水泥返高对深水高温高压井井口抬升高度的影响

Influence of cement top on wellhead uplift height of deepwater high temperature and high pressure well

郑双进 程霖 谢仁军 黄志强 武治强 钱肖峰

ZHENG Shuangjin CHENG Lin XIE Renjun HUANG Zhiqiang WU Zhiqiang QIAN Xiaofeng

长江大学石油工程学院 中海油研究总院有限责任公司

College of Petroleum Engineering, Yangtze University, Wuhan 430100, Hubei, China CNOOC Research Institute Company Limited, Beijing 100028, China

深水高温高压井油气开采过程中，油气流将井底热量携带至井口致使自由段套管受热伸长，继而导致井口抬升，使井口存在装置密封失效的风险。建立了深水高温高压井油气开采阶段井口抬升高度计算模型，基于自主研制的高温高压井口抬升模拟实验装置，开展了双层管柱不同水泥返高及多层管柱耦合固井条件下的井口抬升模拟实验。研究结果表明，相比水泥返高50%工况，双层管柱水泥返高100%工况下各层管柱伸长量明显降低，多层管柱耦合固井工况相比不固井工况下的各层管柱最大伸长量也明显降低，表明水泥封固对井口抬升具有一定的束缚作用。经模拟实验验证，建立的模型计算结果与实验数据相比误差小于10%，可用于预测不同工况条件下的井口抬升高度，为科学设计预防井口抬升措施提供了技术参考。

During the oil and gas production of deepwater high temperature and high pressure well, the oil and gas flow carries the bottom heat to the wellhead, leading to thermal elongation of free casing and then wellhead uplift, and thus there is failure risk of device seal at the wellhead. In this paper, a model for calculating the wellhead uplift height in the oil and gas production stage of deepwater high temperature and high pressure well was established. Then, the simulation experiments of wellhead uplift under the conditions of double-layer string with different cement tops and multi-layer string coupling cementing were carried out based on the independently developed simulation experimental device of wellhead uplift of high temperature and high pressure well. It is shown that the elongation of each layer of string under the working condition of double-layer string with 100% cement top is much smaller than that under the working condition with 50% cement top, and the maximum elongation of each string under the working condition of multi-layer string coupling cementing is also greatly smaller than that in the working condition without cementing. It is indicated that cementing has a certain binding effect on wellhead uplift. The simulation experiment verifies that the error between the calculation result obtained by the established model and the experimental data is less than 10%, so the model can be used to predict wellhead uplift height under different working conditions and provide a technical reference for the scientific design of wellhead uplift prevention measures.

10.13639/j.odpt.2021.05.007