钻进

In pressure of influence underbalanced drilling,such as drilling fluid column pressure,annulus pressure,underbalance pressure,wellhead back pressure and formation pressure etc.,the formation pressure is basic pressure.Because all pressure calculations are built on the basic pressure.

认为在影响欠平衡钻井的钻井液静液柱压力、环空压耗、欠压值、井口回压、地层压力中，地层压力是首先要搞清楚的最基础的压力，最好先求出地层压力而不必急于进行欠平衡钻进，因为一切欠平衡的压力计算都是建立在这个基础压力之上的；再根据地层压力确定合理的欠压值，确定所用的钻井液密度。

The core catcher serves to grip the bottom of the core and, as tension is applied to the drillstring, the rock under the core breaks away from the undrilled formation below it.

岩心爪用于抓住岩心的底端，当施加拉力给钻柱时，使得岩心以下的岩石与下部尚未碑钻进的地层脱离。

Application of downhole hydrodynamic propulsors solves the problem of exerting WOB, and are helpful to enhancing penetration rate.

井下液力推进器的应用在一定程度上解决了钻压的施加问题，有利于提高钻进速度。

The practical application and computer simulation research show that the application of BP neural network to real-time diagnosis and modeling for optimizing WOB is practicable and efficacious.

实际应用和计算机仿真研究表明：采用这些新方法可以实时地实现钻进过程的事故诊断，建立的模型不但能够满足自动送钻实时优化钻压的要求，而且也可以用于离线的钻压参数优选

The practical application and computer simulation research show that the application of BP neural network to real-time diagnosis and modeling for optimizing WOB is practicable and efficacious.

BP网络作为一种非线性映射，可以逼近任意的非线性函数，所以它不仅适用线性系统，也适用非线性系统。本文选用BP网络作为钻进过程实时事故诊断和建立钻压优化模型的工具。一般B

Pneumatic hammer drilling technology with low wob,low rate of revolution and high capacity to break rock is one of the best effective methods to solve the problems of hard rock drilling.It includes air drilling and rotary drilling technology,so its penetration rate is usually two or three times higher than rotary drilling.

空气锤钻井是一种低钻压、低转速、高冲击破岩回转钻进技术，它兼容了气体钻井和冲击回转钻井的优势，其机械钻速一般比回转钻井高，是当今解决硬岩钻井难题的一种有效方法。

Diamond bits require lower WOB,high rotary speed and small flow rate,useful for hole straightening and inclining prevention,and it can be used high-density drilling fluids.But diamond bits can′t effectively drill heterogeneous hard formations which contain chert,pyrite and silicastone.

金刚石钻头的钻压小、转速高、排量小，有利于纠斜防斜，可在高密度钻井液条件下使用，但它不能有效地钻进含燧石、黄铁矿和硅质的不均质坚硬地层。

SUMMARY A more accurate steady drillstring tension-torque model has been established by taking into account of drillstring, wellbore condition , drilling operation and drilling parameters. This model has been used in scientific calculations of directional and horizontal wells, such as determing the friction factor between wellbore and drillstring, calculating the hook load and rotating torque, ckecking the strength and stability of drillstring, optimizing well trajectory, computing the WOB while drilling by downhole motor and predioting the maxinum allowable length of horizontal section.

综合考虑钻柱、井眼环境、作业过程和作业参数的影响，建立了更完善的钻柱稳态拉力和扭矩模型，并将其应用于确定钻柱与井壁的摩擦系数、计算大钩负荷和转盘扭矩、校核钻柱的强度和稳定性、优选井眼剖面、推算井下动力钻进的实际钻压和预测水平井段的最大可钻长度等定向水平井的科学计算中。

To make of monsters, and things indigest, Such cherubins as your sweet self resemble, Creating every bad a perfect best As fast as objects to his beams assemble: O 'tis the first,'tis flattery in my seeing, And my great mind most kingly drinks it up, Mine eye well knows what with his gust is 'greeing, And to his palate doth prepare the cup.

只害怕时光的无数意外事故钻进密约间，勾销帝王的意旨，晒黑美色，并挫钝锋锐的企图，使倔强的心屈从事物的隆替：唉，为什么，既怵于时光的专横，我不可说，&现在我爱你到极点，&当我摆脱掉疑虑，充满着信心，觉得来日不可期，只掌握目前？

Vermeer Corporation of Pella, Iowa, U.S.A., manufactures a full line of grinders, brush chippers, stump grinders and tree spades, as well as horizontal directional drilling systems, mini skid steers, utility and track trenchers and agricultural products.

Vermeer Corporation of Pella， Iowa， U.S.A生产各种磨切机、削片机、残株磨切机和树木铁锹，以及水平定向钻进系统、迷你滑移式装载机、公用设施和轨道挖沟机和农业产品。

And Pharaoh spoke to Joseph, saying, Your father and your brothers have come to you.

47：5 法老对约瑟说，你父亲和你弟兄们到你这里来了。

Additionally, the approximate flattening of surface strip using lines linking midpoints on perpendicular lines between geodesic curves and the unconditional extreme value method are discussed.

提出了用测地线方程、曲面上两点间短程线来计算膜结构曲面测地线的方法，同时，采用测地线间垂线的中点连线和用无约束极值法进行空间条状曲面近似展开的分析。