渤海中深层大位移井管柱下入工具与工艺

Tools and Technologies for Running String in Middle and Deep Extended Reach Wells in Bohai

受到活性泥岩、砂岩夹薄层泥岩、稳斜角、狗腿度等地质工程因素的影响,渤海中深层大位移井采用常规下管柱的方式易发生遇阻、起套管、提前固井等复杂情况。针对这一难题,在分析总结渤海中深层大位移井管柱下入难点的基础上,根据管柱下入遇阻机理,通过引入不同尺寸及类型管柱的旋转下入工具工艺,建立管柱下入过程中的循环、旋转手段,降低管柱下入摩阻。同时,从下管柱前、下管柱时、下管柱遇阻3个阶段入手,采用合成基钻井液、控制压差等手段,降低由于压差、接触面、摩擦系数等因素导致的管柱与井壁间摩擦力。最终形成了全系列管柱旋转下入技术、压差卡套协同控制工艺等一系列渤海中深层大位移井管柱下入技术。渤海4口中深层大位移井采用该技术后,所有管柱均一趟顺利下入,有力保障了大位移井的作业效率。

Due to the influence of geological engineering factors such as active mudstone,sandstone interbedded with thin mudstone,stable inclination angle,dogleg degree,etc.,the conventional way of running pipe string in the middle and deep stretches of Bohai Sea is prone to encounter complicated problems such as blockage,casing running and cementing in advance.To solve this problem,based on the analysis and summary of the difficulty of running pipe string in middle-deep extended reach wells in Bohai Sea,this paper established circulation and rotation means to reduce the friction of running pipe string by introducing rotary running tool technology of different sizes and types of pipe string according to the resistance mechanism of running pipe string.At the same time,starting from three stages before running string,during running string and when running string encountered resistance,the synthetic base drilling fluid and pressure differential control methods were adopted to reduce the fnction between the pipe string and shaft wall caused by pressure difference,contact surface,friction coefficient and other factors,and finally a series of string running technologies for middle—deep extended reach wells in Bohai Sea were formed,such as rotating running technology of all strings,and cooperative control process of differential pressure stuck.By applying this technology in 4 middle and deep extended reach wells in Bohai,all the strings were run smoothly in one run,which effectively guaranteed the operating efficiency of extended reach wells.