自动垂直钻井工具的设计及自动控制方法

设计了一种井下闭环自动垂直钻井工具。该自动垂直钻井工具包含井下微处理器、井斜角测量传感器及井下可控稳定器等。可控稳定器周围均布有四个可独立伸缩的导向块,它们受到内部液压系统的驱动,当井斜角偏离垂直方向时,井下微处理器会自动调整可控稳定器的工作状态,使可控稳定器上位于井眼高边的导向块伸出,顶向井眼高边,使钻头上产生一个降斜力,最后使井眼回到垂直轨道。本文详细介绍了这种自动垂直钻井工具的工作原理及结构组成;对工具内部的液压控制原理及控制回路进行了研究和设计;讨论并设计了对工具进行井下闭环自动控制的原理及具体方法;最后利用纵横弯曲法对包含有该工具的井下钻具组合的降斜能力进行了数值模拟分析,说明该自动垂直钻井工具将能够在地层造斜力很大的高陡构造中高效快速地完成垂直钻井的工作。

THE DESIGN AND CONTROL WAYS OF THE DOWNHOLE AUTOMATIC CLOSED LOOP OF VERTI-CAL DRILLING TOOL

In China the rate of penetration is slow and the well path is hard to keep straight if we use the current drilling tools to drill well at the high steep dip structure.For this reason,authors designed an automatic down hole closed loop of control vertical drilling tool.The tool comprises a microprocessor,an inclination sensor and a controlled stabilizer.The stabilizer includes four undependable movable ribs,which were controlled by hydraulic power.When the well deviated,the rib at the high side of the wellborn is controlled to move out.This produces a drop force on the bit to direct the well to the vertical path.In this way,the tool can keep the well vertical automatically without the human intervention.This article introduces the tool's work principal and its structure;This paper study and design its hydraulic power control system and introduces the tool's automatic down hole closed loop of control principle and ways.Finally,the dropping ability of the bottom hole assembly with the tool was calculated using the beam buckle principle,it proves that the tool can drill the well fast and keep the well path straight,even at the high dip structure where the build up force is very high.