. The measure can also simplify the camera calibration for determining the size of non-square pixel.

Optimization of Parameters CO<SUB>2</SUB>Laser for Drilling Different Types of Glass

The aim of this work is to study in detail the drilling process on glass by CO2 laser. The study parameters considered in the present experiments are based on the laser beam power of range (30% - 80% of 25 W) and an exposure time for drilling (2 - 8 s). The measured diameters of holes by optical methods are between [300 - 800 μm]. The results obtained by optical observations suggest that ordinary and mineral glasses cannot withstand to a contact of the laser beam and crack during the formation of the drilling hole. The minimum power and duration of exposure are the optimal parameters for drilling the organic glass, we observe no micro-cracks, and again we see that the edges of the holes have a good surface quality with a high aspect ratio.

RESEARCH ON THE ADAPTIVE CONTROL OF DRILLING PROCESS

A self-tuning adaptive controller is presented which is used for the adaptive control (AC) of drlling process. The parameters of the controller can be regulated in-processly by on line system identification, so as to fit the variation of the cutting conditions. This control method has been successfully applied to the adaptive control of drilling process. The experimental results indicate that the controller has the ability to adapt to the variation of the cutting process parameters and is good in performance.

矿山救援钻孔中井涌井漏事故预警预测

为解决矿山应急救援钻孔作业过程中井涌井漏事故预警预测困难等问题,建立了基于机器学习的钻进过程井涌井漏事故预警预测模型。首先对井涌井漏事故发生初期时的钻进参数进行事故表征参数分析;其次对事故表征参数进行数据清洗处理,在此基础上,通过XGBoost事故诊断预警模型对井涌井漏事故进行早期诊断识别;随后建立PSO-LSTM事故发展预测模型,对事故发生后的孔底压力参数发展趋势进行预测,提前掌握钻进事故发展状态;最后通过实际钻进数据对预警预测模型的有效性进行验证。结果表明:XGBoost事故诊断预警模型能根据总池体积、立管压力、出入口流量差和动力头负荷这4种钻进参数的异常变化,快速准确诊断钻进过程中的井涌井漏事故;PSO-LSTM事故发展状态预测模型能充分学习孔底压力参数发展规律,综合EMAP、EMA、ERMS、R2这4项误差评价指标,PSO-LSTM模型相较于BP、RNN、SVM模型的预测性能最佳,能准确预测事故发生之后的孔底压力发展趋势,提前掌握井涌井漏事故的严重程度和发展态势。研究结果丰富了钻进过程井涌井漏事故预警预测方法,提高了矿山事故地面救援的可靠性,对矿山应急救援钻孔作业过程中事故控制有着借鉴与指导作用。

井漏风险层位钻前智能识别方法研究

井漏是复杂地层钻井工程常遇到的工程难题,呈现出频发性、随机性与持续性等特征,钻前准确预测井漏风险层位对于安全钻井显得尤为重要。传统井漏层位分析偏重于随钻诊断和钻后总结,主要采用工程数据与现场经验相结合的手段,导致分析结果存在滞后性,无法在钻前有效指导钻井工程设计。本文以地震属性体数据和漏失工程数据为基础,在具有典型漏失特征单井选取的基础上,提取过井地震属性体数据,通过时深关系将漏失与地震属性相匹配,并采用随机森林方法甄别优选出与井漏预测相关性强的地震属性体,然后运用机器学习方法中的软投票算法建立集成学习模型,该模型融合了逻辑回归、随机森林和支持向量机3个子模型,实现了多元地震属性体与漏失工程数据之间的非线性映射关系及其对应权重的表征,同时获得基于地震与工程数据融合驱动的漏失风险层位分布概率,实现钻前井漏风险层位三维空间分布预测。研究结果表明,方差、时频衰减、甜点和均方根振幅与井漏的相关性最高,综合上述多种属性体可以实现更为精确的井漏风险预测,而过多增加地震属性数据并不能显著提升预测效果精度,相反还会增加计算成本。与单一机器学习模型相比,集成学习模型由于融合了多个子模型的优点,能够取得更好的预测效果。实际应用效果表明,采用地震属性体进行漏失风险预测,其精度取决于地震数据的采样率,井漏风险层位区域横向预测分辨率约为25 m,纵向预测分辨率约为6m(2ms),预测结果表明横向相比于纵向更为可靠。但由于时深关系的影响,可能导致纵向预测精度的偏移。本研究能够较好的进行钻前漏失预测,为钻前漏失预测提供了一种新的思路,对于指导井位部署、井眼轨道优化以及安全钻井具有重要意义。

