深井和大位移井套管磨损程度预测

Casing Abrasion Prediction for Deep and Extended Reach Wells

为提高套管柱强度设计准确性,防止磨损失控情况发生,深入分析了套管磨损预测技术。结合定向井钻柱力学研究成果,考虑钻柱刚度和屈曲的影响,推导了深井和大位移井的钻柱拉力-扭矩方程,建立了基于能量原理的套管磨损程度预测模型,并编制了预测软件。该预测软件可以预测包括钻进、起下钻具等作业过程的,不同套管柱层次、钻具组合、井眼轨迹、钻井液类型和钻井参数等情况的全井段不同井深所对应的套管磨损量。实例计算结果表明,编制的预测软件减小了人为的估计误差,预测值更为准确可靠。研究成果为深井和大位移井安全高效钻进提供了新的技术支持。

In order to improve the design of casing strength and prevent severe casing wear out, casing abrasion prediction technology was analyzed. The tensiowtorque equation of drill string in deep wells and extended reach wells was deduced through identifying the drill string mechanics for directional wells, and considering stiffness and buckling of drill string. The prediction model of casing abrasion was established according to the energy principle and prediction software was developed. The software can predict casing abrasion at different depths in hole, for different casing program,BHA, well track, drilling fluid types and drilling parameters, during drilling and tripping. Its application shows that the software can give a more ac- curate and reliable prediction,with less artificial error. It provides new technical support to ensure safe and efficient drilling of deep wells and extended reach wells.