3D mechanical modeling of soil orthogonal cutting under a single reamer cutter based on Drucker–Prager criterion

Reamers have been the major implement used to enlarge the hole size in reaming stage of horizontal directional drilling (HDD). The choice of its available structural design becomes critical to maximize the rate of penetration and minimize the tripping time, thereby decreasing the cost of operations and the risk of experiencing stability problems. Moreover, because the duration period of a HDD project is largely dependent on the reaming stage, it is crucial to study the reaming efficiency by use of the appropriate operating conditions (cutting angle and depth). In the paper, the reaming efficiency of reamer is analyzed based on the development of a 3D analytical cutting force model of soil orthogonal cutting under a single reamer cutter. Focusing on the soil orthogonal cutting mechanism under a single reamer cutter, the interaction and friction between soil and cutter and the shear action of 3D shear zone are comprehensively considered, consequently the mechanical properties are given. Based on these analyses and using the Drucker–Prager criterion given a weight to the intermediate principal stress, the analytical models are proposed. In addition, this paper presents 3D FEM simulations for the analysis of soil orthogonal cutting under a single reamer cutter. The subject has been covered in two parts. Part one deals with the verification of the analytical cutting force model, the other focuses on the assessment and selection of the criterions of shear angle. The analytical cutting force model presented provides the capability to evaluate cutter loading for utilization of a single cutter with different rake angles to cut soils, and to plot the effect of change in the rake angle. Finally, the optimum rake angle of single reamer cutter was obtained. The results of this analysis can be integrated to study reamer performance. It can also provide a guideline to the application and design of the reamer assembly for various soils.     

大直径簿壁零件径向钻孔加工

阐述零件12-φ20 mm孔加工难点,提出创新方案,设计支撑支架,利用万向钻床,设计制造扩孔钻头,成功解决了加工难度,加工质量基本合格,加工效率有所提高。     

膨胀管技术在西北油田TH10233CH井的应用

侧钻是降低油气开采成本的有效途径之一。西北油田受井眼尺寸、避水要求、不稳定泥岩、复杂压力体系等原因的影响,侧钻难度极大。为解决这一难题,在TH10233CH井采用膨胀管技术进行了实际应用。采用φ139.7mm膨胀管封固上部不稳定地层,膨胀管膨胀前内径124.2mm,膨胀后内径可达134.5mm,采用φ130mm钻头钻进,顺利完钻。膨胀管钻井技术在TH10233CH井的成功应用对西北油田侧钻井钻进具有重大指导意义。     

Prediction of rotational torque and design of reaming program using horizontal directional drilling in rock strata

Horizontal directional drilling (HDD) has been widely used to efficiently and cost-effectively install pipelines in a variety of conditions. In particular, during application of HDD in the recent West-East Natural Gas Transmission Project in China, rocky conditions were encountered. In such difficult situations, it is necessary to predict the torque required for performing the reaming operation, as well as to select the appropriate type and size of reamers. However, there is presently not an appropriate and convenient method to accomplish these tasks, especially for large pipelines, such as 1219 mm (48 in.) diameter, which typically require a borehole of approximately 1600 mm (64 in.). The process of expanding the initial borehole to the ultimate required diameter in rocky strata is often a complicated procedure involving several passes of intermediate size reamers. Although available information for drilling techniques does provide some means of predicting the torque, it is not sufficient for meeting the present needs, including providing guidelines for determining the corresponding reaming program. Therefore, the results of recent research, which addresses rock crushing energy, have been incorporated to develop an improved prediction method. The results reflect rock characteristics collected at different job sites, which may be applied to new projects containing similar rock strata. The improved methodology is a valuable aide for engineers in their selection of an appropriate back-reaming program.     

对高精度偏心衬套更换方法的研究

用传统的方法更换高精度偏心衬套，难以消除新旧偏心衬套外径不同轴对内孔同轴度的影响，作者研制了一种特殊铰孔工装及对线工具，较好的解决了这一技术难题。     

电子枪G5／06栅极部件全自动扩孔机

介绍了一种采用PLC作为控制核心的电子枪G5／G6栅极部件全自动扩孔机,并着重介绍了设备各部分的设计构成。采用该设备可以自动完成电子枪G5／G6栅极部件产品的扩孔加工功能。该自动扩孔设备加工质量可靠,生产效率高,具有一定的应用价值。     

单刃铰薄壁深孔工艺的试验研究

研究了用于薄壁深孔加工的单刃铰刀的设计、铰孔时切削液的供给及切削用量的确定等问题，为薄壁深孔的加工提供了借鉴。     

采用随钻扩眼技术提高海相气藏盐岩夹层套管服役的安全性

随着以南方海相碳酸盐岩储层为主要勘探目标的中国石油工业二次创业的展开,气井服役套管全寿命期内的完整性管理必将成为长期、高效开采海相气藏资源过程中一个不可回避的难点。为此,基于四川盆地川东地区三叠系现场地质资料和岩心蠕变试验数据建立了套管、水泥环和盐岩夹层耦合三维力学模型,耦合应力场、温度场及非线性蠕变,研究了深部海相气藏盐岩夹层服役套管的安全性变化规律;提出了采用随钻扩眼技术提高海相气藏盐岩夹层服役套管安全性的新思路、基于附加载荷和等效抵抗强度的扩眼尺寸设计方法,以及海相气藏盐岩夹层服役套管剩余强度和剩余寿命的定量预测方法,研究了扩眼对套管服役安全性的影响情况。结果表明:(1)扩眼可增大服役套管的剩余强度,扩眼率40%时的完整套管剩余强度为无扩眼时的1.57倍,且在一定程度上能改善腐蚀套管应力集中的状况;(2)套管设计服役寿命越长,扩眼对提高服役套管安全性的贡献就越明显。该研究成果可为海相气藏井服役套管全寿命期内的完整性管理提供新的思路及定量决策依据。     

天井钻机工作参数的合理选择

ＴＹＺ系列天井钻机在压外事导向孔和拉扩通风井,充填井或管道井等的作业中起着至关重要的作用。作业中应根据该机所具备的技术性能和现场的岩石情况。正确选择工作参数（主要是转速和轴压）以便保证成井质量（偏斜率小）充分发挥设备效能。本文论述了天井钻机主极工作参数的确定方法,并进行了实例计算。     

软硬交界面扩孔轨迹预测

水平定向钻穿越施工,在我国已有20多年的历史,克服了传统管道穿越道路、河流等地形时带来的交通阻塞、出行不便、城市绿化等一系列的问题。水平定向钻穿越以其众多优势在天然气等相关线路施工中独占鳌头。然而,现阶段水平定向钻穿越技术还有很多不足,常常因为一些技术上的因素导致整个穿越过程的失败。扩孔过程是定向钻穿越的重要部分,通过研究岩石本构关系、岩石弹塑性力学、岩石损伤以及断裂力学,运用ABAQUS软件对扩孔过程进行仿真,在计算结果中输出扩孔过程经过软硬交界面处其扩孔轨迹的变化情况,使施工人员事先了解扩孔轨迹,并加以控制,避免因扩孔失败而导致整过穿越过程的失败,为顺利铺管提供指导。