In this paper, the casing strings of cement slurry during the curing period are taken as the research object in order to build a force model, with comprehensively considering the influence factors such as the phase transition heat transfer and volume change of the cement slurry during the curing period. The random contacts between casings and well walls were simulated by establishing a gap element between two phases of cement slurry. Formulas of axial loadings on the casings during curing of cement slurry were obtained using the finite element method. With this method and on-site measurement, the wellhead axial loads of three wells during cement slurry curing were calculated and tested. The results revealed that the maximum relative deviation between the theoretical prediction results by the model and the actual field test data was 10.42%, indicating that the model established is reliable. Finally, using the established finite element calculation method, the effects of the cementing section length on extra loadings on the wellhead were analyzed. This study serves as an accurate reference to calculations of extra loadings on the wellhead during curing of cement slurry and optimization of cementing section length, thus facilitating well cementation.

以固化期水泥浆的套管柱为研究对象，建立了力模型，综合考虑了水泥浆在固化过程中的相变传热和体积变化等影响因素。固化期。通过在水泥浆两相之间建立间隙元素，模拟了套管与井壁之间的随机接触。利用有限元方法获得了水泥浆固化过程中套管轴向载荷的计算公式。通过这种方法和现场测量，计算并测试了水泥浆固化过程中三口井的井口轴向载荷。结果表明，该模型的理论预测结果与实际现场测试数据之间的最大相对偏差为10.42％，表明所建立的模型是可靠的。最后，使用建立的有限元计算方法，分析了固井段长度对井口额外荷载的影响。该研究为水泥浆固化过程中井口额外载荷的计算和固井段长度的优化提供了准确的参考，从而有利于固井。