机液串联式钻机推进系统设计与仿真分析

针对工程钻机推进系统存在的行程大而造成体积和质量大的问题,基于其工作机制进行研究,提出一种机液串联式的钻机推进系统,详细阐述了其工作原理,推导了钻机推进位移与电液比例阀阀门开度的函数关系式。理论分析和仿真验证表明:机液串联式的推进系统具有省距不省力的特点;在钻机工作过程中,动力头的推进速度和位移可达到液压油缸的2倍,液压油缸传递至动力头的推进力为液压油缸活塞输出力的一半,从而减少了钻机桅杆的长度,降低了推进系统的体积和质量;通过电液比例阀调节阀门开度,可以调节动力头的推进位移和速度,使得钻机推进系统满足不同工况的需求。

智能钻井多目标协同优化系统研究与应用

在深井超深井钻探过程中,井眼中高强度、高研磨性地层导致的钻头早期磨损、井下钻具振动剧烈、井眼清洁不足等,严重制约了深井超深井的安全快速钻进。针对上述问题,文章提出了一种智能钻井多目标协同优化系统,可以实时跟踪、优化钻井参数,提高钻井性能。同时基于机械钻速和机械比能,定义了钻井性能综合评价指标;结合地应力、钻具振动、摩阻扭矩、井眼清洁和破岩能效等地质、物理模型,提出了包含探索、学习和应用三种模式的钻井参数实时优化流程,训练了融合支持向量回归模型和随机森林回归模型的钻井参数实时优化算法。该系统在深地川科1井进行了现场应用,提速比达到了41.5%,为深井超深井钻井优化提速提供了一种新的技术手段。

油田通井机噪声危害分析与治理

目的针对油田通井机噪声危害的问题,寻求合理的解决方案。方法选择某油田油气井下作业单位的柴油驱动通井机作为研究对象,通过采取振动与噪声测试,分析TJL-12通井机主要噪声源和传播途径,对驾驶舱和发动机舱进行隔声和吸声,对调节阀处进行消声等设计和改造,降低噪声接触水平,使其低于国家职业接触限值要求,改善油气井下作业环境。结果噪声检测结果显示,通井机司钻接触噪声强度由95.2 dB(A)降至84.2 dB(A),低于85 dB(A)的噪声接触限值。结论噪声危害分析和综合治理方案可有效解决油田行业在修井作业时通井机噪声危害控制难题。

机器学习在钻柱振动识别与预测中的研究进展

钻柱振动是影响钻井效率、钻柱失效、井眼稳定和钻井安全的主要因素,复杂振动的早期识别对于缓解井下工具受损、提高生产时间至关重要。为此,充分调研国内外机器学习在钻柱振动识别方法方面的研究成果,从数据获取角度对钻柱振动识别与预测方法进行了全面分析,对比研究了各算法模型的框架、特征参数和测试效果,系统评估了各算法模型的优缺点,并对未来振动识别与预测的发展方向提出思考。研究结果表明:①机器学习算法可以从大量振动数据中学习和提取特征来建立模型,对振动进行分类和预测,通过不断优化算法和模型,提高钻柱振动识别与预测的准确性和可靠性;②随着数据采集和处理技术的不断进步,地面与井下多源数据融合方法将多种数据共同分析处理,可以最大程度地发掘地面和井下数据特征,有望成为解决井下问题的重要途径;③随着钻井工程与人工智能技术的不断融合与发展,振动缓解与钻井提速联合优化,将为钻井工程提供更为可靠的指导和决策。结论认为,机器学习在钻柱振动识别与预测方面的应用和发展进一步缓解了超深井井下钻柱振动这一复杂问题,提高了钻井工程的效率和安全性,推进了钻井过程的高效化和智能化发展步伐。

钻装机扒装机构斗齿根与主刀板焊接强度分析

通过SYSWELD对扒装机构斗齿齿根与主刀板焊接部分进行残余应力分析,在保持统一的焊接参数下,采用ZG22CrMnMo代替ZG25CrMnMo制造斗齿,对仿真结果进行分析,得出ZG22CrMnMo焊接变形小。通过改变焊接电流、焊接电压,得到焊接仿真结果。采用ZG22CrMnMo作为钻装机扒装机构斗齿材料满足扒装机构工作强度,在焊接电流200 A、电弧电压24 V时,焊接件的内部残余应力最小,对扒装机构的影响最小,可以增加扒装机构铲斗的使用寿命。

基于PLC和组态软件的钻孔机电气控制系统设计

传统钻孔机主要依靠手动操作,存在电气化利用率不高、操作不便的缺点。为此,采用可编程逻辑控制器(PLC)作为主控制器,结合组态软件实现人机界面的设计。在梳理钻孔机工作流程及环节后,明确电气控制系统的硬件结构和软件功能。硬件系统部分由PLC、传感器、执行器等组成,软件系统部分则由PLC程序和组态设计组成。设计过程中,在功能性和实用性的基础上充分考虑了系统的可靠性、灵活性、稳定性和可维护性。经测试,该系统能够实现对钻孔机的精确控制,提高了加工效率和质量。