【作者】 房昕；

【导师】 赵大军；

【作者基本信息】 吉林大学 ， 地质工程， 2014， 博士

【摘要】 上天、入地、下海、登极，被称为人类征服自然的四大梦想。从本世纪初，人类对太空、海洋和极地的了解已达到了一定的高度，但对于人类赖以生存的地球却知之甚少，在入地的探索中更是举步维艰。获取地球深部的信息最直接、最有效的就是科学钻探。深部大陆科学钻探被称为伸入地球内部的望远镜，是人类探索地球奥秘、探寻地下资源、保护环境、减轻灾害的重要举措。苏联在超深钻中发现了极端条件下的生物、深部油气和矿化显示，突破了传统油气成藏理论，拓展了人类索取资源的空间，加深了对生命演化的认识。由于深部大陆科学钻探工程涉及地学、力学、机械、仪电、材料、物理、化学甚至仿生学等多个学科和领域。可以说，深部大陆科学钻探的技术水平代表了一个国家的科技水平和经济实力。到目前为止，世界上只有少数国家实施过科学钻探计划，并取得了巨大成就。科学钻探根据钻探的地理位置不同，分为大陆科学钻探、大洋科学钻探和极地科学钻探，本课题的研究范围属于大陆科学钻探。为满足深部大陆科学钻探金刚石钻进工艺的需要，需对作用于钻头的压力进行精确控制。钻压过小，钻头不能压碎岩石，钻进速度将变慢甚至不进尺；钻压过大，加速钻头的磨损，缩短钻头使用寿命。科学钻探取心过程中，传统的送钻方式是手动送钻。手动送钻时，容易造成钻杆系统下放的不连续，从而造成钻头上的压力不均匀。尤其在地层条件复杂时，钻压波动大，经常导致憋泵等钻探事故的发生。此外，由于操作人员技术水平的差异或者失误等，也会导致钻压波动过大。自动送钻技术应运而生。即，钻机在正常钻进过程中，不依靠司钻人员调节钻进参数，而是按钻进工艺要求，通过控制系统自动调节钻压，实现钻具自动给进。恒钻压自动送钻系统作为钻探过程中的钻压控制系统，主要负责钻探过程中钻压的自动控制，而不需要手动控制。地层均匀时，自动送钻系统保证钻头得到平稳的钻压，以减少钻头在钻进过程中的不正常跳动。本文依托深部大陆科学钻探装备研制与实验项目，针对国内外自动送钻技术的研究现状，分别对盘刹自动送钻和小电机自动送钻进行试验研究和仿真分析，对比分析钻压控制效果。主要得到以下结论：（1）摩擦力可以转化成梁与刚性面的接触碰撞。针对深部大陆科学钻探的技术要求，综合分析钻压、转速和泵量对机械钻速、钻头使用寿命、回次进尺、岩心采取率和钻孔垂直度的影响。根据地层条件和钻探要求估算最优钻压的取值范围。对作用于岩石上的压力传递过程进行分析，重点分析摩擦力，将摩擦力的计算转换成梁与刚性面的接触碰撞问题。（2）推导出恒钻压自动送钻系统竖直方向的力学方程，并确定自动送钻结构方案。在原有恒钻压控制原理的基础上，分析钻杆系统竖直方向的受力情况。总结钻具自重、冲洗液浮力、举升力和摩擦力的计算方法，推导出恒钻压自动送钻系统竖直方向的力学方程。通过实地调研及理论研究，结合项目要求，确定两种结构方案：小电机自动送钻装置和盘刹自动送钻装置。（3）基于AMESim法对小电机自动送钻系统进行了动态仿真分析，结果表明钻压波动范围可达±3kN。钻头施加在岩石上的压力，既有静载（钻杆自重）又有动载（冲洗液浮力和孔内摩擦等），情况非常复杂。本文采用一个悬挂在滑轮组下方的重物表示静载，而动载则用可以修改的周期性或随机性变化的载荷函数进行近似模拟。借助软件AMESim进行恒压钻进仿真计算，结果表明钻压波动范围可达±3kN。（4）通过模拟试验测试盘刹自动送钻系统的钻压波动范围,结果表明钻压波动范围可达±5kN。为了验证盘刹自动送钻的控制效果，在四川进行试验研究。根据卵砾石地层条件，设计试验台的控制方案和检测方案。试验中采用PID控制算法。完成检测仪器的安装，进行调试，调试成功后，进行两组现场试验，实测钻进过程中钻压的变化。一组试验中，给定钻压为140kN，通过实验发现，孔底实测的钻压在130kN上下波动，钻压波动范围大于5kN且小于10kN，偶尔时刻的钻压为100kN、160kN，已大大超出设计（钻压波动范围不超过±5kN）对钻压的控制要求。另一组试验给定钻压为90kN，测得的给定钻压曲线与钻压曲线重合处较多，钻压的波动范围为±5kN，符合钻压波动要求。更多还原

