Applying finite element method,the dynamic characteristics of drill string with cone bit in straight hole were simulated,and the whirl,deformation and the dynamic stress in air drilling were compared with the ones in drilling fluid drilling .

應(yīng)用有限元方法，仿真了空氣鉆井時斜直井眼中帶牙輪鉆頭鉆柱的動力學(xué)特性欧美在线观看精品，比較了空氣鉆井和鉆井液鉆井條件下鉆柱的渦動、變形以及動態(tài)應(yīng)力狀況色的日本视频，探討了空氣鉆井鉆柱失效的動力學(xué)機(jī)理午夜三级亚洲。

This paper studied the annulus whirl ing motion of rotary drill string.

把旋轉(zhuǎn)鉆柱簡化為一內(nèi)外有流體的柔性轉(zhuǎn)子系統(tǒng)，分析了在內(nèi)外鉆井液流體作用下的鉆柱渦動行為超碰AV在线一区。

It is shown that the contact interaction enables bottom drillstring to whirl backward, and then an alternate bending stress with higher frequency is produced. So the drillstring fatigue failure could be accelerated. At the same time, a quite strong wallop force of high frequency is produced on the contacting point, and the contacting zone is next to the screw coupling of drill collars. It will easily result in the failure of screw couplings. The research results provide theoretical basis for the prevention of drillstring failure.

研究表明帮我收一下欧洲黄色视频，下部鉆柱與井壁的碰摩作用使下部鉆柱反向渦動，產(chǎn)生高頻的交變彎曲應(yīng)力台湾一级婬片A片AAA毛片在线，會加速下部鉆柱疲勞破壞韩日欧美激情一区二区；下部鉆柱與井壁接觸點處存在較大的高頻沖擊力，并且接觸區(qū)域靠近鉆鋌螺紋聯(lián)結(jié)處日本xx黄色，更容易誘發(fā)螺紋聯(lián)結(jié)處失效日韩在线观看自拍网址，該研究成果可為預(yù)防鉆柱失效提供理論依據(jù)。