关于套管柱井口装定问题的再认识

Recognition of wellhead setting issue for casing string

曹传文

CAO Chuanwen

辽河油田公司钻井工程部，辽宁盘锦　124010

Liaohe Oilfield Company Drilling Department, Panjin 124010, China

针对石油钻井工程中套管柱井口装定载荷的设定和控制方法存在的缺陷，对套管柱受力情况进行了分析，认为在固井水泥浆候凝期间，井下套管柱所受外力存在不确定性，不能据此计算井口装定载荷，相关的行业标准亦存在缺陷。分析了影响和限制井口装定载荷的各项因素，认为井口装定载荷只要满足一定的区间要求即可，实际工作中可以直接设定，使其略大于自由套管段的重力。根据自由套管段在水泥浆候凝期间受力和变形情况，提出了控制套管柱井口装定载荷的实用方法：通过公式可以计算出在水泥浆稠化前和装定后两种状态下自由套管段实际变形长度的差值?L；在水泥浆稠化前将套管柱从坐放位置上提?L；到最后一级注水泥作业水泥浆凝固后，再将套管柱和套管悬挂器坐放到位。该井口装定方法对不同井型、不同类型的套管悬挂器以及单级和分级注水泥工艺都适用。

Because the wellhead setting load for casing string has some defects in setting and control method during petroleum drilling engineering, the whole force condition of casing string has been analyzed, and with the uncertainty of the loaded force during the period of slurry cementing, wellhead setting load can not be calculated by this data, and related industry standard was defective too. This paper analyzed each factor that impacted and controlled the wellhead setting load, and found that when the load meets some certain interval requirement, it can be determined directly by making the load slightly heavier than the weight of free casing section. According to the force and deformation of free casing section in the process of slurry solid, a practice method of controlling the setting load was proposed: to calculate the real differential deformation length ΔL of non-consolidated casing section under two conditions: before slurry cementing and after setting, so before slurry cementing move the casing strings upward by length of ΔL; at the last stage of slurry injection, put the casing string and casing suspender onto the exactly position after the latest slurry cementing. This wellhead setting method is suitable for different well types and different kinds of casing suspender with one-stage or multistage slurry injection technique.