钻柱卡点预测实验

卡点预测是处理卡钻事故的关键。利用管柱扭转变形的特性,设计了无钻杆接头的单一管柱和有钻杆接头的组合管柱,并分别建立了卡点预测计算公式。利用管柱力学实验平台、四分量传感器、数据无线传输系统、HP数据采集系统和相关数据处理软件,对两种管柱进行了扭转实验。本次实验结果为:对于单一管柱,相对误差为-1.88%;对于组合管柱,当不考虑钻柱接头的影响时,相对误差为-3.8%,考虑钻柱接头的影响时,相对误差为-1.02%。实验结果表明:扭转法可用于直井中钻柱卡点预测,钻杆接头和钻柱加厚部分对卡点计算的影响较大,用带有修正系数的计算公式预测精度较高。

Experiment on the Stuck-Point Prediction of Drill String

Stuck-point prediction is the key to deal with stuck accidents. Two types of drill string were designed by using pipe torsional deformation characteristics. One is the single string without drill stem joints, and the other one is the assembly string with drill stem joints. Calculation formulas were established, respectively to predict the depth of stuck-point (DSP). Loading experiments were carried out on the experimental platform of pipe mechanics. Equipment's accessories were used in experiments, such as four-component sensors, wireless data transportation system, HP data sampling system and relevant data processing software. Experimental results are presented as follows: the relative error is -1.88% for single string, is -3.8% for assembly string without taking into account the effect of joints, and is -1.02% for assembly string taking into account the effect of joints. Experimental results show that the torsion method can be used to predict the stuck-point of drill string in vertical wells, the precision of prediction is affected by joints and the upset parts to assembly string, and the prediction precision is higher when Calculation formulas with modified coefficient are used.