【Abstract】 The sky、the earth、the sea and the polar were the four human dreams that humanconquer the nature.From the20th century,our understanding of the space、the oceanand the polar have reached a certain height. Conversely we knew too little about theearth. It was difficult to gain the information of the earth, Drilling engineering wasthe best way of gain information of deep earth.Deep continental scientific drilling was regard as a telescope penetrating into theinterior earth, which was a significant measure to explore the underground mysteriesand resources. The deep continental scientific drilling of the Soviet Union foundbiological under extreme conditions, deep oil and gas and mineralization, which brokethrough the traditional theory of hydrocarbon accumulation, expanded the space ofresources, and deepened the understanding of the evolution of life.However, deep continental scientific drilling project involved multipledisciplines and fields, such as geoscience、 mechanics、 machinery、electronics、material、 physics、 chemistry and bionics. Technology level of the drilling, in acertain sense, reflected the scientific and technological level and economic strength ofa country. Up to now, the scientific drilling program was carried out by only a fewcountries in the world. According to the different geographical position, scientificdrilling can be divided into continental scientific drilling, ocean scientific drilling andpolar scientific drilling. The research in this paper was based on the continentalscientific drilling.In order to meet the requirement of the diamond drilling in the continentalscientific drilling, the weight on bit was controlled accurately. If the weight on bit wastoo small, it would shorten the footage per run; If the weight on bit was too big, itwould accelerated the wear of the bit, and shorten bit service life.In the process of drilling，the traditional way of bit feed was the manual bit feed,which would be easy to cause discontinuous when the drill pipes were down, and uneven pressure on the drill bit. Especially in the complex geological conditions, theundulation swing of the weight on bit would lead drilling accidents, such as bitbouncing. In addition, due to difference of the technical level of the operator orfailures, the weight on bit would fluctuate severely. And then the auto-drillingtechnology arises because of the disadvantages of manual bit feed. Auto-drillingtechnology was an advanced drilling method, which doesn’t adjust the parameters ofthe drilling relying on the drillers, but according to the requirements of drilling. Whendrilling using the auto-drilling technology, the weight on bit will be adjustedautomatically by the control system to realize automatic feed drilling tools.The auto-drilling system with constant drilling pressure, as the weight on bitcontrol system of drilling, was mainly responsible for automatic drilling with constantdrilling pressure when tripping or drilling, without the need for manual control. Whendrilling in homogeneous formations, automatic drilling system can guarantee the bit toget a smooth weight on bit, so that the bit jumping would be reduced in drillingprocess.This paper was based on the continental scientific drilling equipmentdevelopment project. Aiming at the current situation of the auto-drilling technology,dynamic simulation of small motor auto-drilling system was made on AMESim.Experimental investigation of the disc brake auto-drilling system was carried on inthe paper. Comparison and analysis of two structure scheme were carried out. Theconclusions were made as follow.(1)In the first instance the analysis of pressure transmission process in theborehole was made especially the friction. The calculation of the friction wasconverted into contact-impact research between the beam and the rigid beam.According to the technical requirements of deep continental scientific drillingproject, Comprehensive analysis of the weight on bit、rotational speed and thepumping capacity was made for the technical requirements which was penetrationrate、bit service life、footage per run、core recovery and borehole deviation. Throughthe formation conditions and drilling requirement, the optimal weight on bit was estimated. The analysis of pressure transmission process in the borehole was madeespecially the friction. The calculation of the friction was converted intocontact-impact research between the beam and the rigid beam.(2) Secondly the theory equation of constant weight on bit drilling system wasdeduced and the structure scheme was proposed.The vertical stress of drill pipe system was analyzed in this paper based on theexisting theory equation with constant drilling pressure, And the theory equation ofconstant weight on bit drilling system was deduced, which was gained bysummarizing the conventional calculation of drilling pipes weight、 buoyancy ofdrilling fluid、 lifting force and friction. Based on the spot investigation andtheoretical research, combined with the project requirements, two auto-drillingsystems were proposed: small motor auto-drilling system and disc brake auto-drillingsystem.(3) For the second time dynamic simulation of small motor auto-drilling systemwas made on AMESim, and results show that the fluctuation range of the weight onbit can be up to±3kN.The pressure which applied on the bit was divided into two types. It was staticload (drilling pipes weight)and dynamic load (buoyancy of drilling fluid andfriction),which was very complex.In this paper, the static load was represented by theweight of a mass at the bottom of the block and tackle, and the dynamic load wassimulated by a load function of periodical or random changing. The simulation ofconstant weight on bit drilling was conducted in the software of AMESim, and resultsshow that the control precision of the weight on bit can be up to±3kN.(4) Finally this paper analyzed control effect of disc brake auto-drilling systemin experimental investigation, the fluctuation range of the weight on bit can be up to±5kN.In order to validate the control effect, the disc brake auto-drilling experiment wascarried out in Sichuan province. According to the formation conditions of gravel.Thecontrol scheme and detection scheme were designed. PID control algorithm was used in the test. The instrument needed to be debugged successfully after installation. Twoexperients were conducted and the weight on bit was tested. In one of the test, theweight on bit was set to140kN, and the weight on bit measured at the bottom of thebore was about130kN, the fluctuation range was greater than5kN and less than10kN.Sometimes the weight on bit would be100kN or160kN, which has been far morethan the designed control requirement of the weight on bit (fluctuation range shouldnot be more than5kN). In the other test, the weight on bit was set to90kN, and theresult showed that the measured weight on bit curve coincided the given drillingpressure curve very well, the fluctuation range of the weight on bit can be up to±5kN.and the fluctuation range of the weight on bit met the requirements.更多还原