温度效应及环空条件对井口抬升影响规律研究  

Influence Rules of Temperature Effect and Annular Conditions on Wellhead Uplift

作　　者：谢仁军 张伟国 徐国贤 刘书杰 武治强 Xie Renjun;Zhang Weiguo;Xu Guoxian;Liu Shujie;Wu Zhiqiang(CNOOC Research Institute Co.,Ltd.;CNOOC Deepwater Development Ltd.)

机构地区：[1]中海油研究总院有限责任公司 [2]中海石油深海开发有限公司

出　　处：《石油机械》2020年第2期72-79,共8页China Petroleum Machinery

基　　金：中国海洋石油集团公司“十三五”重大科研项目之子课题1“深水开发井钻完井关键技术研究”(CNOOC-KJ135ZDXM05LTD01SHENHAI2016)。

摘　　要：为预测深水高温井生产过程中的井口抬升量,基于套管热膨胀效应及热力学基本原理,建立了不同温升条件下单层自由套管及多层套管耦合井口系统抬升量预测模型,设计了3层同心钢管柱为主体的试验装置,开展了不同工况下井口抬升模拟试验,得到了温度效应、环空上端部约束状态和环空压力等因素对井口抬升量的影响规律,提出了解决深水水下井口抬升的主要工程措施。研究结果表明:以试验模型为例,当最内层管柱温度从45℃升高至150℃的过程中,在模拟传热条件下,3层管柱环空上端部敞开时,各层管柱抬升量与其温升呈线性增长规律;环空上端部焊接为整体时,73.0和114.3 mm管柱最终抬升量相对上端部敞开状态分别减小26.50%和21.80%,177.8 mm管柱最终抬升量增加4.06%;环空密闭并加压20 MPa时,73.0、114.3和177.8 mm管柱最终抬升量相对无压力时分别增加了23.84%、26.79%和25.36%;温度及环空条件对井口抬升量影响显著,理论预测值与试验值误差为1.59%~8.93%。研究结果可为深水高温井井口抬升控制措施的制定提供技术支持。In order to predict the wellhead uplift in deep-water high temperature well production,uplift prediction models for single-layer free casing and multilayer casing coupling wellhead system under different temperature rise conditions.Then,a testing apparatus mainly consisting of a three-layer concentric steel pipe string fabricated with three sections of pipes was designed.Wellhead uplift simulation tests under different operating conditions were conducted and the influence rules of the temperature effect,restrained condition of the upper section of the annulus and annular pressure and other factions on wellhead uplift were obtained.And thus,major engineering measures to solve the wellhead uplift problem of subsea wells in deep waters were proposed in this paper.The results show that,taking the testing model as an example,during the period of which the innermost pipe string temperature increased from 45℃ to 150℃,a linear growth rule for the relationship between the uplift and temperature rise of each string was observed under the simulated heat transfer conditions when the upper section of the three-layer string was open;the ultimate uplifts of the 73.0 mm and 114.3 mm strings were reduced by 26.50%,21.80% respectively relative to the scenario that the upper section of the annulus is open,while that of the 177.8 mm string was increased by 4.06%,when the upper section of the annulus is welded;the final uplifts of 73.0 mm,114.3 mm and 177.8 mm strings were increased by 23.84%,26.79%,25.36% relevant to the no-pressure scenario,when the annulus is enclosed and the annular pressure was increased to 20 MPa;the temperature and annular conditions have significant impact on the wellhead uplift,and the error between the predicted theoretical values and experimental values is 1.59%~8.93%.The study results can provide technical support for developing wellhead uplift control measures for deep-water high temperature wells.

关 键 词：温度效应 井口抬升 历史载荷 环空耦合状态 环空压力 深水高温井 

分 类 号：TE951[石油与天然气工程—石油机械设备]